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| author | Alexei Starovoitov <ast@plumgrid.com> | 2014-03-10 15:56:51 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-31 09:58:13 -0700 |
| commit | 32f139873e89672cbd5b28f5da944201e86fdb92 (patch) | |
| tree | 82d7b1abeefc6a6b141e25e3361d4f7bed49650a | |
| parent | 21680f38b5994c8d839380e7cf002496a51962a2 (diff) | |
| download | lwn-32f139873e89672cbd5b28f5da944201e86fdb92.tar.gz lwn-32f139873e89672cbd5b28f5da944201e86fdb92.zip | |
x86: bpf_jit: support negative offsets
commit fdfaf64e75397567257e1051931f9a3377360665 upstream.
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 <ast@plumgrid.com>
Cc: Jan Seiffert <kaffeemonster@googlemail.com>
Cc: Eric Dumazet <edumazet@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/net/bpf_jit.S | 2 |
1 files changed, 1 insertions, 1 deletions
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; \ |