linux-toradex.git/kernel/trace/trace_kprobe.c, branch v6.14-rc3

tracing/kprobes: Simplify __trace_kprobe_create() by removing gotos

2025-01-10T00:01:14+00:00

Simplify __trace_kprobe_create() by removing gotos.

Link: https://lore.kernel.org/all/173643301102.1514810.6149004416601259466.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google)

tracing: Use __free() for kprobe events to cleanup

2025-01-10T00:01:01+00:00

Use __free() in trace_kprobe.c to cleanup code.

Link: https://lore.kernel.org/all/173643299989.1514810.2924926552980462072.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google)

tracing/kprobe: Adopt guard() and scoped_guard()

2025-01-10T00:00:12+00:00

Use guard() or scoped_guard() in kprobe events for critical sections
rather than discrete lock/unlock pairs.

Link: https://lore.kernel.org/all/173289888883.73724.6586200652276577583.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google)

tracing/kprobes: Fix to free objects when failed to copy a symbol

2025-01-09T23:57:18+00:00

In __trace_kprobe_create(), if something fails it must goto error block
to free objects. But when strdup() a symbol, it returns without that.
Fix it to goto the error block to free objects correctly.

Link: https://lore.kernel.org/all/173643297743.1514810.2408159540454241947.stgit@devnote2/

Fixes: 6212dd29683e ("tracing/kprobes: Use dyn_event framework for kprobe events")
Signed-off-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google)

tracing/kprobe: Make trace_kprobe's module callback called after jump_label update

2024-12-23T15:08:13+00:00

Make sure the trace_kprobe's module notifer callback function is called
after jump_label's callback is called. Since the trace_kprobe's callback
eventually checks jump_label address during registering new kprobe on
the loading module, jump_label must be updated before this registration
happens.

Link: https://lore.kernel.org/all/173387585556.995044.3157941002975446119.stgit@devnote2/

Fixes: 614243181050 ("tracing/kprobes: Support module init function probing")
Signed-off-by: Masami Hiramatsu (Google)

tracing/probes: Fix MAX_TRACE_ARGS limit handling

2024-10-23T08:24:44+00:00

When creating a trace_probe we would set nr_args prior to truncating the
arguments to MAX_TRACE_ARGS. However, we would only initialize arguments
up to the limit.

This caused invalid memory access when attempting to set up probes with
more than 128 fetchargs.

  BUG: kernel NULL pointer dereference, address: 0000000000000020
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 UID: 0 PID: 1769 Comm: cat Not tainted 6.11.0-rc7+ #8
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
  RIP: 0010:__set_print_fmt+0x134/0x330

Resolve the issue by applying the MAX_TRACE_ARGS limit earlier. Return
an error when there are too many arguments instead of silently
truncating.

Link: https://lore.kernel.org/all/20240930202656.292869-1-mikel@mikelr.com/

Fixes: 035ba76014c0 ("tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init")
Signed-off-by: Mikel Rychliski 
Signed-off-by: Masami Hiramatsu (Google)

tracing/kprobes: Fix build error when find_module() is not available

2024-07-10T00:47:00+00:00

The kernel test robot reported that the find_module() is not available
if CONFIG_MODULES=n.
Fix this error by hiding find_modules() in #ifdef CONFIG_MODULES with
related rcu locks as try_module_get_by_name().

Link: https://lore.kernel.org/all/172056819167.201571.250053007194508038.stgit@devnote2/

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202407070744.RcLkn8sq-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202407070917.VVUCBlaS-lkp@intel.com/
Signed-off-by: Masami Hiramatsu (Google)

tracing/kprobes: Add symbol counting check when module loads

2024-07-06T00:27:47+00:00

Currently, kprobe event checks whether the target symbol name is unique
or not, so that it does not put a probe on an unexpected place. But this
skips the check if the target is on a module because the module may not
be loaded.

To fix this issue, this patch checks the number of probe target symbols
in a target module when the module is loaded. If the probe is not on the
unique name symbols in the module, it will be rejected at that point.

Note that the symbol which has a unique name in the target module,
it will be accepted even if there are same-name symbols in the
kernel or other modules,

Link: https://lore.kernel.org/all/172016348553.99543.2834679315611882137.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google)

tracing/kprobe: Remove cleanup code unrelated to selftest

2024-06-11T23:46:00+00:00

This cleanup all kprobe events code is not related to the selftest
itself, and it can fail by the reason unrelated to this test.
If the test is successful, the generated events are cleaned up.
And if not, we cannot guarantee that the kprobe events will work
correctly. So, anyway, there is no need to clean it up.

Link: https://lore.kernel.org/all/171811265627.85078.16897867213512435822.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google)

tracing/kprobe: Integrate test warnings into WARN_ONCE

2024-06-11T23:44:44+00:00

Cleanup the redundant WARN_ON_ONCE(cond) + pr_warn(msg) into
WARN_ONCE(cond, msg). Also add some WARN_ONCE() for hitcount check.
These WARN_ONCE() errors makes it easy to handle errors from ktest.

Link: https://lore.kernel.org/all/171811264685.85078.8068819097047430463.stgit@devnote2/

Suggested-by: Steven Rostedt 
Signed-off-by: Masami Hiramatsu (Google) 
Reviewed-by: Steven Rostedt (Google)