[PATCH bpf-next 2/2] bpf, mips: Modify check condition about tail call count

From: Tiezhu Yang
Date: Sat Oct 09 2021 - 06:58:21 EST


In emit_tail_call() of bpf_jit_comp32.c, "blez t2" (t2 <= 0) is not
consistent with the comment "t2 < 0", modify the check condition to
keep consistency.

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
arch/mips/net/bpf_jit_comp32.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/mips/net/bpf_jit_comp32.c b/arch/mips/net/bpf_jit_comp32.c
index 9d7041a..b887c01 100644
--- a/arch/mips/net/bpf_jit_comp32.c
+++ b/arch/mips/net/bpf_jit_comp32.c
@@ -1312,12 +1312,12 @@ static int emit_tail_call(struct jit_context *ctx)
emit(ctx, sltu, t1, ind, t1); /* t1 = ind < t1 */
emit(ctx, beqz, t1, get_offset(ctx, 1)); /* PC += off(1) if t1 == 0 */
/* (next insn delay slot) */
- /* if (TCC-- <= 0) goto out */
+ /* if (--TCC < 0) goto out */
emit(ctx, lw, t2, ctx->stack_size, MIPS_R_SP); /* t2 = *(SP + size) */
emit_load_delay(ctx); /* Load delay slot */
- emit(ctx, blez, t2, get_offset(ctx, 1)); /* PC += off(1) if t2 < 0 */
emit(ctx, addiu, t2, t2, -1); /* t2-- (delay slot) */
emit(ctx, sw, t2, ctx->stack_size, MIPS_R_SP); /* *(SP + size) = t2 */
+ emit(ctx, bltz, t2, get_offset(ctx, 1)); /* PC += off(1) if t2 < 0 */

/* prog = ary->ptrs[ind] */
off = offsetof(struct bpf_array, ptrs);
--
2.1.0