Messages in this thread Patch in this message | | | From | Eric Biggers <> | Subject | [PATCH 5.4 02/17] panic: unset panic_on_warn inside panic() | Date | Wed, 1 Feb 2023 20:42:40 -0800 |
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From: Tiezhu Yang <yangtiezhu@loongson.cn>
commit 1a2383e8b84c0451fd9b1eec3b9aab16f30b597c upstream.
In the current code, the following three places need to unset panic_on_warn before calling panic() to avoid recursive panics:
kernel/kcsan/report.c: print_report() kernel/sched/core.c: __schedule_bug() mm/kfence/report.c: kfence_report_error()
In order to avoid copy-pasting "panic_on_warn = 0" all over the places, it is better to move it inside panic() and then remove it from the other places.
Link: https://lkml.kernel.org/r/1644324666-15947-4-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Reviewed-by: Marco Elver <elver@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Xuefeng Li <lixuefeng@loongson.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eric Biggers <ebiggers@google.com> --- kernel/panic.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/kernel/panic.c b/kernel/panic.c index f470a038b05bd..5e2b764ff5d54 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -173,6 +173,16 @@ void panic(const char *fmt, ...) int old_cpu, this_cpu; bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers; + if (panic_on_warn) { + /* + * This thread may hit another WARN() in the panic path. + * Resetting this prevents additional WARN() from panicking the + * system on this thread. Other threads are blocked by the + * panic_mutex in panic(). + */ + panic_on_warn = 0; + } + /* * Disable local interrupts. This will prevent panic_smp_self_stop * from deadlocking the first cpu that invokes the panic, since @@ -571,16 +581,8 @@ void __warn(const char *file, int line, void *caller, unsigned taint, if (args) vprintk(args->fmt, args->args); - if (panic_on_warn) { - /* - * This thread may hit another WARN() in the panic path. - * Resetting this prevents additional WARN() from panicking the - * system on this thread. Other threads are blocked by the - * panic_mutex in panic(). - */ - panic_on_warn = 0; + if (panic_on_warn) panic("panic_on_warn set ...\n"); - } print_modules(); -- 2.39.1
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