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authorHuang Ying <ying.huang@intel.com>2011-07-14 09:34:37 +0800
committerGreg Kroah-Hartman <gregkh@suse.de>2011-08-08 10:23:11 -0700
commit1932c7417939ce69f98926c204220fafbce31a7a (patch)
tree728ab239a7b45414223f708bd010046559d1755c
parent8d858047ce89c147eb9f14457cb31265967d110e (diff)
downloadlinux-linaro-stable-1932c7417939ce69f98926c204220fafbce31a7a.tar.gz
kexec, x86: Fix incorrect jump back address if not preserving context
commit 050438ed5a05b25cdf287f5691e56a58c2606997 upstream. In kexec jump support, jump back address passed to the kexeced kernel via function calling ABI, that is, the function call return address is the jump back entry. Furthermore, jump back entry == 0 should be used to signal that the jump back or preserve context is not enabled in the original kernel. But in the current implementation the stack position used for function call return address is not cleared context preservation is disabled. The patch fixes this bug. Reported-and-tested-by: Yin Kangkai <kangkai.yin@intel.com> Signed-off-by: Huang Ying <ying.huang@intel.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Link: http://lkml.kernel.org/r/1310607277-25029-1-git-send-email-ying.huang@intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--arch/x86/kernel/relocate_kernel_32.S2
-rw-r--r--arch/x86/kernel/relocate_kernel_64.S2
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S
index 41235531b11c..36818f8ec2be 100644
--- a/arch/x86/kernel/relocate_kernel_32.S
+++ b/arch/x86/kernel/relocate_kernel_32.S
@@ -97,6 +97,8 @@ relocate_kernel:
ret
identity_mapped:
+ /* set return address to 0 if not preserving context */
+ pushl $0
/* store the start address on the stack */
pushl %edx
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index 4de8f5b3d476..7a6f3b3be3cf 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -100,6 +100,8 @@ relocate_kernel:
ret
identity_mapped:
+ /* set return address to 0 if not preserving context */
+ pushq $0
/* store the start address on the stack */
pushq %rdx