LoongArch: Adjust PC value when unwind next frame in unwinder

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>

diff --git a/arch/loongarch/kernel/unwind_prologue.c b/arch/loongarch/kernel/unwind_prologue.c
index 0f8d145..e98b004 100644 (file)
--- a/arch/loongarch/kernel/unwind_prologue.c
+++ b/arch/loongarch/kernel/unwind_prologue.c
@@ -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;