linux-stable.git/kernel/trace, branch linux-6.9.y Linux kernel stable tree tracing: Add MODULE_DESCRIPTION() to preemptirq_delay_test 2024-06-27T11:52:31+00:00 Jeff Johnson quic_jjohnson@quicinc.com 2024-05-18T22:54:49+00:00 71f4f0673715346cfc36a88740872c8d60afff20 [ Upstream commit 23748e3e0fbfe471eff5ce439921629f6a427828 ] Fix the 'make W=1' warning: WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/trace/preemptirq_delay_test.o Link: https://lore.kernel.org/linux-trace-kernel/20240518-md-preemptirq_delay_test-v1-1-387d11b30d85@quicinc.com Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: f96e8577da10 ("lib: Add module for testing preemptoff/irqsoff latency tracers") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 23748e3e0fbfe471eff5ce439921629f6a427828 ]

Fix the 'make W=1' warning:

WARNING: modpost: missing MODULE_DESCRIPTION() in kernel/trace/preemptirq_delay_test.o

Link: https://lore.kernel.org/linux-trace-kernel/20240518-md-preemptirq_delay_test-v1-1-387d11b30d85@quicinc.com

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: f96e8577da10 ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tracing: Build event generation tests only as modules 2024-06-27T11:52:19+00:00 Masami Hiramatsu (Google) mhiramat@kernel.org 2024-06-11T13:30:37+00:00 72a0199b361df2387018697b023fdcdd357449a9 [ Upstream commit 3572bd5689b0812b161b40279e39ca5b66d73e88 ] The kprobes and synth event generation test modules add events and lock (get a reference) those event file reference in module init function, and unlock and delete it in module exit function. This is because those are designed for playing as modules. If we make those modules as built-in, those events are left locked in the kernel, and never be removed. This causes kprobe event self-test failure as below. [ 97.349708] ------------[ cut here ]------------ [ 97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.357106] Modules linked in: [ 97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14 [ 97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 [ 97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90 [ 97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286 [ 97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000 [ 97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68 [ 97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000 [ 97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000 [ 97.381536] FS: 0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000 [ 97.383813] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0 [ 97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 97.391196] Call Trace: [ 97.391967] <TASK> [ 97.392647] ? __warn+0xcc/0x180 [ 97.393640] ? kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.395181] ? report_bug+0xbd/0x150 [ 97.396234] ? handle_bug+0x3e/0x60 [ 97.397311] ? exc_invalid_op+0x1a/0x50 [ 97.398434] ? asm_exc_invalid_op+0x1a/0x20 [ 97.399652] ? trace_kprobe_is_busy+0x20/0x20 [ 97.400904] ? tracing_reset_all_online_cpus+0x15/0x90 [ 97.402304] ? kprobe_trace_self_tests_init+0x3f1/0x480 [ 97.403773] ? init_kprobe_trace+0x50/0x50 [ 97.404972] do_one_initcall+0x112/0x240 [ 97.406113] do_initcall_level+0x95/0xb0 [ 97.407286] ? kernel_init+0x1a/0x1a0 [ 97.408401] do_initcalls+0x3f/0x70 [ 97.409452] kernel_init_freeable+0x16f/0x1e0 [ 97.410662] ? rest_init+0x1f0/0x1f0 [ 97.411738] kernel_init+0x1a/0x1a0 [ 97.412788] ret_from_fork+0x39/0x50 [ 97.413817] ? rest_init+0x1f0/0x1f0 [ 97.414844] ret_from_fork_asm+0x11/0x20 [ 97.416285] </TASK> [ 97.417134] irq event stamp: 13437323 [ 97.418376] hardirqs last enabled at (13437337): [<ffffffff8110bc0c>] console_unlock+0x11c/0x150 [ 97.421285] hardirqs last disabled at (13437370): [<ffffffff8110bbf1>] console_unlock+0x101/0x150 [ 97.423838] softirqs last enabled at (13437366): [<ffffffff8108e17f>] handle_softirqs+0x23f/0x2a0 [ 97.426450] softirqs last disabled at (13437393): [<ffffffff8108e346>] __irq_exit_rcu+0x66/0xd0 [ 97.428850] ---[ end trace 0000000000000000 ]--- And also, since we can not cleanup dynamic_event file, ftracetest are failed too. To avoid these issues, build these tests only as modules. Link: https://lore.kernel.org/all/171811263754.85078.5877446624311852525.stgit@devnote2/ Fixes: 9fe41efaca08 ("tracing: Add synth event generation test module") Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3572bd5689b0812b161b40279e39ca5b66d73e88 ]

The kprobes and synth event generation test modules add events and lock
(get a reference) those event file reference in module init function,
and unlock and delete it in module exit function. This is because those
are designed for playing as modules.

