Line data    Source code

       1             : /* SPDX-License-Identifier: GPL-2.0-only */
       2             : #ifndef _ASM_X86_ENTRY_COMMON_H
       3             : #define _ASM_X86_ENTRY_COMMON_H
       4             : 
       5             : #include <linux/user-return-notifier.h>
       6             : 
       7             : #include <asm/nospec-branch.h>
       8             : #include <asm/io_bitmap.h>
       9             : #include <asm/fpu/api.h>
      10             : 
      11             : /* Check that the stack and regs on entry from user mode are sane. */
      12      442540 : static __always_inline void arch_check_user_regs(struct pt_regs *regs)
      13             : {
      14      442540 :         if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) {
      15             :                 /*
      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.
      19             :                  */
      20             :                 unsigned long flags = native_save_fl();
      21             :                 unsigned long mask = X86_EFLAGS_DF | X86_EFLAGS_NT;
      22             : 
      23             :                 /*
      24             :                  * For !SMAP hardware we patch out CLAC on entry.
      25             :                  */
      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;
      29             : 
      30             :                 WARN_ON_ONCE(flags & mask);
      31             : 
      32             :                 /* We think we came from user mode. Make sure pt_regs agrees. */
      33             :                 WARN_ON_ONCE(!user_mode(regs));
      34             : 
      35             :                 /*
      36             :                  * All entries from user mode (except #DF) should be on the
      37             :                  * normal thread stack and should have user pt_regs in the
      38             :                  * correct location.
      39             :                  */
      40             :                 WARN_ON_ONCE(!on_thread_stack());
      41             :                 WARN_ON_ONCE(regs != task_pt_regs(current));
      42             :         }
      43             : }
      44             : #define arch_check_user_regs arch_check_user_regs
      45             : 
      46      442495 : static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs,
      47             :                                                   unsigned long ti_work)
      48             : {
      49      442495 :         if (ti_work & _TIF_USER_RETURN_NOTIFY)
      50             :                 fire_user_return_notifiers();
      51             : 
      52      442495 :         if (unlikely(ti_work & _TIF_IO_BITMAP))
      53             :                 tss_update_io_bitmap();
      54             : 
      55      442495 :         fpregs_assert_state_consistent();
      56      442495 :         if (unlikely(ti_work & _TIF_NEED_FPU_LOAD))
      57        9160 :                 switch_fpu_return();
      58             : 
      59             : #ifdef CONFIG_COMPAT
      60             :         /*
      61             :          * Compat syscalls set TS_COMPAT.  Make sure we clear it before
      62             :          * returning to user mode.  We need to clear it *after* signal
      63             :          * handling, because syscall restart has a fixup for compat
      64             :          * syscalls.  The fixup is exercised by the ptrace_syscall_32
      65             :          * selftest.
      66             :          *
      67             :          * We also need to clear TS_REGS_POKED_I386: the 32-bit tracer
      68             :          * special case only applies after poking regs and before the
      69             :          * very next return to user mode.
      70             :          */
      71      442497 :         current_thread_info()->status &= ~(TS_COMPAT | TS_I386_REGS_POKED);
      72             : #endif
      73      442497 : }
      74             : #define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare
      75             : 
      76      442589 : static __always_inline void arch_exit_to_user_mode(void)
      77             : {
      78      442589 :         mds_user_clear_cpu_buffers();
      79             : }
      80             : #define arch_exit_to_user_mode arch_exit_to_user_mode
      81             : 
      82             : #endif