From: "Peter Zijlstra (Intel)" <peterz@infradead.org> mainline inclusion from mainline-5.12-rc1 commit 40607ee97e4eec5655cc0f76a720bdc4c63a6434 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I410UT CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... --------------------------- Provide static call to control IRQ preemption (called in CONFIG_PREEMPT) so that we can override its behaviour when preempt= is overriden. Since the default behaviour is full preemption, its call is initialized to provide IRQ preemption when preempt= isn't passed. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20210118141223.123667-8-frederic@kernel.org Signed-off-by: Ma Junhai <majunhai2@huawei.com> Reviewed-by: Chen Hui <judy.chenhui@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- include/linux/entry-common.h | 4 ++++ kernel/entry/common.c | 10 +++++++++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index 7dff07713a07..d8e1c798dc9d 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -2,6 +2,7 @@ #ifndef __LINUX_ENTRYCOMMON_H #define __LINUX_ENTRYCOMMON_H +#include <linux/static_call_types.h> #include <linux/tracehook.h> #include <linux/syscalls.h> #include <linux/seccomp.h> @@ -403,6 +404,9 @@ irqentry_state_t noinstr irqentry_enter(struct pt_regs *regs); * Conditional reschedule with additional sanity checks. */ void irqentry_exit_cond_resched(void); +#ifdef CONFIG_PREEMPT_DYNAMIC +DECLARE_STATIC_CALL(irqentry_exit_cond_resched, irqentry_exit_cond_resched); +#endif /** * irqentry_exit - Handle return from exception that used irqentry_enter() diff --git a/kernel/entry/common.c b/kernel/entry/common.c index e289e6773292..8a4dd7027e90 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -357,6 +357,9 @@ void irqentry_exit_cond_resched(void) preempt_schedule_irq(); } } +#ifdef CONFIG_PREEMPT_DYNAMIC +DEFINE_STATIC_CALL(irqentry_exit_cond_resched, irqentry_exit_cond_resched); +#endif noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) { @@ -383,8 +386,13 @@ noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) } instrumentation_begin(); - if (IS_ENABLED(CONFIG_PREEMPTION)) + if (IS_ENABLED(CONFIG_PREEMPTION)) { +#ifdef CONFIG_PREEMT_DYNAMIC + static_call(irqentry_exit_cond_resched)(); +#else irqentry_exit_cond_resched(); +#endif + } /* Covers both tracing and lockdep */ trace_hardirqs_on(); instrumentation_end(); -- 2.20.1