On 05/08/25 1:04 pm, Christophe Leroy wrote:

Le 05/08/2025 à 08:27, Saket Kumar Bhaskar a écrit :

quoted

bpf_jit_emit_probe_mem_store() is introduced to emit instructions for
storing memory values depending on the size (byte, halfword,
word, doubleword).

Build break with this patch

  CC      arch/powerpc/net/bpf_jit_comp64.o
arch/powerpc/net/bpf_jit_comp64.c:395:12: error: 
'bpf_jit_emit_probe_mem_store' defined but not used 
[-Werror=unused-function]
 static int bpf_jit_emit_probe_mem_store(struct codegen_context *ctx, 
u32 src_reg, s16 off,
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[4]: *** [scripts/Makefile.build:287: 
arch/powerpc/net/bpf_jit_comp64.o] Error 1

I tried this on top of bpf-next, and for me build passed.

Note: I applied 
https://lore.kernel.org/bpf/20250717202935.29018-2-puranjay@kernel.org/ (local) 
before applying current patch.

gcc version 14.2.1 20250110

uname -r: 6.16.0-gf2844c7fdb07

bpf-next repo: 
https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next

HEAD:

commit f3af62b6cee8af9f07012051874af2d2a451f0e5 (origin/master, origin/HEAD)
Author: Tao Chen [off-list ref]
Date:   Wed Jul 23 22:44:42 2025 +0800

     bpftool: Add bash completion for token argument


Build Success logs:

   TEST-OBJ [test_progs-cpuv4] xdp_vlan.test.o
   TEST-OBJ [test_progs-cpuv4] xdpwall.test.o
   TEST-OBJ [test_progs-cpuv4] xfrm_info.test.o
   BINARY   bench
   BINARY   test_maps
   BINARY   test_progs
   BINARY   test_progs-no_alu32
   BINARY   test_progs-cpuv4


Regards,

Venkat.

quoted

Signed-off-by: Saket Kumar Bhaskar <redacted>
---
  arch/powerpc/net/bpf_jit_comp64.c | 30 ++++++++++++++++++++++++++++++
  1 file changed, 30 insertions(+)

diff --git a/arch/powerpc/net/bpf_jit_comp64.c 

b/arch/powerpc/net/bpf_jit_comp64.c
index 025524378443..489de21fe3d6 100644

--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c

@@ -409,6 +409,36 @@ asm (

  "        blr                ;"
  );
  +static int bpf_jit_emit_probe_mem_store(struct codegen_context 
*ctx, u32 src_reg, s16 off,
+                    u32 code, u32 *image)
+{
+    u32 tmp1_reg = bpf_to_ppc(TMP_REG_1);
+    u32 tmp2_reg = bpf_to_ppc(TMP_REG_2);
+
+    switch (BPF_SIZE(code)) {
+    case BPF_B:
+        EMIT(PPC_RAW_STB(src_reg, tmp1_reg, off));
+        break;
+    case BPF_H:
+        EMIT(PPC_RAW_STH(src_reg, tmp1_reg, off));
+        break;
+    case BPF_W:
+        EMIT(PPC_RAW_STW(src_reg, tmp1_reg, off));
+        break;
+    case BPF_DW:
+        if (off % 4) {
+            EMIT(PPC_RAW_LI(tmp2_reg, off));
+            EMIT(PPC_RAW_STDX(src_reg, tmp1_reg, tmp2_reg));
+        } else {
+            EMIT(PPC_RAW_STD(src_reg, tmp1_reg, off));
+        }
+        break;
+    default:
+        return -EINVAL;
+    }
+    return 0;
+}
+
  static int emit_atomic_ld_st(const struct bpf_insn insn, struct 
codegen_context *ctx, u32 *image)
  {
      u32 code = insn.code;