5057 Commits

Author SHA1 Message Date
Yipeng Zou
3c90af5a77 tracing: hold caller_addr to hardirq_{enable,disable}_ip
[ Upstream commit 54c3931957f6a6194d5972eccc36d052964b2abe ]

Currently, The arguments passing to lockdep_hardirqs_{on,off} was fixed
in CALLER_ADDR0.
The function trace_hardirqs_on_caller should have been intended to use
caller_addr to represent the address that caller wants to be traced.

For example, lockdep log in riscv showing the last {enabled,disabled} at
__trace_hardirqs_{on,off} all the time(if called by):
[   57.853175] hardirqs last  enabled at (2519): __trace_hardirqs_on+0xc/0x14
[   57.853848] hardirqs last disabled at (2520): __trace_hardirqs_off+0xc/0x14

After use trace_hardirqs_xx_caller, we can get more effective information:
[   53.781428] hardirqs last  enabled at (2595): restore_all+0xe/0x66
[   53.782185] hardirqs last disabled at (2596): ret_from_exception+0xa/0x10

Link: https://lkml.kernel.org/r/20220901104515.135162-2-zouyipeng@huawei.com

Cc: stable@vger.kernel.org
Fixes: c3bc8fd637a96 ("tracing: Centralize preemptirq tracepoints and unify their usage")
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-20 12:39:43 +02:00
Nick Desaulniers
f9571a9699 lockdep: Fix -Wunused-parameter for _THIS_IP_
[ Upstream commit 8b023accc8df70e72f7704d29fead7ca914d6837 ]

While looking into a bug related to the compiler's handling of addresses
of labels, I noticed some uses of _THIS_IP_ seemed unused in lockdep.
Drive by cleanup.

-Wunused-parameter:
kernel/locking/lockdep.c:1383:22: warning: unused parameter 'ip'
kernel/locking/lockdep.c:4246:48: warning: unused parameter 'ip'
kernel/locking/lockdep.c:4844:19: warning: unused parameter 'ip'

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20220314221909.2027027-1-ndesaulniers@google.com
Stable-dep-of: 54c3931957f6 ("tracing: hold caller_addr to hardirq_{enable,disable}_ip")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-20 12:39:42 +02:00
Masami Hiramatsu (Google)
75082adeb4 tracing: Fix to check event_mutex is held while accessing trigger list
commit cecf8e128ec69149fe53c9a7bafa505a4bee25d9 upstream.

Since the check_user_trigger() is called outside of RCU
read lock, this list_for_each_entry_rcu() caused a suspicious
RCU usage warning.

 # echo hist:keys=pid > events/sched/sched_stat_runtime/trigger
 # cat events/sched/sched_stat_runtime/trigger
[   43.167032]
[   43.167418] =============================
[   43.167992] WARNING: suspicious RCU usage
[   43.168567] 5.19.0-rc5-00029-g19ebe4651abf #59 Not tainted
[   43.169283] -----------------------------
[   43.169863] kernel/trace/trace_events_trigger.c:145 RCU-list traversed in non-reader section!!
...

However, this file->triggers list is safe when it is accessed
under event_mutex is held.
To fix this warning, adds a lockdep_is_held check to the
list_for_each_entry_rcu().

Link: https://lkml.kernel.org/r/166226474977.223837.1992182913048377113.stgit@devnote2

Cc: stable@vger.kernel.org
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-15 11:30:02 +02:00
Yang Jihong
e4ae972959 ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead
commit c3b0f72e805f0801f05fa2aa52011c4bfc694c44 upstream.

ftrace_startup does not remove ops from ftrace_ops_list when
ftrace_startup_enable fails:

register_ftrace_function
  ftrace_startup
    __register_ftrace_function
      ...
      add_ftrace_ops(&ftrace_ops_list, ops)
      ...
    ...
    ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1
    ...
  return 0 // ops is in the ftrace_ops_list.

When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything:
unregister_ftrace_function
  ftrace_shutdown
    if (unlikely(ftrace_disabled))
            return -ENODEV;  // return here, __unregister_ftrace_function is not executed,
                             // as a result, ops is still in the ftrace_ops_list
    __unregister_ftrace_function
    ...

If ops is dynamically allocated, it will be free later, in this case,
is_ftrace_trampoline accesses NULL pointer:

is_ftrace_trampoline
  ftrace_ops_trampoline
    do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL!

Syzkaller reports as follows:
[ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b
[ 1203.508039] #PF: supervisor read access in kernel mode
[ 1203.508798] #PF: error_code(0x0000) - not-present page
[ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0
[ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI
[ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G    B   W         5.10.0 #8
[ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0
[ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00
[ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246
[ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866
[ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b
[ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07
[ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399
[ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008
[ 1203.525634] FS:  00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
[ 1203.526801] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0
[ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Therefore, when ftrace_startup_enable fails, we need to rollback registration
process and remove ops from ftrace_ops_list.

Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.com

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05 10:30:07 +02:00
Steven Rostedt (Google)
1c7e569c0e tracing/eprobes: Fix reading of string fields
commit f04dec93466a0481763f3b56cdadf8076e28bfbf upstream.

Currently when an event probe (eprobe) hooks to a string field, it does
not display it as a string, but instead as a number. This makes the field
rather useless. Handle the different kinds of strings, dynamic, static,
relational/dynamic etc.

Now when a string field is used, the ":string" type can be used to display
it:

  echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events

Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:40:28 +02:00
Steven Rostedt (Google)
2fb8f62ee3 tracing: Have filter accept "common_cpu" to be consistent
commit b2380577d4fe1c0ef3fa50417f1e441c016e4cbe upstream.

Make filtering consistent with histograms. As "cpu" can be a field of an
event, allow for "common_cpu" to keep it from being confused with the
"cpu" field of the event.

Link: https://lkml.kernel.org/r/20220820134401.513062765@goodmis.org
Link: https://lore.kernel.org/all/20220820220920.e42fa32b70505b1904f0a0ad@kernel.org/

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 1e3bac71c5053 ("tracing/histogram: Rename "cpu" to "common_cpu"")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:39:58 +02:00
Steven Rostedt (Google)
dac2b60345 tracing/probes: Have kprobes and uprobes use $COMM too
commit ab8384442ee512fc0fc72deeb036110843d0e7ff upstream.

Both $comm and $COMM can be used to get current->comm in eprobes and the
filtering and histogram logic. Make kprobes and uprobes consistent in this
regard and allow both $comm and $COMM as well. Currently kprobes and
uprobes only handle $comm, which is inconsistent with the other utilities,
and can be confusing to users.

Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org
Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.org/

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:39:58 +02:00
Steven Rostedt (Google)
b489aca082 tracing/eprobes: Have event probes be consistent with kprobes and uprobes
commit 6a832ec3d680b3a4f4fad5752672827d71bae501 upstream.

Currently, if a symbol "@" is attempted to be used with an event probe
(eprobes), it will cause a NULL pointer dereference crash.

Both kprobes and uprobes can reference data other than the main registers.
Such as immediate address, symbols and the current task name. Have eprobes
do the same thing.

For "comm", if "comm" is used and the event being attached to does not
have the "comm" field, then make it the "$comm" that kprobes has. This is
consistent to the way histograms and filters work.

Link: https://lkml.kernel.org/r/20220820134401.136924220@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:39:58 +02:00
Steven Rostedt (Google)
a11ce7bfbd tracing/eprobes: Do not hardcode $comm as a string
commit 02333de90e5945e2fe7fc75b15b4eb9aee187f0a upstream.

The variable $comm is hard coded as a string, which is true for both
kprobes and uprobes, but for event probes (eprobes) it is a field name. In
most cases the "comm" field would be a string, but there's no guarantee of
that fact.

