On 20/02/26 12:09 pm, Hari Bathini wrote:
Do not increment tailcall count, if tailcall did not succeed due to missing BPF program. Fixes: ce0761419fae ("powerpc/bpf: Implement support for tail calls") Cc: [email protected] Signed-off-by: Hari Bathini <[email protected]> --- * No changes since v1. arch/powerpc/net/bpf_jit_comp64.c | 39 +++++++++++++++++-------------- 1 file changed, 21 insertions(+), 18 deletions(-) diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index b1a3945ccc9f..44ce8a8783f9 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -522,9 +522,30 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o/** tail_call_info++; <- Actual value of tcc here + * Writeback this updated value only if tailcall succeeds. */ EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 1));+ /* prog = array->ptrs[index]; */+ EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_2), b2p_index, 8)); + EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), b2p_bpf_array)); + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + offsetof(struct bpf_array, ptrs))); + + /* + * if (prog == NULL) + * goto out; + */ + EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_2), 0)); + PPC_BCC_SHORT(COND_EQ, out); + + /* goto *(prog->bpf_func + prologue_size); */ + EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + offsetof(struct bpf_prog, bpf_func))); + EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_2), bpf_to_ppc(TMP_REG_2), + FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size)); + EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_2))); + /* * Before writing updated tail_call_info, distinguish if current frame * is storing a reference to tail_call_info or actual tcc value in @@ -539,24 +560,6 @@ static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 o /* Writeback updated value to tail_call_info */ EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_2), 0));- /* prog = array->ptrs[index]; */- EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_1), b2p_index, 8)); - EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), b2p_bpf_array)); - EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_array, ptrs))); - - /* - * if (prog == NULL) - * goto out; - */ - EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_1), 0)); - PPC_BCC_SHORT(COND_EQ, out); - - /* goto *(prog->bpf_func + prologue_size); */ - EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_prog, bpf_func))); - EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), - FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size)); - EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1))); - /* tear down stack, restore NVRs, ... */ bpf_jit_emit_common_epilogue(image, ctx);
Tested this by patch, Please add below tag. Tested-by: Venkat Rao Bagalkote <[email protected]> Regards, Venkat.
