diff options
| author | Huang Ying <ying.huang@intel.com> | 2008-08-15 00:40:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-15 08:35:42 -0700 |
| commit | fb45daa69d287b394eca1619b3fadff7c0215c71 (patch) | |
| tree | aeb5a247b105d3b7e7ef2cdb0db5743574d9c480 | |
| parent | 163f6876f5c3ff8215e900b93779e960a56b3694 (diff) | |
| download | lwn-fb45daa69d287b394eca1619b3fadff7c0215c71.tar.gz lwn-fb45daa69d287b394eca1619b3fadff7c0215c71.zip | |
kexec jump: check code size in control page
Kexec/Kexec-jump require code size in control page is less than
PAGE_SIZE/2. This patch add link-time checking for this.
ASSERT() of ld link script is used as the link-time checking mechanism.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/x86/kernel/machine_kexec_32.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_32.S | 10 | ||||
| -rw-r--r-- | arch/x86/kernel/vmlinux_32.lds.S | 8 | ||||
| -rw-r--r-- | include/asm-x86/kexec.h | 4 |
4 files changed, 20 insertions, 4 deletions
diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c index 466450167dea..5c8e7735c896 100644 --- a/arch/x86/kernel/machine_kexec_32.c +++ b/arch/x86/kernel/machine_kexec_32.c @@ -138,7 +138,7 @@ void machine_kexec(struct kimage *image) } control_page = page_address(image->control_code_page); - memcpy(control_page, relocate_kernel, PAGE_SIZE/2); + memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE); relocate_kernel_ptr = control_page; page_list[PA_CONTROL_PAGE] = __pa(control_page); diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S index 703310a99023..6f50664b2ba5 100644 --- a/arch/x86/kernel/relocate_kernel_32.S +++ b/arch/x86/kernel/relocate_kernel_32.S @@ -20,10 +20,11 @@ #define PAGE_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY) #define PAE_PGD_ATTR (_PAGE_PRESENT) -/* control_page + PAGE_SIZE/2 ~ control_page + PAGE_SIZE * 3/4 are - * used to save some data for jumping back +/* control_page + KEXEC_CONTROL_CODE_MAX_SIZE + * ~ control_page + PAGE_SIZE are used as data storage and stack for + * jumping back */ -#define DATA(offset) (PAGE_SIZE/2+(offset)) +#define DATA(offset) (KEXEC_CONTROL_CODE_MAX_SIZE+(offset)) /* Minimal CPU state */ #define ESP DATA(0x0) @@ -376,3 +377,6 @@ swap_pages: popl %ebx popl %ebp ret + + .globl kexec_control_code_size +.set kexec_control_code_size, . - relocate_kernel diff --git a/arch/x86/kernel/vmlinux_32.lds.S b/arch/x86/kernel/vmlinux_32.lds.S index cdb2363697d2..af5bdad84604 100644 --- a/arch/x86/kernel/vmlinux_32.lds.S +++ b/arch/x86/kernel/vmlinux_32.lds.S @@ -209,3 +209,11 @@ SECTIONS DWARF_DEBUG } + +#ifdef CONFIG_KEXEC +/* Link time checks */ +#include <asm/kexec.h> + +ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, + "kexec control code size is too big") +#endif diff --git a/include/asm-x86/kexec.h b/include/asm-x86/kexec.h index f6fb3d21883c..4246ab7dc988 100644 --- a/include/asm-x86/kexec.h +++ b/include/asm-x86/kexec.h @@ -41,6 +41,10 @@ # define PAGES_NR 17 #endif +#ifdef CONFIG_X86_32 +# define KEXEC_CONTROL_CODE_MAX_SIZE 2048 +#endif + #ifndef __ASSEMBLY__ #include <linux/string.h> |