| Message ID | 20230912224654.6556-5-puranjay12@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: verifier: stop emitting zext for LDX | expand |
| Context | Check | Description |
|---|---|---|
| bpf/vmtest-bpf-next-PR | pending | PR summary |
| bpf/vmtest-bpf-next-VM_Test-4 | success | Logs for build for x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-3 | success | Logs for build for x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-1 | success | Logs for build for aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-0 | success | Logs for ShellCheck |
| bpf/vmtest-bpf-next-VM_Test-2 | pending | Logs for build for s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-5 | success | Logs for set-matrix |
| netdev/series_format | success | Posting correctly formatted |
| netdev/tree_selection | success | Clearly marked for bpf-next |
| netdev/fixes_present | success | Fixes tag not required for -next series |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 9 this patch: 9 |
| netdev/cc_maintainers | success | CCed 21 of 21 maintainers |
| netdev/build_clang | success | Errors and warnings before: 9 this patch: 9 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/deprecated_api | success | None detected |
| netdev/check_selftest | success | No net selftest shell script |
| netdev/verify_fixes | success | No Fixes tag |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 9 this patch: 9 |
| netdev/checkpatch | warning | WARNING: line length of 100 exceeds 80 columns WARNING: line length of 96 exceeds 80 columns |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index 7f91ea064c08..0a952a2cfaac 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -936,14 +936,13 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * PPC_BCC_SHORT(COND_GT, (ctx->idx + 4) * 4); EMIT(PPC_RAW_LI(dst_reg, 0)); /* - * For BPF_DW case, "li reg_h,0" would be needed when - * !fp->aux->verifier_zext. Emit NOP otherwise. + * For BPF_DW case, "li reg_h,0" would be needed emit NOP otherwise. * * Note that "li reg_h,0" is emitted for BPF_B/H/W case, * if necessary. So, jump there insted of emitting an * additional "li reg_h,0" instruction. */ - if (size == BPF_DW && !fp->aux->verifier_zext) + if (size == BPF_DW) EMIT(PPC_RAW_LI(dst_reg_h, 0)); else EMIT(PPC_RAW_NOP()); @@ -974,7 +973,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * break; } - if (size != BPF_DW && !fp->aux->verifier_zext) + if (size != BPF_DW) EMIT(PPC_RAW_LI(dst_reg_h, 0)); if (BPF_MODE(code) == BPF_PROBE_MEM) { @@ -982,20 +981,12 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * int jmp_off = 4; /* - * In case of BPF_DW, two lwz instructions are emitted, one - * for higher 32-bit and another for lower 32-bit. So, set - * ex->insn to the first of the two and jump over both - * instructions in fixup. - * - * Similarly, with !verifier_zext, two instructions are - * emitted for BPF_B/H/W case. So, set ex->insn to the - * instruction that could fault and skip over both - * instructions. + * Two instructions are emitted for LDX. + * So, set ex->insn to the instruction that could fault and skip + * over both instructions. */ - if (size == BPF_DW || !fp->aux->verifier_zext) { - insn_idx -= 1; - jmp_off += 4; - } + insn_idx -= 1; + jmp_off += 4; ret = bpf_add_extable_entry(fp, image, pass, ctx, insn_idx, jmp_off, dst_reg);
The JITs should not depend on the verifier for zero extending the upper 32 bits of the destination register when loading a byte, half-word, or word. A following patch will make the verifier stop patching zext instructions after LDX. Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> --- arch/powerpc/net/bpf_jit_comp32.c | 25 ++++++++----------------- 1 file changed, 8 insertions(+), 17 deletions(-)