IF YOU WOULD LIKE TO GET AN ACCOUNT, please write an
email to Administrator. User accounts are meant only to access repo
and report issues and/or generate pull requests.
This is a purpose-specific Git hosting for
BaseALT
projects. Thank you for your understanding!
Только зарегистрированные пользователи имеют доступ к сервису!
Для получения аккаунта, обратитесь к администратору.
print_trace_line may overflow seq_file buffer. If the event is not
consumed, the while loop keeps peeking this event, causing a infinite loop.
Link: https://lkml.kernel.org/r/20221129113009.182425-1-yangjihong1@huawei.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 088b1e427d ("ftrace: pipe fixes")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Merge cpuidle changes, updates related to system sleep amd generic power
domains code fixes for 6.2-rc1:
- Improve kernel messages printed by the cpuidle PCI driver (Ulf
Hansson).
- Make the DT cpuidle driver return the correct number of parsed idle
states, clean it up and clarify a comment in it (Ulf Hansson).
- Modify the tasks freezing code to avoid using pr_cont() and refine an
error message printed by it (Rafael Wysocki).
- Make the hibernation core code complain about memory map mismatches
during resume to help diagnostics (Xueqin Luo).
- Fix mistake in a kerneldoc comment in the hibernation code (xiongxin).
- Reverse the order of performance and enabling operations in the
generic power domains code (Abel Vesa).
- Power off[on] domains in hibernate .freeze[thaw]_noirq hook of in the
generic power domains code (Abel Vesa).
- Consolidate genpd_restore_noirq() and genpd_resume_noirq() (Shawn
Guo).
- Pass generic PM noirq hooks to genpd_finish_suspend() (Shawn Guo).
- Drop generic power domain status manipulation during hibernate
restore (Shawn Guo).
* pm-cpuidle:
cpuidle: dt: Clarify a comment and simplify code in dt_init_idle_driver()
cpuidle: dt: Return the correct numbers of parsed idle states
cpuidle: psci: Extend information in log about OSI/PC mode
* pm-sleep:
PM: sleep: Refine error message in try_to_freeze_tasks()
PM: sleep: Avoid using pr_cont() in the tasks freezing code
PM: hibernate: Complain about memory map mismatches during resume
PM: hibernate: Fix mistake in kerneldoc comment
* pm-domains:
PM: domains: Reverse the order of performance and enabling ops
PM: domains: Power off[on] domain in hibernate .freeze[thaw]_noirq hook
PM: domains: Consolidate genpd_restore_noirq() and genpd_resume_noirq()
PM: domains: Pass generic PM noirq hooks to genpd_finish_suspend()
PM: domains: Drop genpd status manipulation for hibernate restore
The 'padding' field of the 'rchan_buf' structure is an array of 'size_t'
elements, but the memory is allocated for an array of 'size_t *' elements.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lkml.kernel.org/r/20221129092002.3538384-1-Ilia.Gavrilov@infotecs.ru
Fixes: b86ff981a8 ("[PATCH] relay: migrate from relayfs to a generic relay API")
Signed-off-by: Ilia.Gavrilov <Ilia.Gavrilov@infotecs.ru>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: wuchi <wuchi.zero@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Building kcsan_test with structleak plugin enabled makes the stack frame
size to grow.
kernel/kcsan/kcsan_test.c:704:1: error: the frame size of 3296 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
Turn off the structleak plugin checks for kcsan_test.
Link: https://lkml.kernel.org/r/20221128104358.2660634-1-anders.roxell@linaro.org
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Marco Elver <elver@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Gow <davidgow@google.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The implementation of strscpy() is more robust and safer. That's now the
recommended way to copy NUL terminated strings.
Link: https://lkml.kernel.org/r/202211220853259244666@zte.com.cn
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: wuchi <wuchi.zero@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lockdep and KMSAN used to play badly together, causing deadlocks when
KMSAN instrumentation of lockdep.c called lockdep functions recursively.
Looks like this is no more the case, and a kernel can run (yet slower)
with both KMSAN and lockdep enabled. This patch should fix false
positives on wq_head->lock->dep_map, which KMSAN used to consider
uninitialized because of lockdep.c not being instrumented.
Link: https://lore.kernel.org/lkml/Y3b9AAEKp2Vr3e6O@sol.localdomain/
Link: https://lkml.kernel.org/r/20221128094541.2645890-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
An update for verifier.c:states_equal()/regsafe() to use check_ids()
for active spin lock comparisons. This fixes the issue reported by
Kumar Kartikeya Dwivedi in [1] using technique suggested by Edward Cree.
W/o this commit the verifier might be tricked to accept the following
program working with a map containing spin locks:
0: r9 = map_lookup_elem(...) ; Returns PTR_TO_MAP_VALUE_OR_NULL id=1.
1: r8 = map_lookup_elem(...) ; Returns PTR_TO_MAP_VALUE_OR_NULL id=2.
2: if r9 == 0 goto exit ; r9 -> PTR_TO_MAP_VALUE.
3: if r8 == 0 goto exit ; r8 -> PTR_TO_MAP_VALUE.
4: r7 = ktime_get_ns() ; Unbound SCALAR_VALUE.
5: r6 = ktime_get_ns() ; Unbound SCALAR_VALUE.
6: bpf_spin_lock(r8) ; active_lock.id == 2.
7: if r6 > r7 goto +1 ; No new information about the state
; is derived from this check, thus
; produced verifier states differ only
; in 'insn_idx'.
8: r9 = r8 ; Optionally make r9.id == r8.id.
--- checkpoint --- ; Assume is_state_visisted() creates a
; checkpoint here.
9: bpf_spin_unlock(r9) ; (a,b) active_lock.id == 2.
; (a) r9.id == 2, (b) r9.id == 1.
10: exit(0)
Consider two verification paths:
(a) 0-10
(b) 0-7,9-10
The path (a) is verified first. If checkpoint is created at (8)
the (b) would assume that (8) is safe because regsafe() does not
compare register ids for registers of type PTR_TO_MAP_VALUE.
[1] https://lore.kernel.org/bpf/20221111202719.982118-1-memxor@gmail.com/
Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Suggested-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20221209135733.28851-6-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
verifier.c:states_equal() must maintain register ID mapping across all
function frames. Otherwise the following example might be erroneously
marked as safe:
main:
fp[-24] = map_lookup_elem(...) ; frame[0].fp[-24].id == 1
fp[-32] = map_lookup_elem(...) ; frame[0].fp[-32].id == 2
r1 = &fp[-24]
r2 = &fp[-32]
call foo()
r0 = 0
exit
foo:
0: r9 = r1
1: r8 = r2
2: r7 = ktime_get_ns()
3: r6 = ktime_get_ns()
4: if (r6 > r7) goto skip_assign
5: r9 = r8
skip_assign: ; <--- checkpoint
6: r9 = *r9 ; (a) frame[1].r9.id == 2
; (b) frame[1].r9.id == 1
7: if r9 == 0 goto exit: ; mark_ptr_or_null_regs() transfers != 0 info
; for all regs sharing ID:
; (a) r9 != 0 => &frame[0].fp[-32] != 0
; (b) r9 != 0 => &frame[0].fp[-24] != 0
8: r8 = *r8 ; (a) r8 == &frame[0].fp[-32]
; (b) r8 == &frame[0].fp[-32]
9: r0 = *r8 ; (a) safe
; (b) unsafe
exit:
10: exit
While processing call to foo() verifier considers the following
execution paths:
(a) 0-10
(b) 0-4,6-10
(There is also path 0-7,10 but it is not interesting for the issue at
hand. (a) is verified first.)
Suppose that checkpoint is created at (6) when path (a) is verified,
next path (b) is verified and (6) is reached.
If states_equal() maintains separate 'idmap' for each frame the
mapping at (6) for frame[1] would be empty and
regsafe(r9)::check_ids() would add a pair 2->1 and return true,
which is an error.
If states_equal() maintains single 'idmap' for all frames the mapping
at (6) would be { 1->1, 2->2 } and regsafe(r9)::check_ids() would
return false when trying to add a pair 2->1.
This issue was suggested in the following discussion:
https://lore.kernel.org/bpf/CAEf4BzbFB5g4oUfyxk9rHy-PJSLQ3h8q9mV=rVoXfr_JVm8+1Q@mail.gmail.com/
Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20221209135733.28851-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The verifier.c:regsafe() has the following shortcut:
equal = memcmp(rold, rcur, offsetof(struct bpf_reg_state, parent)) == 0;
...
if (equal)
return true;
Which is executed regardless old register type. This is incorrect for
register types that might have an ID checked by check_ids(), namely:
- PTR_TO_MAP_KEY
- PTR_TO_MAP_VALUE
- PTR_TO_PACKET_META
- PTR_TO_PACKET
The following pattern could be used to exploit this:
0: r9 = map_lookup_elem(...) ; Returns PTR_TO_MAP_VALUE_OR_NULL id=1.
1: r8 = map_lookup_elem(...) ; Returns PTR_TO_MAP_VALUE_OR_NULL id=2.
2: r7 = ktime_get_ns() ; Unbound SCALAR_VALUE.
3: r6 = ktime_get_ns() ; Unbound SCALAR_VALUE.
4: if r6 > r7 goto +1 ; No new information about the state
; is derived from this check, thus
; produced verifier states differ only
; in 'insn_idx'.
5: r9 = r8 ; Optionally make r9.id == r8.id.
--- checkpoint --- ; Assume is_state_visisted() creates a
; checkpoint here.
6: if r9 == 0 goto <exit> ; Nullness info is propagated to all
; registers with matching ID.
7: r1 = *(u64 *) r8 ; Not always safe.
Verifier first visits path 1-7 where r8 is verified to be not null
at (6). Later the jump from 4 to 6 is examined. The checkpoint for (6)
looks as follows:
R8_rD=map_value_or_null(id=2,off=0,ks=4,vs=8,imm=0)
R9_rwD=map_value_or_null(id=2,off=0,ks=4,vs=8,imm=0)
R10=fp0
The current state is:
R0=... R6=... R7=... fp-8=...
R8=map_value_or_null(id=2,off=0,ks=4,vs=8,imm=0)
R9=map_value_or_null(id=1,off=0,ks=4,vs=8,imm=0)
R10=fp0
Note that R8 states are byte-to-byte identical, so regsafe() would
exit early and skip call to check_ids(), thus ID mapping 2->2 will not
be added to 'idmap'. Next, states for R9 are compared: these are not
identical and check_ids() is executed, but 'idmap' is empty, so
check_ids() adds mapping 2->1 to 'idmap' and returns success.
This commit pushes the 'equal' down to register types that don't need
check_ids().
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20221209135733.28851-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The osnoise workload runs with preemption and IRQs enabled in such
a way as to allow all sorts of noise to disturb osnoise's execution.
hwlat tracer has a similar workload but works with irq disabled,
allowing only NMIs and the hardware to generate noise.
While thinking about adding an options file to hwlat tracer to
allow the system to panic, and other features I was thinking
to add, like having a tracepoint at each noise detection, it
came to my mind that is easier to make osnoise and also do
hardware latency detection than making hwlat "feature compatible"
with osnoise.
Other points are:
- osnoise already has an independent cpu file.
- osnoise has a more intuitive interface, e.g., runtime/period vs.
window/width (and people often need help remembering what it is).
- osnoise: tracepoints
- osnoise stop options
- osnoise options file itself
Moreover, the user-space side (in rtla) is simplified by reusing the
existing osnoise code.
Finally, people have been asking me about using osnoise for hw latency
detection, and I have to explain that it was sufficient but not
necessary. These options make it sufficient and necessary.