If we make those modules as built-in, those events are left locked in the
kernel, and never be removed. This causes kprobe event self-test failure
as below.

[   97.349708] ------------[ cut here ]------------
[   97.353453] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:2133 kprobe_trace_self_tests_init+0x3f1/0x480
[   97.357106] Modules linked in:
[   97.358488] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 6.9.0-g699646734ab5-dirty #14
[   97.361556] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
[   97.363880] RIP: 0010:kprobe_trace_self_tests_init+0x3f1/0x480
[   97.365538] Code: a8 24 08 82 e9 ae fd ff ff 90 0f 0b 90 48 c7 c7 e5 aa 0b 82 e9 ee fc ff ff 90 0f 0b 90 48 c7 c7 2d 61 06 82 e9 8e fd ff ff 90 <0f> 0b 90 48 c7 c7 33 0b 0c 82 89 c6 e8 6e 03 1f ff 41 ff c7 e9 90
[   97.370429] RSP: 0000:ffffc90000013b50 EFLAGS: 00010286
[   97.371852] RAX: 00000000fffffff0 RBX: ffff888005919c00 RCX: 0000000000000000
[   97.373829] RDX: ffff888003f40000 RSI: ffffffff8236a598 RDI: ffff888003f40a68
[   97.375715] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
[   97.377675] R10: ffffffff811c9ae5 R11: ffffffff8120c4e0 R12: 0000000000000000
[   97.379591] R13: 0000000000000001 R14: 0000000000000015 R15: 0000000000000000
[   97.381536] FS:  0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000
[   97.383813] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   97.385449] CR2: 0000000000000000 CR3: 0000000002244000 CR4: 00000000000006b0
[   97.387347] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   97.389277] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   97.391196] Call Trace:
[   97.391967]  <TASK>
[   97.392647]  ? __warn+0xcc/0x180
[   97.393640]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.395181]  ? report_bug+0xbd/0x150
[   97.396234]  ? handle_bug+0x3e/0x60
[   97.397311]  ? exc_invalid_op+0x1a/0x50
[   97.398434]  ? asm_exc_invalid_op+0x1a/0x20
[   97.399652]  ? trace_kprobe_is_busy+0x20/0x20
[   97.400904]  ? tracing_reset_all_online_cpus+0x15/0x90
[   97.402304]  ? kprobe_trace_self_tests_init+0x3f1/0x480
[   97.403773]  ? init_kprobe_trace+0x50/0x50
[   97.404972]  do_one_initcall+0x112/0x240
[   97.406113]  do_initcall_level+0x95/0xb0
[   97.407286]  ? kernel_init+0x1a/0x1a0
[   97.408401]  do_initcalls+0x3f/0x70
[   97.409452]  kernel_init_freeable+0x16f/0x1e0
[   97.410662]  ? rest_init+0x1f0/0x1f0
[   97.411738]  kernel_init+0x1a/0x1a0
[   97.412788]  ret_from_fork+0x39/0x50
[   97.413817]  ? rest_init+0x1f0/0x1f0
[   97.414844]  ret_from_fork_asm+0x11/0x20
[   97.416285]  </TASK>
[   97.417134] irq event stamp: 13437323
[   97.418376] hardirqs last  enabled at (13437337): [<ffffffff8110bc0c>] console_unlock+0x11c/0x150
[   97.421285] hardirqs last disabled at (13437370): [<ffffffff8110bbf1>] console_unlock+0x101/0x150
[   97.423838] softirqs last  enabled at (13437366): [<ffffffff8108e17f>] handle_softirqs+0x23f/0x2a0
[   97.426450] softirqs last disabled at (13437393): [<ffffffff8108e346>] __irq_exit_rcu+0x66/0xd0
[   97.428850] ---[ end trace 0000000000000000 ]---

And also, since we can not cleanup dynamic_event file, ftracetest are
failed too.

To avoid these issues, build these tests only as modules.

