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commit 6bbfa44116689469267f1a6e3d233b52114139d2 upstream.
The 'kprobe::data_size' is unsigned, thus it can not be negative. But if
user sets it enough big number (e.g. (size_t)-8), the result of 'data_size
+ sizeof(struct kretprobe_instance)' becomes smaller than sizeof(struct
kretprobe_instance) or zero. In result, the kretprobe_instance are
allocated without enough memory, and kretprobe accesses outside of
allocated memory.
To avoid this issue, introduce a max limitation of the
kretprobe::data_size. 4KB per instance should be OK.
Link: https://lkml.kernel.org/r/163836995040.432120.10322772773821182925.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: f47cd9b553aa ("kprobes: kretprobe user entry-handler")
Reported-by: zhangyue <zhangyue1@kylinos.cn>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6cb206508b621a9a0a2c35b60540e399225c8243 upstream.
When pid filtering is activated in an instance, all of the events trace
files for that instance has the PID_FILTER flag set. This determines
whether or not pid filtering needs to be done on the event, otherwise the
event is executed as normal.
If pid filtering is enabled when an event is created (via a dynamic event
or modules), its flag is not updated to reflect the current state, and the
events are not filtered properly.
Cc: stable@vger.kernel.org
Fixes: 3fdaf80f4a836 ("tracing: Implement event pid filtering")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit cefcf24b4d351daf70ecd945324e200d3736821e ]
Commit 39fbef4b0f77 ("PM: hibernate: Get block device exclusively in
swsusp_check()") changed the opening mode of the block device to
(FMODE_READ | FMODE_EXCL).
In the corresponding calls to swsusp_close(), the mode is still just
FMODE_READ which triggers the warning in blkdev_flush_mapping() on
resume from hibernate.
So, use the mode (FMODE_READ | FMODE_EXCL) also when closing the
device.
Fixes: 39fbef4b0f77 ("PM: hibernate: Get block device exclusively in swsusp_check()")
Signed-off-by: Thomas Zeitlhofer <thomas.zeitlhofer+lkml@ze-it.at>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a55f224ff5f238013de8762c4287117e47b86e22 upstream.
If a event is filtered by pid and a trigger that requires processing of
the event to happen is a attached to the event, the discard portion does
not take the pid filtering into account, and the event will then be
recorded when it should not have been.
Cc: stable@vger.kernel.org
Fixes: 3fdaf80f4a836 ("tracing: Implement event pid filtering")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 42dc938a590c96eeb429e1830123fef2366d9c80 ]
Nothing protects the access to the per_cpu variable sd_llc_id. When testing
the same CPU (i.e. this_cpu == that_cpu), a race condition exists with
update_top_cache_domain(). One scenario being:
CPU1 CPU2
==================================================================
per_cpu(sd_llc_id, CPUX) => 0
partition_sched_domains_locked()
detach_destroy_domains()
cpus_share_cache(CPUX, CPUX) update_top_cache_domain(CPUX)
per_cpu(sd_llc_id, CPUX) => 0
per_cpu(sd_llc_id, CPUX) = CPUX
per_cpu(sd_llc_id, CPUX) => CPUX
return false
ttwu_queue_cond() wouldn't catch smp_processor_id() == cpu and the result
is a warning triggered from ttwu_queue_wakelist().
Avoid a such race in cpus_share_cache() by always returning true when
this_cpu == that_cpu.
Fixes: 518cd6234178 ("sched: Only queue remote wakeups when crossing cache boundaries")
Reported-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20211104175120.857087-1-vincent.donnefort@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7ee285395b211cad474b2b989db52666e0430daf ]
It was found that the following warning was displayed when remounting
controllers from cgroup v2 to v1:
[ 8042.997778] WARNING: CPU: 88 PID: 80682 at kernel/cgroup/cgroup.c:3130 cgroup_apply_control_disable+0x158/0x190
:
[ 8043.091109] RIP: 0010:cgroup_apply_control_disable+0x158/0x190
[ 8043.096946] Code: ff f6 45 54 01 74 39 48 8d 7d 10 48 c7 c6 e0 46 5a a4 e8 7b 67 33 00 e9 41 ff ff ff 49 8b 84 24 e8 01 00 00 0f b7 40 08 eb 95 <0f> 0b e9 5f ff ff ff 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3
[ 8043.115692] RSP: 0018:ffffba8a47c23d28 EFLAGS: 00010202
[ 8043.120916] RAX: 0000000000000036 RBX: ffffffffa624ce40 RCX: 000000000000181a
[ 8043.128047] RDX: ffffffffa63c43e0 RSI: ffffffffa63c43e0 RDI: ffff9d7284ee1000
[ 8043.135180] RBP: ffff9d72874c5800 R08: ffffffffa624b090 R09: 0000000000000004
[ 8043.142314] R10: ffffffffa624b080 R11: 0000000000002000 R12: ffff9d7284ee1000
[ 8043.149447] R13: ffff9d7284ee1000 R14: ffffffffa624ce70 R15: ffffffffa6269e20
[ 8043.156576] FS: 00007f7747cff740(0000) GS:ffff9d7a5fc00000(0000) knlGS:0000000000000000
[ 8043.164663] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 8043.170409] CR2: 00007f7747e96680 CR3: 0000000887d60001 CR4: 00000000007706e0
[ 8043.177539] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 8043.184673] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 8043.191804] PKRU: 55555554
[ 8043.194517] Call Trace:
[ 8043.196970] rebind_subsystems+0x18c/0x470
[ 8043.201070] cgroup_setup_root+0x16c/0x2f0
[ 8043.205177] cgroup1_root_to_use+0x204/0x2a0
[ 8043.209456] cgroup1_get_tree+0x3e/0x120
[ 8043.213384] vfs_get_tree+0x22/0xb0
[ 8043.216883] do_new_mount+0x176/0x2d0
[ 8043.220550] __x64_sys_mount+0x103/0x140
[ 8043.224474] do_syscall_64+0x38/0x90
[ 8043.228063] entry_SYSCALL_64_after_hwframe+0x44/0xae
It was caused by the fact that rebind_subsystem() disables
controllers to be rebound one by one. If more than one disabled
controllers are originally from the default hierarchy, it means that
cgroup_apply_control_disable() will be called multiple times for the
same default hierarchy. A controller may be killed by css_kill() in
the first round. In the second round, the killed controller may not be
completely dead yet leading to the warning.
To avoid this problem, we collect all the ssid's of controllers that
needed to be disabled from the default hierarchy and then disable them
in one go instead of one by one.