Do not assume that comm is a string. Not to mention, it currently forces
comm fields to fault, as string processing for event probes is currently
broken.

Link: https://lkml.kernel.org/r/20220820134400.756152112@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:39:57 +02:00
Steven Rostedt (Google)
ba53c21ce9 tracing/eprobes: Do not allow eprobes to use $stack, or % for regs
commit 2673c60ee67e71f2ebe34386e62d348f71edee47 upstream.

While playing with event probes (eprobes), I tried to see what would
happen if I attempted to retrieve the instruction pointer (%rip) knowing
that event probes do not use pt_regs. The result was:

 BUG: kernel NULL pointer dereference, address: 0000000000000024
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 1 PID: 1847 Comm: trace-cmd Not tainted 5.19.0-rc5-test+ #309
 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01
v03.03 07/14/2016
 RIP: 0010:get_event_field.isra.0+0x0/0x50
 Code: ff 48 c7 c7 c0 8f 74 a1 e8 3d 8b f5 ff e8 88 09 f6 ff 4c 89 e7 e8
50 6a 13 00 48 89 ef 5b 5d 41 5c 41 5d e9 42 6a 13 00 66 90 <48> 63 47 24
8b 57 2c 48 01 c6 8b 47 28 83 f8 02 74 0e 83 f8 04 74
 RSP: 0018:ffff916c394bbaf0 EFLAGS: 00010086
 RAX: ffff916c854041d8 RBX: ffff916c8d9fbf50 RCX: ffff916c255d2000
 RDX: 0000000000000000 RSI: ffff916c255d2008 RDI: 0000000000000000
 RBP: 0000000000000000 R08: ffff916c3a2a0c08 R09: ffff916c394bbda8
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff916c854041d8
 R13: ffff916c854041b0 R14: 0000000000000000 R15: 0000000000000000
 FS:  0000000000000000(0000) GS:ffff916c9ea40000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000024 CR3: 000000011b60a002 CR4: 00000000001706e0
 Call Trace:
  <TASK>
  get_eprobe_size+0xb4/0x640
  ? __mod_node_page_state+0x72/0xc0
  __eprobe_trace_func+0x59/0x1a0
  ? __mod_lruvec_page_state+0xaa/0x1b0
  ? page_remove_file_rmap+0x14/0x230
  ? page_remove_rmap+0xda/0x170
  event_triggers_call+0x52/0xe0
  trace_event_buffer_commit+0x18f/0x240
  trace_event_raw_event_sched_wakeup_template+0x7a/0xb0
  try_to_wake_up+0x260/0x4c0
  __wake_up_common+0x80/0x180
  __wake_up_common_lock+0x7c/0xc0
  do_notify_parent+0x1c9/0x2a0
  exit_notify+0x1a9/0x220
  do_exit+0x2ba/0x450
  do_group_exit+0x2d/0x90
  __x64_sys_exit_group+0x14/0x20
  do_syscall_64+0x3b/0x90
  entry_SYSCALL_64_after_hwframe+0x46/0xb0

Obviously this is not the desired result.

Move the testing for TPARG_FL_TPOINT which is only used for event probes
to the top of the "$" variable check, as all the other variables are not
used for event probes. Also add a check in the register parsing "%" to
fail if an event probe is used.

Link: https://lkml.kernel.org/r/20220820134400.564426983@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:39:57 +02:00
Steven Rostedt (Google)
0d7970e870 tracing/perf: Fix double put of trace event when init fails
commit 7249921d94ff64f67b733eca0b68853a62032b3d upstream.

If in perf_trace_event_init(), the perf_trace_event_open() fails, then it
will call perf_trace_event_unreg() which will not only unregister the perf
trace event, but will also call the put() function of the tp_event.

The problem here is that the trace_event_try_get_ref() is called by the
caller of perf_trace_event_init() and if perf_trace_event_init() returns a
failure, it will then call trace_event_put(). But since the
perf_trace_event_unreg() already called the trace_event_put() function, it
triggers a WARN_ON().

 WARNING: CPU: 1 PID: 30309 at kernel/trace/trace_dynevent.c:46 trace_event_dyn_put_ref+0x15/0x20

If perf_trace_event_reg() does not call the trace_event_try_get_ref() then
the perf_trace_event_unreg() should not be calling trace_event_put(). This
breaks symmetry and causes bugs like these.

Pull out the trace_event_put() from perf_trace_event_unreg() and call it
in the locations that perf_trace_event_unreg() is called. This not only
fixes this bug, but also brings back the proper symmetry of the reg/unreg
vs get/put logic.

Link: https://lore.kernel.org/all/cover.1660347763.git.kjlx@templeofstupid.com/
Link: https://lkml.kernel.org/r/20220816192817.43d5e17f@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 1d18538e6a092 ("tracing: Have dynamic events have a ref counter")
Reported-by: Krister Johansen <kjlx@templeofstupid.com>
Reviewed-by: Krister Johansen <kjlx@templeofstupid.com>
Tested-by: Krister Johansen <kjlx@templeofstupid.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-25 11:39:57 +02:00
Masami Hiramatsu
994dea8549 tracing: Add '__rel_loc' using trace event macros
[ Upstream commit 55de2c0b5610cba5a5a93c0788031133c457e689 ]

Add '__rel_loc' using trace event macros. These macros are usually
not used in the kernel, except for testing purpose.
This also add "rel_" variant of macros for dynamic_array string,
and bitmask.

Link: https://lkml.kernel.org/r/163757342119.510314.816029622439099016.stgit@devnote2

Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:24:26 +02:00
Bart Van Assche
b4439abfd7 blktrace: Trace remapped requests correctly
[ Upstream commit 22c80aac882f712897b88b7ea8f5a74ea19019df ]

Trace the remapped operation and its flags instead of only the data
direction of remapped operations. This issue was detected by analyzing
the warnings reported by sparse related to the new blk_opf_t type.

Reviewed-by: Jun'ichi Nomura <junichi.nomura@nec.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Fixes: 1b9a9ab78b0a ("blktrace: use op accessors")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-11-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17 14:23:13 +02:00
Wonhyuk Yang
d8413b16fe tracing: Fix return value of trace_pid_write()
[ Upstream commit b27f266f74fbda4ee36c2b2b04d15992860cf23b ]

Setting set_event_pid with trailing whitespace lead to endless write
system calls like below.

    $ strace echo "123 " > /sys/kernel/debug/tracing/set_event_pid
    execve("/usr/bin/echo", ["echo", "123 "], ...) = 0
    ...
    write(1, "123 \n", 5)                   = 4
    write(1, "\n", 1)                       = 0
    write(1, "\n", 1)                       = 0
    write(1, "\n", 1)                       = 0
    write(1, "\n", 1)                       = 0
    write(1, "\n", 1)                       = 0
    ....

This is because, the result of trace_get_user's are not returned when it
read at least one pid. To fix it, update read variable even if
parser->idx == 0.

The result of applied patch is below.

    $ strace echo "123 " > /sys/kernel/debug/tracing/set_event_pid
    execve("/usr/bin/echo", ["echo", "123 "], ...) = 0
    ...
    write(1, "123 \n", 5)                   = 5
    close(1)                                = 0

Link: https://lkml.kernel.org/r/20220503050546.288911-1-vvghjk1234@gmail.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Baik Song An <bsahn@etri.re.kr>
Cc: Hong Yeon Kim <kimhy@etri.re.kr>
Cc: Taeung Song <taeung@reallinux.co.kr>
Cc: linuxgeek@linuxgeek.io
Cc: stable@vger.kernel.org
Fixes: 4909010788640 ("tracing: Add set_event_pid directory for future use")
Signed-off-by: Wonhyuk Yang <vvghjk1234@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:25:29 +02:00
Steven Rostedt (VMware)
d977706172 tracing: Place trace_pid_list logic into abstract functions
[ Upstream commit 6954e415264eeb5ee6be0d22d789ad12c995ee64 ]

Instead of having the logic that does trace_pid_list open coded, wrap it in
abstract functions. This will allow a rewrite of the logic that implements
the trace_pid_list without affecting the users.

