diff options
| author | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:18:27 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-04-14 13:19:04 +0200 |
| commit | 6ac1ef482d7ae0c690f1640bf6eb818ff9a2d91e (patch) | |
| tree | 021cc9f6b477146fcebe6f3be4752abfa2ba18a9 /arch/x86/include/asm/segment.h | |
| parent | 682968e0c425c60f0dde37977e5beb2b12ddc4cc (diff) | |
| parent | a385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (diff) | |
Merge branch 'perf/core' into perf/uprobes
Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/segment.h')
| -rw-r--r-- | arch/x86/include/asm/segment.h | 58 |
1 files changed, 56 insertions, 2 deletions
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index 5e641715c3f..165466233ab 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -212,7 +212,61 @@ #ifdef __KERNEL__ #ifndef __ASSEMBLY__ extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10]; -#endif -#endif + +/* + * Load a segment. Fall back on loading the zero + * segment if something goes wrong.. + */ +#define loadsegment(seg, value) \ +do { \ + unsigned short __val = (value); \ + \ + asm volatile(" \n" \ + "1: movl %k0,%%" #seg " \n" \ + \ + ".section .fixup,\"ax\" \n" \ + "2: xorl %k0,%k0 \n" \ + " jmp 1b \n" \ + ".previous \n" \ + \ + _ASM_EXTABLE(1b, 2b) \ + \ + : "+r" (__val) : : "memory"); \ +} while (0) + +/* + * Save a segment register away + */ +#define savesegment(seg, value) \ + asm("mov %%" #seg ",%0":"=r" (value) : : "memory") + +/* + * x86_32 user gs accessors. + */ +#ifdef CONFIG_X86_32 +#ifdef CONFIG_X86_32_LAZY_GS +#define get_user_gs(regs) (u16)({unsigned long v; savesegment(gs, v); v;}) +#define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v)) +#define task_user_gs(tsk) ((tsk)->thread.gs) +#define lazy_save_gs(v) savesegment(gs, (v)) +#define lazy_load_gs(v) loadsegment(gs, (v)) +#else /* X86_32_LAZY_GS */ +#define get_user_gs(regs) (u16)((regs)->gs) +#define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0) +#define task_user_gs(tsk) (task_pt_regs(tsk)->gs) +#define lazy_save_gs(v) do { } while (0) +#define lazy_load_gs(v) do { } while (0) +#endif /* X86_32_LAZY_GS */ +#endif /* X86_32 */ + +static inline unsigned long get_limit(unsigned long segment) +{ + unsigned long __limit; + asm("lsll %1,%0" : "=r" (__limit) : "r" (segment)); + return __limit + 1; +} + +#endif /* !__ASSEMBLY__ */ +#endif /* __KERNEL__ */ #endif /* _ASM_X86_SEGMENT_H */ |