From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- arch/x86/include/asm/entry-common.h | 85 +++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 arch/x86/include/asm/entry-common.h (limited to 'arch/x86/include/asm/entry-common.h') diff --git a/arch/x86/include/asm/entry-common.h b/arch/x86/include/asm/entry-common.h new file mode 100644 index 000000000..5443851d3 --- /dev/null +++ b/arch/x86/include/asm/entry-common.h @@ -0,0 +1,85 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _ASM_X86_ENTRY_COMMON_H +#define _ASM_X86_ENTRY_COMMON_H + +#include + +#include +#include +#include + +/* Check that the stack and regs on entry from user mode are sane. */ +static __always_inline void arch_check_user_regs(struct pt_regs *regs) +{ + if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) { + /* + * Make sure that the entry code gave us a sensible EFLAGS + * register. Native because we want to check the actual CPU + * state, not the interrupt state as imagined by Xen. + */ + unsigned long flags = native_save_fl(); + unsigned long mask = X86_EFLAGS_DF | X86_EFLAGS_NT; + + /* + * For !SMAP hardware we patch out CLAC on entry. + */ + if (boot_cpu_has(X86_FEATURE_SMAP) || + (IS_ENABLED(CONFIG_64BIT) && boot_cpu_has(X86_FEATURE_XENPV))) + mask |= X86_EFLAGS_AC; + + WARN_ON_ONCE(flags & mask); + + /* We think we came from user mode. Make sure pt_regs agrees. */ + WARN_ON_ONCE(!user_mode(regs)); + + /* + * All entries from user mode (except #DF) should be on the + * normal thread stack and should have user pt_regs in the + * correct location. + */ + WARN_ON_ONCE(!on_thread_stack()); + WARN_ON_ONCE(regs != task_pt_regs(current)); + } +} +#define arch_check_user_regs arch_check_user_regs + +#define ARCH_SYSCALL_EXIT_WORK (_TIF_SINGLESTEP) + +static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs, + unsigned long ti_work) +{ + if (ti_work & _TIF_USER_RETURN_NOTIFY) + fire_user_return_notifiers(); + + if (unlikely(ti_work & _TIF_IO_BITMAP)) + tss_update_io_bitmap(); + + fpregs_assert_state_consistent(); + if (unlikely(ti_work & _TIF_NEED_FPU_LOAD)) + switch_fpu_return(); + +#ifdef CONFIG_COMPAT + /* + * Compat syscalls set TS_COMPAT. Make sure we clear it before + * returning to user mode. We need to clear it *after* signal + * handling, because syscall restart has a fixup for compat + * syscalls. The fixup is exercised by the ptrace_syscall_32 + * selftest. + * + * We also need to clear TS_REGS_POKED_I386: the 32-bit tracer + * special case only applies after poking regs and before the + * very next return to user mode. + */ + current_thread_info()->status &= ~(TS_COMPAT | TS_I386_REGS_POKED); +#endif +} +#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare + +static __always_inline void arch_exit_to_user_mode(void) +{ + mds_user_clear_cpu_buffers(); + amd_clear_divider(); +} +#define arch_exit_to_user_mode arch_exit_to_user_mode + +#endif -- cgit v1.2.3