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: dff883d9e93a ("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>

diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 3665ff8bb4bc944aa03cc16dc58bc23d01cb4ee8..a25a6ffe7d7ccc9b721546230417fa80295d8752 100644 (file)
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -820,13 +820,12 @@ emit_clear:
                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 @@ emit_clear:
                                        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;
 
                /*