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author | Peter Zijlstra <peterz@infradead.org> | 2021-09-15 18:12:59 +0300 |
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committer | Peter Zijlstra <peterz@infradead.org> | 2021-09-21 14:57:43 +0300 |
commit | 44b979fa302cab91bdd2cc982823e5c13202cd4e (patch) | |
tree | 95cda92efb3adb9b44d233dbd979e3ecfd9fa66e /arch/x86/include/asm/irq_stack.h | |
parent | b968e84b509da593c50dc3db679e1d33de701f78 (diff) | |
download | linux-44b979fa302cab91bdd2cc982823e5c13202cd4e.tar.xz |
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/include/asm/irq_stack.h')
-rw-r--r-- | arch/x86/include/asm/irq_stack.h | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/arch/x86/include/asm/irq_stack.h b/arch/x86/include/asm/irq_stack.h index 562854c60808..8d55bd11848c 100644 --- a/arch/x86/include/asm/irq_stack.h +++ b/arch/x86/include/asm/irq_stack.h @@ -77,11 +77,11 @@ * Function calls can clobber anything except the callee-saved * registers. Tell the compiler. */ -#define call_on_irqstack(func, asm_call, argconstr...) \ +#define call_on_stack(stack, func, asm_call, argconstr...) \ { \ register void *tos asm("r11"); \ \ - tos = ((void *)__this_cpu_read(hardirq_stack_ptr)); \ + tos = ((void *)(stack)); \ \ asm_inline volatile( \ "movq %%rsp, (%[tos]) \n" \ @@ -98,6 +98,25 @@ ); \ } +#define ASM_CALL_ARG0 \ + "call %P[__func] \n" + +#define ASM_CALL_ARG1 \ + "movq %[arg1], %%rdi \n" \ + ASM_CALL_ARG0 + +#define ASM_CALL_ARG2 \ + "movq %[arg2], %%rsi \n" \ + ASM_CALL_ARG1 + +#define ASM_CALL_ARG3 \ + "movq %[arg3], %%rdx \n" \ + ASM_CALL_ARG2 + +#define call_on_irqstack(func, asm_call, argconstr...) \ + call_on_stack(__this_cpu_read(hardirq_stack_ptr), \ + func, asm_call, argconstr) + /* Macros to assert type correctness for run_*_on_irqstack macros */ #define assert_function_type(func, proto) \ static_assert(__builtin_types_compatible_p(typeof(&func), proto)) @@ -147,8 +166,7 @@ */ #define ASM_CALL_SYSVEC \ "call irq_enter_rcu \n" \ - "movq %[arg1], %%rdi \n" \ - "call %P[__func] \n" \ + ASM_CALL_ARG1 \ "call irq_exit_rcu \n" #define SYSVEC_CONSTRAINTS , [arg1] "r" (regs) @@ -168,12 +186,10 @@ */ #define ASM_CALL_IRQ \ "call irq_enter_rcu \n" \ - "movq %[arg1], %%rdi \n" \ - "movl %[arg2], %%esi \n" \ - "call %P[__func] \n" \ + ASM_CALL_ARG2 \ "call irq_exit_rcu \n" -#define IRQ_CONSTRAINTS , [arg1] "r" (regs), [arg2] "r" (vector) +#define IRQ_CONSTRAINTS , [arg1] "r" (regs), [arg2] "r" ((unsigned long)vector) #define run_irq_on_irqstack_cond(func, regs, vector) \ { \ @@ -185,9 +201,6 @@ IRQ_CONSTRAINTS, regs, vector); \ } -#define ASM_CALL_SOFTIRQ \ - "call %P[__func] \n" - /* * Macro to invoke __do_softirq on the irq stack. This is only called from * task context when bottom halves are about to be reenabled and soft @@ -197,7 +210,7 @@ #define do_softirq_own_stack() \ { \ __this_cpu_write(hardirq_stack_inuse, true); \ - call_on_irqstack(__do_softirq, ASM_CALL_SOFTIRQ); \ + call_on_irqstack(__do_softirq, ASM_CALL_ARG0); \ __this_cpu_write(hardirq_stack_inuse, false); \ } |