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 |
20 | static inline void map_vsyscall(void) {} |
21 | static 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 | */ |
32 | static 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 | |