Commit e30329b8 authored Jun 19, 2025 by Luis Gerhorst Committed by Alexei Starovoitov Jun 19, 2025

powerpc/bpf: Fix warning for unused ori31_emitted



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: dff883d9 ("bpf, arm64, powerpc: Change nospec to include v1 barrier")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202506180402.uUXwVoSH-lkp@intel.com/


Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/20250619142647.2157017-1-luis.gerhorst@fau.de


Signed-off-by: Alexei Starovoitov <ast@kernel.org>

parent cd7312a7

arch/powerpc/net/bpf_jit_comp64.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -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;

		/*