Fixes: 334c3679ec4b ("cgroup: reimplement rebind_subsystems() using cgroup_apply_control() and friends")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7ce1bb83a14019f8c396d57ec704d19478747716 ]
If CONFIG_CFI_CLANG=y, attempting to read an event histogram will cause
the kernel to panic due to failed CFI check.
1. echo 'hist:keys=common_pid' >> events/sched/sched_switch/trigger
2. cat events/sched/sched_switch/hist
3. kernel panics on attempting to read hist
This happens because the sort() function expects a generic
int (*)(const void *, const void *) pointer for the compare function.
To prevent this CFI failure, change tracing map cmp_entries_* function
signatures to match this.
Also, fix the build error reported by the kernel test robot [1].
[1] https://lore.kernel.org/r/202110141140.zzi4dRh4-lkp@intel.com/
Link: https://lkml.kernel.org/r/20211014045217.3265162-1-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7d613f9f72ec8f90ddefcae038fdae5adb8404b3 upstream.
The existence of sigkill_pending is a little silly as it is
functionally a duplicate of fatal_signal_pending that is used in
exactly one place.
Checking for pending fatal signals and returning early in ptrace_stop
is actively harmful. It casues the ptrace_stop called by
ptrace_signal to return early before setting current->exit_code.
Later when ptrace_signal reads the signal number from
current->exit_code is undefined, making it unpredictable what will
happen.
Instead rely on the fact that schedule will not sleep if there is a
pending signal that can awaken a task.
Removing the explict sigkill_pending test fixes fixes ptrace_signal
when ptrace_stop does not stop because current->exit_code is always
set to to signr.
Cc: stable@vger.kernel.org
Fixes: 3d749b9e676b ("ptrace: simplify ptrace_stop()->sigkill_pending() path")
Fixes: 1a669c2f16d4 ("Add arch_ptrace_stop")
Link: https://lkml.kernel.org/r/87pmsyx29t.fsf@disp2133
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3cffa06aeef7ece30f6b5ac0ea51f264e8fea4d0 upstream.
The commit 48021f98130880dd74 ("printk: handle blank console arguments
passed in.") prevented crash caused by empty console= parameter value.
Unfortunately, this value is widely used on Chromebooks to disable
the console output. The above commit caused performance regression
because the messages were pushed on slow console even though nobody
was watching it.
Use ttynull driver explicitly for console="" and console=null
parameters. It has been created for exactly this purpose.
It causes that preferred_console is set. As a result, ttySX and ttyX
are not used as a fallback. And only ttynull console gets registered by
default.
It still allows to register other consoles either by additional console=
parameters or SPCR. It prevents regression because it worked this way even
before. Also it is a sane semantic. Preventing output on all consoles
should be done another way, for example, by introducing mute_console
parameter.
Link: https://lore.kernel.org/r/20201006025935.GA597@jagdpanzerIV.localdomain
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20201111135450.11214-3-pmladek@suse.com
Cc: Yi Fan <yfa@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ed65df63a39a3f6ed04f7258de8b6789e5021c18 upstream.
While writing an email explaining the "bit = 0" logic for a discussion on
making ftrace_test_recursion_trylock() disable preemption, I discovered a
path that makes the "not do the logic if bit is zero" unsafe.
The recursion logic is done in hot paths like the function tracer. Thus,
any code executed causes noticeable overhead. Thus, tricks are done to try
to limit the amount of code executed. This included the recursion testing
logic.
Having recursion testing is important, as there are many paths that can
end up in an infinite recursion cycle when tracing every function in the
kernel. Thus protection is needed to prevent that from happening.
Because it is OK to recurse due to different running context levels (e.g.
an interrupt preempts a trace, and then a trace occurs in the interrupt
handler), a set of bits are used to know which context one is in (normal,
softirq, irq and NMI). If a recursion occurs in the same level, it is
prevented*.
Then there are infrastructure levels of recursion as well. When more than
one callback is attached to the same function to trace, it calls a loop
function to iterate over all the callbacks. Both the callbacks and the
loop function have recursion protection. The callbacks use the
"ftrace_test_recursion_trylock()" which has a "function" set of context
bits to test, and the loop function calls the internal
trace_test_and_set_recursion() directly, with an "internal" set of bits.
If an architecture does not implement all the features supported by ftrace
then the callbacks are never called directly, and the loop function is
called instead, which will implement the features of ftrace.
Since both the loop function and the callbacks do recursion protection, it
was seemed unnecessary to do it in both locations. Thus, a trick was made
to have the internal set of recursion bits at a more significant bit
location than the function bits. Then, if any of the higher bits were set,
the logic of the function bits could be skipped, as any new recursion
would first have to go through the loop function.
This is true for architectures that do not support all the ftrace
features, because all functions being traced must first go through the
loop function before going to the callbacks. But this is not true for
architectures that support all the ftrace features. That's because the
loop function could be called due to two callbacks attached to the same
function, but then a recursion function inside the callback could be
called that does not share any other callback, and it will be called
directly.
i.e.
traced_function_1: [ more than one callback tracing it ]
call loop_func
loop_func:
trace_recursion set internal bit
call callback
callback:
trace_recursion [ skipped because internal bit is set, return 0 ]
call traced_function_2
traced_function_2: [ only traced by above callback ]
call callback
callback:
trace_recursion [ skipped because internal bit is set, return 0 ]
call traced_function_2
[ wash, rinse, repeat, BOOM! out of shampoo! ]
Thus, the "bit == 0 skip" trick is not safe, unless the loop function is
call for all functions.
Since we want to encourage architectures to implement all ftrace features,
having them slow down due to this extra logic may encourage the
maintainers to update to the latest ftrace features. And because this
logic is only safe for them, remove it completely.
[*] There is on layer of recursion that is allowed, and that is to allow
for the transition between interrupt context (normal -> softirq ->
irq -> NMI), because a trace may occur before the context update is
visible to the trace recursion logic.
Link: https://lore.kernel.org/all/609b565a-ed6e-a1da-f025-166691b5d994@linux.alibaba.com/
Link: https://lkml.kernel.org/r/20211018154412.09fcad3c@gandalf.local.home
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Jisheng Zhang <jszhang@kernel.org>
Cc: =?utf-8?b?546L6LSH?= <yun.wang@linux.alibaba.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: stable@vger.kernel.org
Fixes: edc15cafcbfa3 ("tracing: Avoid unnecessary multiple recursion checks")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 30e29a9a2bc6a4888335a6ede968b75cd329657a ]
In prealloc_elems_and_freelist(), the multiplication to calculate the
size passed to bpf_map_area_alloc() could lead to an integer overflow.
As a result, out-of-bounds write could occur in pcpu_freelist_populate()
as reported by KASAN:
[...]
