diff options
Diffstat (limited to 'include/asm-i386/system.h')
| -rw-r--r-- | include/asm-i386/system.h | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h index db398d88b1d95..098bcee94e389 100644 --- a/include/asm-i386/system.h +++ b/include/asm-i386/system.h @@ -11,9 +11,14 @@ struct task_struct; /* one of the stranger aspects of C forward declarations.. */ extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struct task_struct *next)); +/* + * Saving eflags is important. It switches not only IOPL between tasks, + * it also protects other tasks from NT leaking through sysenter etc. + */ #define switch_to(prev,next,last) do { \ unsigned long esi,edi; \ - asm volatile("pushl %%ebp\n\t" \ + asm volatile("pushfl\n\t" /* Save flags */ \ + "pushl %%ebp\n\t" \ "movl %%esp,%0\n\t" /* save ESP */ \ "movl %5,%%esp\n\t" /* restore ESP */ \ "movl $1f,%1\n\t" /* save EIP */ \ @@ -21,6 +26,7 @@ extern struct task_struct * FASTCALL(__switch_to(struct task_struct *prev, struc "jmp __switch_to\n" \ "1:\t" \ "popl %%ebp\n\t" \ + "popfl" \ :"=m" (prev->thread.esp),"=m" (prev->thread.eip), \ "=a" (last),"=S" (esi),"=D" (edi) \ :"m" (next->thread.esp),"m" (next->thread.eip), \ @@ -82,10 +88,6 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \ #define savesegment(seg, value) \ asm volatile("mov %%" #seg ",%0":"=rm" (value)) -/* - * Clear and set 'TS' bit respectively - */ -#define clts() __asm__ __volatile__ ("clts") #define read_cr0() ({ \ unsigned int __dummy; \ __asm__ __volatile__( \ @@ -94,7 +96,7 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \ __dummy; \ }) #define write_cr0(x) \ - __asm__ __volatile__("movl %0,%%cr0": :"r" (x)); + __asm__ __volatile__("movl %0,%%cr0": :"r" (x)) #define read_cr2() ({ \ unsigned int __dummy; \ @@ -104,7 +106,7 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \ __dummy; \ }) #define write_cr2(x) \ - __asm__ __volatile__("movl %0,%%cr2": :"r" (x)); + __asm__ __volatile__("movl %0,%%cr2": :"r" (x)) #define read_cr3() ({ \ unsigned int __dummy; \ @@ -114,7 +116,7 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \ __dummy; \ }) #define write_cr3(x) \ - __asm__ __volatile__("movl %0,%%cr3": :"r" (x)); + __asm__ __volatile__("movl %0,%%cr3": :"r" (x)) #define read_cr4() ({ \ unsigned int __dummy; \ @@ -123,7 +125,6 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \ :"=r" (__dummy)); \ __dummy; \ }) - #define read_cr4_safe() ({ \ unsigned int __dummy; \ /* This could fault if %cr4 does not exist */ \ @@ -135,15 +136,19 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" \ : "=r" (__dummy): "0" (0)); \ __dummy; \ }) - #define write_cr4(x) \ - __asm__ __volatile__("movl %0,%%cr4": :"r" (x)); + __asm__ __volatile__("movl %0,%%cr4": :"r" (x)) + +/* + * Clear and set 'TS' bit respectively + */ +#define clts() __asm__ __volatile__ ("clts") #define stts() write_cr0(8 | read_cr0()) #endif /* __KERNEL__ */ #define wbinvd() \ - __asm__ __volatile__ ("wbinvd": : :"memory"); + __asm__ __volatile__ ("wbinvd": : :"memory") static inline unsigned long get_limit(unsigned long segment) { @@ -454,8 +459,6 @@ static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long l #define set_mb(var, value) do { var = value; barrier(); } while (0) #endif -#define set_wmb(var, value) do { var = value; wmb(); } while (0) - #include <linux/irqflags.h> /* |