| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _ASM_X86_VSYSCALL_H |
| #define _ASM_X86_VSYSCALL_H |
| |
| #include <linux/seqlock.h> |
| #include <uapi/asm/vsyscall.h> |
| #include <asm/page_types.h> |
| |
| #ifdef CONFIG_X86_VSYSCALL_EMULATION |
| extern void map_vsyscall(void); |
| extern void set_vsyscall_pgtable_user_bits(pgd_t *root); |
| |
| /* |
| * Called on instruction fetch fault in vsyscall page. |
| * Returns true if handled. |
| */ |
| extern bool emulate_vsyscall(unsigned long error_code, |
| struct pt_regs *regs, unsigned long address); |
| #else |
| static inline void map_vsyscall(void) {} |
| static inline bool emulate_vsyscall(unsigned long error_code, |
| struct pt_regs *regs, unsigned long address) |
| { |
| return false; |
| } |
| #endif |
| |
| /* |
| * The (legacy) vsyscall page is the long page in the kernel portion |
| * of the address space that has user-accessible permissions. |
| */ |
| static inline bool is_vsyscall_vaddr(unsigned long vaddr) |
| { |
| return unlikely((vaddr & PAGE_MASK) == VSYSCALL_ADDR); |
| } |
| |
| #endif /* _ASM_X86_VSYSCALL_H */ |