[ 16.968613] BUG: KASAN: slab-out-of-bounds in pcpu_freelist_populate+0xd9/0x100
[ 16.969408] Write of size 8 at addr ffff888104fc6ea0 by task crash/78
[ 16.970038]
[ 16.970195] CPU: 0 PID: 78 Comm: crash Not tainted 5.15.0-rc2+ #1
[ 16.970878] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
[ 16.972026] Call Trace:
[ 16.972306] dump_stack_lvl+0x34/0x44
[ 16.972687] print_address_description.constprop.0+0x21/0x140
[ 16.973297] ? pcpu_freelist_populate+0xd9/0x100
[ 16.973777] ? pcpu_freelist_populate+0xd9/0x100
[ 16.974257] kasan_report.cold+0x7f/0x11b
[ 16.974681] ? pcpu_freelist_populate+0xd9/0x100
[ 16.975190] pcpu_freelist_populate+0xd9/0x100
[ 16.975669] stack_map_alloc+0x209/0x2a0
[ 16.976106] __sys_bpf+0xd83/0x2ce0
[...]
The possibility of this overflow was originally discussed in [0], but
was overlooked.
Fix the integer overflow by changing elem_size to u64 from u32.
[0] https://lore.kernel.org/bpf/728b238e-a481-eb50-98e9-b0f430ab01e7@gmail.com/
Fixes: 557c0c6e7df8 ("bpf: convert stackmap to pre-allocation")
Signed-off-by: Tatsuhiko Yasumatsu <th.yasumatsu@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210930135545.173698-1-th.yasumatsu@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 2d186afd04d669fe9c48b994c41a7405a3c9f16d upstream.
Syzbot reported shift-out-of-bounds bug in profile_init().
The problem was in incorrect prof_shift. Since prof_shift value comes from
userspace we need to clamp this value into [0, BITS_PER_LONG -1]
boundaries.
Second possible shiht-out-of-bounds was found by Tetsuo:
sample_step local variable in read_profile() had "unsigned int" type,
but prof_shift allows to make a BITS_PER_LONG shift. So, to prevent
possible shiht-out-of-bounds sample_step type was changed to
"unsigned long".
Also, "unsigned short int" will be sufficient for storing
[0, BITS_PER_LONG] value, that's why there is no need for
"unsigned long" prof_shift.
Link: https://lkml.kernel.org/r/20210813140022.5011-1-paskripkin@gmail.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-and-tested-by: syzbot+e68c89a9510c159d9684@syzkaller.appspotmail.com
Suggested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e1fbbd073137a9d63279f6bf363151a938347640 upstream.
Keno Fischer reported that when a binray loaded via ld-linux-x the
prctl(PR_SET_MM_MAP) doesn't allow to setup brk value because it lays
before mm:end_data.
For example a test program shows
| # ~/t
|
| start_code 401000
| end_code 401a15
| start_stack 7ffce4577dd0
| start_data 403e10
| end_data 40408c
| start_brk b5b000
| sbrk(0) b5b000
and when executed via ld-linux
| # /lib64/ld-linux-x86-64.so.2 ~/t
|
| start_code 7fc25b0a4000
| end_code 7fc25b0c4524
| start_stack 7fffcc6b2400
| start_data 7fc25b0ce4c0
| end_data 7fc25b0cff98
| start_brk 55555710c000
| sbrk(0) 55555710c000
This of course prevent criu from restoring such programs. Looking into
how kernel operates with brk/start_brk inside brk() syscall I don't see
any problem if we allow to setup brk/start_brk without checking for
end_data. Even if someone pass some weird address here on a purpose then
the worst possible result will be an unexpected unmapping of existing vma
(own vma, since prctl works with the callers memory) but test for
RLIMIT_DATA is still valid and a user won't be able to gain more memory in
case of expanding VMAs via new values shipped with prctl call.
Link: https://lkml.kernel.org/r/20210121221207.GB2174@grain
Fixes: bbdc6076d2e5 ("binfmt_elf: move brk out of mmap when doing direct loader exec")
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reported-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Andrey Vagin <avagin@gmail.com>
Tested-by: Andrey Vagin <avagin@gmail.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b89a05b21f46150ac10a962aa50109250b56b03b upstream.
In perf_event_addr_filters_apply, the task associated with
the event (event->ctx->task) is read using READ_ONCE at the beginning
of the function, checked, and then re-read from event->ctx->task,
voiding all guarantees of the checks. Reuse the value that was read by
READ_ONCE to ensure the consistency of the task struct throughout the
function.
Fixes: 375637bc52495 ("perf/core: Introduce address range filtering")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210906015310.12802-1-baptiste.lepers@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fab827dbee8c2e06ca4ba000fa6c48bcf9054aba upstream.
Commit 5d097056c9a0 ("kmemcg: account certain kmem allocations to memcg")
enabled memcg accounting for pids allocated from init_pid_ns.pid_cachep,
but forgot to adjust the setting for nested pid namespaces. As a result,
pid memory is not accounted exactly where it is really needed, inside
memcg-limited containers with their own pid namespaces.
Pid was one the first kernel objects enabled for memcg accounting.
init_pid_ns.pid_cachep marked by SLAB_ACCOUNT and we can expect that any
new pids in the system are memcg-accounted.
Though recently I've noticed that it is wrong. nested pid namespaces
creates own slab caches for pid objects, nested pids have increased size
because contain id both for all parent and for own pid namespaces. The
problem is that these slab caches are _NOT_ marked by SLAB_ACCOUNT, as a
result any pids allocated in nested pid namespaces are not
memcg-accounted.
Pid struct in nested pid namespace consumes up to 500 bytes memory, 100000
such objects gives us up to ~50Mb unaccounted memory, this allow container
to exceed assigned memcg limits.
Link: https://lkml.kernel.org/r/8b6de616-fd1a-02c6-cbdb-976ecdcfa604@virtuozzo.com
Fixes: 5d097056c9a0 ("kmemcg: account certain kmem allocations to memcg")
Cc: stable@vger.kernel.org
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 13db8c50477d83ad3e3b9b0ae247e5cd833a7ae4 upstream.
After fork, the child process will get incorrect (2x) hugetlb_usage. If
a process uses 5 2MB hugetlb pages in an anonymous mapping,
HugetlbPages: 10240 kB
and then forks, the child will show,
HugetlbPages: 20480 kB
The reason for double the amount is because hugetlb_usage will be copied
from the parent and then increased when we copy page tables from parent
to child. Child will have 2x actual usage.
Fix this by adding hugetlb_count_init in mm_init.
