[PATCH v2] csky: kprobe: fix unreachable code in simulate_blz32

From: menglong8 . dong
Date: Mon Jan 11 2021 - 22:11:26 EST


From: Menglong Dong <dong.menglong@xxxxxxxxxx>

The type of 'val' is 'unsigned long' in simulate_blz32, so 'val < 0'
can't be true.

Cast 'val' to 'long' here to determine branch token or not,
as Guo Ren suggested.

Fixes: 33e53ae1ce41 ("csky: Add kprobes supported")
Signed-off-by: Menglong Dong <dong.menglong@xxxxxxxxxx>
---
v2:
- Cast 'val' to 'long'.
---
arch/csky/kernel/probes/simulate-insn.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/csky/kernel/probes/simulate-insn.c b/arch/csky/kernel/probes/simulate-insn.c
index 4e464fed52ec..9ad771c47670 100644
--- a/arch/csky/kernel/probes/simulate-insn.c
+++ b/arch/csky/kernel/probes/simulate-insn.c
@@ -348,7 +348,7 @@ simulate_blz32(u32 opcode, long addr, struct pt_regs *regs)

csky_insn_reg_get_val(regs, tmp, &val);

- if (val < 0) {
+ if ((long)val < 0) {
instruction_pointer_set(regs,
addr + sign_extend32((opcode & 0xffff0000) >> 15, 15));
} else
--
2.17.1