Adding a Suggested-by Clark, as he often asked me about this
possibility.
Link: https://lkml.kernel.org/r/d9c6c19135497054986900f94c8e47410b15316a.1670623111.git.bristot@kernel.org
Cc: Suggested-by: Clark Williams <williams@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Often the latency observed in a CPU is not caused by the work being done
in the CPU itself, but by work done on another CPU that causes the
hardware to stall all CPUs. In this case, it is interesting to know
what is happening on ALL CPUs, and the best way to do this is via
crash dump analysis.
Add the PANIC_ON_STOP option to osnoise/timerlat tracers. The default
behavior is having this option off. When enabled by the user, the system
will panic after hitting a stop tracing condition.
This option was motivated by a real scenario that Juri Lelli and I
were debugging.
Link: https://lkml.kernel.org/r/249ce4287c6725543e6db845a6e0df621dc67db5.1670623111.git.bristot@kernel.org
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Make osnoise_options static, as reported by the kernel test robot.
Link: https://lkml.kernel.org/r/63255826485400d7a2270e9c5e66111079671e7a.1670228712.git.bristot@kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The trace_trigger command line option introduced by
commit a01fdc897f ("tracing: Add trace_trigger kernel command line option")
doesn't need to depend on the CONFIG_HIST_TRIGGERS kernel config option.
This code doesn't depend on the histogram code, and the run-time
selection of triggers is usable without CONFIG_HIST_TRIGGERS.
Link: https://lore.kernel.org/linux-trace-kernel/20221209003310.1737039-1-zwisler@google.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: a01fdc897f ("tracing: Add trace_trigger kernel command line option")
Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
With the new command line option that allows trace event triggers to be
added at boot, the "snapshot" trigger will allocate the snapshot buffer
very early, when interrupts can not be enabled. Allocating the ring buffer
is not the problem, but it also resizes it, which is, as the resize code
does synchronization that can not be preformed at early boot.
To handle this, first change the raw_spin_lock_irq() in rb_insert_pages()
to raw_spin_lock_irqsave(), such that the unlocking of that spin lock will
not enable interrupts.
Next, where it calls schedule_work_on(), disable migration and check if
the CPU to update is the current CPU, and if so, perform the work
directly, otherwise re-enable migration and call the schedule_work_on() to
the CPU that is being updated. The rb_insert_pages() just needs to be run
on the CPU that it is updating, and does not need preemption nor
interrupts disabled when calling it.
Link: https://lore.kernel.org/lkml/Y5J%2FCajlNh1gexvo@google.com/
Link: https://lore.kernel.org/linux-trace-kernel/20221209101151.1fec1167@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: a01fdc897f ("tracing: Add trace_trigger kernel command line option")
Reported-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When input some constructed invalid 'trigger' command, command info
in 'error_log' are lost [1].
The root cause is that there is a path that event_hist_trigger_parse()
is recursely called once and 'last_cmd' which save origin command is
cleared, then later calling of hist_err() will no longer record origin
command info:
event_hist_trigger_parse() {
last_cmd_set() // <1> 'last_cmd' save origin command here at first
create_actions() {
onmatch_create() {
action_create() {
trace_action_create() {
trace_action_create_field_var() {
create_field_var_hist() {
event_hist_trigger_parse() { // <2> recursely called once
hist_err_clear() // <3> 'last_cmd' is cleared here
}
hist_err() // <4> No longer find origin command!!!
Since 'glob' is empty string while running into the recurse call, we
can trickly check it and bypass the call of hist_err_clear() to solve it.
[1]
# cd /sys/kernel/tracing
# echo "my_synth_event int v1; int v2; int v3;" >> synthetic_events
# echo 'hist:keys=pid' >> events/sched/sched_waking/trigger
# echo "hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(\
pid,pid1)" >> events/sched/sched_switch/trigger
# cat error_log
[ 8.405018] hist:sched:sched_switch: error: Couldn't find synthetic event
Command:
hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(pid,pid1)
^
[ 8.816902] hist:sched:sched_switch: error: Couldn't find field
Command:
hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(pid,pid1)
^
[ 8.816902] hist:sched:sched_switch: error: Couldn't parse field variable
Command:
hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(pid,pid1)
^
[ 8.999880] : error: Couldn't find field
Command:
^
[ 8.999880] : error: Couldn't parse field variable
Command:
^
[ 8.999880] : error: Couldn't find field
Command:
^
[ 8.999880] : error: Couldn't create histogram for field
Command:
^
Link: https://lore.kernel.org/linux-trace-kernel/20221207135326.3483216-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <zanussi@kernel.org>
Fixes: f404da6e1d ("tracing: Add 'last error' error facility for hist triggers")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The maximum number of synthetic fields supported is defined as
SYNTH_FIELDS_MAX which value currently is 64, but it actually fails
when try to generate a synthetic event with 64 fields by executing like:
# echo "my_synth_event int v1; int v2; int v3; int v4; int v5; int v6;\
int v7; int v8; int v9; int v10; int v11; int v12; int v13; int v14;\
int v15; int v16; int v17; int v18; int v19; int v20; int v21; int v22;\
int v23; int v24; int v25; int v26; int v27; int v28; int v29; int v30;\
int v31; int v32; int v33; int v34; int v35; int v36; int v37; int v38;\
int v39; int v40; int v41; int v42; int v43; int v44; int v45; int v46;\
int v47; int v48; int v49; int v50; int v51; int v52; int v53; int v54;\
int v55; int v56; int v57; int v58; int v59; int v60; int v61; int v62;\
int v63; int v64" >> /sys/kernel/tracing/synthetic_events
Correct the field counting to fix it.
Link: https://lore.kernel.org/linux-trace-kernel/20221207091557.3137904-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: c9e759b1e8 ("tracing: Rework synthetic event command parsing")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When generate a synthetic event with many params and then create a trace
action for it [1], kernel panic happened [2].
It is because that in trace_action_create() 'data->n_params' is up to
SYNTH_FIELDS_MAX (current value is 64), and array 'data->var_ref_idx'
keeps indices into array 'hist_data->var_refs' for each synthetic event
param, but the length of 'data->var_ref_idx' is TRACING_MAP_VARS_MAX
(current value is 16), so out-of-bound write happened when 'data->n_params'
more than 16. In this case, 'data->match_data.event' is overwritten and
eventually cause the panic.
To solve the issue, adjust the length of 'data->var_ref_idx' to be
SYNTH_FIELDS_MAX and add sanity checks to avoid out-of-bound write.
[1]
# cd /sys/kernel/tracing/
# echo "my_synth_event int v1; int v2; int v3; int v4; int v5; int v6;\
int v7; int v8; int v9; int v10; int v11; int v12; int v13; int v14;\
int v15; int v16; int v17; int v18; int v19; int v20; int v21; int v22;\
int v23; int v24; int v25; int v26; int v27; int v28; int v29; int v30;\
int v31; int v32; int v33; int v34; int v35; int v36; int v37; int v38;\
int v39; int v40; int v41; int v42; int v43; int v44; int v45; int v46;\
int v47; int v48; int v49; int v50; int v51; int v52; int v53; int v54;\
int v55; int v56; int v57; int v58; int v59; int v60; int v61; int v62;\
int v63" >> synthetic_events
# echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="bash"' >> \
events/sched/sched_waking/trigger
# echo "hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(\
pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,\
pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,\
pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,\
pid,pid,pid,pid,pid,pid,pid,pid,pid)" >> events/sched/sched_switch/trigger
[2]
BUG: unable to handle page fault for address: ffff91c900000000
PGD 61001067 P4D 61001067 PUD 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 2 PID: 322 Comm: bash Tainted: G W 6.1.0-rc8+ #229
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:strcmp+0xc/0x30
Code: 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee
c3 cc cc cc cc 0f 1f 00 31 c0 eb 08 48 83 c0 01 84 d2 74 13 <0f> b6 14
07 3a 14 06 74 ef 19 c0 83 c8 01 c3 cc cc cc cc 31 c3
RSP: 0018:ffff9b3b00f53c48 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffffba958a68 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffff91c943d33a90 RDI: ffff91c900000000
RBP: ffff91c900000000 R08: 00000018d604b529 R09: 0000000000000000
R10: ffff91c9483eddb1 R11: ffff91ca483eddab R12: ffff91c946171580
R13: ffff91c9479f0538 R14: ffff91c9457c2848 R15: ffff91c9479f0538
FS: 00007f1d1cfbe740(0000) GS:ffff91c9bdc80000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff91c900000000 CR3: 0000000006316000 CR4: 00000000000006e0
Call Trace:
<TASK>
__find_event_file+0x55/0x90
action_create+0x76c/0x1060
event_hist_trigger_parse+0x146d/0x2060
? event_trigger_write+0x31/0xd0
trigger_process_regex+0xbb/0x110
event_trigger_write+0x6b/0xd0
vfs_write+0xc8/0x3e0
? alloc_fd+0xc0/0x160
? preempt_count_add+0x4d/0xa0
? preempt_count_add+0x70/0xa0
ksys_write+0x5f/0xe0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f1d1d0cf077
Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e
fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00
f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74
RSP: 002b:00007ffcebb0e568 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000143 RCX: 00007f1d1d0cf077
RDX: 0000000000000143 RSI: 00005639265aa7e0 RDI: 0000000000000001
RBP: 00005639265aa7e0 R08: 000000000000000a R09: 0000000000000142
R10: 000056392639c017 R11: 0000000000000246 R12: 0000000000000143
R13: 00007f1d1d1ae6a0 R14: 00007f1d1d1aa4a0 R15: 00007f1d1d1a98a0
</TASK>
Modules linked in:
CR2: ffff91c900000000
---[ end trace 0000000000000000 ]---
RIP: 0010:strcmp+0xc/0x30
Code: 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee
c3 cc cc cc cc 0f 1f 00 31 c0 eb 08 48 83 c0 01 84 d2 74 13 <0f> b6 14
07 3a 14 06 74 ef 19 c0 83 c8 01 c3 cc cc cc cc 31 c3
RSP: 0018:ffff9b3b00f53c48 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffffba958a68 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffff91c943d33a90 RDI: ffff91c900000000
RBP: ffff91c900000000 R08: 00000018d604b529 R09: 0000000000000000
R10: ffff91c9483eddb1 R11: ffff91ca483eddab R12: ffff91c946171580
R13: ffff91c9479f0538 R14: ffff91c9457c2848 R15: ffff91c9479f0538
FS: 00007f1d1cfbe740(0000) GS:ffff91c9bdc80000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff91c900000000 CR3: 0000000006316000 CR4: 00000000000006e0
Link: https://lore.kernel.org/linux-trace-kernel/20221207035143.2278781-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: d380dcde9a ("tracing: Fix now invalid var_ref_vals assumption in trace action")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Both CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER partially enables the
CONFIG_TRACER_MAX_TRACE code, but that is complicated and has
introduced a bug; It declares tracing_max_lat_fops data structure outside
of #ifdefs, but since it is defined only when CONFIG_TRACER_MAX_TRACE=y
or CONFIG_HWLAT_TRACER=y, if only CONFIG_OSNOISE_TRACER=y, that
declaration comes to a definition(!).
To fix this issue, and do not repeat the similar problem, makes
CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER enables the
CONFIG_TRACER_MAX_TRACE always. It has there benefits;
- Fix the tracing_max_lat_fops bug
- Simplify the #ifdefs
- CONFIG_TRACER_MAX_TRACE code is fully enabled, or not.