Note, this causes a change in behavior. Every time a pid is written into
the set_*_pid file, it creates a new list and uses RCU to update it. If
pid_max is lowered, but there was a pid currently in the list that was
higher than pid_max, those pids will now be removed on updating the list.
The old behavior kept that from happening.

The rewrite of the pid_list logic will no longer depend on pid_max,
and will return the old behavior.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:25:29 +02:00
Steven Rostedt (Google)
6107b01416 tracing: Have event format check not flag %p* on __get_dynamic_array()
[ Upstream commit 499f12168aebd6da8fa32c9b7d6203ca9b5eb88d ]

The print fmt check against trace events to make sure that the format does
not use pointers that may be freed from the time of the trace to the time
the event is read, gives a false positive on %pISpc when reading data that
was saved in __get_dynamic_array() when it is perfectly fine to do so, as
the data being read is on the ring buffer.

Link: https://lore.kernel.org/all/20220407144524.2a592ed6@canb.auug.org.au/

Cc: stable@vger.kernel.org
Fixes: 5013f454a352c ("tracing: Add check of trace event print fmts for dereferencing pointers")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:25:29 +02:00
Douglas Anderson
af515a6339 tracing: Fix sleeping while atomic in kdb ftdump
[ Upstream commit 495fcec8648cdfb483b5b9ab310f3839f07cb3b8 ]

If you drop into kdb and type "ftdump" you'll get a sleeping while
atomic warning from memory allocation in trace_find_next_entry().

This appears to have been caused by commit ff895103a84a ("tracing:
Save off entry when peeking at next entry"), which added the
allocation in that path. The problematic commit was already fixed by
commit 8e99cf91b99b ("tracing: Do not allocate buffer in
trace_find_next_entry() in atomic") but that fix missed the kdb case.

The fix here is easy: just move the assignment of the static buffer to
the place where it should have been to begin with:
trace_init_global_iter(). That function is called in two places, once
is right before the assignment of the static buffer added by the
previous fix and once is in kdb.

Note that it appears that there's a second static buffer that we need
to assign that was added in commit efbbdaa22bb7 ("tracing: Show real
address for trace event arguments"), so we'll move that too.

Link: https://lkml.kernel.org/r/20220708170919.1.I75844e5038d9425add2ad853a608cb44bb39df40@changeid

Fixes: ff895103a84a ("tracing: Save off entry when peeking at next entry")
Fixes: efbbdaa22bb7 ("tracing: Show real address for trace event arguments")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-21 21:24:24 +02:00
Zheng Yejian
22eeff5567 tracing/histograms: Fix memory leak problem
commit 7edc3945bdce9c39198a10d6129377a5c53559c2 upstream.

This reverts commit 46bbe5c671e06f070428b9be142cc4ee5cedebac.

As commit 46bbe5c671e0 ("tracing: fix double free") said, the
"double free" problem reported by clang static analyzer is:
  > In parse_var_defs() if there is a problem allocating
  > var_defs.expr, the earlier var_defs.name is freed.
  > This free is duplicated by free_var_defs() which frees
  > the rest of the list.

However, if there is a problem allocating N-th var_defs.expr:
  + in parse_var_defs(), the freed 'earlier var_defs.name' is
    actually the N-th var_defs.name;
  + then in free_var_defs(), the names from 0th to (N-1)-th are freed;

                        IF ALLOCATING PROBLEM HAPPENED HERE!!! -+
                                                                 \
                                                                  |
          0th           1th                 (N-1)-th      N-th    V
          +-------------+-------------+-----+-------------+-----------
var_defs: | name | expr | name | expr | ... | name | expr | name | ///
          +-------------+-------------+-----+-------------+-----------

These two frees don't act on same name, so there was no "double free"
problem before. Conversely, after that commit, we get a "memory leak"
problem because the above "N-th var_defs.name" is not freed.

If enable CONFIG_DEBUG_KMEMLEAK and inject a fault at where the N-th
var_defs.expr allocated, then execute on shell like:
  $ echo 'hist:key=call_site:val=$v1,$v2:v1=bytes_req,v2=bytes_alloc' > \
/sys/kernel/debug/tracing/events/kmem/kmalloc/trigger

Then kmemleak reports:
  unreferenced object 0xffff8fb100ef3518 (size 8):
    comm "bash", pid 196, jiffies 4295681690 (age 28.538s)
    hex dump (first 8 bytes):
      76 31 00 00 b1 8f ff ff                          v1......
    backtrace:
      [<0000000038fe4895>] kstrdup+0x2d/0x60
      [<00000000c99c049a>] event_hist_trigger_parse+0x206f/0x20e0
      [<00000000ae70d2cc>] trigger_process_regex+0xc0/0x110
      [<0000000066737a4c>] event_trigger_write+0x75/0xd0
      [<000000007341e40c>] vfs_write+0xbb/0x2a0
      [<0000000087fde4c2>] ksys_write+0x59/0xd0
      [<00000000581e9cdf>] do_syscall_64+0x3a/0x80
      [<00000000cf3b065c>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Link: https://lkml.kernel.org/r/20220711014731.69520-1-zhengyejian1@huawei.com

Cc: stable@vger.kernel.org
Fixes: 46bbe5c671e0 ("tracing: fix double free")
Reported-by: Hulk Robot <hulkci@huawei.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-21 21:24:11 +02:00
Masami Hiramatsu (Google)
bae4d6a2dd tracing/kprobes: Check whether get_kretprobe() returns NULL in kretprobe_dispatcher()
commit cc72b72073ac982a954d3b43519ca1c28f03c27c upstream.

There is a small chance that get_kretprobe(ri) returns NULL in
kretprobe_dispatcher() when another CPU unregisters the kretprobe
right after __kretprobe_trampoline_handler().

To avoid this issue, kretprobe_dispatcher() checks the get_kretprobe()
return value again. And if it is NULL, it returns soon because that
kretprobe is under unregistering process.

This issue has been introduced when the kretprobe is decoupled
from the struct kretprobe_instance by commit d741bf41d7c7
("kprobes: Remove kretprobe hash"). Before that commit, the
struct kretprob_instance::rp directly points the kretprobe
and it is never be NULL.

Link: https://lkml.kernel.org/r/165366693881.797669.16926184644089588731.stgit@devnote2

Reported-by: Yonghong Song <yhs@fb.com>
Fixes: d741bf41d7c7 ("kprobes: Remove kretprobe hash")
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: bpf <bpf@vger.kernel.org>
Cc: Kernel Team <kernel-team@fb.com>
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29 09:03:20 +02:00
Mark-PK Tsai
6eb85cbd9e tracing: Avoid adding tracer option before update_tracer_options
[ Upstream commit ef9188bcc6ca1d8a2ad83e826b548e6820721061 ]

To prepare for support asynchronous tracer_init_tracefs initcall,
avoid calling create_trace_option_files before __update_tracer_options.
Otherwise, create_trace_option_files will show warning because
some tracers in trace_types list are already in tr->topts.

For example, hwlat_tracer call register_tracer in late_initcall,
and global_trace.dir is already created in tracing_init_dentry,
hwlat_tracer will be put into tr->topts.
Then if the __update_tracer_options is executed after hwlat_tracer
registered, create_trace_option_files find that hwlat_tracer is
already in tr->topts.