Link: https://lkml.kernel.org/r/20210826071742.877-1-liuzixian4@huawei.com
Fixes: 5d317b2b6536 ("mm: hugetlb: proc: add HugetlbPages field to /proc/PID/status")
Signed-off-by: Liu Zixian <liuzixian4@huawei.com>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 67f0d6d9883c13174669f88adac4f0ee656cc16a upstream.
The "rb_per_cpu_empty()" misinterpret the condition (as not-empty) when
"head_page" and "commit_page" of "struct ring_buffer_per_cpu" points to
the same buffer page, whose "buffer_data_page" is empty and "read" field
is non-zero.
An error scenario could be constructed as followed (kernel perspective):
1. All pages in the buffer has been accessed by reader(s) so that all of
them will have non-zero "read" field.
2. Read and clear all buffer pages so that "rb_num_of_entries()" will
return 0 rendering there's no more data to read. It is also required
that the "read_page", "commit_page" and "tail_page" points to the same
page, while "head_page" is the next page of them.
3. Invoke "ring_buffer_lock_reserve()" with large enough "length"
so that it shot pass the end of current tail buffer page. Now the
"head_page", "commit_page" and "tail_page" points to the same page.
4. Discard current event with "ring_buffer_discard_commit()", so that
"head_page", "commit_page" and "tail_page" points to a page whose buffer
data page is now empty.
When the error scenario has been constructed, "tracing_read_pipe" will
be trapped inside a deadloop: "trace_empty()" returns 0 since
"rb_per_cpu_empty()" returns 0 when it hits the CPU containing such
constructed ring buffer. Then "trace_find_next_entry_inc()" always
return NULL since "rb_num_of_entries()" reports there's no more entry
to read. Finally "trace_seq_to_user()" returns "-EBUSY" spanking
"tracing_read_pipe" back to the start of the "waitagain" loop.
I've also written a proof-of-concept script to construct the scenario
and trigger the bug automatically, you can use it to trace and validate
my reasoning above:
https://github.com/aegistudio/RingBufferDetonator.git
Tests has been carried out on linux kernel 5.14-rc2
(2734d6c1b1a089fb593ef6a23d4b70903526fe0c), my fixed version
of kernel (for testing whether my update fixes the bug) and
some older kernels (for range of affected kernels). Test result is
also attached to the proof-of-concept repository.
Link: https://lore.kernel.org/linux-trace-devel/YPaNxsIlb2yjSi5Y@aegistudio/
Link: https://lore.kernel.org/linux-trace-devel/YPgrN85WL9VyrZ55@aegistudio
Cc: stable@vger.kernel.org
Fixes: bf41a158cacba ("ring-buffer: make reentrant")
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Haoran Luo <www@aegistudio.net>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 72d0ad7cb5bad265adb2014dbe46c4ccb11afaba ]
The time remaining until expiry of the refresh_timer can be negative.
Casting the type to an unsigned 64-bit value will cause integer
underflow, making the runtime_refresh_within return false instead of
true. These situations are rare, but they do happen.
This does not cause user-facing issues or errors; other than
possibly unthrottling cfs_rq's using runtime from the previous period(s),
making the CFS bandwidth enforcement less strict in those (special)
situations.
Signed-off-by: Odin Ugedal <odin@uged.al>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ben Segall <bsegall@google.com>
Link: https://lore.kernel.org/r/20210629121452.18429-1-odin@uged.al
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5fa54346caf67b4b1b10b1f390316ae466da4d53 upstream.
The system might hang with the following backtrace:
schedule+0x80/0x100
schedule_timeout+0x48/0x138
wait_for_common+0xa4/0x134
wait_for_completion+0x1c/0x2c
kthread_flush_work+0x114/0x1cc
kthread_cancel_work_sync.llvm.16514401384283632983+0xe8/0x144
kthread_cancel_delayed_work_sync+0x18/0x2c
xxxx_pm_notify+0xb0/0xd8
blocking_notifier_call_chain_robust+0x80/0x194
pm_notifier_call_chain_robust+0x28/0x4c
suspend_prepare+0x40/0x260
enter_state+0x80/0x3f4
pm_suspend+0x60/0xdc
state_store+0x108/0x144
kobj_attr_store+0x38/0x88
sysfs_kf_write+0x64/0xc0
kernfs_fop_write_iter+0x108/0x1d0
vfs_write+0x2f4/0x368
ksys_write+0x7c/0xec
It is caused by the following race between kthread_mod_delayed_work()
and kthread_cancel_delayed_work_sync():
CPU0 CPU1
Context: Thread A Context: Thread B
kthread_mod_delayed_work()
spin_lock()
__kthread_cancel_work()
spin_unlock()
del_timer_sync()
kthread_cancel_delayed_work_sync()
spin_lock()
__kthread_cancel_work()
spin_unlock()
del_timer_sync()
spin_lock()
work->canceling++
spin_unlock
spin_lock()
queue_delayed_work()
// dwork is put into the worker->delayed_work_list
spin_unlock()
kthread_flush_work()
// flush_work is put at the tail of the dwork
wait_for_completion()
Context: IRQ
kthread_delayed_work_timer_fn()
spin_lock()
list_del_init(&work->node);
spin_unlock()
BANG: flush_work is not longer linked and will never get proceed.
The problem is that kthread_mod_delayed_work() checks work->canceling
flag before canceling the timer.
A simple solution is to (re)check work->canceling after
__kthread_cancel_work(). But then it is not clear what should be
returned when __kthread_cancel_work() removed the work from the queue
(list) and it can't queue it again with the new @delay.
The return value might be used for reference counting. The caller has
to know whether a new work has been queued or an existing one was
replaced.
The proper solution is that kthread_mod_delayed_work() will remove the
work from the queue (list) _only_ when work->canceling is not set. The
flag must be checked after the timer is stopped and the remaining
operations can be done under worker->lock.
Note that kthread_mod_delayed_work() could remove the timer and then
bail out. It is fine. The other canceling caller needs to cancel the
timer as well. The important thing is that the queue (list)
manipulation is done atomically under worker->lock.
Link: https://lkml.kernel.org/r/20210610133051.15337-3-pmladek@suse.com
Fixes: 9a6b06c8d9a220860468a ("kthread: allow to modify delayed kthread work")
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reported-by: Martin Liu <liumartin@google.com>
Cc: <jenhaochen@google.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 34b3d5344719d14fd2185b2d9459b3abcb8cf9d8 upstream.
Patch series "kthread_worker: Fix race between kthread_mod_delayed_work()
and kthread_cancel_delayed_work_sync()".
This patchset fixes the race between kthread_mod_delayed_work() and
kthread_cancel_delayed_work_sync() including proper return value
handling.
