LoongArch: Adjust PC value when unwind next frame in unwinder
authorJinyang He <hejinyang@loongson.cn>
Tue, 17 Jan 2023 03:42:16 +0000 (11:42 +0800)
committerHuacai Chen <chenhuacai@loongson.cn>
Tue, 17 Jan 2023 03:42:16 +0000 (11:42 +0800)
When state->first is not set, the PC is a return address in the previous
frame. We need to adjust its value in case overflow to the next symbol.

Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
arch/loongarch/kernel/unwind_prologue.c

index 0f8d1451ebb848d8a88f8a5c9405903a8d4c93c0..e98b00432c885ea9ac30eb239d406114a566ee0e 100644 (file)
@@ -56,7 +56,7 @@ static bool unwind_by_prologue(struct unwind_state *state)
 {
        long frame_ra = -1;
        unsigned long frame_size = 0;
-       unsigned long size, offset, pc = state->pc;
+       unsigned long size, offset, pc;
        struct pt_regs *regs;
        struct stack_info *info = &state->stack_info;
        union loongarch_instruction *ip, *ip_end;
@@ -78,6 +78,11 @@ static bool unwind_by_prologue(struct unwind_state *state)
                return true;
        }
 
+       /*
+        * When first is not set, the PC is a return address in the previous frame.
+        * We need to adjust its value in case overflow to the next symbol.
+        */
+       pc = state->pc - (state->first ? 0 : LOONGARCH_INSN_SIZE);
        if (!kallsyms_lookup_size_offset(pc, &size, &offset))
                return false;