Link: https://lore.kernel.org/linux-trace-kernel/167033628155.4111793.12185405690820208159.stgit@devnote3
Fixes: 424b650f35 ("tracing: Fix missing osnoise tracer on max_latency")
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: stable@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/all/166992525941.1716618.13740663757583361463.stgit@warthog.procyon.org.uk/ (original thread and v1)
Link: https://lore.kernel.org/all/202212052253.VuhZ2ulJ-lkp@intel.com/T/#u (v1 error report)
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When creating probe names, a check is done to make sure it matches basic C
standard variable naming standards. Basically, starts with alphabetic or
underline, and then the rest of the characters have alpha-numeric or
underline in them.
But system names do not have any true naming conventions, as they are
created by the TRACE_SYSTEM macro and nothing tests to see what they are.
The "xhci-hcd" trace events has a '-' in the system name. When trying to
attach a eprobe to one of these trace points, it fails because the system
name does not follow the variable naming convention because of the
hyphen, and the eprobe checks fail on this.
Allow hyphens in the system name so that eprobes can attach to the
"xhci-hcd" trace events.
Link: https://lore.kernel.org/all/Y3eJ8GiGnEvVd8%2FN@macondo/
Link: https://lore.kernel.org/linux-trace-kernel/20221122122345.160f5077@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 5b7a962209 ("tracing/probe: Check event/group naming rule at parsing")
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Function __kprobe_trace_func calls ring_buffer_event_data to
get a ring buffer, however, it has been done in above call
trace_event_buffer_reserve. So does __kretprobe_trace_func.
This patch removes those duplicated calls.
Link: https://lore.kernel.org/all/1666145478-4706-1-git-send-email-chensong_2000@189.cn/
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Song Chen <chensong_2000@189.cn>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
The hitcount is treated specially in the histograms - since it's
always expected to be there regardless of whether the user specified
anything or not, it's always added as the first histogram value.
Currently the code doesn't allow it to be added more than once as a
value, which is inconsistent with all the other possible values. It
would seem to be a pointless thing to want to do, but other features
being added such as percent and graph modifiers don't work properly
with the current hitcount restrictions.
Fix this by allowing multiple hitcounts to be added.
Link: https://lore.kernel.org/linux-trace-kernel/166610812248.56030.16754785928712505251.stgit@devnote2
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.
Prior to 347c4a8747 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently dropped
the file type check with it allowing any file to slip through. With the
invarients broken, the d_name and parent accesses can now race against
renames and removals of arbitrary files and cause use-after-free's.
Fix the bug by resurrecting the file type check in __file_cft(). Now that
cgroupfs is implemented through kernfs, checking the file operations needs
to go through a layer of indirection. Instead, let's check the superblock
and dentry type.
Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org
Fixes: 347c4a8747 ("memcg: remove cgroup_event->cft")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org> [3.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It may happen that destination buffer memory overlaps with memory dynptr
points to. Hence, we must use memmove to correctly copy from dynptr to
destination buffer, or source buffer to dynptr.
This actually isn't a problem right now, as memcpy implementation falls
back to memmove on detecting overlap and warns about it, but we
shouldn't be relying on that.
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
After previous commit, we are minimizing helper specific assumptions
from check_func_arg_reg_off, making it generic, and offloading checks
for a specific argument type to their respective functions called after
check_func_arg_reg_off has been called.
This allows relying on a consistent set of guarantees after that call
and then relying on them in code that deals with registers for each
argument type later. This is in line with how process_spin_lock,
process_timer_func, process_kptr_func check reg->var_off to be constant.
The same reasoning is used here to move the alignment check into
process_dynptr_func. Note that it also needs to check for constant
var_off, and accumulate the constant var_off when computing the spi in
get_spi, but that fix will come in later changes.
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
While check_func_arg_reg_off is the place which performs generic checks
needed by various candidates of reg->type, there is some handling for
special cases, like ARG_PTR_TO_DYNPTR, OBJ_RELEASE, and
ARG_PTR_TO_RINGBUF_MEM.
This commit aims to streamline these special cases and instead leave
other things up to argument type specific code to handle. The function
will be restrictive by default, and cover all possible cases when
OBJ_RELEASE is set, without having to update the function again (and
missing to do that being a bug).
This is done primarily for two reasons: associating back reg->type to
its argument leaves room for the list getting out of sync when a new
reg->type is supported by an arg_type.
The other case is ARG_PTR_TO_RINGBUF_MEM. The problem there is something
we already handle, whenever a release argument is expected, it should
be passed as the pointer that was received from the acquire function.
Hence zero fixed and variable offset.
There is nothing special about ARG_PTR_TO_RINGBUF_MEM, where technically
its target register type PTR_TO_MEM | MEM_RINGBUF can already be passed
with non-zero offset to other helper functions, which makes sense.
Hence, lift the arg_type_is_release check for reg->off and cover all
possible register types, instead of duplicating the same kind of check
twice for current OBJ_RELEASE arg_types (alloc_mem and ptr_to_btf_id).
For the release argument, arg_type_is_dynptr is the special case, where
we go to actual object being freed through the dynptr, so the offset of
the pointer still needs to allow fixed and variable offset and
process_dynptr_func will verify them later for the release argument case
as well.
This is not specific to ARG_PTR_TO_DYNPTR though, we will need to make
this exception for any future object on the stack that needs to be
released. In this sense, PTR_TO_STACK as a candidate for object on stack
argument is a special case for release offset checks, and they need to
be done by the helper releasing the object on stack.
Since the check has been lifted above all register type checks, remove
the duplicated check that is being done for PTR_TO_BTF_ID.
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Recently, user ringbuf support introduced a PTR_TO_DYNPTR register type
for use in callback state, because in case of user ringbuf helpers,
there is no dynptr on the stack that is passed into the callback. To
reflect such a state, a special register type was created.
However, some checks have been bypassed incorrectly during the addition
of this feature. First, for arg_type with MEM_UNINIT flag which
initialize a dynptr, they must be rejected for such register type.
Secondly, in the future, there are plans to add dynptr helpers that
operate on the dynptr itself and may change its offset and other
properties.
In all of these cases, PTR_TO_DYNPTR shouldn't be allowed to be passed
to such helpers, however the current code simply returns 0.
The rejection for helpers that release the dynptr is already handled.
For fixing this, we take a step back and rework existing code in a way
that will allow fitting in all classes of helpers and have a coherent
model for dealing with the variety of use cases in which dynptr is used.
First, for ARG_PTR_TO_DYNPTR, it can either be set alone or together
with a DYNPTR_TYPE_* constant that denotes the only type it accepts.
Next, helpers which initialize a dynptr use MEM_UNINIT to indicate this
fact. To make the distinction clear, use MEM_RDONLY flag to indicate
that the helper only operates on the memory pointed to by the dynptr,
not the dynptr itself. In C parlance, it would be equivalent to taking
the dynptr as a point to const argument.
When either of these flags are not present, the helper is allowed to
mutate both the dynptr itself and also the memory it points to.
Currently, the read only status of the memory is not tracked in the
dynptr, but it would be trivial to add this support inside dynptr state
of the register.
With these changes and renaming PTR_TO_DYNPTR to CONST_PTR_TO_DYNPTR to
better reflect its usage, it can no longer be passed to helpers that
initialize a dynptr, i.e. bpf_dynptr_from_mem, bpf_ringbuf_reserve_dynptr.
A note to reviewers is that in code that does mark_stack_slots_dynptr,
and unmark_stack_slots_dynptr, we implicitly rely on the fact that
PTR_TO_STACK reg is the only case that can reach that code path, as one
cannot pass CONST_PTR_TO_DYNPTR to helpers that don't set MEM_RDONLY. In
both cases such helpers won't be setting that flag.
The next patch will add a couple of selftest cases to make sure this
doesn't break.
Fixes: 2057156738 ("bpf: Add bpf_user_ringbuf_drain() helper")
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
ARG_PTR_TO_DYNPTR is akin to ARG_PTR_TO_TIMER, ARG_PTR_TO_KPTR, where
the underlying register type is subjected to more special checks to
determine the type of object represented by the pointer and its state
consistency.
Move dynptr checks to their own 'process_dynptr_func' function so that
is consistent and in-line with existing code. This also makes it easier
to reuse this code for kfunc handling.
Then, reuse this consolidated function in kfunc dynptr handling too.
Note that for kfuncs, the arg_type constraint of DYNPTR_TYPE_LOCAL has
been lifted.
Acked-by: David Vernet <void@manifault.com>
Acked-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221207204141.308952-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
If there are pending rcu callback, free_mem_alloc() will use
rcu_barrier_tasks_trace() and rcu_barrier() to wait for the pending
__free_rcu_tasks_trace() and __free_rcu() callback.
If rcu_trace_implies_rcu_gp() is true, there will be no pending
__free_rcu(), so it will be OK to skip rcu_barrier() as well.
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20221209010947.3130477-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When there are batched freeing operations on a specific CPU, part of
the freed elements ((high_watermark - lower_watermark) / 2 + 1) will be
indirectly moved into waiting_for_gp list through free_by_rcu list.
After call_rcu_in_progress becomes false again, the remaining elements
in free_by_rcu list will be moved to waiting_for_gp list by the next
invocation of free_bulk(). However if the expiration of RCU tasks trace
grace period is relatively slow, none element in free_by_rcu list will
be moved.
So instead of invoking __alloc_percpu_gfp() or kmalloc_node() to
allocate a new object, in alloc_bulk() just check whether or not there is
freed element in free_by_rcu list and reuse it if available.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20221209010947.3130477-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.
Prior to 347c4a8747 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently
dropped the file type check with it allowing any file to slip through.
With the invarients broken, the d_name and parent accesses can now race
against renames and removals of arbitrary files and cause
use-after-free's.
Fix the bug by resurrecting the file type check in __file_cft(). Now
that cgroupfs is implemented through kernfs, checking the file
operations needs to go through a layer of indirection. Instead, let's
check the superblock and dentry type.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 347c4a8747 ("memcg: remove cgroup_event->cft")
Cc: stable@kernel.org # v3.14+
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
insn->imm for kfunc is the relative address of __bpf_call_base,
instead of __bpf_base_call, Fix the comment error.
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20221208013724.257848-1-yangjihong1@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In BPF all global functions, and BPF helpers return a 64-bit
value. For kfunc calls, this is not the case, and they can return
e.g. 32-bit values.
The return register R0 for kfuncs calls can therefore be marked as
subreg_def != DEF_NOT_SUBREG. In general, if a register is marked with
subreg_def != DEF_NOT_SUBREG, some archs (where bpf_jit_needs_zext()
returns true) require the verifier to insert explicit zero-extension
instructions.
For kfuncs calls, however, the caller should do sign/zero extension
for return values. In other words, the compiler is responsible to
insert proper instructions, not the verifier.
An example, provided by Yonghong Song:
$ cat t.c
extern unsigned foo(void);
unsigned bar1(void) {
return foo();
}
unsigned bar2(void) {
if (foo()) return 10; else return 20;
}
$ clang -target bpf -mcpu=v3 -O2 -c t.c && llvm-objdump -d t.o
t.o: file format elf64-bpf
Disassembly of section .text:
0000000000000000 <bar1>:
0: 85 10 00 00 ff ff ff ff call -0x1
1: 95 00 00 00 00 00 00 00 exit
0000000000000010 <bar2>:
2: 85 10 00 00 ff ff ff ff call -0x1
3: bc 01 00 00 00 00 00 00 w1 = w0
4: b4 00 00 00 14 00 00 00 w0 = 0x14
5: 16 01 01 00 00 00 00 00 if w1 == 0x0 goto +0x1 <LBB1_2>
6: b4 00 00 00 0a 00 00 00 w0 = 0xa
0000000000000038 <LBB1_2>:
7: 95 00 00 00 00 00 00 00 exit
If the return value of 'foo()' is used in the BPF program, the proper
zero-extension will be done.
