Messages in this thread | | | Date | Wed, 13 Aug 2008 13:48:59 +1000 | From | Simon Horman <> | Subject | Re: [PATCH] kexec jump: fix code size checking |
| |
On Wed, Aug 13, 2008 at 11:05:15AM +0800, Huang Ying wrote: > On Wed, 2008-08-13 at 12:47 +1000, Simon Horman wrote: > > On Wed, Aug 13, 2008 at 09:04:35AM +0800, Huang Ying wrote: > > > Fix building issue when CONFIG_KEXEC=n. Thanks to Vivek Goyal for his > > > reminding. > > > > > > Signed-off-by: Huang Ying <ying.huang@intel.com> > > > > > > --- > > > include/asm-x86/kexec.h | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > --- a/include/asm-x86/kexec.h > > > +++ b/include/asm-x86/kexec.h > > > @@ -43,6 +43,9 @@ > > > > > > #ifdef CONFIG_X86_32 > > > # define KEXEC_CONTROL_CODE_MAX_SIZE 2048 > > > +# ifndef CONFIG_KEXEC > > > +# define kexec_control_code_size 0 > > > +# endif > > > #endif > > > > > > #ifndef __ASSEMBLY__ > > > > Is it impossible to skip the linker check in the !CONFIG_KEXEC case? > > It is possible. I think there are several ways to do that. > > 1) use #ifdef in vmlinux_32.lds.S, such as: > > #ifdef CONFIG_KEXEC > ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, > "kexec control code size is too big") > #endif > > 2) #define a macro for kexec check ld script in asm/kexec.h, such as: > > #define LD_CHECK_KEXEC() ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, \ > "kexec control code size is too big") > > and use that in vmlinux_32.lds.S. > > 3) #define kexec_control_code_size 0. So that the check can be passed > always. And, code size = 0 is reasonable for no code (CONFIG_KEXEC=n). > > > I think 3) is better. What do you think about?
Hi Huang,
I think that 1) with possibly the slight variation of moving #include <asm/kexec.h> inside #ifdef CONFIG_KEXEC is better because it avoids introducing kexec_control_code_size, which is currently only used in arch/x86/kernel/relocate_kernel_32.S and arch/x86/kernel/vmlinux_32.lds.S, into kexec.h.
/* Link time checks */
#ifdef CONFIG_KEXEC #include <asm/kexec.h>
ASSERT(kexec_control_code_size <= KEXEC_CONTROL_CODE_MAX_SIZE, "kexec control code size is too big") #endif
My second preference would be 3) as it seems simpler than 2).
| |