Link: https://lore.kernel.org/all/171811263754.85078.5877446624311852525.stgit@devnote2/

Fixes: 9fe41efaca08 ("tracing: Add synth event generation test module")
Fixes: 64836248dda2 ("tracing: Add kprobe event command generation test module")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
kprobe/ftrace: bail out if ftrace was killed 2024-06-27T11:52:17+00:00 Stephen Brennan stephen.s.brennan@oracle.com 2024-05-01T16:29:56+00:00 81d5125b08dc677df63b8f2737044270e525a156 [ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ] If an error happens in ftrace, ftrace_kill() will prevent disarming kprobes. Eventually, the ftrace_ops associated with the kprobes will be freed, yet the kprobes will still be active, and when triggered, they will use the freed memory, likely resulting in a page fault and panic. This behavior can be reproduced quite easily, by creating a kprobe and then triggering a ftrace_kill(). For simplicity, we can simulate an ftrace error with a kernel module like [1]: [1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer sudo perf probe --add commit_creds sudo perf trace -e probe:commit_creds # In another terminal make sudo insmod ftrace_killer.ko # calls ftrace_kill(), simulating bug # Back to perf terminal # ctrl-c sudo perf probe --del commit_creds After a short period, a page fault and panic would occur as the kprobe continues to execute and uses the freed ftrace_ops. While ftrace_kill() is supposed to be used only in extreme circumstances, it is invoked in FTRACE_WARN_ON() and so there are many places where an unexpected bug could be triggered, yet the system may continue operating, possibly without the administrator noticing. If ftrace_kill() does not panic the system, then we should do everything we can to continue operating, rather than leave a ticking time bomb. Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/ Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Guo Ren <guoren@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1a7d0890dd4a502a202aaec792a6c04e6e049547 ]

If an error happens in ftrace, ftrace_kill() will prevent disarming
kprobes. Eventually, the ftrace_ops associated with the kprobes will be
freed, yet the kprobes will still be active, and when triggered, they
will use the freed memory, likely resulting in a page fault and panic.

This behavior can be reproduced quite easily, by creating a kprobe and
then triggering a ftrace_kill(). For simplicity, we can simulate an
ftrace error with a kernel module like [1]:

[1]: https://github.com/brenns10/kernel_stuff/tree/master/ftrace_killer

  sudo perf probe --add commit_creds
  sudo perf trace -e probe:commit_creds
  # In another terminal
  make
  sudo insmod ftrace_killer.ko  # calls ftrace_kill(), simulating bug
  # Back to perf terminal
  # ctrl-c
  sudo perf probe --del commit_creds

After a short period, a page fault and panic would occur as the kprobe
continues to execute and uses the freed ftrace_ops. While ftrace_kill()
is supposed to be used only in extreme circumstances, it is invoked in
FTRACE_WARN_ON() and so there are many places where an unexpected bug
could be triggered, yet the system may continue operating, possibly
without the administrator noticing. If ftrace_kill() does not panic the
system, then we should do everything we can to continue operating,
rather than leave a ticking time bomb.

Link: https://lore.kernel.org/all/20240501162956.229427-1-stephen.s.brennan@oracle.com/

Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
bpf: fix multi-uprobe PID filtering logic 2024-06-16T11:51:15+00:00 Andrii Nakryiko andrii@kernel.org 2024-05-21T16:33:57+00:00 0f4b00cdf3e52b73e74e177f5d40007aec1e5605 commit 46ba0e49b64232adac35a2bc892f1710c5b0fb7f upstream. Current implementation of PID filtering logic for multi-uprobes in uprobe_prog_run() is filtering down to exact *thread*, while the intent for PID filtering it to filter by *process* instead. The check in uprobe_prog_run() also differs from the analogous one in uprobe_multi_link_filter() for some reason. The latter is correct, checking task->mm, not the task itself. Fix the check in uprobe_prog_run() to perform the same task->mm check. While doing this, we also update get_pid_task() use to use PIDTYPE_TGID type of lookup, given the intent is to get a representative task of an entire process. This doesn't change behavior, but seems more logical. It would hold task group leader task now, not any random thread task. Last but not least, given multi-uprobe support is half-broken due to this PID filtering logic (depending on whether PID filtering is important or not), we need to make it easy for user space consumers (including libbpf) to easily detect whether PID filtering logic was already fixed. We do it here by adding an early check on passed pid parameter. If it's negative (and so has no chance of being a valid PID), we return -EINVAL. Previous behavior would eventually return -ESRCH ("No process found"), given there can't be any process with negative PID. This subtle change won't make any practical change in behavior, but will allow applications to detect PID filtering fixes easily. Libbpf fixes take advantage of this in the next patch. Cc: stable@vger.kernel.org Acked-by: Jiri Olsa <jolsa@kernel.org> Fixes: b733eeade420 ("bpf: Add pid filter support for uprobe_multi link") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240521163401.3005045-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 46ba0e49b64232adac35a2bc892f1710c5b0fb7f upstream.

