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 bool emulate_vsyscall_pf(unsigned long error_code, struct pt_regs *regs, unsigned long address); 18 bool emulate_vsyscall_gp(struct pt_regs *regs); 19 #else 20 static inline void map_vsyscall(void) {} 21 static inline bool emulate_vsyscall_pf(unsigned long error_code, 22 struct pt_regs *regs, unsigned long address) 23 { 24 return false; 25 } 26 27 static inline bool emulate_vsyscall_gp(struct pt_regs *regs) 28 { 29 return false; 30 } 31 #endif 32 33 /* 34 * The (legacy) vsyscall page is the long page in the kernel portion 35 * of the address space that has user-accessible permissions. 36 */ 37 static inline bool is_vsyscall_vaddr(unsigned long vaddr) 38 { 39 return unlikely((vaddr & PAGE_MASK) == VSYSCALL_ADDR); 40 } 41 42 #endif /* _ASM_X86_VSYSCALL_H */ 43