This patch (of 2):
Simple code refactoring as a preparation step for fixing a race between
kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync().
It does not modify the existing behavior.
Link: https://lkml.kernel.org/r/20210610133051.15337-2-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: <jenhaochen@google.com>
Cc: Martin Liu <liumartin@google.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fe19bd3dae3d15d2fbfdb3de8839a6ea0fe94264 ]
If more than one futex is placed on a shmem huge page, it can happen
that waking the second wakes the first instead, and leaves the second
waiting: the key's shared.pgoff is wrong.
When 3.11 commit 13d60f4b6ab5 ("futex: Take hugepages into account when
generating futex_key"), the only shared huge pages came from hugetlbfs,
and the code added to deal with its exceptional page->index was put into
hugetlb source. Then that was missed when 4.8 added shmem huge pages.
page_to_pgoff() is what others use for this nowadays: except that, as
currently written, it gives the right answer on hugetlbfs head, but
nonsense on hugetlbfs tails. Fix that by calling hugetlbfs-specific
hugetlb_basepage_index() on PageHuge tails as well as on head.
Yes, it's unconventional to declare hugetlb_basepage_index() there in
pagemap.h, rather than in hugetlb.h; but I do not expect anything but
page_to_pgoff() ever to need it.
[akpm@linux-foundation.org: give hugetlb_basepage_index() prototype the correct scope]
Link: https://lkml.kernel.org/r/b17d946b-d09-326e-b42a-52884c36df32@google.com
Fixes: 800d8c63b2e9 ("shmem: add huge pages support")
Reported-by: Neel Natu <neelnatu@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Zhang Yi <wetpzy@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Note on stable backport: leave redundant #include <linux/hugetlb.h>
in kernel/futex.c, to avoid conflict over the header files included.
Resolved trivial conflicts in include/linux/hugetlb.h.
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4fdd595e4f9a1ff6d93ec702eaecae451cfc6591 upstream.
A while ago, when the "trace" file was opened, tracing was stopped, and
code was added to stop recording the comms to saved_cmdlines, for mapping
of the pids to the task name.
Code has been added that only records the comm if a trace event occurred,
and there's no reason to not trace it if the trace file is opened.
Cc: stable@vger.kernel.org
Fixes: 7ffbd48d5cab2 ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 85550c83da421fb12dc1816c45012e1e638d2b38 upstream.
The saved_cmdlines is used to map pids to the task name, such that the
output of the tracing does not just show pids, but also gives a human
readable name for the task.
If the name is not mapped, the output looks like this:
<...>-1316 [005] ...2 132.044039: ...
Instead of this:
gnome-shell-1316 [005] ...2 132.044039: ...
The names are updated when tracing is running, but are skipped if tracing
is stopped. Unfortunately, this stops the recording of the names if the
top level tracer is stopped, and not if there's other tracers active.
The recording of a name only happens when a new event is written into a
ring buffer, so there is no need to test if tracing is on or not. If
tracing is off, then no event is written and no need to test if tracing is
off or not.
Remove the check, as it hides the names of tasks for events in the
instance buffers.
Cc: stable@vger.kernel.org
Fixes: 7ffbd48d5cab2 ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 89529d8b8f8daf92d9979382b8d2eb39966846ea upstream.
The trace_clock_global() tries to make sure the events between CPUs is
somewhat in order. A global value is used and updated by the latest read
of a clock. If one CPU is ahead by a little, and is read by another CPU, a
lock is taken, and if the timestamp of the other CPU is behind, it will
simply use the other CPUs timestamp.
The lock is also only taken with a "trylock" due to tracing, and strange
recursions can happen. The lock is not taken at all in NMI context.
In the case where the lock is not able to be taken, the non synced
timestamp is returned. But it will not be less than the saved global
timestamp.
The problem arises because when the time goes "backwards" the time
returned is the saved timestamp plus 1. If the lock is not taken, and the
plus one to the timestamp is returned, there's a small race that can cause
the time to go backwards!
CPU0 CPU1
---- ----
trace_clock_global() {
ts = clock() [ 1000 ]
trylock(clock_lock) [ success ]
global_ts = ts; [ 1000 ]
<interrupted by NMI>
trace_clock_global() {
ts = clock() [ 999 ]
if (ts < global_ts)
ts = global_ts + 1 [ 1001 ]
trylock(clock_lock) [ fail ]
return ts [ 1001]
}
unlock(clock_lock);
return ts; [ 1000 ]
}
trace_clock_global() {
ts = clock() [ 1000 ]
if (ts < global_ts) [ false 1000 == 1000 ]
trylock(clock_lock) [ success ]
global_ts = ts; [ 1000 ]
unlock(clock_lock)
return ts; [ 1000 ]
}
The above case shows to reads of trace_clock_global() on the same CPU, but
the second read returns one less than the first read. That is, time when
backwards, and this is not what is allowed by trace_clock_global().
This was triggered by heavy tracing and the ring buffer checker that tests
for the clock going backwards:
Ring buffer clock went backwards: 20613921464 -> 20613921463
------------[ cut here ]------------
WARNING: CPU: 2 PID: 0 at kernel/trace/ring_buffer.c:3412 check_buffer+0x1b9/0x1c0
Modules linked in:
[..]
[CPU: 2]TIME DOES NOT MATCH expected:20620711698 actual:20620711697 delta:6790234 before:20613921463 after:20613921463
[20613915818] PAGE TIME STAMP
[20613915818] delta:0
[20613915819] delta:1
[20613916035] delta:216
[20613916465] delta:430
[20613916575] delta:110
[20613916749] delta:174
[20613917248] delta:499
[20613917333] delta:85
[20613917775] delta:442
[20613917921] delta:146
[20613918321] delta:400
[20613918568] delta:247
[20613918768] delta:200
[20613919306] delta:538
[20613919353] delta:47
[20613919980] delta:627
[20613920296] delta:316
[20613920571] delta:275
[20613920862] delta:291
[20613921152] delta:290
[20613921464] delta:312
[20613921464] delta:0 TIME EXTEND
[20613921464] delta:0
This happened more than once, and always for an off by one result. It also
started happening after commit aafe104aa9096 was added.
Cc: stable@vger.kernel.org
Fixes: aafe104aa9096 ("tracing: Restructure trace_clock_global() to never block")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6c14133d2d3f768e0a35128faac8aa6ed4815051 upstream.
It was reported that a bug on arm64 caused a bad ip address to be used for
updating into a nop in ftrace_init(), but the error path (rightfully)
returned -EINVAL and not -EFAULT, as the bug caused more than one error to
occur. But because -EINVAL was returned, the ftrace_bug() tried to report
what was at the location of the ip address, and read it directly. This
caused the machine to panic, as the ip was not pointing to a valid memory
address.