Current implementation of PID filtering logic for multi-uprobes in
uprobe_prog_run() is filtering down to exact *thread*, while the intent
for PID filtering it to filter by *process* instead. The check in
uprobe_prog_run() also differs from the analogous one in
uprobe_multi_link_filter() for some reason. The latter is correct,
checking task->mm, not the task itself.

Fix the check in uprobe_prog_run() to perform the same task->mm check.

While doing this, we also update get_pid_task() use to use PIDTYPE_TGID
type of lookup, given the intent is to get a representative task of an
entire process. This doesn't change behavior, but seems more logical. It
would hold task group leader task now, not any random thread task.

Last but not least, given multi-uprobe support is half-broken due to
this PID filtering logic (depending on whether PID filtering is
important or not), we need to make it easy for user space consumers
(including libbpf) to easily detect whether PID filtering logic was
already fixed.

We do it here by adding an early check on passed pid parameter. If it's
negative (and so has no chance of being a valid PID), we return -EINVAL.
Previous behavior would eventually return -ESRCH ("No process found"),
given there can't be any process with negative PID. This subtle change
won't make any practical change in behavior, but will allow applications
to detect PID filtering fixes easily. Libbpf fixes take advantage of
this in the next patch.

Cc: stable@vger.kernel.org
Acked-by: Jiri Olsa <jolsa@kernel.org>
Fixes: b733eeade420 ("bpf: Add pid filter support for uprobe_multi link")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240521163401.3005045-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing/probes: fix error check in parse_btf_field() 2024-06-12T09:39:45+00:00 Carlos López clopez@suse.de 2024-05-27T09:43:52+00:00 4ed468edfeb54c7202e559eba74c25fac6a0dad0 [ Upstream commit e569eb34970281438e2b48a3ef11c87459fcfbcb ] btf_find_struct_member() might return NULL or an error via the ERR_PTR() macro. However, its caller in parse_btf_field() only checks for the NULL condition. Fix this by using IS_ERR() and returning the error up the stack. Link: https://lore.kernel.org/all/20240527094351.15687-1-clopez@suse.de/ Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access") Signed-off-by: Carlos López <clopez@suse.de> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit e569eb34970281438e2b48a3ef11c87459fcfbcb ]

btf_find_struct_member() might return NULL or an error via the
ERR_PTR() macro. However, its caller in parse_btf_field() only checks
for the NULL condition. Fix this by using IS_ERR() and returning the
error up the stack.

Link: https://lore.kernel.org/all/20240527094351.15687-1-clopez@suse.de/

Fixes: c440adfbe3025 ("tracing/probes: Support BTF based data structure field access")
Signed-off-by: Carlos López <clopez@suse.de>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
rv: Update rv_en(dis)able_monitor doc to match kernel-doc 2024-06-12T09:39:41+00:00 Yang Li yang.lee@linux.alibaba.com 2024-05-20T05:42:39+00:00 08611d65715cc835513efc9b24de83ae6da3c7ab [ Upstream commit 1e8b7b3dbb3103d577a586ca72bc329f7b67120b ] The patch updates the function documentation comment for rv_en(dis)able_monitor to adhere to the kernel-doc specification. Link: https://lore.kernel.org/linux-trace-kernel/20240520054239.61784-1-yang.lee@linux.alibaba.com Fixes: 102227b970a15 ("rv: Add Runtime Verification (RV) interface") Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1e8b7b3dbb3103d577a586ca72bc329f7b67120b ]

The patch updates the function documentation comment for
rv_en(dis)able_monitor to adhere to the kernel-doc specification.

Link: https://lore.kernel.org/linux-trace-kernel/20240520054239.61784-1-yang.lee@linux.alibaba.com

