diff options
| author | Vivian Wang <wangruikang@iscas.ac.cn> | 2025-12-02 13:25:07 +0800 |
|---|---|---|
| committer | Eric Biggers <ebiggers@kernel.org> | 2025-12-09 15:10:20 -0800 |
| commit | 43169328c7b4623b54b7713ec68479cebda5465f (patch) | |
| tree | 3c0392c35cd0f409d87c9fe6d8095ddfd8978a3f /lib | |
| parent | 7a3984bbd69055898add0fe22445f99435f33450 (diff) | |
lib/crypto: riscv/chacha: Avoid s0/fp register
In chacha_zvkb, avoid using the s0 register, which is the frame pointer,
by reallocating KEY0 to t5. This makes stack traces available if e.g. a
crash happens in chacha_zvkb.
No frame pointer maintenance is otherwise required since this is a leaf
function.
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
Fixes: bb54668837a0 ("crypto: riscv - add vector crypto accelerated ChaCha20")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20251202-riscv-chacha_zvkb-fp-v2-1-7bd00098c9dc@iscas.ac.cn
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/crypto/riscv/chacha-riscv64-zvkb.S | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/lib/crypto/riscv/chacha-riscv64-zvkb.S b/lib/crypto/riscv/chacha-riscv64-zvkb.S index b777d0b4e379..3d183ec818f5 100644 --- a/lib/crypto/riscv/chacha-riscv64-zvkb.S +++ b/lib/crypto/riscv/chacha-riscv64-zvkb.S @@ -60,7 +60,8 @@ #define VL t2 #define STRIDE t3 #define ROUND_CTR t4 -#define KEY0 s0 +#define KEY0 t5 +// Avoid s0/fp to allow for unwinding #define KEY1 s1 #define KEY2 s2 #define KEY3 s3 @@ -143,7 +144,6 @@ // The updated 32-bit counter is written back to state->x[12] before returning. SYM_FUNC_START(chacha_zvkb) addi sp, sp, -96 - sd s0, 0(sp) sd s1, 8(sp) sd s2, 16(sp) sd s3, 24(sp) @@ -280,7 +280,6 @@ SYM_FUNC_START(chacha_zvkb) bnez NBLOCKS, .Lblock_loop sw COUNTER, 48(STATEP) - ld s0, 0(sp) ld s1, 8(sp) ld s2, 16(sp) ld s3, 24(sp) |