[PATCH v2 4/9] powerpc/bpf/32: BPF prog is never called with more than one arg

From: Christophe Leroy
Date: Wed Feb 01 2023 - 05:07:00 EST


BPF progs are never called with more than one argument, plus the
tail call count as a second argument when needed.

So, no need to retrieve 9th and 10th argument (5th 64 bits argument)
from the stack in prologue.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/net/bpf_jit_comp32.c | 6 ------
1 file changed, 6 deletions(-)

diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c
index 7f54d37bede6..7c129fe810f5 100644
--- a/arch/powerpc/net/bpf_jit_comp32.c
+++ b/arch/powerpc/net/bpf_jit_comp32.c
@@ -159,12 +159,6 @@ void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
if (bpf_is_seen_register(ctx, i))
EMIT(PPC_RAW_STW(i, _R1, bpf_jit_stack_offsetof(ctx, i)));

- /* If needed retrieve arguments 9 and 10, ie 5th 64 bits arg.*/
- if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_5))) {
- EMIT(PPC_RAW_LWZ(bpf_to_ppc(BPF_REG_5) - 1, _R1, BPF_PPC_STACKFRAME(ctx)) + 8);
- EMIT(PPC_RAW_LWZ(bpf_to_ppc(BPF_REG_5), _R1, BPF_PPC_STACKFRAME(ctx)) + 12);
- }
-
/* Setup frame pointer to point to the bpf stack area */
if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP))) {
EMIT(PPC_RAW_LI(bpf_to_ppc(BPF_REG_FP) - 1, 0));
--
2.39.1