This patch fixes an underflow issue in the return value within the exception path, specifically at .Llt8 when the remaining length is less than 8 bytes.

Cc: stable@vger.kernel.org Fixes: 8941e93ca590 ("LoongArch: Optimize memory ops (memset/memcpy/memmove)") Reported-by: Weihao Li liweihao@loongson.cn Signed-off-by: WANG Rui wangrui@loongson.cn --- arch/loongarch/lib/clear_user.S | 3 ++- arch/loongarch/lib/copy_user.S | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/loongarch/lib/clear_user.S b/arch/loongarch/lib/clear_user.S index fd1d62b244f2..9dcf71719387 100644 --- a/arch/loongarch/lib/clear_user.S +++ b/arch/loongarch/lib/clear_user.S @@ -108,6 +108,7 @@ SYM_FUNC_START(__clear_user_fast) addi.d a3, a2, -8 bgeu a0, a3, .Llt8 15: st.d zero, a0, 0 + addi.d a0, a0, 8

.Llt8: 16: st.d zero, a2, -8 @@ -188,7 +189,7 @@ SYM_FUNC_START(__clear_user_fast) _asm_extable 13b, .L_fixup_handle_0 _asm_extable 14b, .L_fixup_handle_1 _asm_extable 15b, .L_fixup_handle_0 - _asm_extable 16b, .L_fixup_handle_1 + _asm_extable 16b, .L_fixup_handle_0 _asm_extable 17b, .L_fixup_handle_s0 _asm_extable 18b, .L_fixup_handle_s0 _asm_extable 19b, .L_fixup_handle_s0 diff --git a/arch/loongarch/lib/copy_user.S b/arch/loongarch/lib/copy_user.S index b21f6d5d38f5..fecd08cad702 100644 --- a/arch/loongarch/lib/copy_user.S +++ b/arch/loongarch/lib/copy_user.S @@ -136,6 +136,7 @@ SYM_FUNC_START(__copy_user_fast) bgeu a1, a4, .Llt8 30: ld.d t0, a1, 0 31: st.d t0, a0, 0 + addi.d a0, a0, 8

.Llt8: 32: ld.d t0, a3, -8 @@ -246,7 +247,7 @@ SYM_FUNC_START(__copy_user_fast) _asm_extable 30b, .L_fixup_handle_0 _asm_extable 31b, .L_fixup_handle_0 _asm_extable 32b, .L_fixup_handle_0 - _asm_extable 33b, .L_fixup_handle_1 + _asm_extable 33b, .L_fixup_handle_0 _asm_extable 34b, .L_fixup_handle_s0 _asm_extable 35b, .L_fixup_handle_s0 _asm_extable 36b, .L_fixup_handle_s0