patches/glibc/ports-2.10.1/120-i386-x86_64-revert-clone-cfi.patch
author "Yann E. MORIN" <yann.morin.1998@free.fr>
Mon Feb 13 21:47:25 2012 +0100 (2012-02-13)
changeset 2883 cea814c9932a
permissions -rw-r--r--
libc/glibc: do not consume parameters when parsing them

Currently, there are two constructs used to parse arguments in
glibc backends, one that consumes args as they are parsed, and
one that does not.

Always use the construct that does not eat args as they are parsed.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
     1 revert cfi additions to clone on i386/x86_64 to workaround problems in
     2 gcc's unwinder code.  this is not a bug in glibc, it triggers problems
     3 elsewhere.  this cfi code does not gain us a whole lot anyways.
     4 
     5 http://gcc.gnu.org/ml/gcc/2006-12/msg00293.html
     6 
     7 Index: sysdeps/unix/sysv/linux/i386/clone.S
     8 ===================================================================
     9 RCS file: /cvs/glibc/libc/sysdeps/unix/sysv/linux/i386/clone.S,v
    10 retrieving revision 1.27
    11 retrieving revision 1.26
    12 diff -u -p -r1.27 -r1.26
    13 
    14 diff -durN glibc-2.10.1.orig/sysdeps/unix/sysv/linux/i386/clone.S glibc-2.10.1/sysdeps/unix/sysv/linux/i386/clone.S
    15 --- glibc-2.10.1.orig/sysdeps/unix/sysv/linux/i386/clone.S	2006-12-04 00:12:36.000000000 +0100
    16 +++ glibc-2.10.1/sysdeps/unix/sysv/linux/i386/clone.S	2009-11-13 00:49:45.000000000 +0100
    17 @@ -120,9 +120,6 @@
    18  	ret
    19  
    20  L(thread_start):
    21 -	cfi_startproc;
    22 -	/* Clearing frame pointer is insufficient, use CFI.  */
    23 -	cfi_undefined (eip);
    24  	/* Note: %esi is zero.  */
    25  	movl	%esi,%ebp	/* terminate the stack frame */
    26  #ifdef RESET_PID
    27 @@ -155,7 +152,6 @@
    28  	jmp	L(haspid)
    29  	.previous
    30  #endif
    31 -	cfi_endproc;
    32  
    33  	cfi_startproc
    34  PSEUDO_END (BP_SYM (__clone))
    35 diff -durN glibc-2.10.1.orig/sysdeps/unix/sysv/linux/x86_64/clone.S glibc-2.10.1/sysdeps/unix/sysv/linux/x86_64/clone.S
    36 --- glibc-2.10.1.orig/sysdeps/unix/sysv/linux/x86_64/clone.S	2006-12-04 00:12:36.000000000 +0100
    37 +++ glibc-2.10.1/sysdeps/unix/sysv/linux/x86_64/clone.S	2009-11-13 00:49:45.000000000 +0100
    38 @@ -89,9 +89,6 @@
    39  	ret
    40  
    41  L(thread_start):
    42 -	cfi_startproc;
    43 -	/* Clearing frame pointer is insufficient, use CFI.  */
    44 -	cfi_undefined (rip);
    45  	/* Clear the frame pointer.  The ABI suggests this be done, to mark
    46  	   the outermost frame obviously.  */
    47  	xorl	%ebp, %ebp
    48 @@ -116,7 +113,6 @@
    49  	/* Call exit with return value from function call. */
    50  	movq	%rax, %rdi
    51  	call	HIDDEN_JUMPTARGET (_exit)
    52 -	cfi_endproc;
    53  
    54  	cfi_startproc;
    55  PSEUDO_END (BP_SYM (__clone))