Link: https://lkml.kernel.org/r/20220426122407.17042-2-mark-pk.tsai@mediatek.com

Link: https://lore.kernel.org/lkml/20220322133339.GA32582@xsang-OptiPlex-9020/
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:36:14 +02:00
Jun Miao
9b534640a2 tracing: Fix sleeping function called from invalid context on RT kernel
[ Upstream commit 12025abdc8539ed9d5014e2d647a3fd1bd3de5cd ]

When setting bootparams="trace_event=initcall:initcall_start tp_printk=1" in the
cmdline, the output_printk() was called, and the spin_lock_irqsave() was called in the
atomic and irq disable interrupt context suitation. On the PREEMPT_RT kernel,
these locks are replaced with sleepable rt-spinlock, so the stack calltrace will
be triggered.
Fix it by raw_spin_lock_irqsave when PREEMPT_RT and "trace_event=initcall:initcall_start
tp_printk=1" enabled.

 BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
 preempt_count: 2, expected: 0
 RCU nest depth: 0, expected: 0
 Preemption disabled at:
 [<ffffffff8992303e>] try_to_wake_up+0x7e/0xba0
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.1-rt17+ #19 34c5812404187a875f32bee7977f7367f9679ea7
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
 Call Trace:
  <TASK>
  dump_stack_lvl+0x60/0x8c
  dump_stack+0x10/0x12
  __might_resched.cold+0x11d/0x155
  rt_spin_lock+0x40/0x70
  trace_event_buffer_commit+0x2fa/0x4c0
  ? map_vsyscall+0x93/0x93
  trace_event_raw_event_initcall_start+0xbe/0x110
  ? perf_trace_initcall_finish+0x210/0x210
  ? probe_sched_wakeup+0x34/0x40
  ? ttwu_do_wakeup+0xda/0x310
  ? trace_hardirqs_on+0x35/0x170
  ? map_vsyscall+0x93/0x93
  do_one_initcall+0x217/0x3c0
  ? trace_event_raw_event_initcall_level+0x170/0x170
  ? push_cpu_stop+0x400/0x400
  ? cblist_init_generic+0x241/0x290
  kernel_init_freeable+0x1ac/0x347
  ? _raw_spin_unlock_irq+0x65/0x80
  ? rest_init+0xf0/0xf0
  kernel_init+0x1e/0x150
  ret_from_fork+0x22/0x30
  </TASK>

Link: https://lkml.kernel.org/r/20220419013910.894370-1-jun.miao@intel.com

Signed-off-by: Jun Miao <jun.miao@intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:36:14 +02:00
Jeff Xie
c1c62c5fa9 tracing: Make tp_printk work on syscall tracepoints
[ Upstream commit cb1c45fb68b8a4285ccf750842b1136f26cfe267 ]

Currently the tp_printk option has no effect on syscall tracepoint.
When adding the kernel option parameter tp_printk, then:

echo 1 > /sys/kernel/debug/tracing/events/syscalls/enable

When running any application, no trace information is printed on the
terminal.

Now added printk for syscall tracepoints.

Link: https://lkml.kernel.org/r/20220410145025.681144-1-xiehuan09@gmail.com

Signed-off-by: Jeff Xie <xiehuan09@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-14 18:36:14 +02:00
Song Liu
cae2978d69 ftrace: Clean up hash direct_functions on register failures
commit 7d54c15cb89a29a5f59e5ffc9ee62e6591769ef1 upstream.

We see the following GPF when register_ftrace_direct fails:

[ ] general protection fault, probably for non-canonical address \
  0x200000000000010: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[...]
[ ] RIP: 0010:ftrace_find_rec_direct+0x53/0x70
[ ] Code: 48 c1 e0 03 48 03 42 08 48 8b 10 31 c0 48 85 d2 74 [...]
[ ] RSP: 0018:ffffc9000138bc10 EFLAGS: 00010206
[ ] RAX: 0000000000000000 RBX: ffffffff813e0df0 RCX: 000000000000003b
[ ] RDX: 0200000000000000 RSI: 000000000000000c RDI: ffffffff813e0df0
[ ] RBP: ffffffffa00a3000 R08: ffffffff81180ce0 R09: 0000000000000001
[ ] R10: ffffc9000138bc18 R11: 0000000000000001 R12: ffffffff813e0df0
[ ] R13: ffffffff813e0df0 R14: ffff888171b56400 R15: 0000000000000000
[ ] FS:  00007fa9420c7780(0000) GS:ffff888ff6a00000(0000) knlGS:000000000
[ ] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ ] CR2: 000000000770d000 CR3: 0000000107d50003 CR4: 0000000000370ee0
[ ] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ ] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ ] Call Trace:
[ ]  <TASK>
[ ]  register_ftrace_direct+0x54/0x290
[ ]  ? render_sigset_t+0xa0/0xa0
[ ]  bpf_trampoline_update+0x3f5/0x4a0
[ ]  ? 0xffffffffa00a3000
[ ]  bpf_trampoline_link_prog+0xa9/0x140
[ ]  bpf_tracing_prog_attach+0x1dc/0x450
[ ]  bpf_raw_tracepoint_open+0x9a/0x1e0
[ ]  ? find_held_lock+0x2d/0x90
[ ]  ? lock_release+0x150/0x430
[ ]  __sys_bpf+0xbd6/0x2700
[ ]  ? lock_is_held_type+0xd8/0x130
[ ]  __x64_sys_bpf+0x1c/0x20
[ ]  do_syscall_64+0x3a/0x80
[ ]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[ ] RIP: 0033:0x7fa9421defa9
[ ] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 9 f8 [...]
[ ] RSP: 002b:00007ffed743bd78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
[ ] RAX: ffffffffffffffda RBX: 00000000069d2480 RCX: 00007fa9421defa9
[ ] RDX: 0000000000000078 RSI: 00007ffed743bd80 RDI: 0000000000000011
[ ] RBP: 00007ffed743be00 R08: 0000000000bb7270 R09: 0000000000000000
[ ] R10: 00000000069da210 R11: 0000000000000246 R12: 0000000000000001
[ ] R13: 00007ffed743c4b0 R14: 00000000069d2480 R15: 0000000000000001
[ ]  </TASK>
[ ] Modules linked in: klp_vm(OK)
[ ] ---[ end trace 0000000000000000 ]---

One way to trigger this is:
  1. load a livepatch that patches kernel function xxx;
  2. run bpftrace -e 'kfunc:xxx {}', this will fail (expected for now);
  3. repeat #2 => gpf.

This is because the entry is added to direct_functions, but not removed.
Fix this by remove the entry from direct_functions when
register_ftrace_direct fails.

Also remove the last trailing space from ftrace.c, so we don't have to
worry about it anymore.

Link: https://lkml.kernel.org/r/20220524170839.900849-1-song@kernel.org

Cc: stable@vger.kernel.org
Fixes: 763e34e74bb7 ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:27 +02:00
Gautam Menghani
4ef5ab5344 tracing: Initialize integer variable to prevent garbage return value
commit 154827f8e53d8c492b3fb0cb757fbcadb5d516b5 upstream.

Initialize the integer variable to 0 to fix the clang scan warning:
Undefined or garbage value returned to caller
[core.uninitialized.UndefReturn]
        return ret;

Link: https://lkml.kernel.org/r/20220522061826.1751-1-gautammenghani201@gmail.com

Cc: stable@vger.kernel.org
Fixes: 8993665abcce ("tracing/boot: Support multiple handlers for per-event histogram")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:21 +02:00
Keita Suzuki
37443b3508 tracing: Fix potential double free in create_var_ref()
commit 99696a2592bca641eb88cc9a80c90e591afebd0f upstream.

