From e77900abfd8be4e207412d8b7752dbb9838e2571 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Sun, 17 Sep 2017 21:05:02 +0200 Subject: parisc: Stop unwinding at start of stack Check stack pointer if we are reaching the stack end and stop unwinding if we do. This fixes early backtraces and avoids showing unrealistic call stacks. Signed-off-by: Helge Deller --- arch/parisc/kernel/unwind.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/parisc/kernel/unwind.c b/arch/parisc/kernel/unwind.c index 48dc7d4d20bb..caab39dfa95d 100644 --- a/arch/parisc/kernel/unwind.c +++ b/arch/parisc/kernel/unwind.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -279,6 +280,17 @@ static void unwind_frame_regs(struct unwind_frame_info *info) info->prev_sp = sp - 64; info->prev_ip = 0; + + /* The stack is at the end inside the thread_union + * struct. If we reach data, we have reached the + * beginning of the stack and should stop unwinding. */ + if (info->prev_sp >= (unsigned long) task_thread_info(info->t) && + info->prev_sp < ((unsigned long) task_thread_info(info->t) + + THREAD_SZ_ALGN)) { + info->prev_sp = 0; + break; + } + if (get_user(tmp, (unsigned long *)(info->prev_sp - RP_OFFSET))) break; info->prev_ip = tmp; -- cgit v1.2.3