Fixes: 102227b970a15 ("rv: Add Runtime Verification (RV) interface")
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tracing/user_events: Fix non-spaced field matching 2024-05-30T07:45:01+00:00 Beau Belgrave beaub@linux.microsoft.com 2024-04-23T16:23:37+00:00 52e665d950e3dc84c2533d98f58c81c317da2643 [ Upstream commit bd125a084091396f3e796bb3dc009940d9771811 ] When the ABI was updated to prevent same name w/different args, it missed an important corner case when fields don't end with a space. Typically, space is used for fields to help separate them, like "u8 field1; u8 field2". If no spaces are used, like "u8 field1;u8 field2", then the parsing works for the first time. However, the match check fails on a subsequent register, leading to confusion. This is because the match check uses argv_split() and assumes that all fields will be split upon the space. When spaces are used, we get back { "u8", "field1;" }, without spaces we get back { "u8", "field1;u8" }. This causes a mismatch, and the user program gets back -EADDRINUSE. Add a method to detect this case before calling argv_split(). If found force a space after the field separator character ';'. This ensures all cases work properly for matching. With this fix, the following are all treated as matching: u8 field1;u8 field2 u8 field1; u8 field2 u8 field1;\tu8 field2 u8 field1;\nu8 field2 Link: https://lore.kernel.org/linux-trace-kernel/20240423162338.292-2-beaub@linux.microsoft.com Fixes: ba470eebc2f6 ("tracing/user_events: Prevent same name but different args event") Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit bd125a084091396f3e796bb3dc009940d9771811 ]

When the ABI was updated to prevent same name w/different args, it
missed an important corner case when fields don't end with a space.
Typically, space is used for fields to help separate them, like
"u8 field1; u8 field2". If no spaces are used, like
"u8 field1;u8 field2", then the parsing works for the first time.
However, the match check fails on a subsequent register, leading to
confusion.

This is because the match check uses argv_split() and assumes that all
fields will be split upon the space. When spaces are used, we get back
{ "u8", "field1;" }, without spaces we get back { "u8", "field1;u8" }.
This causes a mismatch, and the user program gets back -EADDRINUSE.

Add a method to detect this case before calling argv_split(). If found
force a space after the field separator character ';'. This ensures all
cases work properly for matching.

With this fix, the following are all treated as matching:
u8 field1;u8 field2
u8 field1; u8 field2
u8 field1;\tu8 field2
u8 field1;\nu8 field2

Link: https://lore.kernel.org/linux-trace-kernel/20240423162338.292-2-beaub@linux.microsoft.com