In create_var_ref(), init_var_ref() is called to initialize the fields
of variable ref_field, which is allocated in the previous function call
to create_hist_field(). Function init_var_ref() allocates the
corresponding fields such as ref_field->system, but frees these fields
when the function encounters an error. The caller later calls
destroy_hist_field() to conduct error handling, which frees the fields
and the variable itself. This results in double free of the fields which
are already freed in the previous function.

Fix this by storing NULL to the corresponding fields when they are freed
in init_var_ref().

Link: https://lkml.kernel.org/r/20220425063739.3859998-1-keitasuzuki.park@sslab.ics.keio.ac.jp

Fixes: 067fe038e70f ("tracing: Add variable reference handling to hist triggers")
CC: stable@vger.kernel.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-09 10:23:20 +02:00
Hao Luo
2a77c58726 bpf: Add MEM_RDONLY for helper args that are pointers to rdonly mem.
commit 216e3cd2f28dbbf1fe86848e0e29e6693b9f0a20 upstream.

Some helper functions may modify its arguments, for example,
bpf_d_path, bpf_get_stack etc. Previously, their argument types
were marked as ARG_PTR_TO_MEM, which is compatible with read-only
mem types, such as PTR_TO_RDONLY_BUF. Therefore it's legitimate,
but technically incorrect, to modify a read-only memory by passing
it into one of such helper functions.

This patch tags the bpf_args compatible with immutable memory with
MEM_RDONLY flag. The arguments that don't have this flag will be
only compatible with mutable memory types, preventing the helper
from modifying a read-only memory. The bpf_args that have
MEM_RDONLY are compatible with both mutable memory and immutable
memory.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211217003152.48334-9-haoluo@google.com
Cc: stable@vger.kernel.org # 5.15.x
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-01 17:22:26 +02:00
Steven Rostedt (Google)
14d552ab31 tracing: Have type enum modifications copy the strings
commit 795301d3c28996219d555023ac6863401b6076bc upstream.

When an enum is used in the visible parts of a trace event that is
exported to user space, the user space applications like perf and
trace-cmd do not have a way to know what the value of the enum is. To
solve this, at boot up (or module load) the printk formats are modified to
replace the enum with their numeric value in the string output.

Array fields of the event are defined by [<nr-elements>] in the type
portion of the format file so that the user space parsers can correctly
parse the array into the appropriate size chunks. But in some trace
events, an enum is used in defining the size of the array, which once
again breaks the parsing of user space tooling.

This was solved the same way as the print formats were, but it modified
the type strings of the trace event. This caused crashes in some
architectures because, as supposed to the print string, is a const string
value. This was not detected on x86, as it appears that const strings are
still writable (at least in boot up), but other architectures this is not
the case, and writing to a const string will cause a kernel fault.

To fix this, use kstrdup() to copy the type before modifying it. If the
trace event is for the core kernel there's no need to free it because the
string will be in use for the life of the machine being on line. For
modules, create a link list to store all the strings being allocated for
modules and when the module is removed, free them.

Link: https://lore.kernel.org/all/yt9dr1706b4i.fsf@linux.ibm.com/
Link: https://lkml.kernel.org/r/20220318153432.3984b871@gandalf.local.home

Tested-by: Marc Zyngier <maz@kernel.org>
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Fixes: b3bc8547d3be ("tracing: Have TRACE_DEFINE_ENUM affect trace event types as well")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:24:13 +02:00
Steven Rostedt (Google)
7c6bd60999 tracing: Have TRACE_DEFINE_ENUM affect trace event types as well
[ Upstream commit b3bc8547d3be60898818885f5bf22d0a62e2eb48 ]

The macro TRACE_DEFINE_ENUM is used to convert enums in the kernel to
their actual value when they are exported to user space via the trace
event format file.

Currently only the enums in the "print fmt" (TP_printk in the TRACE_EVENT
macro) have the enums converted. But the enums can be used to denote array
size:

        field:unsigned int fc_ineligible_rc[EXT4_FC_REASON_MAX]; offset:12;      size:36;        signed:0;

The EXT4_FC_REASON_MAX has no meaning to userspace but it needs to know
that information to know how to parse the array.

Have the array indexes also be parsed as well.

Link: https://lore.kernel.org/all/cover.1646922487.git.riteshh@linux.ibm.com/

Reported-by: Ritesh Harjani <riteshh@linux.ibm.com>
Tested-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:24:02 +02:00
Steven Rostedt (Google)
39483fd3b2 tracing: Have trace event string test handle zero length strings
commit eca344a7362e0f34f179298fd8366bcd556eede1 upstream.

If a trace event has in its TP_printk():

 "%*.s", len, len ? __get_str(string) : NULL

It is perfectly valid if len is zero and passing in the NULL.
Unfortunately, the runtime string check at time of reading the trace sees
the NULL and flags it as a bad string and produces a WARN_ON().

Handle this case by passing into the test function if the format has an
asterisk (star) and if so, if the length is zero, then mark it as safe.

Link: https://lore.kernel.org/all/YjsWzuw5FbWPrdqq@bfoster/

Cc: stable@vger.kernel.org
Reported-by: Brian Foster <bfoster@redhat.com>
Tested-by: Brian Foster <bfoster@redhat.com>
Fixes: 9a6944fee68e2 ("tracing: Add a verifier to check string pointers for trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-08 14:22:57 +02:00
Nicolas Saenz Julienne
42aaf726c9 tracing/osnoise: Force quiescent states while tracing
commit caf4c86bf136845982c5103b2661751b40c474c0 upstream.

At the moment running osnoise on a nohz_full CPU or uncontested FIFO
priority and a PREEMPT_RCU kernel might have the side effect of
extending grace periods too much. This will entice RCU to force a
context switch on the wayward CPU to end the grace period, all while
introducing unwarranted noise into the tracer. This behaviour is
unavoidable as overly extending grace periods might exhaust the system's
memory.

This same exact problem is what extended quiescent states (EQS) were
created for, conversely, rcu_momentary_dyntick_idle() emulates them by
performing a zero duration EQS. So let's make use of it.

In the common case rcu_momentary_dyntick_idle() is fairly inexpensive:
atomically incrementing a local per-CPU counter and doing a store. So it
shouldn't affect osnoise's measurements (which has a 1us granularity),
so we'll call it unanimously.

The uncommon case involve calling rcu_momentary_dyntick_idle() after
having the osnoise process:

 - Receive an expedited quiescent state IPI with preemption disabled or
   during an RCU critical section. (activates rdp->cpu_no_qs.b.exp
   code-path).

 - Being preempted within in an RCU critical section and having the
   subsequent outermost rcu_read_unlock() called with interrupts
   disabled. (t->rcu_read_unlock_special.b.blocked code-path).

Neither of those are possible at the moment, and are unlikely to be in
the future given the osnoise's loop design. On top of this, the noise
generated by the situations described above is unavoidable, and if not
exposed by rcu_momentary_dyntick_idle() will be eventually seen in
subsequent rcu_read_unlock() calls or schedule operations.

Link: https://lkml.kernel.org/r/20220307180740.577607-1-nsaenzju@redhat.com

Cc: stable@vger.kernel.org
Fixes: bce29ac9ce0b ("trace: Add osnoise tracer")
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-16 14:23:43 +01:00
Daniel Bristot de Oliveira
9d95b7e239 tracing/osnoise: Make osnoise_main to sleep for microseconds
[ Upstream commit dd990352f01ee9a6c6eee152e5d11c021caccfe4 ]

osnoise's runtime and period are in the microseconds scale, but it is
currently sleeping in the millisecond's scale. This behavior roots in the
usage of hwlat as the skeleton for osnoise.

