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| author | Vladimir Riabchun <ferr.lambarginio@gmail.com> | 2025-09-12 13:28:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-11-24 10:29:46 +0100 |
| commit | e81e6d6d99b16dae11adbeda5c996317942a940c (patch) | |
| tree | aaae86480053503c0ac11ece4bbedb907d3a07d4 /kernel/trace/ftrace.c | |
| parent | e09a096104fc65859422817fb2211f35855983fe (diff) | |
| download | linux-e81e6d6d99b16dae11adbeda5c996317942a940c.tar.gz linux-e81e6d6d99b16dae11adbeda5c996317942a940c.tar.bz2 linux-e81e6d6d99b16dae11adbeda5c996317942a940c.zip | |
ftrace: Fix softlockup in ftrace_module_enable
[ Upstream commit 4099b98203d6b33d990586542fa5beee408032a3 ]
A soft lockup was observed when loading amdgpu module.
If a module has a lot of tracable functions, multiple calls
to kallsyms_lookup can spend too much time in RCU critical
section and with disabled preemption, causing kernel panic.
This is the same issue that was fixed in
commit d0b24b4e91fc ("ftrace: Prevent RCU stall on PREEMPT_VOLUNTARY
kernels") and commit 42ea22e754ba ("ftrace: Add cond_resched() to
ftrace_graph_set_hash()").
Fix it the same way by adding cond_resched() in ftrace_module_enable.
Link: https://lore.kernel.org/aMQD9_lxYmphT-up@vova-pc
Signed-off-by: Vladimir Riabchun <ferr.lambarginio@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
| -rw-r--r-- | kernel/trace/ftrace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 15785a729a0c..398992597685 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -6873,6 +6873,8 @@ void ftrace_module_enable(struct module *mod) if (!within_module(rec->ip, mod)) break; + cond_resched(); + /* Weak functions should still be ignored */ if (!test_for_valid_rec(rec)) { /* Clear all other flags. Should not be enabled anyway */ |