diff options
Diffstat (limited to 'include/asm-i386/kexec.h')
| -rw-r--r-- | include/asm-i386/kexec.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/asm-i386/kexec.h b/include/asm-i386/kexec.h index d80d446498fb..8fb1defd98c6 100644 --- a/include/asm-i386/kexec.h +++ b/include/asm-i386/kexec.h @@ -2,6 +2,7 @@ #define _I386_KEXEC_H #include <asm/fixmap.h> +#include <asm/ptrace.h> /* * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return. @@ -27,4 +28,48 @@ #define MAX_NOTE_BYTES 1024 +/* CPU does not save ss and esp on stack if execution is already + * running in kernel mode at the time of NMI occurrence. This code + * fixes it. + */ +static inline void crash_fixup_ss_esp(struct pt_regs *newregs, + struct pt_regs *oldregs) +{ + memcpy(newregs, oldregs, sizeof(*newregs)); + newregs->esp = (unsigned long)&(oldregs->esp); + __asm__ __volatile__( + "xorl %%eax, %%eax\n\t" + "movw %%ss, %%ax\n\t" + :"=a"(newregs->xss)); +} + +/* + * This function is responsible for capturing register states if coming + * via panic otherwise just fix up the ss and esp if coming via kernel + * mode exception. + */ +static inline void crash_setup_regs(struct pt_regs *newregs, + struct pt_regs *oldregs) +{ + if (oldregs) + crash_fixup_ss_esp(newregs, oldregs); + else { + __asm__ __volatile__("movl %%ebx,%0" : "=m"(newregs->ebx)); + __asm__ __volatile__("movl %%ecx,%0" : "=m"(newregs->ecx)); + __asm__ __volatile__("movl %%edx,%0" : "=m"(newregs->edx)); + __asm__ __volatile__("movl %%esi,%0" : "=m"(newregs->esi)); + __asm__ __volatile__("movl %%edi,%0" : "=m"(newregs->edi)); + __asm__ __volatile__("movl %%ebp,%0" : "=m"(newregs->ebp)); + __asm__ __volatile__("movl %%eax,%0" : "=m"(newregs->eax)); + __asm__ __volatile__("movl %%esp,%0" : "=m"(newregs->esp)); + __asm__ __volatile__("movw %%ss, %%ax;" :"=a"(newregs->xss)); + __asm__ __volatile__("movw %%cs, %%ax;" :"=a"(newregs->xcs)); + __asm__ __volatile__("movw %%ds, %%ax;" :"=a"(newregs->xds)); + __asm__ __volatile__("movw %%es, %%ax;" :"=a"(newregs->xes)); + __asm__ __volatile__("pushfl; popl %0" :"=m"(newregs->eflags)); + + newregs->eip = (unsigned long)current_text_addr(); + } +} + #endif /* _I386_KEXEC_H */ |