diff options
Diffstat (limited to 'include/asm-i386/system.h')
| -rw-r--r-- | include/asm-i386/system.h | 54 |
1 files changed, 19 insertions, 35 deletions
diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h index 19cc79c9a35..098bcee94e3 100644 --- a/include/asm-i386/system.h +++ b/include/asm-i386/system.h @@ -1,7 +1,6 @@ #ifndef __ASM_SYSTEM_H #define __ASM_SYSTEM_H -#include <linux/config.h> #include <linux/kernel.h> #include <asm/segment.h> #include <asm/cpufeature.h> @@ -12,9 +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 */ \ @@ -22,6 +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), \ @@ -83,10 +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__( \ @@ -95,7 +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; \ @@ -105,7 +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; \ @@ -115,7 +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; \ @@ -124,7 +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 */ \ @@ -136,15 +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) { @@ -428,7 +432,7 @@ static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long l * does not enforce ordering, since there is no data dependency between * the read of "a" and the read of "b". Therefore, on some CPUs, such * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb() - * in cases like thiswhere there are no data dependencies. + * in cases like this where there are no data dependencies. **/ #define read_barrier_depends() do { } while(0) @@ -455,27 +459,7 @@ 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) - -/* interrupt control.. */ -#define local_save_flags(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */); } while (0) -#define local_irq_restore(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory", "cc"); } while (0) -#define local_irq_disable() __asm__ __volatile__("cli": : :"memory") -#define local_irq_enable() __asm__ __volatile__("sti": : :"memory") -/* used in the idle loop; sti takes one instruction cycle to complete */ -#define safe_halt() __asm__ __volatile__("sti; hlt": : :"memory") -/* used when interrupts are already enabled or to shutdown the processor */ -#define halt() __asm__ __volatile__("hlt": : :"memory") - -#define irqs_disabled() \ -({ \ - unsigned long flags; \ - local_save_flags(flags); \ - !(flags & (1<<9)); \ -}) - -/* For spinlocks etc */ -#define local_irq_save(x) __asm__ __volatile__("pushfl ; popl %0 ; cli":"=g" (x): /* no input */ :"memory") +#include <linux/irqflags.h> /* * disable hlt during certain critical i/o operations |