[PATCH powerpc/next 01/17] powerpc/bpf: Skip branch range validation during first pass
From: Naveen N. Rao <hidden>
Date: 2022-02-14 11:13:13
Also in:
bpf
Subsystem:
bpf jit for powerpc (32-bit and 64-bit), bpf [general] (safe dynamic programs and tools), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Hari Bathini, Christophe Leroy, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Madhavan Srinivasan, Linus Torvalds
During the first pass, addrs[] is still being populated. So, all branches to following instructions will appear to be going to the start of the JIT program. Ignore branch range validation for such instructions and assume those to be in range. Branch range validation will happen during the second pass after addrs[] is setup properly. Signed-off-by: Naveen N. Rao <redacted> --- arch/powerpc/net/bpf_jit.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
index b20a2a83a6e75b..9cdd33d6be4cc0 100644
--- a/arch/powerpc/net/bpf_jit.h
+++ b/arch/powerpc/net/bpf_jit.h@@ -27,7 +27,7 @@ #define PPC_JMP(dest) \ do { \ long offset = (long)(dest) - (ctx->idx * 4); \ - if (!is_offset_in_branch_range(offset)) { \ + if ((dest) != 0 && !is_offset_in_branch_range(offset)) { \ pr_err_ratelimited("Branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ return -ERANGE; \ } \
@@ -41,7 +41,7 @@ #define PPC_BCC_SHORT(cond, dest) \ do { \ long offset = (long)(dest) - (ctx->idx * 4); \ - if (!is_offset_in_cond_branch_range(offset)) { \ + if ((dest) != 0 && !is_offset_in_cond_branch_range(offset)) { \ pr_err_ratelimited("Conditional branch offset 0x%lx (@%u) out of range\n", offset, ctx->idx); \ return -ERANGE; \ } \
--
2.35.1