Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:

 - an s2ram related fix on AMD systems

 - a perf fault handling bug that is relatively old but which has become
   much easier to trigger in v3.13 after commit e00b12e64b ("perf/x86:
   Further optimize copy_from_user_nmi()")

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/ibs: Fix waking up from S3 for AMD family 10h
  x86, mm, perf: Allow recursive faults from interrupts
This commit is contained in:
Linus Torvalds 2014-01-19 13:06:51 -08:00
commit 16ec54ad15
2 changed files with 63 additions and 8 deletions

View File

@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ptrace.h>
#include <linux/syscore_ops.h>
#include <asm/apic.h>
@ -816,6 +817,18 @@ out:
return ret;
}
static void ibs_eilvt_setup(void)
{
/*
* Force LVT offset assignment for family 10h: The offsets are
* not assigned by the BIOS for this family, so the OS is
* responsible for doing it. If the OS assignment fails, fall
* back to BIOS settings and try to setup this.
*/
if (boot_cpu_data.x86 == 0x10)
force_ibs_eilvt_setup();
}
static inline int get_ibs_lvt_offset(void)
{
u64 val;
@ -851,6 +864,36 @@ static void clear_APIC_ibs(void *dummy)
setup_APIC_eilvt(offset, 0, APIC_EILVT_MSG_FIX, 1);
}
#ifdef CONFIG_PM
static int perf_ibs_suspend(void)
{
clear_APIC_ibs(NULL);
return 0;
}
static void perf_ibs_resume(void)
{
ibs_eilvt_setup();
setup_APIC_ibs(NULL);
}
static struct syscore_ops perf_ibs_syscore_ops = {
.resume = perf_ibs_resume,
.suspend = perf_ibs_suspend,
};
static void perf_ibs_pm_init(void)
{
register_syscore_ops(&perf_ibs_syscore_ops);
}
#else
static inline void perf_ibs_pm_init(void) { }
#endif
static int
perf_ibs_cpu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
{
@ -877,18 +920,12 @@ static __init int amd_ibs_init(void)
if (!caps)
return -ENODEV; /* ibs not supported by the cpu */
/*
* Force LVT offset assignment for family 10h: The offsets are
* not assigned by the BIOS for this family, so the OS is
* responsible for doing it. If the OS assignment fails, fall
* back to BIOS settings and try to setup this.
*/
if (boot_cpu_data.x86 == 0x10)
force_ibs_eilvt_setup();
ibs_eilvt_setup();
if (!ibs_eilvt_valid())
goto out;
perf_ibs_pm_init();
get_online_cpus();
ibs_caps = caps;
/* make ibs_caps visible to other cpus: */

View File

@ -641,6 +641,20 @@ no_context(struct pt_regs *regs, unsigned long error_code,
/* Are we prepared to handle this kernel fault? */
if (fixup_exception(regs)) {
/*
* Any interrupt that takes a fault gets the fixup. This makes
* the below recursive fault logic only apply to a faults from
* task context.
*/
if (in_interrupt())
return;
/*
* Per the above we're !in_interrupt(), aka. task context.
*
* In this case we need to make sure we're not recursively
* faulting through the emulate_vsyscall() logic.
*/
if (current_thread_info()->sig_on_uaccess_error && signal) {
tsk->thread.trap_nr = X86_TRAP_PF;
tsk->thread.error_code = error_code | PF_USER;
@ -649,6 +663,10 @@ no_context(struct pt_regs *regs, unsigned long error_code,
/* XXX: hwpoison faults will set the wrong code. */
force_sig_info_fault(signal, si_code, address, tsk, 0);
}
/*
* Barring that, we can do the fixup and be happy.
*/
return;
}