On Wed, Aug 06, 2025 at 08:59:59AM +0200, Christophe Leroy wrote:
Le 05/08/2025 à 13:59, Venkat Rao Bagalkote a écrit :
On 05/08/25 1:04 pm, Christophe Leroy wrote:
Le 05/08/2025 à 08:27, Saket Kumar Bhaskar a écrit :
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.
Build of _this_ patch (alone) passed ?
This patch defines a static function but doesn't use it, so the build must breaks because of that, unless you have set CONFIG_PPC_DISABLE_WERROR.
Following patch starts using this function so then the build doesn't break anymore. But until next patch is applied the build doesn't work. Both patches have to be squashed together in order to not break bisectability of the kernel.
Christophe
Got it Chris, will squash both the patches together in v2.
Note: I applied https://eur01.safelinks.protection.outlook.com/? url=https%3A%2F%2Flore.kernel.org%2Fbpf%2F20250717202935.29018-2- puranjay%40kernel.org%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C0468473019834e07ef2b08ddd4179b9c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638899920058624267%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=iZLg9NUWxtH3vO1STI8wRYLzwvhohd2KKTAGYDe3WnM%3D&reserved=0 before applying current patch.
gcc version 14.2.1 20250110
uname -r: 6.16.0-gf2844c7fdb07
bpf-next repo: https://eur01.safelinks.protection.outlook.com/? url=https%3A%2F%2Fkernel.googlesource.com%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fbpf%2Fbpf-next&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7C0468473019834e07ef2b08ddd4179b9c%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638899920058644309%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=OrMauttrzPbaFYhzKdkH5l%2FltISc95MwitnUC7YLhJQ%3D&reserved=0
HEAD:
commit f3af62b6cee8af9f07012051874af2d2a451f0e5 (origin/master, origin/ HEAD) Author: Tao Chen chen.dylane@linux.dev 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.
Signed-off-by: Saket Kumar Bhaskar skb99@linux.ibm.com
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;