Commit-ID:  45670be075ce96566bc6b6ca0b579f17ed6f94f3
Gitweb:     http://git.kernel.org/tip/45670be075ce96566bc6b6ca0b579f17ed6f94f3
Author:     Josh Poimboeuf <jpoim...@redhat.com>
AuthorDate: Thu, 21 Jan 2016 16:49:27 -0600
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Tue, 23 Feb 2016 09:03:59 +0100

x86/asm/bpf: Create stack frames in bpf_jit.S

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 <jpoim...@redhat.com>
Acked-by: Alexei Starovoitov <a...@kernel.org>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Arnaldo Carvalho de Melo <a...@kernel.org>
Cc: Bernd Petrovitsch <be...@petrovitsch.priv.at>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Chris J Arges <chris.j.ar...@canonical.com>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Jiri Slaby <jsl...@suse.cz>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Michal Marek <mma...@suse.cz>
Cc: Namhyung Kim <namhy...@gmail.com>
Cc: Pedro Alves <pal...@redhat.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: live-patch...@vger.kernel.org
Cc: net...@vger.kernel.org
Link: 
http://lkml.kernel.org/r/fa4c41976b438b51954cb8021f06bceb1d1d66cc.1453405861.git.jpoim...@redhat.com
Signed-off-by: Ingo Molnar <mi...@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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