Commit-ID:  d21001cc15ba9f63b0334d60942278587471a451
Gitweb:     http://git.kernel.org/tip/d21001cc15ba9f63b0334d60942278587471a451
Author:     Josh Poimboeuf <[email protected]>
AuthorDate: Thu, 21 Jan 2016 16:49:27 -0600
Committer:  Ingo Molnar <[email protected]>
CommitDate: Wed, 24 Feb 2016 08:35:44 +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 <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Bernd Petrovitsch <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Chris J Arges <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michal Marek <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Pedro Alves <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: 
http://lkml.kernel.org/r/fa4c41976b438b51954cb8021f06bceb1d1d66cc.1453405861.git.jpoim...@redhat.com
Signed-off-by: Ingo Molnar <[email protected]>
---
 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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