Instead, read the ip address with copy_from_kernel_nofault() to safely
access the memory, and if it faults, report that the address faulted,
otherwise report what was in that location.
Link: https://lore.kernel.org/lkml/20210607032329.28671-1-mark-pk.tsai@mediatek.com/
Cc: stable@vger.kernel.org
Fixes: 05736a427f7e1 ("ftrace: warn on failure to disable mcount callers")
Reported-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6c605f8371159432ec61cbb1488dcf7ad24ad19a upstream.
KCSAN reports a data race between increment and decrement of pin_count:
write to 0xffff888237c2d4e0 of 4 bytes by task 15740 on cpu 1:
find_get_context kernel/events/core.c:4617
__do_sys_perf_event_open kernel/events/core.c:12097 [inline]
__se_sys_perf_event_open kernel/events/core.c:11933
...
read to 0xffff888237c2d4e0 of 4 bytes by task 15743 on cpu 0:
perf_unpin_context kernel/events/core.c:1525 [inline]
__do_sys_perf_event_open kernel/events/core.c:12328 [inline]
__se_sys_perf_event_open kernel/events/core.c:11933
...
Because neither read-modify-write here is atomic, this can lead to one
of the operations being lost, resulting in an inconsistent pin_count.
Fix it by adding the missing locking in the CPU-event case.
Fixes: fe4b04fa31a6 ("perf: Cure task_oncpu_function_call() races")
Reported-by: syzbot+142c9018f5962db69c7e@syzkaller.appspotmail.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210527104711.2671610-1-elver@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 940d71c6462e8151c78f28e4919aa8882ff2054e ]
If VCPU is suspended (VM suspend) in wq_watchdog_timer_fn() then
once this VCPU resumes it will see the new jiffies value, while it
may take a while before IRQ detects PVCLOCK_GUEST_STOPPED on this
VCPU and updates all the watchdogs via pvclock_touch_watchdogs().
There is a small chance of misreported WQ stalls in the meantime,
because new jiffies is time_after() old 'ts + thresh'.
wq_watchdog_timer_fn()
{
for_each_pool(pool, pi) {
if (time_after(jiffies, ts + thresh)) {
pr_emerg("BUG: workqueue lockup - pool");
}
}
}
Save jiffies at the beginning of this function and use that value
for stall detection. If VM gets suspended then we continue using
"old" jiffies value and old WQ touch timestamps. If IRQ at some
point restarts the stall detection cycle (pvclock_touch_watchdogs())
then old jiffies will always be before new 'ts + thresh'.
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 45e1ba40837ac2f6f4d4716bddb8d44bd7e4a251 ]
This patch effectively reverts the commit a3e72739b7a7 ("cgroup: fix
too early usage of static_branch_disable()"). The commit 6041186a3258
("init: initialize jump labels before command line option parsing") has
moved the jump_label_init() before parse_args() which has made the
commit a3e72739b7a7 unnecessary. On the other hand there are
consequences of disabling the controllers later as there are subsystems
doing the controller checks for different decisions. One such incident
is reported [1] regarding the memory controller and its impact on memory
reclaim code.
[1] https://lore.kernel.org/linux-mm/921e53f3-4b13-aab8-4a9e-e83ff15371e4@nec.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: NOMURA JUNICHI(野村 淳一) <junichi.nomura@nec.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Jun'ichi Nomura <junichi.nomura@nec.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dbb5afad100a828c97e012c6106566d99f041db6 ]
Suppose we have 2 threads, the group-leader L and a sub-theread T,
both parked in ptrace_stop(). Debugger tries to resume both threads
and does
ptrace(PTRACE_CONT, T);
ptrace(PTRACE_CONT, L);
If the sub-thread T execs in between, the 2nd PTRACE_CONT doesn not
resume the old leader L, it resumes the post-exec thread T which was
actually now stopped in PTHREAD_EVENT_EXEC. In this case the
PTHREAD_EVENT_EXEC event is lost, and the tracer can't know that the
tracee changed its pid.
This patch makes ptrace() fail in this case until debugger does wait()
and consumes PTHREAD_EVENT_EXEC which reports old_pid. This affects all
ptrace requests except the "asynchronous" PTRACE_INTERRUPT/KILL.
The patch doesn't add the new PTRACE_ option to not complicate the API,
and I _hope_ this won't cause any noticeable regression:
- If debugger uses PTRACE_O_TRACEEXEC and the thread did an exec
and the tracer does a ptrace request without having consumed
the exec event, it's 100% sure that the thread the ptracer
thinks it is targeting does not exist anymore, or isn't the
same as the one it thinks it is targeting.
- To some degree this patch adds nothing new. In the scenario
above ptrace(L) can fail with -ESRCH if it is called after the
execing sub-thread wakes the leader up and before it "steals"
the leader's pid.
Test-case:
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <errno.h>
#include <pthread.h>
#include <assert.h>
void *tf(void *arg)
{
execve("/usr/bin/true", NULL, NULL);
assert(0);
return NULL;
}
int main(void)
{
int leader = fork();
if (!leader) {
kill(getpid(), SIGSTOP);
pthread_t th;
pthread_create(&th, NULL, tf, NULL);
for (;;)
pause();
return 0;
}
waitpid(leader, NULL, WSTOPPED);
ptrace(PTRACE_SEIZE, leader, 0,
PTRACE_O_TRACECLONE | PTRACE_O_TRACEEXEC);
waitpid(leader, NULL, 0);
ptrace(PTRACE_CONT, leader, 0,0);
waitpid(leader, NULL, 0);
int status, thread = waitpid(-1, &status, 0);
assert(thread > 0 && thread != leader);
assert(status == 0x80137f);
ptrace(PTRACE_CONT, thread, 0,0);
/*
* waitid() because waitpid(leader, &status, WNOWAIT) does not
* report status. Why ????
*
* Why WEXITED? because we have another kernel problem connected
* to mt-exec.
*/
siginfo_t info;
assert(waitid(P_PID, leader, &info, WSTOPPED|WEXITED|WNOWAIT) == 0);
assert(info.si_pid == leader && info.si_status == 0x0405);
/* OK, it sleeps in ptrace(PTRACE_EVENT_EXEC == 0x04) */
assert(ptrace(PTRACE_CONT, leader, 0,0) == -1);
assert(errno == ESRCH);
assert(leader == waitpid(leader, &status, WNOHANG));
assert(status == 0x04057f);
assert(ptrace(PTRACE_CONT, leader, 0,0) == 0);
return 0;
}
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Simon Marchi <simon.marchi@efficios.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Pedro Alves <palves@redhat.com>
Acked-by: Simon Marchi <simon.marchi@efficios.com>
Acked-by: Jan Kratochvil <jan.kratochvil@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 31d82c2c787d5cf65fedd35ebbc0c1bd95c1a679 ]
When vzalloc() returns NULL to sha_regions, no error return code of
kexec_calculate_store_digests() is assigned. To fix this bug, ret is
assigned with -ENOMEM in this case.
