From: Jan Kratochvil <jan.kratochvil@redhat.com>
Date: Tue, 16 Nov 2010 02:47:22 +0000 (+0100)
Subject: Fix incorrect backtrace unwinding through thread_start() on x86_64
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fb8fb8464c2b5a44b69e62bcc3211b9c769416da;p=thirdparty%2Fglibc.git

Fix incorrect backtrace unwinding through thread_start() on x86_64

Provide CFI for the outermost clone() to ensure proper unwinding stop
of gdb.
---

diff --git a/ChangeLog b/ChangeLog
index c7174be1062..9f0a7a94c31 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2006-11-30  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	[BZ #6693]
+	* sysdeps/unix/sysv/linux/x86_64/clone.S: Provide CFI for the outermost
+	`clone' function to ensure proper unwinding stop of gdb.
+
 2010-05-31  Petr Baudis  <pasky@suse.cz>
 
 	[BZ #11149]
diff --git a/sysdeps/unix/sysv/linux/x86_64/clone.S b/sysdeps/unix/sysv/linux/x86_64/clone.S
index db42f209c9f..8a12b09035e 100644
--- a/sysdeps/unix/sysv/linux/x86_64/clone.S
+++ b/sysdeps/unix/sysv/linux/x86_64/clone.S
@@ -89,9 +89,6 @@ L(pseudo_end):
 	ret
 
 L(thread_start):
-	cfi_startproc;
-	/* Clearing frame pointer is insufficient, use CFI.  */
-	cfi_undefined (rip);
 	/* Clear the frame pointer.  The ABI suggests this be done, to mark
 	   the outermost frame obviously.  */
 	xorl	%ebp, %ebp
@@ -116,7 +113,6 @@ L(thread_start):
 	/* Call exit with return value from function call. */
 	movq	%rax, %rdi
 	call	HIDDEN_JUMPTARGET (_exit)
-	cfi_endproc;
 
 	cfi_startproc;
 PSEUDO_END (BP_SYM (__clone))