diff options
Diffstat (limited to 'arch/arm/kernel/stacktrace.c')
| -rw-r--r-- | arch/arm/kernel/stacktrace.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index 65228bf4c6df..ba9b9a77bcd2 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -20,6 +20,19 @@ * A simple function epilogue looks like this: * ldm sp, {fp, sp, pc} * + * When compiled with clang, pc and sp are not pushed. A simple function + * prologue looks like this when built with clang: + * + * stmdb {..., fp, lr} + * add fp, sp, #x + * sub sp, sp, #y + * + * A simple function epilogue looks like this when built with clang: + * + * sub sp, fp, #x + * ldm {..., fp, pc} + * + * * Note that with framepointer enabled, even the leaf functions have the same * prologue and epilogue, therefore we can ignore the LR value in this case. */ @@ -32,6 +45,16 @@ int notrace unwind_frame(struct stackframe *frame) low = frame->sp; high = ALIGN(low, THREAD_SIZE); +#ifdef CONFIG_CC_IS_CLANG + /* check current frame pointer is within bounds */ + if (fp < low + 4 || fp > high - 4) + return -EINVAL; + + frame->sp = frame->fp; + frame->fp = *(unsigned long *)(fp); + frame->pc = frame->lr; + frame->lr = *(unsigned long *)(fp + 4); +#else /* check current frame pointer is within bounds */ if (fp < low + 12 || fp > high - 4) return -EINVAL; @@ -40,6 +63,7 @@ int notrace unwind_frame(struct stackframe *frame) frame->fp = *(unsigned long *)(fp - 12); frame->sp = *(unsigned long *)(fp - 8); frame->pc = *(unsigned long *)(fp - 4); +#endif return 0; } |