[PATCH 23/33] x86/asm/bpf: Create stack frames in bpf_jit.S
From: Josh Poimboeuf <hidden>
Date: 2016-01-21 22:56:56
Also in:
lkml
Subsystem:
bpf jit for x86 64-bit, bpf [general] (safe dynamic programs and tools), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
bpf_jit.S has several callable non-leaf functions which don't honor CONFIG_FRAME_POINTER, which can result in bad stack traces. Create a stack frame before the call instructions when CONFIG_FRAME_POINTER is enabled. Signed-off-by: Josh Poimboeuf <redacted> Cc: Alexei Starovoitov <ast@kernel.org> Cc: netdev@vger.kernel.org --- arch/x86/net/bpf_jit.S | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/arch/x86/net/bpf_jit.S b/arch/x86/net/bpf_jit.S
index eb4a3bd..f2a7faf 100644
--- a/arch/x86/net/bpf_jit.S
+++ b/arch/x86/net/bpf_jit.S@@ -8,6 +8,7 @@ * of the License. */ #include <linux/linkage.h> +#include <asm/frame.h> /* * Calling convention :
@@ -65,16 +66,18 @@ FUNC(sk_load_byte_positive_offset) /* rsi contains offset and can be scratched */ #define bpf_slow_path_common(LEN) \ + lea -MAX_BPF_STACK + 32(%rbp), %rdx;\ + FRAME_BEGIN; \ mov %rbx, %rdi; /* arg1 == skb */ \ push %r9; \ push SKBDATA; \ /* rsi already has offset */ \ mov $LEN,%ecx; /* len */ \ - lea - MAX_BPF_STACK + 32(%rbp),%rdx; \ call skb_copy_bits; \ test %eax,%eax; \ pop SKBDATA; \ - pop %r9; + pop %r9; \ + FRAME_END bpf_slow_path_word:
@@ -99,6 +102,7 @@ bpf_slow_path_byte: ret #define sk_negative_common(SIZE) \ + FRAME_BEGIN; \ mov %rbx, %rdi; /* arg1 == skb */ \ push %r9; \ push SKBDATA; \
@@ -108,6 +112,7 @@ bpf_slow_path_byte: test %rax,%rax; \ pop SKBDATA; \ pop %r9; \ + FRAME_END; \ jz bpf_error bpf_slow_path_word_neg:
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2.4.3