Currently, the verifier correctly marks, say, a 32-bit return value as
subreg_def != DEF_NOT_SUBREG, but will fail performing the actual
zero-extension, due to a verifier bug in
opt_subreg_zext_lo32_rnd_hi32(). load_reg is not properly set to R0,
and the following path will be taken:
if (WARN_ON(load_reg == -1)) {
verbose(env, "verifier bug. zext_dst is set, but no reg is defined\n");
return -EFAULT;
}
A longer discussion from v1 can be found in the link below.
Correct the verifier by avoiding doing explicit zero-extension of R0
for kfunc calls. Note that R0 will still be marked as a sub-register
for return values smaller than 64-bit.
Fixes: 83a2881903 ("bpf: Account for BPF_FETCH in insn_has_def32()")
Link: https://lore.kernel.org/bpf/20221202103620.1915679-1-bjorn@kernel.org/
Suggested-by: Yonghong Song <yhs@meta.com>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221207103540.396496-1-bjorn@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When the blk_classic option is enabled, non-blktrace events must be
filtered out. Otherwise, events of other types are output in the blktrace
classic format, which is unexpected.
The problem can be triggered in the following ways:
# echo 1 > /sys/kernel/debug/tracing/options/blk_classic
# echo 1 > /sys/kernel/debug/tracing/events/enable
# echo blk > /sys/kernel/debug/tracing/current_tracer
# cat /sys/kernel/debug/tracing/trace_pipe
Fixes: c71a896154 ("blktrace: add ftrace plugin")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20221122040410.85113-1-yangjihong1@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bpf_cgroup_acquire(), bpf_cgroup_release(), bpf_cgroup_kptr_get(), and
bpf_cgroup_ancestor(), are kfuncs that were recently added to
kernel/bpf/helpers.c. These are "core" kfuncs in that they're available
for use in any tracepoint or struct_ops BPF program. Though they have no
ABI stability guarantees, we should still document them. This patch adds
a struct cgroup * subsection to the Core kfuncs section which describes
each of these kfuncs.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20221207204911.873646-3-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
bpf_task_acquire(), bpf_task_release(), and bpf_task_from_pid() are
kfuncs that were recently added to kernel/bpf/helpers.c. These are
"core" kfuncs in that they're available for use for any tracepoint or
struct_ops BPF program. Though they have no ABI stability guarantees, we
should still document them. This patch adds a new Core kfuncs section to
the BPF kfuncs doc, and adds entries for all of these task kfuncs.
Note that bpf_task_kptr_get() is not documented, as it still returns
NULL while we're working to resolve how it can use RCU to ensure struct
task_struct * lifetime.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20221207204911.873646-2-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Number of total instructions in BPF program (including subprogs) can and
is accessed from env->prog->len. visit_func_call_insn() doesn't do any
checks against insn_cnt anymore, relying on push_insn() to do this check
internally. So remove unnecessary insn_cnt input argument from
visit_func_call_insn() and visit_insn() functions.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20221207195534.2866030-1-andrii@kernel.org
-----BEGIN PGP SIGNATURE-----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=FX5W
-----END PGP SIGNATURE-----
Merge "do not rely on ALLOW_ERROR_INJECTION for fmod_ret" into bpf-next
Merge commit 5b481acab4 ("bpf: do not rely on ALLOW_ERROR_INJECTION for fmod_ret")
from hid tree into bpf-next.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for zstd compressed modules to the in-kernel decompression
code. This allows zstd compressed modules to be decompressed by the
kernel, similar to the existing support for gzip and xz compressed
modules.
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Piotr Gorski <lucjan.lucjanov@gmail.com>
Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Piotr Gorski <lucjan.lucjanov@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
The current way of expressing that a non-bpf kernel component is willing
to accept that bpf programs can be attached to it and that they can change
the return value is to abuse ALLOW_ERROR_INJECTION.
This is debated in the link below, and the result is that it is not a
reasonable thing to do.
Reuse the kfunc declaration structure to also tag the kernel functions
we want to be fmodret. This way we can control from any subsystem which
functions are being modified by bpf without touching the verifier.
Link: https://lore.kernel.org/all/20221121104403.1545f9b5@gandalf.local.home/
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20221206145936.922196-2-benjamin.tissoires@redhat.com
Don't mark some instructions as jump points when there are actually no
jumps and instructions are just processed sequentially. Such case is
handled naturally by precision backtracking logic without the need to
update jump history. See get_prev_insn_idx(). It goes back linearly by
one instruction, unless current top of jmp_history is pointing to
current instruction. In such case we use `st->jmp_history[cnt - 1].prev_idx`
to find instruction from which we jumped to the current instruction
non-linearly.
Also remove both jump and prune point marking for instruction right
after unconditional jumps, as program flow can get to the instruction
right after unconditional jump instruction only if there is a jump to
that instruction from somewhere else in the program. In such case we'll
mark such instruction as prune/jump point because it's a destination of
a jump.
This change has no changes in terms of number of instructions or states
processes across Cilium and selftests programs.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/20221206233345.438540-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Jump history updating and state equivalence checks are conceptually
independent, so move push_jmp_history() out of is_state_visited(). Also
make a decision whether to perform state equivalence checks or not one
layer higher in do_check(), keeping is_state_visited() unconditionally
performing state checks.
push_jmp_history() should be performed after state checks. There is just
one small non-uniformity. When is_state_visited() finds already
validated equivalent state, it propagates precision marks to current
state's parent chain. For this to work correctly, jump history has to be
updated, so is_state_visited() is doing that internally.
But if no equivalent verified state is found, jump history has to be
updated in a newly cloned child state, so is_jmp_point()
+ push_jmp_history() is performed after is_state_visited() exited with
zero result, which means "proceed with validation".
This change has no functional changes. It's not strictly necessary, but
feels right to decouple these two processes.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221206233345.438540-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
BPF verifier marks some instructions as prune points. Currently these
prune points serve two purposes.
It's a point where verifier tries to find previously verified state and
check current state's equivalence to short circuit verification for
current code path.
But also currently it's a point where jump history, used for precision
backtracking, is updated. This is done so that non-linear flow of
execution could be properly backtracked.
Such coupling is coincidental and unnecessary. Some prune points are not
part of some non-linear jump path, so don't need update of jump history.
On the other hand, not all instructions which have to be recorded in
jump history necessarily are good prune points.
This patch splits prune and jump points into independent flags.
Currently all prune points are marked as jump points to minimize amount
of changes in this patch, but next patch will perform some optimization
of prune vs jmp point placement.
No functional changes are intended.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221206233345.438540-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
btf->struct_meta_tab is populated by btf_parse_struct_metas in btf.c.
There, a BTF record is created for any type containing a spin_lock or
any next-gen datastructure node/head.
Currently, for non-MAP_VALUE types, reg_btf_record will only search for
a record using struct_meta_tab if the reg->type exactly matches
(PTR_TO_BTF_ID | MEM_ALLOC). This exact match is too strict: an
"allocated obj" type - returned from bpf_obj_new - might pick up other
flags while working its way through the program.
Loosen the check to be exact for base_type and just use MEM_ALLOC mask
for type_flag.
This patch is marked Fixes as the original intent of reg_btf_record was
unlikely to have been to fail finding btf_record for valid alloc obj
types with additional flags, some of which (e.g. PTR_UNTRUSTED)
are valid register type states for alloc obj independent of this series.
However, I didn't find a specific broken repro case outside of this
series' added functionality, so it's possible that nothing was
triggering this logic error before.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Fixes: 4e814da0d5 ("bpf: Allow locking bpf_spin_lock in allocated objects")
Link: https://lore.kernel.org/r/20221206231000.3180914-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A series of prior patches added some kfuncs that allow struct
task_struct * objects to be used as kptrs. These kfuncs leveraged the
'refcount_t rcu_users' field of the task for performing refcounting.
This field was used instead of 'refcount_t usage', as we wanted to
leverage the safety provided by RCU for ensuring a task's lifetime.
A struct task_struct is refcounted by two different refcount_t fields:
1. p->usage: The "true" refcount field which task lifetime. The
task is freed as soon as this refcount drops to 0.
2. p->rcu_users: An "RCU users" refcount field which is statically
initialized to 2, and is co-located in a union with
a struct rcu_head field (p->rcu). p->rcu_users
essentially encapsulates a single p->usage
refcount, and when p->rcu_users goes to 0, an RCU
callback is scheduled on the struct rcu_head which
decrements the p->usage refcount.
Our logic was that by using p->rcu_users, we would be able to use RCU to
safely issue refcount_inc_not_zero() a task's rcu_users field to
determine if a task could still be acquired, or was exiting.
Unfortunately, this does not work due to p->rcu_users and p->rcu sharing
a union. When p->rcu_users goes to 0, an RCU callback is scheduled to
drop a single p->usage refcount, and because the fields share a union,
the refcount immediately becomes nonzero again after the callback is
scheduled.
If we were to split the fields out of the union, this wouldn't be a
problem. Doing so should also be rather non-controversial, as there are
a number of places in struct task_struct that have padding which we
could use to avoid growing the structure by splitting up the fields.
For now, so as to fix the kfuncs to be correct, this patch instead
updates bpf_task_acquire() and bpf_task_release() to use the p->usage
field for refcounting via the get_task_struct() and put_task_struct()
functions. Because we can no longer rely on RCU, the change also guts
the bpf_task_acquire_not_zero() and bpf_task_kptr_get() functions
pending a resolution on the above problem.
In addition, the task fixes the kfunc and rcu_read_lock selftests to
expect this new behavior.
Fixes: 90660309b0 ("bpf: Add kfuncs for storing struct task_struct * as a kptr")
Fixes: fca1aa7551 ("bpf: Handle MEM_RCU type properly")
Reported-by: Matus Jokay <matus.jokay@stuba.sk>
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20221206210538.597606-1-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
A previous change amended try_to_freeze_tasks() with the "what"
variable pointing to a string describing the group of tasks subject to
the freezing which may be used in the error message in there too, so
make that happen.
Accordingly, update sleepgraph.py to catch the modified error message
as appropriate.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Using pr_cont() in the tasks freezing code related to system-wide
suspend and hibernation is problematic, because the continuation
messages printed there are susceptible to interspersing with other
unrelated messages which results in output that is hard to
understand.
Address this issue by modifying try_to_freeze_tasks() to print
messages that don't require continuations and adjusting its
callers accordingly.
Reported-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
For supporting post MSI-X enable allocations and for the upcoming PCI/IMS
support a separate interface is required which allows not only the
allocation of a specific index, but also the allocation of any, i.e. the
next free index. The latter is especially required for IMS because IMS
completely does away with index to functionality mappings which are
often found in MSI/MSI-X implementation.
But even with MSI-X there are devices where only the first few indices have
a fixed functionality and the rest is freely assignable by software,
e.g. to queues.
msi_domain_alloc_irq_at() is also different from the range based interfaces
as it always enforces that the MSI descriptor is allocated by the core code
and not preallocated by the caller like the PCI/MSI[-X] enable code path
does.
msi_domain_alloc_irq_at() can be invoked with the index argument set to
MSI_ANY_INDEX which makes the core code pick the next free index. The irq
domain can provide a prepare_desc() operation callback in it's
msi_domain_ops to do domain specific post allocation initialization before
the actual Linux interrupt and the associated interrupt descriptor and
hierarchy alloccations are conducted.
