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| author |   Thomas Gleixner <tglx@linutronix.de> | 2020-07-23 00:00:05 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-07-24 15:04:59 +0200 |
| commit | 167fd210ec0555d371a20435dac7c2c7052df7ed (patch) | |
| tree | 49d6ed8cc7f5f6626399ef7c9d796b934a433111 /arch/x86/include/asm/entry-common.h | |
| parent | x86/entry: Use generic syscall entry function (diff) | |
| download | linux-dev-167fd210ec0555d371a20435dac7c2c7052df7ed.tar.xz linux-dev-167fd210ec0555d371a20435dac7c2c7052df7ed.zip | |
x86/entry: Use generic syscall exit functionality
Replace the x86 variant with the generic version. Provide the relevant
architecture specific helper functions and defines.
Use a temporary define for idtentry_exit_user which will be cleaned up
seperately.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20200722220520.494648601@linutronix.de
Diffstat (limited to 'arch/x86/include/asm/entry-common.h')
| -rw-r--r-- | arch/x86/include/asm/entry-common.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/arch/x86/include/asm/entry-common.h b/arch/x86/include/asm/entry-common.h index 7070b90c8312..a8f9315b9eae 100644 --- a/arch/x86/include/asm/entry-common.h +++ b/arch/x86/include/asm/entry-common.h @@ -2,6 +2,12 @@ #ifndef _ASM_X86_ENTRY_COMMON_H #define _ASM_X86_ENTRY_COMMON_H +#include <linux/user-return-notifier.h> + +#include <asm/nospec-branch.h> +#include <asm/io_bitmap.h> +#include <asm/fpu/api.h> + /* 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) { @@ -29,4 +35,42 @@ static __always_inline void arch_check_user_regs(struct pt_regs *regs) } #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(); +} +#define arch_exit_to_user_mode arch_exit_to_user_mode + #endif |