.

sysdeps/unix/sysv/linux/x86_64/sigaction.c

@@ -1,5 +1,5 @@
 /* POSIX.1 `sigaction' call for Linux/x86-64.
-   Copyright (C) 2001, 2002, 2003, 2005, 2006 Free Software Foundation, Inc.
+   Copyright (C) 2001, 2002, 2003, 2005 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -33,14 +33,17 @@
    translate it here.  */
 #include <kernel_sigaction.h>
 
-#include "ucontext_i.h"
-
 /* We do not globally define the SA_RESTORER flag so do it here.  */
 #define SA_RESTORER 0x04000000
 
 /* Using the hidden attribute here does not change the code but it
    helps to avoid warnings.  */
+#if defined HAVE_HIDDEN && defined HAVE_VISIBILITY_ATTRIBUTE \
+    && !defined HAVE_BROKEN_VISIBILITY_ATTRIBUTE
 extern void restore_rt (void) asm ("__restore_rt") attribute_hidden;
+#else
+static void restore_rt (void) asm ("__restore_rt");
+#endif
 
 
 /* If ACT is not NULL, change the action for SIG to *ACT.
@@ -92,95 +95,18 @@ weak_alias (__libc_sigaction, sigaction)
    signal handlers work right.  Important are both the names
    (__restore_rt) and the exact instruction sequence.
    If you ever feel the need to make any changes, please notify the
-   appropriate GDB maintainer.
-
-   The unwind information starts a byte before __restore_rt, so that
-   it is found when unwinding, to get an address the unwinder assumes
-   will be in the middle of a call instruction.  See the Linux kernel
-   (the i386 vsyscall, in particular) for an explanation of the complex
-   unwind information used here in order to get the traditional CFA.
-   We do not restore cs - it's only stored as two bytes here so that's
-   a bit tricky.  We don't use the gas cfi directives, so that we can
-   reliably add .cfi_signal_frame.  */
-
-#define do_cfa_expr						\
-  "	.byte 0x0f\n"		/* DW_CFA_def_cfa_expression */	\
-  "	.uleb128 2f-1f\n"	/* length */			\
-  "1:	.byte 0x77\n"		/* DW_OP_breg7 */		\
-  "	.sleb128 " CFI_STRINGIFY (oRSP) "\n"			\
-  "	.byte 0x06\n"		/* DW_OP_deref */		\
-  "2:"
-
-#define do_expr(regno, offset)					\
-  "	.byte 0x10\n"		/* DW_CFA_expression */		\
-  "	.uleb128 " CFI_STRINGIFY (regno) "\n"			\
-  "	.uleb128 2f-1f\n"	/* length */			\
-  "1:	.byte 0x77\n"		/* DW_OP_breg7 */		\
-  "	.sleb128 " CFI_STRINGIFY (offset) "\n"			\
-  "2:"
+   appropriate GDB maintainer.  */
 
 #define RESTORE(name, syscall) RESTORE2 (name, syscall)
 # define RESTORE2(name, syscall) \
-asm									\
-  (									\
-   /* `nop' for debuggers assuming `call' should not disalign the code.  */ \
-   "	nop\n"								\
-   ".align 16\n"							\
-   ".LSTART_" #name ":\n"						\
-   "	.type __" #name ",@function\n"					\
-   "__" #name ":\n"							\
-   "	movq $" #syscall ", %rax\n"					\
-   "	syscall\n"							\
-   ".LEND_" #name ":\n"							\
-   ".section .eh_frame,\"a\",@progbits\n"				\
-   ".LSTARTFRAME_" #name ":\n"						\
-   "	.long .LENDCIE_" #name "-.LSTARTCIE_" #name "\n"		\
-   ".LSTARTCIE_" #name ":\n"						\
-   "	.long 0\n"	/* CIE ID */					\
-   "	.byte 1\n"	/* Version number */				\
-   "	.string \"zRS\"\n" /* NUL-terminated augmentation string */	\
-   "	.uleb128 1\n"	/* Code alignment factor */			\
-   "	.sleb128 -8\n"	/* Data alignment factor */			\
-   "	.uleb128 16\n"	/* Return address register column (rip) */	\
-   /* Augmentation value length */					\
-   "	.uleb128 .LENDAUGMNT_" #name "-.LSTARTAUGMNT_" #name "\n"	\
-   ".LSTARTAUGMNT_" #name ":\n"						\
-   "	.byte 0x1b\n"	/* DW_EH_PE_pcrel|DW_EH_PE_sdata4. */		\
-   ".LENDAUGMNT_" #name ":\n"						\
-   "	.align 8\n"							\
-   ".LENDCIE_" #name ":\n"						\
-   "	.long .LENDFDE_" #name "-.LSTARTFDE_" #name "\n" /* FDE len */	\
-   ".LSTARTFDE_" #name ":\n"						\
-   "	.long .LSTARTFDE_" #name "-.LSTARTFRAME_" #name "\n" /* CIE */	\
-   /* `LSTART_' is subtracted 1 as debuggers assume a `call' here.  */	\
-   "	.long (.LSTART_" #name "-1)-.\n" /* PC-relative start addr.  */	\
-   "	.long .LEND_" #name "-(.LSTART_" #name "-1)\n"			\
-   "	.uleb128 0\n"			/* FDE augmentation length */	\
-   do_cfa_expr								\
-   do_expr (8 /* r8 */, oR8)						\
-   do_expr (9 /* r9 */, oR9)						\
-   do_expr (10 /* r10 */, oR10)						\
-   do_expr (11 /* r11 */, oR11)						\
-   do_expr (12 /* r12 */, oR12)						\
-   do_expr (13 /* r13 */, oR13)						\
-   do_expr (14 /* r14 */, oR14)						\
-   do_expr (15 /* r15 */, oR15)						\
-   do_expr (5 /* rdi */, oRDI)						\
-   do_expr (4 /* rsi */, oRSI)						\
-   do_expr (6 /* rbp */, oRBP)						\
-   do_expr (3 /* rbx */, oRBX)						\
-   do_expr (1 /* rdx */, oRDX)						\
-   do_expr (0 /* rax */, oRAX)						\
-   do_expr (2 /* rcx */, oRCX)						\
-   do_expr (7 /* rsp */, oRSP)						\
-   do_expr (16 /* rip */, oRIP)						\
-   /* libgcc-4.1.1 has only `DWARF_FRAME_REGISTERS == 17'.  */		\
-   /* do_expr (49 |* rflags *|, oEFL) */				\
-   /* `cs'/`ds'/`fs' are unaligned and a different size.  */		\
-   /* gas: Error: register save offset not a multiple of 8  */		\
-   "	.align 8\n"							\
-   ".LENDFDE_" #name ":\n"						\
-   "	.previous\n"							\
+asm						\
+  (						\
+   ".align 16\n"				\
+   CFI_STARTPROC "\n"				\
+   "__" #name ":\n"				\
+   "	movq $" #syscall ", %rax\n"		\
+   "	syscall\n"				\
+   CFI_ENDPROC "\n"				\
    );
 /* The return code for realtime-signals.  */
 RESTORE (restore_rt, __NR_rt_sigreturn)