The function also takes an optional @icookie argument which is of type
union msi_instance_cookie. This cookie is not used by the core code and is
stored in the allocated msi_desc::data::icookie. The meaning of the cookie
is completely implementation defined. In case of IMS this might be a PASID
or a pointer to a device queue, but for the MSI core it's opaque and not
used in any way.
The function returns a struct msi_map which on success contains the
allocated index number and the Linux interrupt number so the caller can
spare the index to Linux interrupt number lookup.
On failure map::index contains the error code and map::virq is 0.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232326.501359457@linutronix.de
The existing MSI domain ops msi_prepare() and set_desc() turned out to be
unsuitable for implementing IMS support.
msi_prepare() does not operate on the MSI descriptors. set_desc() lacks
an irq_domain pointer and has a completely different purpose.
Introduce a prepare_desc() op which allows IMS implementations to amend an
MSI descriptor which was allocated by the core code, e.g. by adjusting the
iomem base or adding some data based on the allocated index. This is way
better than requiring that all IMS domain implementations preallocate the
MSI descriptor and then allocate the interrupt.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232326.444560717@linutronix.de
Provide new bus tokens for the upcoming per device PCI/MSI and PCI/MSIX
interrupt domains.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.917219885@linutronix.de
Per device domains provide the real domain size to the core code. This
allows range checking on insertion of MSI descriptors and also paves the
way for dynamic index allocations which are required e.g. for IMS. This
avoids external mechanisms like bitmaps on the device side and just
utilizes the core internal MSI descriptor storxe for it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.798556374@linutronix.de
proc_skip_spaces() seems to think it is working on C strings, and ends
up being just a wrapper around skip_spaces() with a really odd calling
convention.
Instead of basing it on skip_spaces(), it should have looked more like
proc_skip_char(), which really is the exact same function (except it
skips a particular character, rather than whitespace). So use that as
inspiration, odd coding and all.
Now the calling convention actually makes sense and works for the
intended purpose.
Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc_get_long() is passed a size_t, but then assigns it to an 'int'
variable for the length. Let's not do that, even if our IO paths are
limited to MAX_RW_COUNT (exactly because of these kinds of type errors).
So do the proper test in the rigth type.
Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide an interface to match a per device domain bus token. This allows to
query which type of domain is installed for a particular domain id. Will be
used for PCI to avoid frequent create/remove cycles for the MSI resp. MSI-X
domains.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.738047902@linutronix.de
Now that all prerequsites are in place, provide the actual interfaces for
creating and removing per device interrupt domains.
MSI device interrupt domains are created from the provided
msi_domain_template which is duplicated so that it can be modified for the
particular device.
The name of the domain and the name of the interrupt chip are composed by
"$(PREFIX)$(CHIPNAME)-$(DEVNAME)"
$PREFIX: The optional prefix provided by the underlying MSI parent domain
via msi_parent_ops::prefix.
$CHIPNAME: The name of the irq_chip in the template
$DEVNAME: The name of the device
The domain is further initialized through a MSI parent domain callback which
fills in the required functionality for the parent domain or domains further
down the hierarchy. This initialization can fail, e.g. when the requested
feature or MSI domain type cannot be supported.
The domain pointer is stored in the pointer array inside of msi_device_data
which is attached to the domain.
The domain can be removed via the API or left for disposal via devres when
the device is torn down. The API removal is useful e.g. for PCI to have
seperate domains for MSI and MSI-X, which are mutually exclusive and always
occupy the default domain id slot.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.678838546@linutronix.de
Split the functionality of msi_create_irq_domain() so it can
be reused for creating per device irq domains.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.559086358@linutronix.de
To allow proper range checking especially for dynamic allocations add a
size field to struct msi_domain_info. If the field is 0 then the size is
unknown or unlimited (up to MSI_MAX_INDEX) to provide backwards
compability.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.501144862@linutronix.de
MSI parent domains must have some control over the MSI domains which are
built on top. On domain creation they need to fill in e.g. architecture
specific chip callbacks or msi domain ops to make the outermost domain
parent agnostic which is obviously required for architecture independence
etc.
The structure contains:
1) A bitfield which exposes the supported functional features. This
allows to check for features and is also used in the initialization
callback to mask out unsupported features when the actual domain
implementation requests a broader range, e.g. on x86 PCI multi-MSI
is only supported by remapping domains but not by the underlying
vector domain. The PCI/MSI code can then always request multi-MSI
support, but the resulting feature set after creation might not
have it set.
2) An optional string prefix which is put in front of domain and chip
names during creation of the MSI domain. That allows to keep the
naming schemes e.g. on x86 where PCI-MSI domains have a IR- prefix
when interrupt remapping is enabled.
3) An initialization callback to sanity check the domain info of
the to be created MSI domain, to restrict features and to
apply changes in MSI ops and interrupt chip callbacks to
accomodate to the particular MSI parent implementation and/or
the underlying hierarchy.
Add a conveniance function to delegate the initialization from the
MSI parent domain to an underlying domain in the hierarchy.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232325.382485843@linutronix.de
Now that all users are converted remove the old interfaces.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.694291814@linutronix.de
Provide two sorts of interfaces to handle the different use cases:
- msi_domain_alloc_irqs_range():
Handles a caller defined precise range
- msi_domain_alloc_irqs_all():
Allocates all interrupts associated to a domain by scanning the
allocated MSI descriptors
The latter is useful for the existing PCI/MSI support which does not have
range information available.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.396497163@linutronix.de
Provide two sorts of interfaces to handle the different use cases:
- msi_domain_free_irqs_range():
Handles a caller defined precise range
- msi_domain_free_irqs_all():
Frees all interrupts associated to a domain
The latter is useful for device teardown and to handle the legacy MSI support
which does not have any range information available.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.337844751@linutronix.de
Allocating simple interrupt descriptors in the core code has to be multi
device irqdomain aware for the upcoming PCI/IMS support.
Change the interfaces to take a domain id into account. Use the internal
control struct for transport of arguments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.279112474@linutronix.de
Change the descriptor free functions to take a domain id to prepare for the
upcoming multi MSI domain per device support.
To avoid changing and extending the interfaces over and over use an core
internal control struct and hand the pointer through the various functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.220788011@linutronix.de
Change the descriptor allocation and insertion functions to take a domain
id to prepare for the upcoming multi MSI domain per device support.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.163043028@linutronix.de
This reflects the functionality better. No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.103554618@linutronix.de
In preparation of the upcoming per device multi MSI domain support, change
the interface to support lookups based on domain id and zero based index
within the domain.
Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230314.044613697@linutronix.de
To support multiple MSI interrupt domains per device it is necessary to
segment the xarray MSI descriptor storage. Each domain gets up to
MSI_MAX_INDEX entries.
Change the iterators so they operate with domain ids and take the domain
offsets into account.
The publicly available iterators which are mostly used in legacy
implementations and the PCI/MSI core default to MSI_DEFAULT_DOMAIN (0)
which is the id for the existing "global" domains.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.985498981@linutronix.de
With the upcoming per device MSI interrupt domain support it is necessary
to store the domain pointers per device.
Instead of delegating that storage to device drivers or subsystems add a
domain pointer to the msi_dev_domain array in struct msi_device_data.
This pointer is also used to take care of tearing down the irq domains when
msi_device_data is cleaned up via devres.
The interfaces into the MSI core will be changed from irqdomain pointer
based interfaces to domain id based interfaces to support multiple MSI
domains on a single device (e.g. PCI/MSI[-X] and PCI/IMS.
Once the per device domain support is complete the irq domain pointer in
struct device::msi.domain will not longer contain a pointer to the "global"
MSI domain. It will contain a pointer to the MSI parent domain instead.
It would be a horrible maze of conditionals to evaluate all over the place
which domain pointer should be used, i.e. the "global" one in
device::msi::domain or one from the internal pointer array.
To avoid this evaluate in msi_setup_device_data() whether the irq domain
which is associated to a device is a "global" or a parent MSI domain. If it
is global then copy the pointer into the first entry of the msi_dev_domain
array.
This allows to convert interfaces and implementation to domain ids while
keeping everything existing working.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.923860399@linutronix.de
The upcoming support for multiple MSI domains per device requires storage
for the MSI descriptors and in a second step storage for the irqdomain
pointers.
Move the xarray into a separate data structure msi_dev_domain and create an
array with size 1 in msi_device_data, which can be expanded later when the
support for per device domains is implemented.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.864887773@linutronix.de
In the upcoming per device MSI domain concept the MSI parent domains are
not allowed to be used as regular MSI domains where the MSI allocation/free
operations are applicable.
Add appropriate checks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.806128070@linutronix.de
irq_domain::dev is a misnomer as it's usually the rule that a device
pointer points to something which is directly related to the instance.
irq_domain::dev can point to some other device for power management to
ensure that this underlying device is not powered down when an interrupt is
allocated.
The upcoming per device MSI domains really require a pointer to the device
which instantiated the irq domain and not to some random other device which
is required for power management down the chain.
Rename irq_domain::dev to irq_domain::pm_dev and fixup the few sites which
use that pointer.
Conversion was done with the help of coccinelle.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.574541683@linutronix.de
It's truly a MSI only flag and for the upcoming per device MSI domains this
must be in the MSI flags so it can be set during domain setup without
exposing this quirk outside of x86.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.454246167@linutronix.de
Similar to sk/inode/task local storage, enable sleepable support for
cgrp local storage.
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221201050444.2785007-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Martin mentioned that the verifier cannot assume arguments from
LSM hook sk_alloc_security being trusted since after the hook
is called, the sk ref_count is set to 1. This will overwrite
the ref_count changed by the bpf program and may cause ref_count
underflow later on.
I then further checked some other hooks. For example,
for bpf_lsm_file_alloc() hook in fs/file_table.c,
f->f_cred = get_cred(cred);
error = security_file_alloc(f);
if (unlikely(error)) {
file_free_rcu(&f->f_rcuhead);
return ERR_PTR(error);
}
atomic_long_set(&f->f_count, 1);
The input parameter 'f' to security_file_alloc() cannot be trusted
as well.
Specifically, I investiaged bpf_map/bpf_prog/file/sk/task alloc/free
lsm hooks. Except bpf_map_alloc and task_alloc, arguments for all other
hooks should not be considered as trusted. This may not be a complete
list, but it covers common usage for sk and task.
Fixes: 3f00c52393 ("bpf: Allow trusted pointers to be passed to KF_TRUSTED_ARGS kfuncs")
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221203204954.2043348-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit 9bb00b2895 ("bpf: Add kfunc bpf_rcu_read_lock/unlock()")
introduced MEM_RCU and bpf_rcu_read_lock/unlock() support. In that
commit, a rcu pointer is tagged with both MEM_RCU and PTR_TRUSTED
so that it can be passed into kfuncs or helpers as an argument.
Martin raised a good question in [1] such that the rcu pointer,
although being able to accessing the object, might have reference
count of 0. This might cause a problem if the rcu pointer is passed
to a kfunc which expects trusted arguments where ref count should
be greater than 0.
This patch makes the following changes related to MEM_RCU pointer:
- MEM_RCU pointer might be NULL (PTR_MAYBE_NULL).
- Introduce KF_RCU so MEM_RCU ptr can be acquired with
a KF_RCU tagged kfunc which assumes ref count of rcu ptr
could be zero.
- For mem access 'b = ptr->a', say 'ptr' is a MEM_RCU ptr, and
'a' is tagged with __rcu as well. Let us mark 'b' as
MEM_RCU | PTR_MAYBE_NULL.