Make osnoise to sleep in the microseconds scale. Also, move the sleep to
a specialized function.

Link: https://lkml.kernel.org/r/302aa6c7bdf2d131719b22901905e9da122a11b2.1645197336.git.bristot@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-16 14:23:42 +01:00
Sven Schnelle
4d28896915 tracing: Ensure trace buffer is at least 4096 bytes large
[ Upstream commit 7acf3a127bb7c65ff39099afd78960e77b2ca5de ]

Booting the kernel with 'trace_buf_size=1' give a warning at
boot during the ftrace selftests:

[    0.892809] Running postponed tracer tests:
[    0.892893] Testing tracer function:
[    0.901899] Callback from call_rcu_tasks_trace() invoked.
[    0.983829] Callback from call_rcu_tasks_rude() invoked.
[    1.072003] .. bad ring buffer .. corrupted trace buffer ..
[    1.091944] Callback from call_rcu_tasks() invoked.
[    1.097695] PASSED
[    1.097701] Testing dynamic ftrace: .. filter failed count=0 ..FAILED!
[    1.353474] ------------[ cut here ]------------
[    1.353478] WARNING: CPU: 0 PID: 1 at kernel/trace/trace.c:1951 run_tracer_selftest+0x13c/0x1b0

Therefore enforce a minimum of 4096 bytes to make the selftest pass.

Link: https://lkml.kernel.org/r/20220214134456.1751749-1-svens@linux.ibm.com

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-16 14:23:41 +01:00
Randy Dunlap
80660a726d tracing: Fix return value of __setup handlers
commit 1d02b444b8d1345ea4708db3bab4db89a7784b55 upstream.

__setup() handlers should generally return 1 to indicate that the
boot options have been handled.

Using invalid option values causes the entire kernel boot option
string to be reported as Unknown and added to init's environment
strings, polluting it.

  Unknown kernel command line parameters "BOOT_IMAGE=/boot/bzImage-517rc6
    kprobe_event=p,syscall_any,$arg1 trace_options=quiet
    trace_clock=jiffies", will be passed to user space.

 Run /sbin/init as init process
   with arguments:
     /sbin/init
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc6
     kprobe_event=p,syscall_any,$arg1
     trace_options=quiet
     trace_clock=jiffies

Return 1 from the __setup() handlers so that init's environment is not
polluted with kernel boot options.

Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Link: https://lkml.kernel.org/r/20220303031744.32356-1-rdunlap@infradead.org

Cc: stable@vger.kernel.org
Fixes: 7bcfaf54f591 ("tracing: Add trace_options kernel command line parameter")
Fixes: e1e232ca6b8f ("tracing: Add trace_clock=<clock> kernel parameter")
Fixes: 970988e19eb0 ("tracing/kprobe: Add kprobe_event= boot parameter")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:12:54 +01:00
Steven Rostedt (Google)
452f64ee09 tracing/histogram: Fix sorting on old "cpu" value
commit 1d1898f65616c4601208963c3376c1d828cbf2c7 upstream.

When trying to add a histogram against an event with the "cpu" field, it
was impossible due to "cpu" being a keyword to key off of the running CPU.
So to fix this, it was changed to "common_cpu" to match the other generic
fields (like "common_pid"). But since some scripts used "cpu" for keying
off of the CPU (for events that did not have "cpu" as a field, which is
most of them), a backward compatibility trick was added such that if "cpu"
was used as a key, and the event did not have "cpu" as a field name, then
it would fallback and switch over to "common_cpu".

This fix has a couple of subtle bugs. One was that when switching over to
"common_cpu", it did not change the field name, it just set a flag. But
the code still found a "cpu" field. The "cpu" field is used for filtering
and is returned when the event does not have a "cpu" field.

This was found by:

  # cd /sys/kernel/tracing
  # echo hist:key=cpu,pid:sort=cpu > events/sched/sched_wakeup/trigger
  # cat events/sched/sched_wakeup/hist

Which showed the histogram unsorted:

{ cpu:         19, pid:       1175 } hitcount:          1
{ cpu:          6, pid:        239 } hitcount:          2
{ cpu:         23, pid:       1186 } hitcount:         14
{ cpu:         12, pid:        249 } hitcount:          2
{ cpu:          3, pid:        994 } hitcount:          5

Instead of hard coding the "cpu" checks, take advantage of the fact that
trace_event_field_field() returns a special field for "cpu" and "CPU" if
the event does not have "cpu" as a field. This special field has the
"filter_type" of "FILTER_CPU". Check that to test if the returned field is
of the CPU type instead of doing the string compare.

Also, fix the sorting bug by testing for the hist_field flag of
HIST_FIELD_FL_CPU when setting up the sort routine. Otherwise it will use
the special CPU field to know what compare routine to use, and since that
special field does not have a size, it returns tracing_map_cmp_none.

Cc: stable@vger.kernel.org
Fixes: 1e3bac71c505 ("tracing/histogram: Rename "cpu" to "common_cpu"")
Reported-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:12:54 +01:00
Yu Kuai
78acc7dbd8 blktrace: fix use after free for struct blk_trace
commit 30939293262eb433c960c4532a0d59c4073b2b84 upstream.

When tracing the whole disk, 'dropped' and 'msg' will be created
under 'q->debugfs_dir' and 'bt->dir' is NULL, thus blk_trace_free()
won't remove those files. What's worse, the following UAF can be
triggered because of accessing stale 'dropped' and 'msg':

==================================================================
BUG: KASAN: use-after-free in blk_dropped_read+0x89/0x100
Read of size 4 at addr ffff88816912f3d8 by task blktrace/1188

CPU: 27 PID: 1188 Comm: blktrace Not tainted 5.17.0-rc4-next-20220217+ #469
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-4
Call Trace:
 <TASK>
 dump_stack_lvl+0x34/0x44
 print_address_description.constprop.0.cold+0xab/0x381
 ? blk_dropped_read+0x89/0x100
 ? blk_dropped_read+0x89/0x100
 kasan_report.cold+0x83/0xdf
 ? blk_dropped_read+0x89/0x100
 kasan_check_range+0x140/0x1b0
 blk_dropped_read+0x89/0x100
 ? blk_create_buf_file_callback+0x20/0x20
 ? kmem_cache_free+0xa1/0x500
 ? do_sys_openat2+0x258/0x460
 full_proxy_read+0x8f/0xc0
 vfs_read+0xc6/0x260
 ksys_read+0xb9/0x150
 ? vfs_write+0x3d0/0x3d0
 ? fpregs_assert_state_consistent+0x55/0x60
 ? exit_to_user_mode_prepare+0x39/0x1e0
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fbc080d92fd
Code: ce 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 1
RSP: 002b:00007fbb95ff9cb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fbb95ff9dc0 RCX: 00007fbc080d92fd
RDX: 0000000000000100 RSI: 00007fbb95ff9cc0 RDI: 0000000000000045
RBP: 0000000000000045 R08: 0000000000406299 R09: 00000000fffffffd
R10: 000000000153afa0 R11: 0000000000000293 R12: 00007fbb780008c0
R13: 00007fbb78000938 R14: 0000000000608b30 R15: 00007fbb780029c8
 </TASK>

