linux-unwind.h (x86_frob_update_context): New function.

	* config/i386/linux-unwind.h (x86_frob_update_context): New function.
	(MD_FROB_UPDATE_CONTEXT): Define.

From-SVN: r154141

gcc/ChangeLog

+2009-11-13  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* config/i386/linux-unwind.h (x86_frob_update_context): New function.
+	(MD_FROB_UPDATE_CONTEXT): Define.
+
 2009-11-12  Eric Botcazou  <ebotcazou@adacore.com>
             Laurent GUERBY  <laurent@guerby.net>
 

gcc/config/i386/linux-unwind.h

@@ -172,6 +172,25 @@ x86_fallback_frame_state (struct _Unwind_Context *context,
   fs->signal_frame = 1;
   return _URC_NO_REASON;
 }
+
+#define MD_FROB_UPDATE_CONTEXT x86_frob_update_context
+
+/* Fix up for kernels that have vDSO, but don't have S flag in it.  */
+
+static void
+x86_frob_update_context (struct _Unwind_Context *context,
+			 _Unwind_FrameState *fs ATTRIBUTE_UNUSED)
+{
+  unsigned char *pc = context->ra;
+
+  /* movl $__NR_rt_sigreturn,%eax ; {int $0x80 | syscall}  */
+  if (*(unsigned char *)(pc+0) == 0xb8
+      && *(unsigned int *)(pc+1) == 173
+      && (*(unsigned short *)(pc+5) == 0x80cd
+	  || *(unsigned short *)(pc+5) == 0x050f))
+    _Unwind_SetSignalFrame (context, 1);
+}
+
 #endif /* not glibc 2.0 */
 #endif /* ifdef __x86_64__  */
 #endif /* ifdef inhibit_libc  */