[1] https://lore.kernel.org/bpf/ac70f574-4023-664e-b711-e0d3b18117fd@linux.dev/
Fixes: 9bb00b2895 ("bpf: Add kfunc bpf_rcu_read_lock/unlock()")
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221203184602.477272-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
see an already freed event
-----BEGIN PGP SIGNATURE-----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=jo4r
-----END PGP SIGNATURE-----
Merge tag 'perf_urgent_for_v6.1_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fix from Borislav Petkov:
- Fix a use-after-free case where the perf pending task callback would
see an already freed event
* tag 'perf_urgent_for_v6.1_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix perf_pending_task() UaF
When handing the SIGNAL_GROUP_EXIT flag, the info in ksignal isn't cleared.
However, the info acquired by dequeue_synchronous_signal/dequeue_signal is
initialized and can be safely used. Fortunately, the fatal signal process
just uses the si_signo and doesn't use any other member. Even so, the
initialization before use is more safer.
Signed-off-by: haifeng.xu <haifeng.xu@shopee.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221128065606.19570-1-haifeng.xu@shopee.com
Since Warn count is now tracked and is a fairly interesting signal, add
the entry /sys/kernel/warn_count to expose it to userspace.
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-6-keescook@chromium.org
Like oops_limit, add warn_limit for limiting the number of warnings when
panic_on_warn is not set.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-doc@vger.kernel.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-5-keescook@chromium.org
Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
their own warnings, and each check "panic_on_warn". Consolidate this
into a single function so that future instrumentation can be added in
a single location.
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Gow <davidgow@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm@kvack.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org
Resolve conflicts in drivers/vfio/vfio_main.c by using the iommfd version.
The rc fix was done a different way when iommufd patches reworked this
code.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The DYING/STARTING callbacks are not expected to fail. However, as reported
by Derek, buggy drivers such as tboot are still free to return errors
within those sections, which halts the hot(un)plug and leaves the CPU in an
unrecoverable state.
As there is no rollback possible, only log the failures and proceed with
the following steps.
This restores the hotplug behaviour prior to commit 453e410851
("cpu/hotplug: Add cpuhp_invoke_callback_range()")
Fixes: 453e410851 ("cpu/hotplug: Add cpuhp_invoke_callback_range()")
Reported-by: Derek Dolney <z23@posteo.net>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Derek Dolney <z23@posteo.net>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215867
Link: https://lore.kernel.org/r/20220927101259.1149636-1-vdonnefort@google.com
Since the boot cpu does not go through the hotplug process it ends
up with state == CPUHP_ONLINE but target == CPUHP_OFFLINE.
So set the target to match in boot_cpu_hotplug_init().
Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20221117162329.3164999-3-pauld@redhat.com
Writing the current state back in hotplug/target calls cpu_down()
which will set cpu dying even when it isn't and then nothing will
ever clear it. A stress test that reads values and writes them back
for all cpu device files in sysfs will trigger the BUG() in
select_fallback_rq once all cpus are marked as dying.
kernel/cpu.c::target_store()
...
if (st->state < target)
ret = cpu_up(dev->id, target);
else
ret = cpu_down(dev->id, target);
cpu_down() -> cpu_set_state()
bool bringup = st->state < target;
...
if (cpu_dying(cpu) != !bringup)
set_cpu_dying(cpu, !bringup);
Fix this by letting state==target fall through in the target_store()
conditional. Also make sure st->target == target in that case.
Fixes: 757c989b99 ("cpu/hotplug: Make target state writeable")
Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20221117162329.3164999-2-pauld@redhat.com
Commit ca16d5bee5 ("futex: Prevent robust futex exit race") addressed
two cases when tasks waiting on a robust non-PI futex remained blocked
despite the futex not being owned anymore:
* if the owner died after writing zero to the futex word, but before
waking up a waiter
* if a task waiting on the futex was woken up, but died before updating
the futex word (effectively swallowing the notification without acting
on it)
In the second case, the task could be woken up either by the previous
owner (after the futex word was reset to zero) or by the kernel (after
the OWNER_DIED bit was set and the TID part of the futex word was reset
to zero) if the previous owner died without the resetting the futex.
Because the referenced commit wakes up a potential waiter only if the
whole futex word is zero, the latter subcase remains unaddressed.
Fix this by looking only at the TID part of the futex when deciding
whether a wake up is needed.
Fixes: ca16d5bee5 ("futex: Prevent robust futex exit race")
Signed-off-by: Alexey Izbyshev <izbyshev@ispras.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221111215439.248185-1-izbyshev@ispras.ru
Variable and return descriptions were missing from the SRCU read
lock functions. Add them.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/87zgcjpdvo.fsf@jogness.linutronix.de
The console_list_lock provides synchronization for console list and
console->flags updates. All call sites that were using the console_lock
for this synchronization have either switched to use the
console_list_lock or the SRCU list iterator.
Remove console_lock usage for console list updates and console->flags
updates.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-40-john.ogness@linutronix.de
With commit 9e124fe16ff2("xen: Enable console tty by default in domU
if it's not a dummy") a hack was implemented to make sure that the
tty console remains the console behind the /dev/console device. The
main problem with the hack is that, after getting the console pointer
to the tty console, it is assumed the pointer is still valid after
releasing the console_sem. This assumption is incorrect and unsafe.
Make the hack safe by introducing a new function
console_force_preferred_locked() and perform the full operation
under the console_list_lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-33-john.ogness@linutronix.de
Currently it is not possible for drivers to detect if they have
already successfully registered their console. Several drivers
have multiple paths that lead to console registration. To avoid
attempting a 2nd registration (which leads to a WARN), drivers
are implementing their own solution.
Introduce console_is_registered() so drivers can easily identify
if their console is currently registered. A _locked() variant
is also provided if the caller is already holding the
console_list_lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-22-john.ogness@linutronix.de
Use srcu console list iteration for console list traversal. It is
acceptable because the consoles might come and go at any time.
Strict synchronizing with console registration code would not bring
any advantage over srcu.
Document why the console_lock is still necessary. Note that this
is a preparatory change for when console_lock no longer provides
synchronization for the console list.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-21-john.ogness@linutronix.de
With SRCU it is now safe to traverse the console list, even if
the console_trylock() failed. However, overwriting console->seq
when console_trylock() failed is still an issue.
Switch to SRCU iteration and document remaining issue with
console->seq.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-20-john.ogness@linutronix.de
Use srcu console list iteration for console list traversal.
Document why the console_lock is still necessary. Note that this
is a preparatory change for when console_lock no longer provides
synchronization for the console list.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-19-john.ogness@linutronix.de
All users of console_is_usable() are SRCU iterators. Use the
appropriate wrapper function to locklessly read the flags.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-18-john.ogness@linutronix.de
Use srcu console list iteration for console list traversal.
Document why the console_lock is still necessary. Note that this
is a preparatory change for when console_lock no longer provides
synchronization for the console list.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-17-john.ogness@linutronix.de
Guarantee safe iteration of the console list by using SRCU.
Note that in the case of a handover, the SRCU read lock is also
released. This is documented in the function description and as
comments in the code. It is a bit tricky, but this preserves the
lockdep lock ordering for the context handing over the
console_lock:
console_lock()
| mutex_acquire(&console_lock_dep_map) <-- console lock
|
console_unlock()
| console_flush_all()
| | srcu_read_lock(&console_srcu) <-- srcu lock
| | console_emit_next_record()
| | | console_lock_spinning_disable_and_check()
| | | | srcu_read_unlock(&console_srcu) <-- srcu unlock
| | | | mutex_release(&console_lock_dep_map) <-- console unlock
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-16-john.ogness@linutronix.de
Guarantee safe iteration of the console list by using SRCU.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-15-john.ogness@linutronix.de
After switching to SRCU for console list iteration, some readers
will begin readings console->flags as a data race. Locklessly
reading console->flags provides a consistent value because there
is at most one CPU modifying console->flags and that CPU is
using only read-modify-write operations.
Introduce a wrapper for SRCU iterators to read console flags.
Introduce a matching wrapper to write to flags of registered
consoles. Writing to flags of registered consoles is synchronized
by the console_list_lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-13-john.ogness@linutronix.de
Currently there exist races in register_console(), where the types
of registered consoles are checked (without holding the console_lock)
and then after acquiring the console_lock, it is assumed that the list
has not changed. Also, some code that performs console_unregister()
make similar assumptions.
It might be possible to fix these races using the console_lock. But
it would require a complex analysis of all console drivers to make
sure that the console_lock is not taken in match() and setup()
callbacks. And we really prefer to split up and reduce the
responsibilities of console_lock rather than expand its complexity.
Therefore, introduce a new console_list_lock to provide full
synchronization for any console list changes.
In addition, also use console_list_lock for synchronization of
console->flags updates. All flags are either static or modified only
during the console registration. There are only two exceptions.
The first exception is CON_ENABLED, which is also modified by
console_start()/console_stop(). Therefore, these functions must
also take the console_list_lock.
The second exception is when the flags are modified by the console
driver init code before the console is registered. These will be
ignored because they are not visible to the rest of the system
via the console_drivers list.
Note that one of the various responsibilities of the console_lock is
also intended to provide console list and console->flags
synchronization. Later changes will update call sites relying on the
console_lock for these purposes. Once all call sites have been
updated, the console_lock will be relieved of synchronizing
console_list and console->flags updates.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/87sficwokr.fsf@jogness.linutronix.de
It used to be that all consoles were synchronized with respect to
which message they were printing. After commit a699449bb1 ("printk:
refactor and rework printing logic"), all consoles have their own
@seq for tracking which message they are on. That commit also changed
how the initial sequence number was chosen. Instead of choosing the
next non-printed message, it chose the sequence number of the next
message that will be added to the ringbuffer.
That change created a possibility that a non-boot console taking over
for a boot console might skip messages if the boot console was behind
and did not have a chance to catch up before being unregistered.
Since it is not known which boot console is the same device, flush
all consoles and, if necessary, start with the message of the enabled
boot console that is the furthest behind. If no boot consoles are
enabled, begin with the next message that will be added to the
ringbuffer.
Also, since boot consoles are meant to be used at boot time, handle
them the same as CON_PRINTBUFFER to ensure that no initial messages
are skipped.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-7-john.ogness@linutronix.de
The code to initialize @seq for a new console needs to consider
more factors when choosing an initial value. Move the code into
a helper function console_init_seq() "as is" so this code can
be expanded without causing register_console() to become too
long. A later commit will implement the additional code.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-6-john.ogness@linutronix.de
The @bootcon_enabled and @realcon_enabled local variables actually
represent if such console types are registered. In general there
has been a confusion about enabled vs. registered. Incorrectly
naming such variables promotes such confusion.
Rename the variables to _registered.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-5-john.ogness@linutronix.de
Provide an NMI-safe SRCU protected variant to walk the console list.
Note that all console fields are now set before adding the console
to the list to avoid the console becoming visible by SCRU readers
before being fully initialized.
This is a preparatory change for a new console infrastructure which
operates independent of the console BKL.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-4-john.ogness@linutronix.de
Replace the open coded single linked list with a hlist so a conversion
to SRCU protected list walks can reuse the existing primitives.
Co-developed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20221116162152.193147-3-john.ogness@linutronix.de
The elf_check_arch() function is also used to test compatibility of
usermode binaries. Kernel modules may have more specific requirements,
for example powerpc would like to test for ABI version compatibility.
Add a weak module_elf_check_arch() that defaults to true, and call it
from elf_validity_check().