Fixes: ba470eebc2f6 ("tracing/user_events: Prevent same name but different args event")
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
ring-buffer: Fix a race between readers and resize checks 2024-05-30T07:44:00+00:00 Petr Pavlu petr.pavlu@suse.com 2024-05-17T13:40:08+00:00 79b52013429a42b8efdb0cda8bb0041386abab87 commit c2274b908db05529980ec056359fae916939fdaa upstream. The reader code in rb_get_reader_page() swaps a new reader page into the ring buffer by doing cmpxchg on old->list.prev->next to point it to the new page. Following that, if the operation is successful, old->list.next->prev gets updated too. This means the underlying doubly-linked list is temporarily inconsistent, page->prev->next or page->next->prev might not be equal back to page for some page in the ring buffer. The resize operation in ring_buffer_resize() can be invoked in parallel. It calls rb_check_pages() which can detect the described inconsistency and stop further tracing: [ 190.271762] ------------[ cut here ]------------ [ 190.271771] WARNING: CPU: 1 PID: 6186 at kernel/trace/ring_buffer.c:1467 rb_check_pages.isra.0+0x6a/0xa0 [ 190.271789] Modules linked in: [...] [ 190.271991] Unloaded tainted modules: intel_uncore_frequency(E):1 skx_edac(E):1 [ 190.272002] CPU: 1 PID: 6186 Comm: cmd.sh Kdump: loaded Tainted: G E 6.9.0-rc6-default #5 158d3e1e6d0b091c34c3b96bfd99a1c58306d79f [ 190.272011] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552c-rebuilt.opensuse.org 04/01/2014 [ 190.272015] RIP: 0010:rb_check_pages.isra.0+0x6a/0xa0 [ 190.272023] Code: [...] [ 190.272028] RSP: 0018:ffff9c37463abb70 EFLAGS: 00010206 [ 190.272034] RAX: ffff8eba04b6cb80 RBX: 0000000000000007 RCX: ffff8eba01f13d80 [ 190.272038] RDX: ffff8eba01f130c0 RSI: ffff8eba04b6cd00 RDI: ffff8eba0004c700 [ 190.272042] RBP: ffff8eba0004c700 R08: 0000000000010002 R09: 0000000000000000 [ 190.272045] R10: 00000000ffff7f52 R11: ffff8eba7f600000 R12: ffff8eba0004c720 [ 190.272049] R13: ffff8eba00223a00 R14: 0000000000000008 R15: ffff8eba067a8000 [ 190.272053] FS: 00007f1bd64752c0(0000) GS:ffff8eba7f680000(0000) knlGS:0000000000000000 [ 190.272057] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 190.272061] CR2: 00007f1bd6662590 CR3: 000000010291e001 CR4: 0000000000370ef0 [ 190.272070] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 190.272073] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 190.272077] Call Trace: [ 190.272098] <TASK> [ 190.272189] ring_buffer_resize+0x2ab/0x460 [ 190.272199] __tracing_resize_ring_buffer.part.0+0x23/0xa0 [ 190.272206] tracing_resize_ring_buffer+0x65/0x90 [ 190.272216] tracing_entries_write+0x74/0xc0 [ 190.272225] vfs_write+0xf5/0x420 [ 190.272248] ksys_write+0x67/0xe0 [ 190.272256] do_syscall_64+0x82/0x170 [ 190.272363] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 190.272373] RIP: 0033:0x7f1bd657d263 [ 190.272381] Code: [...] [ 190.272385] RSP: 002b:00007ffe72b643f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 190.272391] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1bd657d263 [ 190.272395] RDX: 0000000000000002 RSI: 0000555a6eb538e0 RDI: 0000000000000001 [ 190.272398] RBP: 0000555a6eb538e0 R08: 000000000000000a R09: 0000000000000000 [ 190.272401] R10: 0000555a6eb55190 R11: 0000000000000246 R12: 00007f1bd6662500 [ 190.272404] R13: 0000000000000002 R14: 00007f1bd6667c00 R15: 0000000000000002 [ 190.272412] </TASK> [ 190.272414] ---[ end trace 0000000000000000 ]--- Note that ring_buffer_resize() calls rb_check_pages() only if the parent trace_buffer has recording disabled. Recent commit d78ab792705c ("tracing: Stop current tracer when resizing buffer") causes that it is now always the case which makes it more likely to experience this issue. The window to hit this race is nonetheless very small. To help reproducing it, one can add a delay loop in rb_get_reader_page(): ret = rb_head_page_replace(reader, cpu_buffer->reader_page); if (!ret) goto spin; for (unsigned i = 0; i < 1U << 26; i++) /* inserted delay loop */ __asm__ __volatile__ ("" : : : "memory"); rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list; .. and then run the following commands on the target system: echo 1 > /sys/kernel/tracing/events/sched/sched_switch/enable while true; do echo 16 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1 echo 8 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1 done & while true; do for i in /sys/kernel/tracing/per_cpu/*; do timeout 0.1 cat $i/trace_pipe; sleep 0.2 done done To fix the problem, make sure ring_buffer_resize() doesn't invoke rb_check_pages() concurrently with a reader operating on the same ring_buffer_per_cpu by taking its cpu_buffer->reader_lock. Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-3-petr.pavlu@suse.com Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: 659f451ff213 ("ring-buffer: Add integrity check at end of iter read") Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> [ Fixed whitespace ] Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c2274b908db05529980ec056359fae916939fdaa upstream.

The reader code in rb_get_reader_page() swaps a new reader page into the
ring buffer by doing cmpxchg on old->list.prev->next to point it to the
new page. Following that, if the operation is successful,
old->list.next->prev gets updated too. This means the underlying
doubly-linked list is temporarily inconsistent, page->prev->next or
page->next->prev might not be equal back to page for some page in the
ring buffer.

The resize operation in ring_buffer_resize() can be invoked in parallel.
It calls rb_check_pages() which can detect the described inconsistency
and stop further tracing:

