From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001 From: Yuval Adam <_@yuv.al> Date: Wed, 30 Aug 2017 08:25:59 +0000 Subject: Initial file dump from open source release --- arch/x86/include/asm/vsyscall.h | 44 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 arch/x86/include/asm/vsyscall.h (limited to 'arch/x86/include/asm/vsyscall.h') diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h new file mode 100644 index 00000000..2874be9a --- /dev/null +++ b/arch/x86/include/asm/vsyscall.h @@ -0,0 +1,44 @@ +#ifndef _ASM_X86_VSYSCALL_H +#define _ASM_X86_VSYSCALL_H + +#include +#include + +#define VGETCPU_RDTSCP 1 +#define VGETCPU_LSL 2 + +/* kernel space (writeable) */ +extern int vgetcpu_mode; +extern struct timezone sys_tz; + +#include + +extern void map_vsyscall(void); + +/* + * Called on instruction fetch fault in vsyscall page. + * Returns true if handled. + */ +extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address); + +#ifdef CONFIG_X86_64 + +#define VGETCPU_CPU_MASK 0xfff + +static inline unsigned int __getcpu(void) +{ + unsigned int p; + + if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) { + /* Load per CPU data from RDTSCP */ + native_read_tscp(&p); + } else { + /* Load per CPU data from GDT */ + asm volatile ("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG)); + } + + return p; +} +#endif /* CONFIG_X86_64 */ + +#endif /* _ASM_X86_VSYSCALL_H */ -- cgit v1.3.1