Signed-off-by: Jessica Yu <jeyu@kernel.org>
[np: added changelog, adjust name, rebase]
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221128041539.1742489-2-npiggin@gmail.com
Consider a verifier state with three acquired references, all with
release_on_unlock = true:
idx 0 1 2
state->refs = [2 4 6]
(with 2, 4, and 6 being the ref ids).
When bpf_spin_unlock is called, process_spin_lock will loop through all
acquired_refs and, for each ref, if it's release_on_unlock, calls
release_reference on it. That function in turn calls
release_reference_state, which removes the reference from state->refs by
swapping the reference state with the last reference state in
refs array and decrements acquired_refs count.
process_spin_lock's loop logic, which is essentially:
for (i = 0; i < state->acquired_refs; i++) {
if (!state->refs[i].release_on_unlock)
continue;
release_reference(state->refs[i].id);
}
will fail to release release_on_unlock references which are swapped from
the end. Running this logic on our example demonstrates:
state->refs = [2 4 6] (start of idx=0 iter)
release state->refs[0] by swapping w/ state->refs[2]
state->refs = [6 4] (start of idx=1)
release state->refs[1], no need to swap as it's the last idx
state->refs = [6] (start of idx=2, loop terminates)
ref_id 6 should have been removed but was skipped.
Fix this by looping from back-to-front, which results in refs that are
candidates for removal being swapped with refs which have already been
examined and kept.
If we modify our initial example such that ref 6 is replaced with ref 7,
which is _not_ release_on_unlock, and loop from the back, we'd see:
state->refs = [2 4 7] (start of idx=2)
state->refs = [2 4 7] (start of idx=1)
state->refs = [2 7] (start of idx=0, refs 7 and 4 swapped)
state->refs = [7] (after idx=0, 7 and 2 swapped, loop terminates)
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Fixes: 534e86bc6c ("bpf: Add 'release on unlock' logic for bpf_list_push_{front,back}")
Link: https://lore.kernel.org/r/20221201183406.1203621-1-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
1. With CONFIG_JUMP_LABEL=n static_key_slow_inc() doesn't have any
protection against key->enabled refcounter overflow.
2. With CONFIG_JUMP_LABEL=y static_key_slow_inc_cpuslocked()
still may turn the refcounter negative as (v + 1) may overflow.
key->enabled is indeed a ref-counter as it's documented in multiple
places: top comment in jump_label.h, Documentation/staging/static-keys.rst,
etc.
As -1 is reserved for static key that's in process of being enabled,
functions would break with negative key->enabled refcount:
- for CONFIG_JUMP_LABEL=n negative return of static_key_count()
breaks static_key_false(), static_key_true()
- the ref counter may become 0 from negative side by too many
static_key_slow_inc() calls and lead to use-after-free issues.
These flaws result in that some users have to introduce an additional
mutex and prevent the reference counter from overflowing themselves,
see bpf_enable_runtime_stats() checking the counter against INT_MAX / 2.
Prevent the reference counter overflow by checking if (v + 1) > 0.
Change functions API to return whether the increment was successful.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit adds lockdep checks for illegal use of synchronize_srcu()
within same-type SRCU read-side critical sections and within normal
RCU read-side critical sections. It also makes synchronize_srcu()
be a no-op during early boot.
These changes bring Tiny synchronize_srcu() into line with both Tree
synchronize_srcu() and Tiny synchronize_rcu().
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: John Ogness <john.ogness@linutronix.de>
The system memory map can change over a hibernation-restore cycle due
to a defect in the platform firmware, and some of the page frames used
by the kernel before hibernation may not be available any more during
the subsequent restore which leads to the error below.
[ T357] PM: Image loading progress: 0%
[ T357] PM: Read 2681596 kbytes in 0.03 seconds (89386.53 MB/s)
[ T357] PM: Error -14 resuming
[ T357] PM: Failed to load hibernation image, recovering.
[ T357] PM: Basic memory bitmaps freed
[ T357] OOM killer enabled.
[ T357] Restarting tasks ... done.
[ T357] PM: resume from hibernation failed (-14)
[ T357] PM: Hibernation image not present or could not be loaded.
Add an error message to the unpack() function to allow problematic
page frames to be identified and the source of the problem to be
diagnosed more easily. This can save developers quite a bit of
debugging time.
Signed-off-by: Xueqin Luo <luoxueqin@kylinos.cn>
[ rjw: New subject, edited changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since Oops count is now tracked and is a fairly interesting signal, add
the entry /sys/kernel/oops_count to expose it to userspace.
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jann Horn <jannh@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@chromium.org
Many Linux systems are configured to not panic on oops; but allowing an
attacker to oops the system **really** often can make even bugs that look
completely unexploitable exploitable (like NULL dereferences and such) if
each crash elevates a refcount by one or a lock is taken in read mode, and
this causes a counter to eventually overflow.
The most interesting counters for this are 32 bits wide (like open-coded
refcounts that don't use refcount_t). (The ldsem reader count on 32-bit
platforms is just 16 bits, but probably nobody cares about 32-bit platforms
that much nowadays.)
So let's panic the system if the kernel is constantly oopsing.
The speed of oopsing 2^32 times probably depends on several factors, like
how long the stack trace is and which unwinder you're using; an empirically
important one is whether your console is showing a graphical environment or
a text console that oopses will be printed to.
In a quick single-threaded benchmark, it looks like oopsing in a vfork()
child with a very short stack trace only takes ~510 microseconds per run
when a graphical console is active; but switching to a text console that
oopses are printed to slows it down around 87x, to ~45 milliseconds per
run.
(Adding more threads makes this faster, but the actual oops printing
happens under &die_lock on x86, so you can maybe speed this up by a factor
of around 2 and then any further improvement gets eaten up by lock
contention.)
It looks like it would take around 8-12 days to overflow a 32-bit counter
with repeated oopsing on a multi-core X86 system running a graphical
environment; both me (in an X86 VM) and Seth (with a distro kernel on
normal hardware in a standard configuration) got numbers in that ballpark.
12 days aren't *that* short on a desktop system, and you'd likely need much
longer on a typical server system (assuming that people don't run graphical
desktop environments on their servers), and this is a *very* noisy and
violent approach to exploiting the kernel; and it also seems to take orders
of magnitude longer on some machines, probably because stuff like EFI
pstore will slow it down a ton if that's active.
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20221107201317.324457-1-jannh@google.com
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-2-keescook@chromium.org
In preparation for adding more sysctls directly in kernel/panic.c, split
CONFIG_SMP from the logic that adds sysctls.
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-1-keescook@chromium.org
Use only one hyphen in kernel-doc notation between the function name
and its short description.
The is the documented kerenl-doc format. It also fixes the HTML
presentation to be consistent with other functions.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Link: https://lore.kernel.org/r/20221201070331.25685-1-rdunlap@infradead.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since the introduction of clockevents, i.e., commit d316c57ff6
("clockevents: add core functionality"), there has been a mismatch between
the function and the kernel-doc comment for clockevent_delta2ns().
Hence, ./scripts/kernel-doc -none kernel/time/clockevents.c warns about it.
Adjust the kernel-doc comment for clockevent_delta2ns() for make W=1
happiness.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221102091048.15068-1-lukas.bulwahn@gmail.com
The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL terminated strings.
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/202211301601416229001@zte.com.cn
find_timens_vvar_page() is not architecture-specific, as can be seen from
how all five per-architecture versions of it are the same.
(arm64, powerpc and riscv are exactly the same; x86 and s390 have two
characters difference inside a comment, less blank lines, and mark the
!CONFIG_TIME_NS version as inline.)
Refactor the five copies into a central copy in kernel/time/namespace.c.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221130115320.2918447-1-jannh@google.com
When building the kernel with clang lto (CONFIG_LTO_CLANG_FULL=y), the
following compilation error will appear:
$ make LLVM=1 LLVM_IAS=1 -j
...
ld.lld: error: ld-temp.o <inline asm>:26889:1: symbol 'cgroup_storage_map_btf_ids' is already defined
cgroup_storage_map_btf_ids:;
^
make[1]: *** [/.../bpf-next/scripts/Makefile.vmlinux_o:61: vmlinux.o] Error 1
In local_storage.c, we have
BTF_ID_LIST_SINGLE(cgroup_storage_map_btf_ids, struct, bpf_local_storage_map)
Commit c4bcfb38a9 ("bpf: Implement cgroup storage available to
non-cgroup-attached bpf progs") added the above identical BTF_ID_LIST_SINGLE
definition in bpf_cgrp_storage.c. With duplicated definitions, llvm linker
complains with lto build.
Also, extracting btf_id of 'struct bpf_local_storage_map' is defined four times
for sk, inode, task and cgrp local storages. Let us define a single global one
with a different name than cgroup_storage_map_btf_ids, which also fixed
the lto compilation error.
Fixes: c4bcfb38a9 ("bpf: Implement cgroup storage available to non-cgroup-attached bpf progs")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221130052147.1591625-1-yhs@fb.com
Following the pattern of io_uring, perf, skb, and bpf, iommfd will use
user->locked_vm for accounting pinned pages. Ensure the value is included
in the struct and export free_uid() as iommufd is modular.
user->locked_vm is the good accounting to use for ulimit because it is
per-user, and the security sandboxing of locked pages is not supposed to
be per-process. Other places (vfio, vdpa and infiniband) have used
mm->pinned_vm and/or mm->locked_vm for accounting pinned pages, but this
is only per-process and inconsistent with the new FOLL_LONGTERM users in
the kernel.
Concurrent work is underway to try to put this in a cgroup, so everything
can be consistent and the kernel can provide a FOLL_LONGTERM limit that
actually provides security.
Link: https://lore.kernel.org/r/7-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The integer overflow is descripted with following codes:
> 317 static comp_t encode_comp_t(u64 value)
> 318 {
> 319 int exp, rnd;
......
> 341 exp <<= MANTSIZE;
> 342 exp += value;
> 343 return exp;
> 344 }
Currently comp_t is defined as type of '__u16', but the variable 'exp' is
type of 'int', so overflow would happen when variable 'exp' in line 343 is
greater than 65535.
Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Jinhao <zhangjinhao2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Fix encode_comp_t()".
Type conversion in encode_comp_t() may look a bit problematic.
This patch (of 2):
See calculation of ac_{u,s}time in fill_ac():
> ac->ac_utime = encode_comp_t(nsec_to_AHZ(pacct->ac_utime));
> ac->ac_stime = encode_comp_t(nsec_to_AHZ(pacct->ac_stime));
Return value of nsec_to_AHZ() is always type of 'u64', but it is handled
as type of 'unsigned long' in encode_comp_t, and accuracy loss would
happen on 32-bit platform when 'unsigned long' value is 32-bit-width.
So 'u64' value of encode_comp_t() may look better.
Link: https://lkml.kernel.org/r/20210515140631.369106-1-zhengyejian1@huawei.com
Link: https://lkml.kernel.org/r/20210515140631.369106-2-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org> # build-tested
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Jinhao <zhangjinhao2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Though vmcoreinfo is intended to be small, at just one page, useful
information is still added to it, so we risk running out of space.
Currently there is no runtime check to see whether the vmcoreinfo buffer
has been exhausted. Add a warning for this case.
Currently, my static checking tool[1] indicates that a good upper bound
for vmcoreinfo size is currently 3415 bytes, but the best time to add
warnings is before the risk becomes too high.
