x86/hpet: Do not use smp_processor_id() in preemptible code
Borislav Petkov
maintainerPATCH 1/1 x86/hpet: Do not use smp_processor_id() in preemptible code
From: Borislav Petkov <[email protected]>
When hpet=force is supplied on the kernel command line and the HPET supports the Legacy Replacement Interrupt Route option (HPET_ID_LEGSUP), the legacy interrupts init code uses the boot CPU's mask initially by calling smp_processor_id() assuming that it is running on the BSP.
And it does run on the BSP but the code region is preemptible and the preemption check fires.
Simply use the BSP's id directly to avoid the warning.
--- arch/x86/kernel/hpet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/kernel/hpet.c +1 -1
@@ -285,7 +285,7 @@ static void hpet_legacy_clockevent_register(void)* Start hpet with the boot cpu mask and make it * global after the IO_APIC has been initialized. */ - hpet_clockevent.cpumask =cpumask_of (smp_processor_id ()); + hpet_clockevent.cpumask =cpumask_of (boot_cpu_data.cpu_index);clockevents_config_and_register (&hpet_clockevent, hpet_freq,HPET_MIN_PROG_DELTA ,0x7FFFFFFF ); global_clock_event = &hpet_clockevent;
Signature · 1 line
2.13.0
tip-bot for Borislav Petkov
merge botx86/hpet: Do not use smp_processor_id() in preemptible code
Commit-ID: 803ff8a7a6c9f89945edc07c5e969c2e11e2209b Gitweb: http://git.kernel.org/tip/803ff8a7a6c9f89945edc07c5e969c2e11e2209b Author: Borislav Petkov <[email protected]> AuthorDate: Tue, 20 Jun 2017 11:31:54 +0200 Committer: Thomas Gleixner <[email protected]> CommitDate: Tue, 20 Jun 2017 12:23:26 +0200
x86/hpet: Do not use smp_processor_id() in preemptible code
When hpet=force is supplied on the kernel command line and the HPET supports the Legacy Replacement Interrupt Route option (HPET_ID_LEGSUP), the legacy interrupts init code uses the boot CPU's mask initially by calling smp_processor_id() assuming that it is running on the BSP.
It does run on the BSP but the code region is preemptible and the preemption check fires.
Simply use the BSP's id directly to avoid the warning.
--- arch/x86/kernel/hpet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
arch/x86/kernel/hpet.c +1 -1
@@ -285,7 +285,7 @@ static void hpet_legacy_clockevent_register(void)* Start hpet with the boot cpu mask and make it * global after the IO_APIC has been initialized. */ - hpet_clockevent.cpumask =cpumask_of (smp_processor_id ()); + hpet_clockevent.cpumask =cpumask_of (boot_cpu_data.cpu_index);clockevents_config_and_register (&hpet_clockevent, hpet_freq,HPET_MIN_PROG_DELTA ,0x7FFFFFFF ); global_clock_event = &hpet_clockevent;