diff options
| -rw-r--r-- | arch/i386/kernel/process.c | 4 | ||||
| -rw-r--r-- | include/asm-i386/system.h | 13 |
2 files changed, 14 insertions, 3 deletions
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index 2333aea..6081a10 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c @@ -308,9 +308,7 @@ void show_regs(struct pt_regs * regs) cr0 = read_cr0(); cr2 = read_cr2(); cr3 = read_cr3(); - if (current_cpu_data.x86 > 4) { - cr4 = read_cr4(); - } + cr4 = read_cr4_safe(); printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4); show_trace(NULL, ®s->esp); } diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h index 772f85d..88b4d5c 100644 --- a/include/asm-i386/system.h +++ b/include/asm-i386/system.h @@ -140,6 +140,19 @@ static inline unsigned long _get_base(char * addr) :"=r" (__dummy)); \ __dummy; \ }) + +#define read_cr4_safe() ({ \ + unsigned int __dummy; \ + /* This could fault if %cr4 does not exist */ \ + __asm__("1: movl %%cr4, %0 \n" \ + "2: \n" \ + ".section __ex_table,\"a\" \n" \ + ".long 1b,2b \n" \ + ".previous \n" \ + : "=r" (__dummy): "0" (0)); \ + __dummy; \ +}) + #define write_cr4(x) \ __asm__ __volatile__("movl %0,%%cr4": :"r" (x)); #define stts() write_cr0(8 | read_cr0()) |