Separate getcontext implementation for x86

src/Makefile.am

@@ -230,7 +230,7 @@ libunwind_la_SOURCES_x86 = $(libunwind_la_SOURCES_x86_common)		\
 	x86/Lcreate_addr_space.c x86/Lget_save_loc.c x86/Lglobal.c	\
 	x86/Linit.c x86/Linit_local.c x86/Linit_remote.c		\
 	x86/Lget_proc_info.c x86/Lregs.c				\
-	x86/Lresume.c x86/Lstep.c x86/getcontext.S
+	x86/Lresume.c x86/Lstep.c
 
 # The list of files that go into libunwind-x86:
 libunwind_x86_la_SOURCES_x86 = $(libunwind_la_SOURCES_x86_common)	\
@@ -351,6 +351,7 @@ if OS_LINUX
  libunwind_la_SOURCES_os	      = $(libunwind_la_SOURCES_os_linux)
  libunwind_la_SOURCES_os_local	      = $(libunwind_la_SOURCES_os_linux_local)
  libunwind_la_SOURCES_x86_os          = x86/Gos-linux.c
+ libunwind_x86_la_SOURCES_os	      = x86/getcontext-linux.S
  libunwind_la_SOURCES_x86_os_local    = x86/Los-linux.c
  libunwind_la_SOURCES_x86_64_os       = x86_64/Gos-linux.c
  libunwind_la_SOURCES_x86_64_os_local = x86_64/Los-linux.c
@@ -365,6 +366,7 @@ if OS_FREEBSD
  libunwind_la_SOURCES_os	= $(libunwind_la_SOURCES_os_freebsd)
  libunwind_la_SOURCES_os_local	= $(libunwind_la_SOURCES_os_freebsd_local)
  libunwind_la_SOURCES_x86_os          = x86/Gos-freebsd.c
+ libunwind_x86_la_SOURCES_os	      = x86/getcontext-freebsd.S
  libunwind_la_SOURCES_x86_os_local    = x86/Los-freebsd.c
  libunwind_la_SOURCES_x86_64_os       = x86_64/Gos-freebsd.c
  libunwind_la_SOURCES_x86_64_os_local = x86_64/Los-freebsd.c
@@ -424,7 +426,7 @@ endif
 else
 if ARCH_X86
  lib_LTLIBRARIES_arch = libunwind-x86.la
- libunwind_la_SOURCES = $(libunwind_la_SOURCES_x86)
+ libunwind_la_SOURCES = $(libunwind_la_SOURCES_x86) $(libunwind_x86_la_SOURCES_os)
  libunwind_x86_la_SOURCES = $(libunwind_x86_la_SOURCES_x86)
  libunwind_x86_la_LDFLAGS = $(COMMON_SO_LDFLAGS) -version-info $(SOVERSION)
 if !REMOTE_ONLY

src/x86/getcontext-freebsd.S

@@ -1,6 +1,4 @@
 /* libunwind - a platform-independent unwind library
-   Copyright (C) 2009 Google, Inc
-	Contributed by Paul Pluzhnikov <ppluzhnikov@google.com>
    Copyright (C) 2010 Konstantin Belousov <kib@freebsd.org>
 
 This file is part of libunwind.
@@ -26,46 +24,9 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 
 #include "offsets.h"
 
-/*  int _Ux86_getcontext (ucontext_t *ucp)
-
-  Saves the machine context in UCP necessary for libunwind.
-  Unlike the libc implementation, we don't save the signal mask
-  and hence avoid the cost of a system call per unwind.
-
-*/
-
 	.global _Ux86_getcontext
 	.type _Ux86_getcontext, @function
 _Ux86_getcontext:
-#if defined __linux__
-	mov	4(%esp),%eax  /* ucontext_t* */
-
-	/* EAX is not preserved. */
-	movl	$0, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EAX_OFF)(%eax)
-
-	movl	%ebx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EBX_OFF)(%eax)
-	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ECX_OFF)(%eax)
-	movl	%edx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EDX_OFF)(%eax)
-	movl	%edi, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EDI_OFF)(%eax)
-	movl	%esi, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ESI_OFF)(%eax)
-	movl	%ebp, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EBP_OFF)(%eax)
-
-	movl	(%esp), %ecx
-	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EIP_OFF)(%eax)
-
-	leal	4(%esp), %ecx		/* Exclude the return address.  */
-	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ESP_OFF)(%eax)
-
-	/* glibc getcontext saves FS, but not GS */
-	xorl	%ecx, %ecx
-	movw	%fs, %cx
-	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_FS_OFF)(%eax)
-
-	leal	LINUX_UC_FPREGS_MEM_OFF(%eax), %ecx
-	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_FPSTATE_OFF)(%eax)
-	fnstenv	(%ecx)
-	fldenv	(%ecx)
-#elif defined __FreeBSD__
 	pushl	%eax
 	mov	8(%esp),%eax  /* ucontext_t* */
 	popl	FREEBSD_UC_MCONTEXT_EAX_OFF(%eax)
@@ -110,9 +71,8 @@ _Ux86_getcontext:
 
 	movl	$FREEBSD_UC_MCONTEXT_MC_LEN_VAL,\
 		FREEBSD_UC_MCONTEXT_MC_LEN_OFF(%eax)
-#endif
 
-	xor	%eax, %eax
+	xorl	%eax, %eax
 	ret
 	.size	_Ux86_getcontext, . - _Ux86_getcontext
 

src/x86/getcontext-linux.S

@@ -0,0 +1,72 @@
+/* libunwind - a platform-independent unwind library
+   Copyright (C) 2009 Google, Inc
+	Contributed by Paul Pluzhnikov <ppluzhnikov@google.com>
+
+This file is part of libunwind.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+
+#include "offsets.h"
+
+/*  int _Ux86_getcontext (ucontext_t *ucp)
+
+  Saves the machine context in UCP necessary for libunwind.
+  Unlike the libc implementation, we don't save the signal mask
+  and hence avoid the cost of a system call per unwind.
+
+*/
+
+	.global _Ux86_getcontext
+	.type _Ux86_getcontext, @function
+_Ux86_getcontext:
+	mov	4(%esp),%eax  /* ucontext_t* */
+
+	/* EAX is not preserved. */
+	movl	$0, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EAX_OFF)(%eax)
+
+	movl	%ebx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EBX_OFF)(%eax)
+	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ECX_OFF)(%eax)
+	movl	%edx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EDX_OFF)(%eax)
+	movl	%edi, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EDI_OFF)(%eax)
+	movl	%esi, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ESI_OFF)(%eax)
+	movl	%ebp, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EBP_OFF)(%eax)
+
+	movl	(%esp), %ecx
+	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_EIP_OFF)(%eax)
+
+	leal	4(%esp), %ecx		/* Exclude the return address.  */
+	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_ESP_OFF)(%eax)
+
+	/* glibc getcontext saves FS, but not GS */
+	xorl	%ecx, %ecx
+	movw	%fs, %cx
+	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_FS_OFF)(%eax)
+
+	leal	LINUX_UC_FPREGS_MEM_OFF(%eax), %ecx
+	movl	%ecx, (LINUX_UC_MCONTEXT_OFF+LINUX_SC_FPSTATE_OFF)(%eax)
+	fnstenv	(%ecx)
+	fldenv	(%ecx)
+
+	xor	%eax, %eax
+	ret
+	.size	_Ux86_getcontext, . - _Ux86_getcontext
+
+	/* We do not need executable stack.  */
+	.section        .note.GNU-stack,"",@progbits