Link: https://lkml.kernel.org/r/20210309083904.24321-1-baijiaju1990@gmail.com
Fixes: a43cac0d9dc2 ("kexec: split kexec_file syscall code to kexec_file.c")
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit aafe104aa9096827a429bc1358f8260ee565b7cc upstream.
It was reported that a fix to the ring buffer recursion detection would
cause a hung machine when performing suspend / resume testing. The
following backtrace was extracted from debugging that case:
Call Trace:
trace_clock_global+0x91/0xa0
__rb_reserve_next+0x237/0x460
ring_buffer_lock_reserve+0x12a/0x3f0
trace_buffer_lock_reserve+0x10/0x50
__trace_graph_return+0x1f/0x80
trace_graph_return+0xb7/0xf0
? trace_clock_global+0x91/0xa0
ftrace_return_to_handler+0x8b/0xf0
? pv_hash+0xa0/0xa0
return_to_handler+0x15/0x30
? ftrace_graph_caller+0xa0/0xa0
? trace_clock_global+0x91/0xa0
? __rb_reserve_next+0x237/0x460
? ring_buffer_lock_reserve+0x12a/0x3f0
? trace_event_buffer_lock_reserve+0x3c/0x120
? trace_event_buffer_reserve+0x6b/0xc0
? trace_event_raw_event_device_pm_callback_start+0x125/0x2d0
? dpm_run_callback+0x3b/0xc0
? pm_ops_is_empty+0x50/0x50
? platform_get_irq_byname_optional+0x90/0x90
? trace_device_pm_callback_start+0x82/0xd0
? dpm_run_callback+0x49/0xc0
With the following RIP:
RIP: 0010:native_queued_spin_lock_slowpath+0x69/0x200
Since the fix to the recursion detection would allow a single recursion to
happen while tracing, this lead to the trace_clock_global() taking a spin
lock and then trying to take it again:
ring_buffer_lock_reserve() {
trace_clock_global() {
arch_spin_lock() {
queued_spin_lock_slowpath() {
/* lock taken */
(something else gets traced by function graph tracer)
ring_buffer_lock_reserve() {
trace_clock_global() {
arch_spin_lock() {
queued_spin_lock_slowpath() {
/* DEAD LOCK! */
Tracing should *never* block, as it can lead to strange lockups like the
above.
Restructure the trace_clock_global() code to instead of simply taking a
lock to update the recorded "prev_time" simply use it, as two events
happening on two different CPUs that calls this at the same time, really
doesn't matter which one goes first. Use a trylock to grab the lock for
updating the prev_time, and if it fails, simply try again the next time.
If it failed to be taken, that means something else is already updating
it.
Link: https://lkml.kernel.org/r/20210430121758.650b6e8a@gandalf.local.home
Cc: stable@vger.kernel.org
Tested-by: Konstantin Kharlamov <hi-angel@yandex.ru>
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Fixes: b02414c8f045 ("ring-buffer: Fix recursion protection transitions between interrupt context") # started showing the problem
Fixes: 14131f2f98ac3 ("tracing: implement trace_clock_*() APIs") # where the bug happened
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212761
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 785e3c0a3a870e72dc530856136ab4c8dd207128 upstream.
The default max PID is set by PID_MAX_DEFAULT, and the tracing
infrastructure uses this number to map PIDs to the comm names of the
tasks, such output of the trace can show names from the recorded PIDs in
the ring buffer. This mapping is also exported to user space via the
"saved_cmdlines" file in the tracefs directory.
But currently the mapping expects the PIDs to be less than
PID_MAX_DEFAULT, which is the default maximum and not the real maximum.
Recently, systemd will increases the maximum value of a PID on the system,
and when tasks are traced that have a PID higher than PID_MAX_DEFAULT, its
comm is not recorded. This leads to the entire trace to have "<...>" as
the comm name, which is pretty useless.
Instead, keep the array mapping the size of PID_MAX_DEFAULT, but instead
of just mapping the index to the comm, map a mask of the PID
(PID_MAX_DEFAULT - 1) to the comm, and find the full PID from the
map_cmdline_to_pid array (that already exists).
This bug goes back to the beginning of ftrace, but hasn't been an issue
until user space started increasing the maximum value of PIDs.
Link: https://lkml.kernel.org/r/20210427113207.3c601884@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: bc0c38d139ec7 ("ftrace: latency tracer infrastructure")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e09e28671cda63e6308b31798b997639120e2a21 upstream.
Strcpy is inherently not safe, and strlcpy() should be used instead.
__trace_find_cmdline() uses strcpy() because the comms saved must have a
terminating nul character, but it doesn't hurt to add the extra protection
of using strlcpy() instead of strcpy().
Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org
Signed-off-by: Amey Telawane <ameyt@codeaurora.org>
[AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10
https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
[ Updated change log and removed the "- 1" from len parameter ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit eaf260ac04d9b4cf9f458d5c97555bfff2da526e upstream.
Currently we stop recording comm for non-idle tasks when switching from/to idle
task since we treat that as a record failure. Fix that by treat recording of
comm for idle task as a success.
Link: http://lkml.kernel.org/r/20170706230023.17942-1-joelaf@google.com
Cc: kernel-team@android.com
Cc: Ingo Molnar <mingo@redhat.com>
Reported-by: Michael Sartain <mikesart@gmail.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8c9af478c06bb1ab1422f90d8ecbc53defd44bc3 upstream.
# echo switch_mm:traceoff > /sys/kernel/tracing/set_ftrace_filter
will cause switch_mm to stop tracing by the traceoff command.
# echo -n switch_mm:traceoff > /sys/kernel/tracing/set_ftrace_filter
does nothing.
The reason is that the parsing in the write function only processes
commands if it finished parsing (there is white space written after the
command). That's to handle:
write(fd, "switch_mm:", 10);
write(fd, "traceoff", 8);
cases, where the command is broken over multiple writes.
The problem is if the file descriptor is closed, then the write call is
not processed, and the command needs to be processed in the release code.
The release code can handle matching of functions, but does not handle
commands.
Cc: stable@vger.kernel.org
Fixes: eda1e32855656 ("tracing: handle broken names in ftrace filter")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4fbf5d6837bf81fd7a27d771358f4ee6c4f243f8 upstream.
