diff options
Diffstat (limited to 'arch/x86/entry/common.c')
| -rw-r--r-- | arch/x86/entry/common.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 7473c1297a84..e4f9f5f2c21b 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -72,10 +72,27 @@ static __always_inline void enter_from_user_mode(void) } #endif -static noinstr void exit_to_user_mode(void) +/** + * exit_to_user_mode - Fixup state when exiting to user mode + * + * Syscall exit enables interrupts, but the kernel state is interrupts + * disabled when this is invoked. Also tell RCU about it. + * + * 1) Trace interrupts on state + * 2) Invoke context tracking if enabled to adjust RCU state + * 3) Clear CPU buffers if CPU is affected by MDS and the migitation is on. + * 4) Tell lockdep that interrupts are enabled + */ +static __always_inline void exit_to_user_mode(void) { + instrumentation_begin(); + trace_hardirqs_on_prepare(); + lockdep_hardirqs_on_prepare(CALLER_ADDR0); + instrumentation_end(); + user_enter_irqoff(); mds_user_clear_cpu_buffers(); + lockdep_hardirqs_on(CALLER_ADDR0); } static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch) |