diff options
Diffstat (limited to 'arch/x86/entry/common.c')
| -rw-r--r-- | arch/x86/entry/common.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index 9892fb7c9d440..7473c1297a841 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -40,19 +40,36 @@ #include <trace/events/syscalls.h> #ifdef CONFIG_CONTEXT_TRACKING -/* Called on entry from user mode with IRQs off. */ +/** + * enter_from_user_mode - Establish state when coming from user mode + * + * Syscall entry disables interrupts, but user mode is traced as interrupts + * enabled. Also with NO_HZ_FULL RCU might be idle. + * + * 1) Tell lockdep that interrupts are disabled + * 2) Invoke context tracking if enabled to reactivate RCU + * 3) Trace interrupts off state + */ __visible noinstr void enter_from_user_mode(void) { enum ctx_state state = ct_state(); + lockdep_hardirqs_off(CALLER_ADDR0); user_exit_irqoff(); instrumentation_begin(); CT_WARN_ON(state != CONTEXT_USER); + trace_hardirqs_off_prepare(); instrumentation_end(); } #else -static inline void enter_from_user_mode(void) {} +static __always_inline void enter_from_user_mode(void) +{ + lockdep_hardirqs_off(CALLER_ADDR0); + instrumentation_begin(); + trace_hardirqs_off_prepare(); + instrumentation_end(); +} #endif static noinstr void exit_to_user_mode(void) |