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author | Peter Zijlstra <peterz@infradead.org> | 2021-09-15 17:12:59 +0200 |
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committer | Peter Zijlstra <peterz@infradead.org> | 2021-09-21 13:57:43 +0200 |
commit | 44b979fa302cab91bdd2cc982823e5c13202cd4e (patch) | |
tree | 95cda92efb3adb9b44d233dbd979e3ecfd9fa66e /arch/x86/kernel/dumpstack_64.c | |
parent | x86/iopl: Fake iopl(3) CLI/STI usage (diff) | |
download | linux-44b979fa302cab91bdd2cc982823e5c13202cd4e.tar.xz linux-44b979fa302cab91bdd2cc982823e5c13202cd4e.zip |
x86/mm/64: Improve stack overflow warnings
Current code has an explicit check for hitting the task stack guard;
but overflowing any of the other stacks will get you a non-descript
general #DF warning.
Improve matters by using get_stack_info_noinstr() to detetrmine if and
which stack guard page got hit, enabling a better stack warning.
In specific, Michael Wang reported what turned out to be an NMI
exception stack overflow, which is now clearly reported as such:
[] BUG: NMI stack guard page was hit at 0000000085fd977b (stack is 000000003a55b09e..00000000d8cce1a5)
Reported-by: Michael Wang <yun.wang@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Wang <yun.wang@linux.alibaba.com>
Link: https://lkml.kernel.org/r/YUTE/NuqnaWbST8n@hirez.programming.kicks-ass.net
Diffstat (limited to 'arch/x86/kernel/dumpstack_64.c')
-rw-r--r-- | arch/x86/kernel/dumpstack_64.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 5601b95944fa..6c5defd6569a 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -32,9 +32,15 @@ const char *stack_type_name(enum stack_type type) { BUILD_BUG_ON(N_EXCEPTION_STACKS != 6); + if (type == STACK_TYPE_TASK) + return "TASK"; + if (type == STACK_TYPE_IRQ) return "IRQ"; + if (type == STACK_TYPE_SOFTIRQ) + return "SOFTIRQ"; + if (type == STACK_TYPE_ENTRY) { /* * On 64-bit, we have a generic entry stack that we |