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authorThomas Gleixner <tglx@linutronix.de>2020-11-04 18:14:52 +0100
committerThomas Gleixner <tglx@linutronix.de>2020-11-04 18:14:52 +0100
commit01be83eea08d6d9f9209843e2e084505fba4053f (patch)
tree95b456e1ac40399fd5f55b57ae0936643bea1836 /kernel/entry
parententry: Fixup irqentry_enter() comment (diff)
parententry: Fix the incorrect ordering of lockdep and RCU check (diff)
downloadlinux-01be83eea08d6d9f9209843e2e084505fba4053f.tar.xz
linux-01be83eea08d6d9f9209843e2e084505fba4053f.zip
Merge branch 'core/urgent' into core/entry
Pick up the entry fix before further modifications.
Diffstat (limited to 'kernel/entry')
-rw-r--r--kernel/entry/common.c47
-rw-r--r--kernel/entry/kvm.c4
2 files changed, 37 insertions, 14 deletions
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index f7ed415a6768..3a1dfecc533e 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -60,6 +60,9 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,
return ret;
}
+ /* Either of the above might have changed the syscall number */
+ syscall = syscall_get_nr(current, regs);
+
if (unlikely(ti_work & _TIF_SYSCALL_TRACEPOINT))
trace_sys_enter(regs, syscall);
@@ -68,22 +71,45 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,
return ret ? : syscall;
}
-noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall)
+static __always_inline long
+__syscall_enter_from_user_work(struct pt_regs *regs, long syscall)
{
unsigned long ti_work;
- enter_from_user_mode(regs);
- instrumentation_begin();
-
- local_irq_enable();
ti_work = READ_ONCE(current_thread_info()->flags);
if (ti_work & SYSCALL_ENTER_WORK)
syscall = syscall_trace_enter(regs, syscall, ti_work);
- instrumentation_end();
return syscall;
}
+long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall)
+{
+ return __syscall_enter_from_user_work(regs, syscall);
+}
+
+noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall)
+{
+ long ret;
+
+ enter_from_user_mode(regs);
+
+ instrumentation_begin();
+ local_irq_enable();
+ ret = __syscall_enter_from_user_work(regs, syscall);
+ instrumentation_end();
+
+ return ret;
+}
+
+noinstr void syscall_enter_from_user_mode_prepare(struct pt_regs *regs)
+{
+ enter_from_user_mode(regs);
+ instrumentation_begin();
+ local_irq_enable();
+ instrumentation_end();
+}
+
/**
* exit_to_user_mode - Fixup state when exiting to user mode
*
@@ -143,7 +169,6 @@ static unsigned long exit_to_user_mode_loop(struct pt_regs *regs,
handle_signal_work(regs, ti_work);
if (ti_work & _TIF_NOTIFY_RESUME) {
- clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
rseq_handle_notify_resume(NULL, regs);
}
@@ -190,7 +215,7 @@ static inline bool report_single_step(unsigned long ti_work)
/*
* If TIF_SYSCALL_EMU is set, then the only reason to report is when
* TIF_SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall
- * instruction has been already reported in syscall_enter_from_usermode().
+ * instruction has been already reported in syscall_enter_from_user_mode().
*/
#define SYSEMU_STEP (_TIF_SINGLESTEP | _TIF_SYSCALL_EMU)
@@ -286,7 +311,7 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
* terminate a grace period, if and only if the timer interrupt is
* not nested into another interrupt.
*
- * Checking for __rcu_is_watching() here would prevent the nesting
+ * Checking for rcu_is_watching() here would prevent the nesting
* interrupt to invoke rcu_irq_enter(). If that nested interrupt is
* the tick then rcu_flavor_sched_clock_irq() would wrongfully
* assume that it is the first interupt and eventually claim
@@ -320,10 +345,10 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
* already contains a warning when RCU is not watching, so no point
* in having another one here.
*/
+ lockdep_hardirqs_off(CALLER_ADDR0);
instrumentation_begin();
rcu_irq_enter_check_tick();
- /* Use the combo lockdep/tracing function */
- trace_hardirqs_off();
+ trace_hardirqs_off_finish();
instrumentation_end();
return ret;
diff --git a/kernel/entry/kvm.c b/kernel/entry/kvm.c
index b828a3ddebf1..49972ee99aff 100644
--- a/kernel/entry/kvm.c
+++ b/kernel/entry/kvm.c
@@ -19,10 +19,8 @@ static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
if (ti_work & _TIF_NEED_RESCHED)
schedule();
- if (ti_work & _TIF_NOTIFY_RESUME) {
- clear_thread_flag(TIF_NOTIFY_RESUME);
+ if (ti_work & _TIF_NOTIFY_RESUME)
tracehook_notify_resume(NULL);
- }
ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
if (ret)