Re: [PATCH bpf-next] powerpc/bpf: Fix warning for unused ori31_emitted
From: Christophe Leroy <hidden>
Date: 2025-06-19 14:50:35
Also in:
bpf, lkml
Le 19/06/2025 à 16:26, Luis Gerhorst a écrit :
Without this, the compiler (clang21) might emit a warning under W=1
because the variable ori31_emitted is set but never used if
CONFIG_PPC_BOOK3S_64=n.
Without this patch:
$ make -j $(nproc) W=1 ARCH=powerpc SHELL=/bin/bash arch/powerpc/net
[...]
CC arch/powerpc/net/bpf_jit_comp.o
CC arch/powerpc/net/bpf_jit_comp64.o
../arch/powerpc/net/bpf_jit_comp64.c: In function 'bpf_jit_build_body':
../arch/powerpc/net/bpf_jit_comp64.c:417:28: warning: variable 'ori31_emitted' set but not used [-Wunused-but-set-variable]
417 | bool sync_emitted, ori31_emitted;
| ^~~~~~~~~~~~~
AR arch/powerpc/net/built-in.a
With this patch:
[...]
CC arch/powerpc/net/bpf_jit_comp.o
CC arch/powerpc/net/bpf_jit_comp64.o
AR arch/powerpc/net/built-in.a
Fixes: dff883d9e93a ("bpf, arm64, powerpc: Change nospec to include v1 barrier")
Reported-by: kernel test robot <redacted>
Closes: https://lore.kernel.org/oe-kbuild-all/202506180402.uUXwVoSH-lkp@intel.com/ (local)
Signed-off-by: Luis Gerhorst <redacted>Reviewed-by: Christophe Leroy <redacted>
quoted hunk ↗ jump to hunk
--- arch/powerpc/net/bpf_jit_comp64.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 3665ff8bb4bc..a25a6ffe7d7c 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c@@ -820,13 +820,12 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code case BPF_ST | BPF_NOSPEC: sync_emitted = false; ori31_emitted = false; -#ifdef CONFIG_PPC_E500 - if (!bpf_jit_bypass_spec_v1()) { + if (IS_ENABLED(CONFIG_PPC_E500) && + !bpf_jit_bypass_spec_v1()) { EMIT(PPC_RAW_ISYNC()); EMIT(PPC_RAW_SYNC()); sync_emitted = true; } -#endif if (!bpf_jit_bypass_spec_v4()) { switch (stf_barrier) { case STF_BARRIER_EIEIO:@@ -849,10 +848,10 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct code break; } } -#ifdef CONFIG_PPC_BOOK3S_64 - if (!bpf_jit_bypass_spec_v1() && !ori31_emitted) + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && + !bpf_jit_bypass_spec_v1() && + !ori31_emitted) EMIT(PPC_RAW_ORI(_R31, _R31, 0)); -#endif break; /*base-commit: cd7312a78f36e981939abe1cd1f21d355e083dfe