From fdfaf64e75397567257e1051931f9a3377360665 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Mon, 10 Mar 2014 15:56:51 -0700 Subject: [PATCH] x86: bpf_jit: support negative offsets Commit a998d4342337 claimed to introduce negative offset support to x86 jit, but it couldn't be working, since at the time of the execution of LD+ABS or LD+IND instructions via call into bpf_internal_load_pointer_neg_helper() the %edx (3rd argument of this func) had junk value instead of access size in bytes (1 or 2 or 4). Store size into %edx instead of %ecx (what original commit intended to do) Fixes: a998d4342337 ("bpf jit: Let the x86 jit handle negative offsets") Signed-off-by: Alexei Starovoitov Cc: Jan Seiffert Cc: Eric Dumazet Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- arch/x86/net/bpf_jit.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/net/bpf_jit.S b/arch/x86/net/bpf_jit.S index 877b9a1b2152..01495755701b 100644 --- a/arch/x86/net/bpf_jit.S +++ b/arch/x86/net/bpf_jit.S @@ -140,7 +140,7 @@ bpf_slow_path_byte_msh: push %r9; \ push SKBDATA; \ /* rsi already has offset */ \ - mov $SIZE,%ecx; /* size */ \ + mov $SIZE,%edx; /* size */ \ call bpf_internal_load_pointer_neg_helper; \ test %rax,%rax; \ pop SKBDATA; \ -- 2.30.2