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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-05-21 22:05:18 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:15:05 +0200 |
| commit | 9f9781b60dfa68d5094a41982f1efa75215a62b1 (patch) | |
| tree | 182035a269657fff26113789b3df6e7c63b4561a /arch/x86 | |
| parent | 3eeec385848855c8109eb72b8b309078d5507968 (diff) | |
| download | linux-stable-9f9781b60dfa68d5094a41982f1efa75215a62b1.tar.gz linux-stable-9f9781b60dfa68d5094a41982f1efa75215a62b1.tar.bz2 linux-stable-9f9781b60dfa68d5094a41982f1efa75215a62b1.zip | |
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 <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202117.289548561@linutronix.de
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/entry/common.c | 31 | ||||
| -rw-r--r-- | arch/x86/include/asm/idtentry.h | 3 |
2 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c index a7f5846a4102..b7fcb1355adf 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 a116b80662d4..b3aca728f2fb 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); |