The FUTEX_WAIT operand has historically a relative timeout which means that
the clock id is irrelevant as relative timeouts on CLOCK_REALTIME are not
subject to wall clock changes and therefore are mapped by the kernel to
CLOCK_MONOTONIC for simplicity.
If a caller would set FUTEX_CLOCK_REALTIME for FUTEX_WAIT the timeout is
still treated relative vs. CLOCK_MONOTONIC and then the wait arms that
timeout based on CLOCK_REALTIME which is broken and obviously has never
been used or even tested.
Reject any attempt to use FUTEX_CLOCK_REALTIME with FUTEX_WAIT again.
The desired functionality can be achieved with FUTEX_WAIT_BITSET and a
FUTEX_BITSET_MATCH_ANY argument.
Fixes: 337f13046ff0 ("futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210422194704.834797921@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0687c66b5f666b5ad433f4e94251590d9bc9d10e ]
The debug_work_activate() is called on the premise that
the work can be inserted, because if wq be in WQ_DRAINING
status, insert work may be failed.
Fixes: e41e704bc4f4 ("workqueue: improve destroy_workqueue() debuggability")
Signed-off-by: Zqiang <qiang.zhang@windriver.com>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3054d06719079388a543de6adb812638675ad8f5 upstream.
If audit_list_rules_send() fails when trying to create a new thread
to send the rules it also fails to cleanup properly, leaking a
reference to a net structure. This patch fixes the error patch and
renames audit_send_list() to audit_send_list_thread() to better
match its cousin, audit_send_reply_thread().
Reported-by: teroincn@gmail.com
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Cc: <stable@vger.kernel.org> # 4.9.x
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a48b284b403a4a073d8beb72d2bb33e54df67fb6 upstream.
If audit_send_reply() fails when trying to create a new thread to
send the reply it also fails to cleanup properly, leaking a reference
to a net structure. This patch fixes the error path and makes a
handful of other cleanups that came up while fixing the code.
Reported-by: teroincn@gmail.com
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Cc: <stable@vger.kernel.org> # 4.9.x
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9deb193af69d3fd6dd8e47f292b67c805a787010 upstream.
Commit cbc3b92ce037 fixed an issue to modify the macros of the stack trace
event so that user space could parse it properly. Originally the stack
trace format to user space showed that the called stack was a dynamic
array. But it is not actually a dynamic array, in the way that other
dynamic event arrays worked, and this broke user space parsing for it. The
update was to make the array look to have 8 entries in it. Helper
functions were added to make it parse it correctly, as the stack was
dynamic, but was determined by the size of the event stored.
Although this fixed user space on how it read the event, it changed the
internal structure used for the stack trace event. It changed the array
size from [0] to [8] (added 8 entries). This increased the size of the
stack trace event by 8 words. The size reserved on the ring buffer was the
size of the stack trace event plus the number of stack entries found in
the stack trace. That commit caused the amount to be 8 more than what was
needed because it did not expect the caller field to have any size. This
produced 8 entries of garbage (and reading random data) from the stack
trace event:
<idle>-0 [002] d... 1976396.837549: <stack trace>
=> trace_event_raw_event_sched_switch
=> __traceiter_sched_switch
=> __schedule
=> schedule_idle
=> do_idle
=> cpu_startup_entry
=> secondary_startup_64_no_verify
=> 0xc8c5e150ffff93de
=> 0xffff93de
=> 0
=> 0
=> 0xc8c5e17800000000
=> 0x1f30affff93de
=> 0x00000004
=> 0x200000000
Instead, subtract the size of the caller field from the size of the event
to make sure that only the amount needed to store the stack trace is
reserved.
Link: https://lore.kernel.org/lkml/your-ad-here.call-01617191565-ext-9692@work.hours/
Cc: stable@vger.kernel.org
Fixes: cbc3b92ce037 ("tracing: Set kernel_stack's caller size properly")
Reported-by: Vasily Gorbik <gor@linux.ibm.com>
Tested-by: Vasily Gorbik <gor@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9f5d1c336a10c0d24e83e40b4c1b9539f7dba627 upstream.
Gratian managed to trigger the BUG_ON(!newowner) in fixup_pi_state_owner().
This is one possible chain of events leading to this:
Task Prio Operation
T1 120 lock(F)
T2 120 lock(F) -> blocks (top waiter)
T3 50 (RT) lock(F) -> boosts T1 and blocks (new top waiter)
XX timeout/ -> wakes T2
signal
T1 50 unlock(F) -> wakes T3 (rtmutex->owner == NULL, waiter bit is set)
T2 120 cleanup -> try_to_take_mutex() fails because T3 is the top waiter
and the lower priority T2 cannot steal the lock.
-> fixup_pi_state_owner() sees newowner == NULL -> BUG_ON()
The comment states that this is invalid and rt_mutex_real_owner() must
return a non NULL owner when the trylock failed, but in case of a queued
and woken up waiter rt_mutex_real_owner() == NULL is a valid transient
state. The higher priority waiter has simply not yet managed to take over
the rtmutex.
The BUG_ON() is therefore wrong and this is just another retry condition in
fixup_pi_state_owner().
Drop the locks, so that T3 can make progress, and then try the fixup again.
Gratian provided a great analysis, traces and a reproducer. The analysis is
to the point, but it confused the hell out of that tglx dude who had to
page in all the futex horrors again. Condensed version is above.
[ tglx: Wrote comment and changelog ]
Fixes: c1e2f0eaf015 ("futex: Avoid violating the 10th rule of futex")
Reported-by: Gratian Crisan <gratian.crisan@ni.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87a6w6x7bb.fsf@ni.com
Link: https://lore.kernel.org/r/87sg9pkvf7.fsf@nanos.tec.linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Masami Hiramatsu
Steven Rostedt (VMware)
Thomas Zeitlhofer
Vincent Donnefort
Waiman Long
Ye Bin
Kalesh Singh
Peter Zijlstra
Eric W. Biederman
Lorenz Bauer
Petr Mladek
Tatsuhiko Yasumatsu
Kevin Hao
Zhihao Cheng
Pavel Skripkin
Cyrill Gorcunov
Baptiste Lepers
Vasily Averin
Liu Zixian
Yang Yingliang
Haoran Luo
Odin Ugedal
Hugh Dickins
Liangyan
Marco Elver
Alexander Kuznetsov
Sergey Senozhatsky
Shakeel Butt
Oleg Nesterov
Jia-Ju Bai
Amey Telawane
Joel Fernandes
Thomas Gleixner
Zqiang
Paul Moore
Mike Galbraith