[  190.271762] ------------[ cut here ]------------
[  190.271771] WARNING: CPU: 1 PID: 6186 at kernel/trace/ring_buffer.c:1467 rb_check_pages.isra.0+0x6a/0xa0
[  190.271789] Modules linked in: [...]
[  190.271991] Unloaded tainted modules: intel_uncore_frequency(E):1 skx_edac(E):1
[  190.272002] CPU: 1 PID: 6186 Comm: cmd.sh Kdump: loaded Tainted: G            E      6.9.0-rc6-default #5 158d3e1e6d0b091c34c3b96bfd99a1c58306d79f
[  190.272011] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552c-rebuilt.opensuse.org 04/01/2014
[  190.272015] RIP: 0010:rb_check_pages.isra.0+0x6a/0xa0
[  190.272023] Code: [...]
[  190.272028] RSP: 0018:ffff9c37463abb70 EFLAGS: 00010206
[  190.272034] RAX: ffff8eba04b6cb80 RBX: 0000000000000007 RCX: ffff8eba01f13d80
[  190.272038] RDX: ffff8eba01f130c0 RSI: ffff8eba04b6cd00 RDI: ffff8eba0004c700
[  190.272042] RBP: ffff8eba0004c700 R08: 0000000000010002 R09: 0000000000000000
[  190.272045] R10: 00000000ffff7f52 R11: ffff8eba7f600000 R12: ffff8eba0004c720
[  190.272049] R13: ffff8eba00223a00 R14: 0000000000000008 R15: ffff8eba067a8000
[  190.272053] FS:  00007f1bd64752c0(0000) GS:ffff8eba7f680000(0000) knlGS:0000000000000000
[  190.272057] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  190.272061] CR2: 00007f1bd6662590 CR3: 000000010291e001 CR4: 0000000000370ef0
[  190.272070] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  190.272073] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  190.272077] Call Trace:
[  190.272098]  <TASK>
[  190.272189]  ring_buffer_resize+0x2ab/0x460
[  190.272199]  __tracing_resize_ring_buffer.part.0+0x23/0xa0
[  190.272206]  tracing_resize_ring_buffer+0x65/0x90
[  190.272216]  tracing_entries_write+0x74/0xc0
[  190.272225]  vfs_write+0xf5/0x420
[  190.272248]  ksys_write+0x67/0xe0
[  190.272256]  do_syscall_64+0x82/0x170
[  190.272363]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  190.272373] RIP: 0033:0x7f1bd657d263
[  190.272381] Code: [...]
[  190.272385] RSP: 002b:00007ffe72b643f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  190.272391] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1bd657d263
[  190.272395] RDX: 0000000000000002 RSI: 0000555a6eb538e0 RDI: 0000000000000001
[  190.272398] RBP: 0000555a6eb538e0 R08: 000000000000000a R09: 0000000000000000
[  190.272401] R10: 0000555a6eb55190 R11: 0000000000000246 R12: 00007f1bd6662500
[  190.272404] R13: 0000000000000002 R14: 00007f1bd6667c00 R15: 0000000000000002
[  190.272412]  </TASK>
[  190.272414] ---[ end trace 0000000000000000 ]---

Note that ring_buffer_resize() calls rb_check_pages() only if the parent
trace_buffer has recording disabled. Recent commit d78ab792705c
("tracing: Stop current tracer when resizing buffer") causes that it is
now always the case which makes it more likely to experience this issue.

The window to hit this race is nonetheless very small. To help
reproducing it, one can add a delay loop in rb_get_reader_page():

 ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
 if (!ret)
 	goto spin;
 for (unsigned i = 0; i < 1U << 26; i++)  /* inserted delay loop */
 	__asm__ __volatile__ ("" : : : "memory");
 rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list;

.. and then run the following commands on the target system:

 echo 1 > /sys/kernel/tracing/events/sched/sched_switch/enable
 while true; do
 	echo 16 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
 	echo 8 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
 done &
 while true; do
 	for i in /sys/kernel/tracing/per_cpu/*; do
 		timeout 0.1 cat $i/trace_pipe; sleep 0.2
 	done
 done

To fix the problem, make sure ring_buffer_resize() doesn't invoke
rb_check_pages() concurrently with a reader operating on the same
ring_buffer_per_cpu by taking its cpu_buffer->reader_lock.

Link: https://lore.kernel.org/linux-trace-kernel/20240517134008.24529-3-petr.pavlu@suse.com

