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| author | Huang Ying <ying.huang@intel.com> | 2011-07-14 09:34:37 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-08-04 21:58:37 -0700 |
| commit | b0d8db08455d752cd74c29d1b7b765f1624ca4a2 (patch) | |
| tree | f87726dacadc7e963eb02f969827b114061ea3aa | |
| parent | 40a3e9966c347b2e722785aecd9c0165457d61f3 (diff) | |
| download | lwn-b0d8db08455d752cd74c29d1b7b765f1624ca4a2.tar.gz lwn-b0d8db08455d752cd74c29d1b7b765f1624ca4a2.zip | |
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.S | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 2 |
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 |