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 <jpoimboe@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/fa4c41976b438b51954cb8021f06bceb1d1d66cc.1453405861.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 7 insertions, 2 deletions

diff --git a/arch/x86/net/bpf_jit.S b/arch/x86/net/bpf_jit.S
index eb4a3bd293eb..f2a7faf4706e 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: