1 /* SPDX-License-Identifier: GPL-2.0-only */
2 #ifndef _ASM_X86_ENTRY_COMMON_H
3 #define _ASM_X86_ENTRY_COMMON_H
5 #include <linux/user-return-notifier.h>
7 #include <asm/nospec-branch.h>
8 #include <asm/io_bitmap.h>
9 #include <asm/fpu/api.h>
11 /* Check that the stack and regs on entry from user mode are sane. */
12 static __always_inline void arch_check_user_regs(struct pt_regs *regs)
14 if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) {
16 * Make sure that the entry code gave us a sensible EFLAGS
17 * register. Native because we want to check the actual CPU
18 * state, not the interrupt state as imagined by Xen.
20 unsigned long flags = native_save_fl();
21 unsigned long mask = X86_EFLAGS_DF | X86_EFLAGS_NT;
24 * For !SMAP hardware we patch out CLAC on entry.
26 if (boot_cpu_has(X86_FEATURE_SMAP) ||
27 (IS_ENABLED(CONFIG_64_BIT) && boot_cpu_has(X86_FEATURE_XENPV)))
28 mask |= X86_EFLAGS_AC;
30 WARN_ON_ONCE(flags & mask);
32 /* We think we came from user mode. Make sure pt_regs agrees. */
33 WARN_ON_ONCE(!user_mode(regs));
36 * All entries from user mode (except #DF) should be on the
37 * normal thread stack and should have user pt_regs in the
40 WARN_ON_ONCE(!on_thread_stack());
41 WARN_ON_ONCE(regs != task_pt_regs(current));
44 #define arch_check_user_regs arch_check_user_regs
46 #define ARCH_SYSCALL_EXIT_WORK (_TIF_SINGLESTEP)
48 static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
49 unsigned long ti_work)
51 if (ti_work & _TIF_USER_RETURN_NOTIFY)
52 fire_user_return_notifiers();
54 if (unlikely(ti_work & _TIF_IO_BITMAP))
55 tss_update_io_bitmap();
57 fpregs_assert_state_consistent();
58 if (unlikely(ti_work & _TIF_NEED_FPU_LOAD))
63 * Compat syscalls set TS_COMPAT. Make sure we clear it before
64 * returning to user mode. We need to clear it *after* signal
65 * handling, because syscall restart has a fixup for compat
66 * syscalls. The fixup is exercised by the ptrace_syscall_32
69 * We also need to clear TS_REGS_POKED_I386: the 32-bit tracer
70 * special case only applies after poking regs and before the
71 * very next return to user mode.
73 current_thread_info()->status &= ~(TS_COMPAT | TS_I386_REGS_POKED);
76 #define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
78 static __always_inline void arch_exit_to_user_mode(void)
80 mds_user_clear_cpu_buffers();
82 #define arch_exit_to_user_mode arch_exit_to_user_mode