Allocated by task 1050:
 kasan_save_stack+0x1e/0x40
 __kasan_kmalloc+0x81/0xa0
 do_blk_trace_setup+0xcb/0x410
 __blk_trace_setup+0xac/0x130
 blk_trace_ioctl+0xe9/0x1c0
 blkdev_ioctl+0xf1/0x390
 __x64_sys_ioctl+0xa5/0xe0
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 1050:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 kasan_set_free_info+0x20/0x30
 __kasan_slab_free+0x103/0x180
 kfree+0x9a/0x4c0
 __blk_trace_remove+0x53/0x70
 blk_trace_ioctl+0x199/0x1c0
 blkdev_common_ioctl+0x5e9/0xb30
 blkdev_ioctl+0x1a5/0x390
 __x64_sys_ioctl+0xa5/0xe0
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88816912f380
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 88 bytes inside of
 96-byte region [ffff88816912f380, ffff88816912f3e0)
The buggy address belongs to the page:
page:000000009a1b4e7c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0f
flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff)
raw: 0017ffffc0000200 ffffea00044f1100 dead000000000002 ffff88810004c780
raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88816912f280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88816912f300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88816912f380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                                    ^
 ffff88816912f400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88816912f480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================

Fixes: c0ea57608b69 ("blktrace: remove debugfs file dentries from struct blk_trace")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220228034354.4047385-1-yukuai3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:12:43 +01:00
Xiaoke Wang
013c2af6c1 tracing/probes: check the return value of kstrndup() for pbuf
[ Upstream commit 1c1857d400355e96f0fe8b32adc6fa7594d03b52 ]

kstrndup() is a memory allocation-related function, it returns NULL when
some internal memory errors happen. It is better to check the return
value of it so to catch the memory error in time.

Link: https://lkml.kernel.org/r/tencent_4D6E270731456EB88712ED7F13883C334906@qq.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: a42e3c4de964 ("tracing/probe: Add immediate string parameter support")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:12:38 +01:00
Xiaoke Wang
8a20fed48e tracing/uprobes: Check the return value of kstrdup() for tu->filename
[ Upstream commit 8c7224245557707c613f130431cafbaaa4889615 ]

kstrdup() returns NULL when some internal memory errors happen, it is
better to check the return value of it so to catch the memory error in
time.

Link: https://lkml.kernel.org/r/tencent_3C2E330722056D7891D2C83F29C802734B06@qq.com

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:12:38 +01:00
Beau Belgrave
628761fe05 tracing: Do not let synth_events block other dyn_event systems during create
[ Upstream commit 4f67cca70c0f615e9cfe6ac42244f3416ec60877 ]

synth_events is returning -EINVAL if the dyn_event create command does
not contain ' \t'. This prevents other systems from getting called back.
synth_events needs to return -ECANCELED in these cases when the command
is not targeting the synth_event system.

Link: https://lore.kernel.org/linux-trace-devel/20210930223821.11025-1-beaub@linux.microsoft.com

Fixes: c9e759b1e8456 ("tracing: Rework synthetic event command parsing")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:12:35 +01:00
Steven Rostedt
33e22b6c53 tracing: Add ustring operation to filtering string pointers
[ Upstream commit f37c3bbc635994eda203a6da4ba0f9d05165a8d6 ]

Since referencing user space pointers is special, if the user wants to
filter on a field that is a pointer to user space, then they need to
specify it.

Add a ".ustring" attribute to the field name for filters to state that the
field is pointing to user space such that the kernel can take the
appropriate action to read that pointer.

Link: https://lore.kernel.org/all/yt9d8rvmt2jq.fsf@linux.ibm.com/

Fixes: 77360f9bbc7e ("tracing: Add test for user space strings when filtering on string pointers")
Tested-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:12:33 +01:00
Steven Rostedt
60e6d58ef9 tracing: Add test for user space strings when filtering on string pointers
[ Upstream commit 77360f9bbc7e5e2ab7a2c8b4c0244fbbfcfc6f62 ]

Pingfan reported that the following causes a fault:

  echo "filename ~ \"cpu\"" > events/syscalls/sys_enter_openat/filter
  echo 1 > events/syscalls/sys_enter_at/enable

The reason is that trace event filter treats the user space pointer
defined by "filename" as a normal pointer to compare against the "cpu"
string. The following bug happened:

 kvm-03-guest16 login: [72198.026181] BUG: unable to handle page fault for address: 00007fffaae8ef60
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0001) - permissions violation
 PGD 80000001008b7067 P4D 80000001008b7067 PUD 2393f1067 PMD 2393ec067 PTE 8000000108f47867
 Oops: 0001 [#1] PREEMPT SMP PTI
 CPU: 1 PID: 1 Comm: systemd Kdump: loaded Not tainted 5.14.0-32.el9.x86_64 #1
 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
 RIP: 0010:strlen+0x0/0x20
 Code: 48 89 f9 74 09 48 83 c1 01 80 39 00 75 f7 31 d2 44 0f b6 04 16 44 88 04 11
       48 83 c2 01 45 84 c0 75 ee c3 0f 1f 80 00 00 00 00 <80> 3f 00 74 10 48 89 f8
       48 83 c0 01 80 38 00 75 f7 48 29 f8 c3 31
 RSP: 0018:ffffb5b900013e48 EFLAGS: 00010246
 RAX: 0000000000000018 RBX: ffff8fc1c49ede00 RCX: 0000000000000000
 RDX: 0000000000000020 RSI: ffff8fc1c02d601c RDI: 00007fffaae8ef60
 RBP: 00007fffaae8ef60 R08: 0005034f4ddb8ea4 R09: 0000000000000000
 R10: ffff8fc1c02d601c R11: 0000000000000000 R12: ffff8fc1c8a6e380
 R13: 0000000000000000 R14: ffff8fc1c02d6010 R15: ffff8fc1c00453c0
 FS:  00007fa86123db40(0000) GS:ffff8fc2ffd00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007fffaae8ef60 CR3: 0000000102880001 CR4: 00000000007706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 PKRU: 55555554
 Call Trace:
  filter_pred_pchar+0x18/0x40
  filter_match_preds+0x31/0x70
  ftrace_syscall_enter+0x27a/0x2c0
  syscall_trace_enter.constprop.0+0x1aa/0x1d0
  do_syscall_64+0x16/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7fa861d88664

The above happened because the kernel tried to access user space directly
and triggered a "supervisor read access in kernel mode" fault. Worse yet,
the memory could not even be loaded yet, and a SEGFAULT could happen as
well. This could be true for kernel space accessing as well.

To be even more robust, test both kernel and user space strings. If the
string fails to read, then simply have the filter fail.

Note, TASK_SIZE is used to determine if the pointer is user or kernel space
and the appropriate strncpy_from_kernel/user_nofault() function is used to
copy the memory. For some architectures, the compare to TASK_SIZE may always
pick user space or kernel space. If it gets it wrong, the only thing is that
the filter will fail to match. In the future, this needs to be fixed to have
the event denote which should be used. But failing a filter is much better
than panicing the machine, and that can be solved later.

Link: https://lore.kernel.org/all/20220107044951.22080-1-kernelfans@gmail.com/
Link: https://lkml.kernel.org/r/20220110115532.536088fd@gandalf.local.home

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Reported-by: Pingfan Liu <kernelfans@gmail.com>
Tested-by: Pingfan Liu <kernelfans@gmail.com>
Fixes: 87a342f5db69d ("tracing/filters: Support filtering for char * strings")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-08 19:12:32 +01:00
Steven Rostedt (Google)
9000406481 tracing: Have traceon and traceoff trigger honor the instance
commit 302e9edd54985f584cfc180098f3554774126969 upstream.

If a trigger is set on an event to disable or enable tracing within an
instance, then tracing should be disabled or enabled in the instance and
not at the top level, which is confusing to users.

Link: https://lkml.kernel.org/r/20220223223837.14f94ec3@rorschach.local.home

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Tested-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:48:03 +01:00
Daniel Bristot de Oliveira
7e35b31e2c tracing: Dump stacktrace trigger to the corresponding instance
commit ce33c845b030c9cf768370c951bc699470b09fa7 upstream.

