From b0d8db08455d752cd74c29d1b7b765f1624ca4a2 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Thu, 14 Jul 2011 09:34:37 +0800 Subject: [PATCH 587/696] 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 Signed-off-by: Huang Ying Cc: Eric W. Biederman Cc: Vivek Goyal Link: http://lkml.kernel.org/r/1310607277-25029-1-git-send-email-ying.huang@intel.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/relocate_kernel_32.S | 2 ++ 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 4123553..36818f8 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 4de8f5b..7a6f3b3 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 -- 1.7.1