On Tue, Aug 12, 2008 at 11:14:28AM +0800, Huang Ying wrote: > 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. > > Signed-off-by: Huang Ying <ying.huang at intel.com> > > --- > arch/x86/kernel/machine_kexec_32.c | 2 +- > arch/x86/kernel/relocate_kernel_32.S | 10 +++++++--- > arch/x86/kernel/vmlinux_32.lds.S | 6 ++++++ > include/asm-x86/kexec.h | 4 ++++ > 4 files changed, 18 insertions(+), 4 deletions(-) > > --- 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); > --- 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 > --- 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> > --- a/arch/x86/kernel/vmlinux_32.lds.S > +++ b/arch/x86/kernel/vmlinux_32.lds.S > @@ -209,3 +209,9 @@ SECTIONS > > DWARF_DEBUG > } > + > +/* Link time checks */ > +#include <asm/kexec.h> > + > +ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, > + "kexec control code size is too big") Hi Huang, Will above ASSERT() still compile if CONFIG_KEXEC=n? If yes, then it looks good to me. Acked-by: Vivek Goyal <vgoyal at redhat.com> Thanks Vivek