The stacktrace event trigger is not dumping the stacktrace to the instance
where it was enabled, but to the global "instance."

Use the private_data, pointing to the trigger file, to figure out the
corresponding trace instance, and use it in the trigger action, like
snapshot_trigger does.

Link: https://lkml.kernel.org/r/afbb0b4f18ba92c276865bc97204d438473f4ebc.1645396236.git.bristot@kernel.org

Cc: stable@vger.kernel.org
Fixes: ae63b31e4d0e2 ("tracing: Separate out trace events from global variables")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Tested-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-02 11:48:02 +01:00
JaeSang Yoo
eb61dbb192 tracing: Fix tp_printk option related with tp_printk_stop_on_boot
[ Upstream commit 3203ce39ac0b2a57a84382ec184c7d4a0bede175 ]

The kernel parameter "tp_printk_stop_on_boot" starts with "tp_printk" which is
the same as another kernel parameter "tp_printk". If "tp_printk" setup is
called before the "tp_printk_stop_on_boot", it will override the latter
and keep it from being set.

This is similar to other kernel parameter issues, such as:
  Commit 745a600cf1a6 ("um: console: Ignore console= option")
or init/do_mounts.c:45 (setup function of "ro" kernel param)

Fix it by checking for a "_" right after the "tp_printk" and if that
exists do not process the parameter.

Link: https://lkml.kernel.org/r/20220208195421.969326-1-jsyoo5b@gmail.com

Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com>
[ Fixed up change log and added space after if condition ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-02-23 12:03:19 +01:00
Tom Zanussi
78c28fdf16 tracing: Propagate is_signed to expression
commit 097f1eefedeab528cecbd35586dfe293853ffb17 upstream.

During expression parsing, a new expression field is created which
should inherit the properties of the operands, such as size and
is_signed.

is_signed propagation was missing, causing spurious errors with signed
operands.  Add it in parse_expr() and parse_unary() to fix the problem.

Link: https://lkml.kernel.org/r/f4dac08742fd7a0920bf80a73c6c44042f5eaa40.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers")
Reported-by: Yordan Karadzhov <ykaradzhov@vmware.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215513
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16 12:56:08 +01:00
Tom Zanussi
4e5dcbedd4 tracing: Don't inc err_log entry count if entry allocation fails
commit 67ab5eb71b37b55f7c5522d080a1b42823351776 upstream.

tr->n_err_log_entries should only be increased if entry allocation
succeeds.

Doing it when it fails won't cause any problems other than wasting an
entry, but should be fixed anyway.

Link: https://lkml.kernel.org/r/cad1ab28f75968db0f466925e7cba5970cec6c29.1643319703.git.zanussi@kernel.org

Cc: stable@vger.kernel.org
Fixes: 2f754e771b1a6 ("tracing: Don't inc err_log entry count if entry allocation fails")
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01 17:27:00 +01:00
Xiaoke Wang
e33fa4a46e tracing/histogram: Fix a potential memory leak for kstrdup()
commit e629e7b525a179e29d53463d992bdee759c950fb upstream.

kfree() is missing on an error path to free the memory allocated by
kstrdup():

  p = param = kstrdup(data->params[i], GFP_KERNEL);

So it is better to free it via kfree(p).

Link: https://lkml.kernel.org/r/tencent_C52895FD37802832A3E5B272D05008866F0A@qq.com

Cc: stable@vger.kernel.org
Fixes: d380dcde9a07c ("tracing: Fix now invalid var_ref_vals assumption in trace action")
Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-01 17:27:00 +01:00
Nikita Yushchenko
cb77c81d34 tracing/osnoise: Properly unhook events if start_per_cpu_kthreads() fails
commit 0878355b51f5f26632e652c848a8e174bb02d22d upstream.

If start_per_cpu_kthreads() called from osnoise_workload_start() returns
error, event hooks are left in broken state: unhook_irq_events() called
but unhook_thread_events() and unhook_softirq_events() not called, and
trace_osnoise_callback_enabled flag not cleared.

On the next tracer enable, hooks get not installed due to
trace_osnoise_callback_enabled flag.

And on the further tracer disable an attempt to remove non-installed
hooks happened, hitting a WARN_ON_ONCE() in tracepoint_remove_func().

Fix the error path by adding the missing part of cleanup.
While at this, introduce osnoise_unhook_events() to avoid code
duplication between this error path and normal tracer disable.

Link: https://lkml.kernel.org/r/20220109153459.3701773-1-nikita.yushchenko@virtuozzo.com

Cc: stable@vger.kernel.org
Fixes: bce29ac9ce0b ("trace: Add osnoise tracer")
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Nikita Yushchenko <nikita.yushchenko@virtuozzo.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 11:05:18 +01:00
Steven Rostedt
74c0c6483b tracing: Have syscall trace events use trace_event_buffer_lock_reserve()
commit 3e2a56e6f639492311e0a8533f0a7aed60816308 upstream.

Currently, the syscall trace events call trace_buffer_lock_reserve()
directly, which means that it misses out on some of the filtering
optimizations provided by the helper function
trace_event_buffer_lock_reserve(). Have the syscall trace events call that
instead, as it was missed when adding the update to use the temp buffer
when filtering.

Link: https://lkml.kernel.org/r/20220107225839.823118570@goodmis.org

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 0fc1b09ff1ff4 ("tracing: Use temp buffer when filtering events")
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 11:05:09 +01:00
Xiangyang Zhang
40022b3682 tracing/kprobes: 'nmissed' not showed correctly for kretprobe
commit dfea08a2116fe327f79d8f4d4b2cf6e0c88be11f upstream.

The 'nmissed' column of the 'kprobe_profile' file for kretprobe is
not showed correctly, kretprobe can be skipped by two reasons,
shortage of kretprobe_instance which is counted by tk->rp.nmissed,
and kprobe itself is missed by some reason, so to show the sum.

Link: https://lkml.kernel.org/r/20220107150242.5019-1-xyz.sun.ok@gmail.com

Cc: stable@vger.kernel.org
Fixes: 4a846b443b4e ("tracing/kprobes: Cleanup kprobe tracer code")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Xiangyang Zhang <xyz.sun.ok@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27 11:05:09 +01:00
Kajol Jain
33fcd00e0a bpf: Remove config check to enable bpf support for branch records
[ Upstream commit db52f57211b4e45f0ebb274e2c877b211dc18591 ]

Branch data available to BPF programs can be very useful to get stack traces
out of userspace application.

Commit fff7b64355ea ("bpf: Add bpf_read_branch_records() helper") added BPF
support to capture branch records in x86. Enable this feature also for other
architectures as well by removing checks specific to x86.

If an architecture doesn't support branch records, bpf_read_branch_records()
still has appropriate checks and it will return an -EINVAL in that scenario.
Based on UAPI helper doc in include/uapi/linux/bpf.h, unsupported architectures
should return -ENOENT in such case. Hence, update the appropriate check to
return -ENOENT instead.

Selftest 'perf_branches' result on power9 machine which has the branch stacks
support:

 - Before this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:FAIL
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:FAIL
  Summary: 0/1 PASSED, 0 SKIPPED, 1 FAILED

 - After this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:OK
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:OK
  Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED

Selftest 'perf_branches' result on power9 machine which doesn't have branch
stack report:

 - After this patch:

  [command]# ./test_progs -t perf_branches
   #88/1 perf_branches/perf_branches_hw:SKIP
   #88/2 perf_branches/perf_branches_no_hw:OK
   #88 perf_branches:OK
  Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED

Fixes: fff7b64355eac ("bpf: Add bpf_read_branch_records() helper")
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211206073315.77432-1-kjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 11:03:28 +01:00