[1] https://github.com/brenns10/kernel_stuff/blob/master/vmcoreinfosize/vmcoreinfosize.py
Link: https://lkml.kernel.org/r/20221027205008.312534-1-stephen.s.brennan@oracle.com
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The percpu_counter is used for scenarios where performance is more
important than the accuracy. For percpu_counter users, who want more
accurate information in their slowpath, percpu_counter_sum is provided
which traverses all the online CPUs to accumulate the data. The reason it
only needs to traverse online CPUs is because percpu_counter does
implement CPU offline callback which syncs the local data of the offlined
CPU.
However there is a small race window between the online CPUs traversal of
percpu_counter_sum and the CPU offline callback. The offline callback has
to traverse all the percpu_counters on the system to flush the CPU local
data which can be a lot. During that time, the CPU which is going offline
has already been published as offline to all the readers. So, as the
offline callback is running, percpu_counter_sum can be called for one
counter which has some state on the CPU going offline. Since
percpu_counter_sum only traverses online CPUs, it will skip that specific
CPU and the offline callback might not have flushed the state for that
specific percpu_counter on that offlined CPU.
Normally this is not an issue because percpu_counter users can deal with
some inaccuracy for small time window. However a new user i.e. mm_struct
on the cleanup path wants to check the exact state of the percpu_counter
through check_mm(). For such users, this patch introduces
percpu_counter_sum_all() which traverses all possible CPUs and it is used
in fork.c:check_mm() to avoid the potential race.
This issue is exposed by the later patch "mm: convert mm's rss stats into
percpu_counter".
Link: https://lkml.kernel.org/r/20221109012011.881058-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently mm_struct maintains rss_stats which are updated on page fault
and the unmapping codepaths. For page fault codepath the updates are
cached per thread with the batch of TASK_RSS_EVENTS_THRESH which is 64.
The reason for caching is performance for multithreaded applications
otherwise the rss_stats updates may become hotspot for such applications.
However this optimization comes with the cost of error margin in the rss
stats. The rss_stats for applications with large number of threads can be
very skewed. At worst the error margin is (nr_threads * 64) and we have a
lot of applications with 100s of threads, so the error margin can be very
high. Internally we had to reduce TASK_RSS_EVENTS_THRESH to 32.
Recently we started seeing the unbounded errors for rss_stats for specific
applications which use TCP rx0cp. It seems like vm_insert_pages()
codepath does not sync rss_stats at all.
This patch converts the rss_stats into percpu_counter to convert the error
margin from (nr_threads * 64) to approximately (nr_cpus ^ 2). However
this conversion enable us to get the accurate stats for situations where
accuracy is more important than the cpu cost.
This patch does not make such tradeoffs - we can just use
percpu_counter_add_local() for the updates and percpu_counter_sum() (or
percpu_counter_sync() + percpu_counter_read) for the readers. At the
moment the readers are either procfs interface, oom_killer and memory
reclaim which I think are not performance critical and should be ok with
slow read. However I think we can make that change in a separate patch.
Link: https://lkml.kernel.org/r/20221024052841.3291983-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The networking programs typically don't require CAP_PERFMON, but through kfuncs
like bpf_cast_to_kern_ctx() they can access memory through PTR_TO_BTF_ID. In
such case enforce CAP_PERFMON.
Also make sure that only GPL programs can access kernel data structures.
All kfuncs require GPL already.
Also remove allow_ptr_to_map_access. It's the same as allow_ptr_leaks and
different name for the same check only causes confusion.
Fixes: fd264ca020 ("bpf: Add a kfunc to type cast from bpf uapi ctx to kernel ctx")
Fixes: 50c6b8a9ae ("selftests/bpf: Add a test for btf_type_tag "percpu"")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221125220617.26846-1-alexei.starovoitov@gmail.com
As explained in [1], we would like to remove SLOB if possible.
- There are no known users that need its somewhat lower memory footprint
so much that they cannot handle SLUB (after some modifications by the
previous patches) instead.
- It is an extra maintenance burden, and a number of features are
incompatible with it.
- It blocks the API improvement of allowing kfree() on objects allocated
via kmem_cache_alloc().
As the first step, rename the CONFIG_SLOB option in the slab allocator
configuration choice to CONFIG_SLOB_DEPRECATED. Add CONFIG_SLOB
depending on CONFIG_SLOB_DEPRECATED as an internal option to avoid code
churn. This will cause existing .config files and defconfigs with
CONFIG_SLOB=y to silently switch to the default (and recommended
replacement) SLUB, while still allowing SLOB to be configured by anyone
that notices and needs it. But those should contact the slab maintainers
and linux-mm@kvack.org as explained in the updated help. With no valid
objections, the plan is to update the existing defconfigs to SLUB and
remove SLOB in a few cycles.
To make SLUB more suitable replacement for SLOB, a CONFIG_SLUB_TINY
option was introduced to limit SLUB's memory overhead.
There is a number of defconfigs specifying CONFIG_SLOB=y. As part of
this patch, update them to select CONFIG_SLUB and CONFIG_SLUB_TINY.
[1] https://lore.kernel.org/all/b35c3f82-f67b-2103-7d82-7a7ba7521439@suse.cz/
Cc: Russell King <linux@armlinux.org.uk>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Conor Dooley <conor@kernel.org>
Cc: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi> # OMAP1
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> # riscv k210
Acked-by: Arnd Bergmann <arnd@arndb.de> # arm
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Lameter <cl@linux.com>
Earlier commits in this series allow battery-powered systems to build
their kernels with the default-disabled CONFIG_RCU_LAZY=y Kconfig option.
This Kconfig option causes call_rcu() to delay its callbacks in order
to batch them. This means that a given RCU grace period covers more
callbacks, thus reducing the number of grace periods, in turn reducing
the amount of energy consumed, which increases battery lifetime which
can be a very good thing. This is not a subtle effect: In some important
use cases, the battery lifetime is increased by more than 10%.
This CONFIG_RCU_LAZY=y option is available only for CPUs that offload
callbacks, for example, CPUs mentioned in the rcu_nocbs kernel boot
parameter passed to kernels built with CONFIG_RCU_NOCB_CPU=y.
Delaying callbacks is normally not a problem because most callbacks do
nothing but free memory. If the system is short on memory, a shrinker
will kick all currently queued lazy callbacks out of their laziness,
thus freeing their memory in short order. Similarly, the rcu_barrier()
function, which blocks until all currently queued callbacks are invoked,
will also kick lazy callbacks, thus enabling rcu_barrier() to complete
in a timely manner.
However, there are some cases where laziness is not a good option.
For example, synchronize_rcu() invokes call_rcu(), and blocks until
the newly queued callback is invoked. It would not be a good for
synchronize_rcu() to block for ten seconds, even on an idle system.
Therefore, synchronize_rcu() invokes call_rcu_hurry() instead of
call_rcu(). The arrival of a non-lazy call_rcu_hurry() callback on a
given CPU kicks any lazy callbacks that might be already queued on that
CPU. After all, if there is going to be a grace period, all callbacks
might as well get full benefit from it.
Yes, this could be done the other way around by creating a
call_rcu_lazy(), but earlier experience with this approach and
feedback at the 2022 Linux Plumbers Conference shifted the approach
to call_rcu() being lazy with call_rcu_hurry() for the few places
where laziness is inappropriate.
And another call_rcu() instance that cannot be lazy is the one
in queue_rcu_work(), given that callers to queue_rcu_work() are
not necessarily OK with long delays.
Therefore, make queue_rcu_work() use call_rcu_hurry() in order to revert
to the old behavior.
[ paulmck: Apply s/call_rcu_flush/call_rcu_hurry/ feedback from Tejun Heo. ]
Signed-off-by: Uladzislau Rezki <urezki@gmail.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Invoking ./scripts/kernel-doc -none kernel/notifier.c warns:
kernel/notifier.c:71: warning: Excess function parameter 'returns' description in 'notifier_call_chain'
kernel/notifier.c:119: warning: Function parameter or member 'v' not described in 'notifier_call_chain_robust'
These two warning are easy to fix, as they are just due to some minor slips
that makes the comment not follow kernel-doc's syntactic expectation.
Fix those minor slips in kernel-doc comments for make W=1 happiness.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Fault injection tests trigger warnings like this:
kernfs: can not remove 'chip_name', no directory
WARNING: CPU: 0 PID: 253 at fs/kernfs/dir.c:1616 kernfs_remove_by_name_ns+0xce/0xe0
RIP: 0010:kernfs_remove_by_name_ns+0xce/0xe0
Call Trace:
<TASK>
remove_files.isra.1+0x3f/0xb0
sysfs_remove_group+0x68/0xe0
sysfs_remove_groups+0x41/0x70
__kobject_del+0x45/0xc0
kobject_del+0x29/0x40
free_desc+0x42/0x70
irq_free_descs+0x5e/0x90
The reason is that the interrupt descriptor sysfs handling does not roll
back on a failing kobject_add() during allocation. If the descriptor is
freed later on, kobject_del() is invoked with a not added kobject resulting
in the above warnings.
A proper rollback in case of a kobject_add() failure would be the straight
forward solution. But this is not possible due to the way how interrupt
descriptor sysfs handling works.
Interrupt descriptors are allocated before sysfs becomes available. So the
sysfs files for the early allocated descriptors are added later in the boot
process. At this point there can be nothing useful done about a failing
kobject_add(). For consistency the interrupt descriptor allocation always
treats kobject_add() failures as non-critical and just emits a warning.
To solve this problem, keep track in the interrupt descriptor whether
kobject_add() was successful or not and make the invocation of
kobject_del() conditional on that.
[ tglx: Massage changelog, comments and use a state bit. ]
Fixes: ecb3f394c5 ("genirq: Expose interrupt information through sysfs")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20221128151612.1786122-1-yangyingliang@huawei.com
Kernels configured with CONFIG_PRINTK=n and CONFIG_SRCU=n get build
failures. This causes trouble for deep embedded systems. But given
that there are more than 25 instances of "select SRCU" in the kernel,
it is hard to believe that there are many kernels running in production
without SRCU. This commit therefore makes SRCU mandatory. The SRCU
Kconfig option remains for backwards compatibility, and will be removed
when it is no longer used.
[ paulmck: Update per kernel test robot feedback. ]
Reported-by: John Ogness <john.ogness@linutronix.de>
Reported-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Reviewed-by: John Ogness <john.ogness@linutronix.de>
call_rcu() changes to save power will change the behavior of rcutorture
tests. Use the call_rcu_hurry() API instead which reverts to the old
behavior.
[ paulmck: Apply s/call_rcu_flush/call_rcu_hurry/ feedback from Tejun Heo. ]
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
rcuscale uses call_rcu() to queue async readers. With recent changes to
save power, the test will have fewer async readers in flight. Use the
call_rcu_hurry() API instead to revert to the old behavior.
[ paulmck: Apply s/call_rcu_flush/call_rcu_hurry/ feedback from Tejun Heo. ]
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
call_rcu() changes to save power will slow down rcu sync. Use the
call_rcu_hurry() API instead which reverts to the old behavior.
[ paulmck: Apply s/call_rcu_flush/call_rcu_hurry/ feedback from Tejun Heo. ]
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds 2 tests to rcuscale. The first one is a startup test
to check whether we are not too lazy or too hard working. The second
one causes kfree_rcu() itself to use call_rcu() and checks memory
pressure. Testing indicates that the new call_rcu() keeps memory pressure
under control roughly as well as does kfree_rcu().
[ paulmck: Apply checkpatch feedback. ]
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
The shrinker is used to speed up the free'ing of memory potentially held
by RCU lazy callbacks. RCU kernel module test cases show this to be
effective. Test is introduced in a later patch.
Signed-off-by: Vineeth Pillai <vineeth@bitbyteword.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This consolidates the code a bit and makes it cleaner. Functionally it
is the same.
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
