diff options
| author | Tiezhu Yang <yangtiezhu@loongson.cn> | 2021-05-15 19:02:01 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-16 11:34:52 +0200 |
| commit | d069f110fb74b1dc206e524fc6b187b3dd5486d1 (patch) | |
| tree | ccdeda0f427ff89fa404cb5a5b9660624bcb1c50 | |
| parent | ff4aab297538058ad25783edc8e9ac2e49231d25 (diff) | |
MIPS: Fix kernel hang under FUNCTION_GRAPH_TRACER and PREEMPT_TRACER
[ Upstream commit 78cf0eb926cb1abeff2106bae67752e032fe5f3e ]
When update the latest mainline kernel with the following three configs,
the kernel hangs during startup:
(1) CONFIG_FUNCTION_GRAPH_TRACER=y
(2) CONFIG_PREEMPT_TRACER=y
(3) CONFIG_FTRACE_STARTUP_TEST=y
When update the latest mainline kernel with the above two configs (1)
and (2), the kernel starts normally, but it still hangs when execute
the following command:
echo "function_graph" > /sys/kernel/debug/tracing/current_tracer
Without CONFIG_PREEMPT_TRACER=y, the above two kinds of kernel hangs
disappeared, so it seems that CONFIG_PREEMPT_TRACER has some influences
with function_graph tracer at the first glance.
I use ejtag to find out the epc address is related with preempt_enable()
in the file arch/mips/lib/mips-atomic.c, because function tracing can
trace the preempt_{enable,disable} calls that are traced, replace them
with preempt_{enable,disable}_notrace to prevent function tracing from
going into an infinite loop, and then it can fix the kernel hang issue.
By the way, it seems that this commit is a complement and improvement of
commit f93a1a00f2bd ("MIPS: Fix crash that occurs when function tracing
is enabled").
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/mips/lib/mips-atomic.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/mips/lib/mips-atomic.c b/arch/mips/lib/mips-atomic.c index 272af8ac2425..fd50aa7b178a 100644 --- a/arch/mips/lib/mips-atomic.c +++ b/arch/mips/lib/mips-atomic.c @@ -37,7 +37,7 @@ */ notrace void arch_local_irq_disable(void) { - preempt_disable(); + preempt_disable_notrace(); __asm__ __volatile__( " .set push \n" @@ -53,7 +53,7 @@ notrace void arch_local_irq_disable(void) : /* no inputs */ : "memory"); - preempt_enable(); + preempt_enable_notrace(); } EXPORT_SYMBOL(arch_local_irq_disable); @@ -62,7 +62,7 @@ notrace unsigned long arch_local_irq_save(void) { unsigned long flags; - preempt_disable(); + preempt_disable_notrace(); __asm__ __volatile__( " .set push \n" @@ -79,7 +79,7 @@ notrace unsigned long arch_local_irq_save(void) : /* no inputs */ : "memory"); - preempt_enable(); + preempt_enable_notrace(); return flags; } @@ -89,7 +89,7 @@ notrace void arch_local_irq_restore(unsigned long flags) { unsigned long __tmp1; - preempt_disable(); + preempt_disable_notrace(); __asm__ __volatile__( " .set push \n" @@ -107,7 +107,7 @@ notrace void arch_local_irq_restore(unsigned long flags) : "0" (flags) : "memory"); - preempt_enable(); + preempt_enable_notrace(); } EXPORT_SYMBOL(arch_local_irq_restore); |