about summary refs log tree commit diff
path: root/sysdeps/unix/sysv/linux/x86_64/__start_context.S
diff options
context:
space:
mode:
authorH.J. Lu <hjl.tools@gmail.com>2015-07-12 14:38:58 -0700
committerH.J. Lu <hjl.tools@gmail.com>2015-08-05 08:36:12 -0700
commit8e1f346462d8c1b238a7c6bb501c45b381a45e4d (patch)
tree9bb295abee3821601b7f076aec181c3f29ad570f /sysdeps/unix/sysv/linux/x86_64/__start_context.S
parent3b8d2eb7f8435c73692f55f95e9a0ef27015b6c3 (diff)
downloadglibc-8e1f346462d8c1b238a7c6bb501c45b381a45e4d.tar.gz
glibc-8e1f346462d8c1b238a7c6bb501c45b381a45e4d.tar.xz
glibc-8e1f346462d8c1b238a7c6bb501c45b381a45e4d.zip
Align stack to 16 bytes when calling __setcontext
Don't use pop to restore %rdi so that stack is aligned to 16 bytes
when calling __setcontext.

	[BZ #18661]
	* sysdeps/unix/sysv/linux/x86_64/__start_context.S
	(__start_context): Don't use pop to restore %rdi so that stack
	is aligned to 16 bytes when calling __setcontext.
Diffstat (limited to 'sysdeps/unix/sysv/linux/x86_64/__start_context.S')
-rw-r--r--sysdeps/unix/sysv/linux/x86_64/__start_context.S4
1 files changed, 2 insertions, 2 deletions
diff --git a/sysdeps/unix/sysv/linux/x86_64/__start_context.S b/sysdeps/unix/sysv/linux/x86_64/__start_context.S
index 52a5afa9a6..96366e0536 100644
--- a/sysdeps/unix/sysv/linux/x86_64/__start_context.S
+++ b/sysdeps/unix/sysv/linux/x86_64/__start_context.S
@@ -31,8 +31,8 @@ ENTRY(__start_context)
 	   on the stack pointer for the next context.  */
 	movq	%rbx, %rsp
 
-	popq	%rdi			/* This is the next context.  */
-	cfi_adjust_cfa_offset(-8)
+	/* Don't use pop here so that stack is aligned to 16 bytes.  */
+	movq	(%rsp), %rdi		/* This is the next context.  */
 	testq	%rdi, %rdi
 	je	2f			/* If it is zero exit.  */