1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_X86_VSYSCALL_H 3 #define _ASM_X86_VSYSCALL_H 4 5 #include <linux/seqlock.h> 6 #include <uapi/asm/vsyscall.h> 7 #include <asm/page_types.h> 8 9 #ifdef CONFIG_X86_VSYSCALL_EMULATION 10 extern void map_vsyscall(void); 11 extern void set_vsyscall_pgtable_user_bits(pgd_t *root); 12 13 /* 14 * Called on instruction fetch fault in vsyscall page. 15 * Returns true if handled. 16 */ 17 extern bool emulate_vsyscall(unsigned long error_code, 18 struct pt_regs *regs, unsigned long address); 19 #else map_vsyscall(void)20static inline void map_vsyscall(void) {} emulate_vsyscall(unsigned long error_code,struct pt_regs * regs,unsigned long address)21static inline bool emulate_vsyscall(unsigned long error_code, 22 struct pt_regs *regs, unsigned long address) 23 { 24 return false; 25 } 26 #endif 27 28 /* 29 * The (legacy) vsyscall page is the long page in the kernel portion 30 * of the address space that has user-accessible permissions. 31 */ is_vsyscall_vaddr(unsigned long vaddr)32static inline bool is_vsyscall_vaddr(unsigned long vaddr) 33 { 34 return unlikely((vaddr & PAGE_MASK) == VSYSCALL_ADDR); 35 } 36 37 #endif /* _ASM_X86_VSYSCALL_H */ 38