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authorHuang Ying <ying.huang@intel.com>2011-07-14 09:34:37 +0800
committerIngo Molnar <mingo@elte.hu>2011-07-21 11:19:28 +0200
commit050438ed5a05b25cdf287f5691e56a58c2606997 (patch)
tree318f9566ba9b060dc61459f12a8fd4f5d9e8c4e4
parentcf6ace16a3cd8b728fb0afa68368fd40bbeae19f (diff)
kexec, x86: Fix incorrect jump back address if not preserving context
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> Cc: <stable@kernel.org> Link: http://lkml.kernel.org/r/1310607277-25029-1-git-send-email-ying.huang@intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
-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 41235531b11..36818f8ec2b 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 4de8f5b3d47..7a6f3b3be3c 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