[PATCH 1/2] arm64: bpf: fix JIT frame pointer setup
From: Yang Shi <hidden>
Date: 2015-11-12 22:16:23
Also in:
linux-arm-kernel, lkml
Subsystem:
arm64 port (aarch64 architecture), bpf jit for arm64, bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Catalin Marinas, Will Deacon, Daniel Borkmann, Alexei Starovoitov, Puranjay Mohan, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
BPF fp should point to the top of the BPF prog stack. The original implementation made it point to the bottom incorrectly. Move A64_SP to fp before reserve BPF prog stack space. CC: Zi Shen Lim <redacted> CC: Xi Wang <xi.wang@gmail.com> Signed-off-by: Yang Shi <redacted> --- arch/arm64/net/bpf_jit_comp.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index a44e529..ac8b548 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c@@ -161,12 +161,12 @@ static void build_prologue(struct jit_ctx *ctx) if (ctx->tmp_used) emit(A64_PUSH(tmp1, tmp2, A64_SP), ctx); - /* Set up BPF stack */ - emit(A64_SUB_I(1, A64_SP, A64_SP, stack_size), ctx); - /* Set up frame pointer */ emit(A64_MOV(1, fp, A64_SP), ctx); + /* Set up BPF stack */ + emit(A64_SUB_I(1, A64_SP, A64_SP, stack_size), ctx); + /* Clear registers A and X */ emit_a64_mov_i64(ra, 0, ctx); emit_a64_mov_i64(rx, 0, ctx);
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2.0.2