The following commit has been merged into the x86/entry branch of tip: Commit-ID: d4b1f51731fd10a836e46f54c96a8913d945735b Gitweb: https://git.kernel.org/tip/d4b1f51731fd10a836e46f54c96a8913d945735b Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Thu, 21 May 2020 22:05:18 +02:00 Committer: Ingo Molnar <mi...@kernel.org> CommitterDate: Tue, 26 May 2020 19:06:27 +02:00
x86/entry: Provide idtentry_enter/exit_user() As there are exceptions which already handle entry from user mode and from kernel mode separately, providing explicit user entry/exit handling callbacks makes sense and makes the code easier to understand. Signed-off-by: Thomas Gleixner <t...@linutronix.de> Signed-off-by: Ingo Molnar <mi...@kernel.org> Acked-by: Andy Lutomirski <l...@kernel.org> Link: https://lore.kernel.org/r/20200521202117.289548...@linutronix.de --- arch/x86/entry/common.c | 31 +++++++++++++++++++++++++++++++ arch/x86/include/asm/idtentry.h | 3 +++ 2 files changed, 34 insertions(+) diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index a7f5846..b7fcb13 100644 --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -658,3 +658,34 @@ void noinstr idtentry_exit_cond_rcu(struct pt_regs *regs, bool rcu_exit) rcu_irq_exit(); } } + +/** + * idtentry_enter_user - Handle state tracking on idtentry from user mode + * @regs: Pointer to pt_regs of interrupted context + * + * Invokes enter_from_user_mode() to establish the proper context for + * NOHZ_FULL. Otherwise scheduling on exit would not be possible. + */ +void noinstr idtentry_enter_user(struct pt_regs *regs) +{ + enter_from_user_mode(); +} + +/** + * idtentry_exit_user - Handle return from exception to user mode + * @regs: Pointer to pt_regs (exception entry regs) + * + * Runs the necessary preemption and work checks and returns to the caller + * with interrupts disabled and no further work pending. + * + * This is the last action before returning to the low level ASM code which + * just needs to return to the appropriate context. + * + * Counterpart to idtentry_enter_user(). + */ +void noinstr idtentry_exit_user(struct pt_regs *regs) +{ + lockdep_assert_irqs_disabled(); + + prepare_exit_to_usermode(regs); +} diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h index a116b80..b3aca72 100644 --- a/arch/x86/include/asm/idtentry.h +++ b/arch/x86/include/asm/idtentry.h @@ -7,6 +7,9 @@ #ifndef __ASSEMBLY__ +void idtentry_enter_user(struct pt_regs *regs); +void idtentry_exit_user(struct pt_regs *regs); + bool idtentry_enter_cond_rcu(struct pt_regs *regs, bool cond_rcu); void idtentry_exit_cond_rcu(struct pt_regs *regs, bool rcu_exit);
