patches/glibc/ports-2.12.1/120-i386-x86_64-revert-clone-cfi.patch
author "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Sun Jul 17 22:43:07 2011 +0200 (2011-07-17)
changeset 2893 a8a65758664f
permissions -rw-r--r--
cc/gcc: do not use the core pass-2 to build the baremetal compiler

In case we build a baremetal compiler, use the standard passes:
- core_cc is used to build the C library;
- as such, it is meant to run on build, not host;
- the final compiler is meant to run on host;

As the current final compiler step can not build a baremetal compiler,
call the core backend from the final step.

NB: Currently, newlib is built during the start_files pass, so we have
to have a core compiler by then... Once we can build the baremetal
compiler from the final cc step, then we can move the newlib build to
the proper step, and then get rid of the core pass-1 static compiler...

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-2.12.1.orig/sysdeps/unix/sysv/linux/i386/clone.S glibc-2.12.1/sysdeps/unix/sysv/linux/i386/clone.S
    15 --- glibc-2.12.1.orig/sysdeps/unix/sysv/linux/i386/clone.S	2006-12-04 00:12:36.000000000 +0100
    16 +++ glibc-2.12.1/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-2.12.1.orig/sysdeps/unix/sysv/linux/x86_64/clone.S glibc-2.12.1/sysdeps/unix/sysv/linux/x86_64/clone.S
    36 --- glibc-2.12.1.orig/sysdeps/unix/sysv/linux/x86_64/clone.S	2006-12-04 00:12:36.000000000 +0100
    37 +++ glibc-2.12.1/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))