Re: [PATCH bpf-next v3 3/6] bpf: fix the usage of BPF_TRAMP_F_SKIP_FRAME

On Fri, Dec 19, 2025 at 9:49 PM Andreas Schwab [off-list ref] wrote:

On Dez 19 2025, Menglong Dong wrote:

quoted

diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index 5f9457e910e8..09b70bf362d3 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c

@@ -1134,7 +1134,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
      store_args(nr_arg_slots, args_off, ctx);

      /* skip to actual body of traced function */
-     if (flags & BPF_TRAMP_F_ORIG_STACK)
+     if (flags & BPF_TRAMP_F_CALL_ORIG)
              orig_call += RV_FENTRY_NINSNS * 4;

There are now three occurrences of that condition, and only the third
one uses orig_call.  How about merging them?

Yeah, I think we can merge it to the third one, like this:

diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index 5f9457e910e8..37888abee70c 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c

@@ -1133,10 +1133,6 @@ static int __arch_prepare_bpf_trampoline(struct

bpf_tramp_image *im,

        store_args(nr_arg_slots, args_off, ctx);

-       /* skip to actual body of traced function */
-       if (flags & BPF_TRAMP_F_ORIG_STACK)
-               orig_call += RV_FENTRY_NINSNS * 4;
-
        if (flags & BPF_TRAMP_F_CALL_ORIG) {
                emit_imm(RV_REG_A0, ctx->insns ? (const s64)im :
RV_MAX_COUNT_IMM, ctx);
                ret = emit_call((const u64)__bpf_tramp_enter, true, ctx);

@@ -1171,6 +1167,8 @@ static int __arch_prepare_bpf_trampoline(struct

bpf_tramp_image *im,
        }

        if (flags & BPF_TRAMP_F_CALL_ORIG) {
+               /* skip to actual body of traced function */
+               orig_call += RV_FENTRY_NINSNS * 4;
                restore_args(min_t(int, nr_arg_slots,
RV_MAX_REG_ARGS), args_off, ctx);
                restore_stack_args(nr_arg_slots - RV_MAX_REG_ARGS,
args_off, stk_arg_off, ctx);
                ret = emit_call((const u64)orig_call, true, ctx);

--
Andreas Schwab, schwab@linux-m68k.org
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