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 659f451ff213 ("ring-buffer: Add integrity check at end of iter read")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
[ Fixed whitespace ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ftrace: Fix possible use-after-free issue in ftrace_location() 2024-05-30T07:43:58+00:00 Zheng Yejian zhengyejian1@huawei.com 2024-05-09T19:28:59+00:00 31310e373f4c8c74e029d4326b283e757edabc0b commit e60b613df8b6253def41215402f72986fee3fc8d upstream. KASAN reports a bug: BUG: KASAN: use-after-free in ftrace_location+0x90/0x120 Read of size 8 at addr ffff888141d40010 by task insmod/424 CPU: 8 PID: 424 Comm: insmod Tainted: G W 6.9.0-rc2+ [...] Call Trace: <TASK> dump_stack_lvl+0x68/0xa0 print_report+0xcf/0x610 kasan_report+0xb5/0xe0 ftrace_location+0x90/0x120 register_kprobe+0x14b/0xa40 kprobe_init+0x2d/0xff0 [kprobe_example] do_one_initcall+0x8f/0x2d0 do_init_module+0x13a/0x3c0 load_module+0x3082/0x33d0 init_module_from_file+0xd2/0x130 __x64_sys_finit_module+0x306/0x440 do_syscall_64+0x68/0x140 entry_SYSCALL_64_after_hwframe+0x71/0x79 The root cause is that, in lookup_rec(), ftrace record of some address is being searched in ftrace pages of some module, but those ftrace pages at the same time is being freed in ftrace_release_mod() as the corresponding module is being deleted: CPU1 | CPU2 register_kprobes() { | delete_module() { check_kprobe_address_safe() { | arch_check_ftrace_location() { | ftrace_location() { | lookup_rec() // USE! | ftrace_release_mod() // Free! To fix this issue: 1. Hold rcu lock as accessing ftrace pages in ftrace_location_range(); 2. Use ftrace_location_range() instead of lookup_rec() in ftrace_location(); 3. Call synchronize_rcu() before freeing any ftrace pages both in ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem(). Link: https://lore.kernel.org/linux-trace-kernel/20240509192859.1273558-1-zhengyejian1@huawei.com Cc: stable@vger.kernel.org Cc: <mhiramat@kernel.org> Cc: <mark.rutland@arm.com> Cc: <mathieu.desnoyers@efficios.com> Fixes: ae6aa16fdc16 ("kprobes: introduce ftrace based optimization") Suggested-by: Steven Rostedt <rostedt@goodmis.org> 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> 
commit e60b613df8b6253def41215402f72986fee3fc8d upstream.

KASAN reports a bug:

  BUG: KASAN: use-after-free in ftrace_location+0x90/0x120
  Read of size 8 at addr ffff888141d40010 by task insmod/424
  CPU: 8 PID: 424 Comm: insmod Tainted: G        W          6.9.0-rc2+
  [...]
  Call Trace:
   <TASK>
   dump_stack_lvl+0x68/0xa0
   print_report+0xcf/0x610
   kasan_report+0xb5/0xe0
   ftrace_location+0x90/0x120
   register_kprobe+0x14b/0xa40
   kprobe_init+0x2d/0xff0 [kprobe_example]
   do_one_initcall+0x8f/0x2d0
   do_init_module+0x13a/0x3c0
   load_module+0x3082/0x33d0
   init_module_from_file+0xd2/0x130
   __x64_sys_finit_module+0x306/0x440
   do_syscall_64+0x68/0x140
   entry_SYSCALL_64_after_hwframe+0x71/0x79

The root cause is that, in lookup_rec(), ftrace record of some address
is being searched in ftrace pages of some module, but those ftrace pages
at the same time is being freed in ftrace_release_mod() as the
corresponding module is being deleted:

           CPU1                       |      CPU2
  register_kprobes() {                | delete_module() {
    check_kprobe_address_safe() {     |
      arch_check_ftrace_location() {  |
        ftrace_location() {           |
          lookup_rec() // USE!        |   ftrace_release_mod() // Free!

To fix this issue:
  1. Hold rcu lock as accessing ftrace pages in ftrace_location_range();
  2. Use ftrace_location_range() instead of lookup_rec() in
     ftrace_location();
  3. Call synchronize_rcu() before freeing any ftrace pages both in
     ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem().

Link: https://lore.kernel.org/linux-trace-kernel/20240509192859.1273558-1-zhengyejian1@huawei.com

Cc: stable@vger.kernel.org
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: <mathieu.desnoyers@efficios.com>
Fixes: ae6aa16fdc16 ("kprobes: introduce ftrace based optimization")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
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>
Merge tag 'probes-fixes-v6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 2024-05-05T16:56:50+00:00 Linus Torvalds torvalds@linux-foundation.org 2024-05-05T16:56:50+00:00 2c17a1cd90a5d385a7138c030e815e3effc45677 Pull probes fix from Masami Hiramatsu: - probe-events: Fix memory leak in parsing probe argument. There is a memory leak (forget to free an allocated buffer) in a memory allocation failure path. Fix it to jump to the correct error handling code. * tag 'probes-fixes-v6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body() 
Pull probes fix from Masami Hiramatsu:

 - probe-events: Fix memory leak in parsing probe argument.

   There is a memory leak (forget to free an allocated buffer) in a
   memory allocation failure path. Fix it to jump to the correct error
   handling code.

* tag 'probes-fixes-v6.9-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing/probes: Fix memory leak in traceprobe_parse_probe_arg_body()