[GIT PULL] perf fixes

From: Ingo Molnar
Date: Sat Jun 12 2021 - 08:48:24 EST


Linus,

Please pull the latest perf/urgent git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-2021-06-12

# HEAD: a8383dfb2138742a1bb77b481ada047aededa2ba x86/nmi_watchdog: Fix old-style NMI watchdog regression on old Intel CPUs

Misc fixes:

- Fix the NMI watchdog on ancient Intel CPUs

- Remove a misguided, NMI-unsafe KASAN callback
from the NMI-safe irq_work path used by perf.

- Fix uncore events on Ice Lake servers.

- Someone booted maxcpus=1 on an SNB-EP, and the
uncore driver emitted warnings and was probably
buggy. Fix it.

- KCSAN found a genuine data race in the core perf
code. Somewhat ironically the bug was introduced
through a recent race fix. :-/ In our defense, the
new race window was much more narrow. Fix it.

Thanks,

Ingo

------------------>
CodyYao-oc (1):
x86/nmi_watchdog: Fix old-style NMI watchdog regression on old Intel CPUs

Kan Liang (2):
perf/x86/intel/uncore: Fix a kernel WARNING triggered by maxcpus=1
perf/x86/intel/uncore: Fix M2M event umask for Ice Lake server

Marco Elver (1):
perf: Fix data race between pin_count increment/decrement

Peter Zijlstra (1):
irq_work: Make irq_work_queue() NMI-safe again


arch/x86/events/intel/uncore_snbep.c | 9 ++++++---
arch/x86/kernel/cpu/perfctr-watchdog.c | 4 ++--
kernel/events/core.c | 2 ++
kernel/irq_work.c | 3 ---
4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index 63f097289a84..3a75a2c601c2 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -1406,6 +1406,8 @@ static int snbep_pci2phy_map_init(int devid, int nodeid_loc, int idmap_loc, bool
die_id = i;
else
die_id = topology_phys_to_logical_pkg(i);
+ if (die_id < 0)
+ die_id = -ENODEV;
map->pbus_to_dieid[bus] = die_id;
break;
}
@@ -1452,14 +1454,14 @@ static int snbep_pci2phy_map_init(int devid, int nodeid_loc, int idmap_loc, bool
i = -1;
if (reverse) {
for (bus = 255; bus >= 0; bus--) {
- if (map->pbus_to_dieid[bus] >= 0)
+ if (map->pbus_to_dieid[bus] != -1)
i = map->pbus_to_dieid[bus];
else
map->pbus_to_dieid[bus] = i;
}
} else {
for (bus = 0; bus <= 255; bus++) {
- if (map->pbus_to_dieid[bus] >= 0)
+ if (map->pbus_to_dieid[bus] != -1)
i = map->pbus_to_dieid[bus];
else
map->pbus_to_dieid[bus] = i;
@@ -5097,9 +5099,10 @@ static struct intel_uncore_type icx_uncore_m2m = {
.perf_ctr = SNR_M2M_PCI_PMON_CTR0,
.event_ctl = SNR_M2M_PCI_PMON_CTL0,
.event_mask = SNBEP_PMON_RAW_EVENT_MASK,
+ .event_mask_ext = SNR_M2M_PCI_PMON_UMASK_EXT,
.box_ctl = SNR_M2M_PCI_PMON_BOX_CTL,
.ops = &snr_m2m_uncore_pci_ops,
- .format_group = &skx_uncore_format_group,
+ .format_group = &snr_m2m_uncore_format_group,
};

static struct attribute *icx_upi_uncore_formats_attr[] = {
diff --git a/arch/x86/kernel/cpu/perfctr-watchdog.c b/arch/x86/kernel/cpu/perfctr-watchdog.c
index 3ef5868ac588..7aecb2fc3186 100644
--- a/arch/x86/kernel/cpu/perfctr-watchdog.c
+++ b/arch/x86/kernel/cpu/perfctr-watchdog.c
@@ -63,7 +63,7 @@ static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr)
case 15:
return msr - MSR_P4_BPU_PERFCTR0;
}
- fallthrough;
+ break;
case X86_VENDOR_ZHAOXIN:
case X86_VENDOR_CENTAUR:
return msr - MSR_ARCH_PERFMON_PERFCTR0;
@@ -96,7 +96,7 @@ static inline unsigned int nmi_evntsel_msr_to_bit(unsigned int msr)
case 15:
return msr - MSR_P4_BSU_ESCR0;
}
- fallthrough;
+ break;
case X86_VENDOR_ZHAOXIN:
case X86_VENDOR_CENTAUR:
return msr - MSR_ARCH_PERFMON_EVENTSEL0;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 6fee4a7e88d7..fe88d6eea3c2 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4609,7 +4609,9 @@ find_get_context(struct pmu *pmu, struct task_struct *task,
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
ctx = &cpuctx->ctx;
get_ctx(ctx);
+ raw_spin_lock_irqsave(&ctx->lock, flags);
++ctx->pin_count;
+ raw_spin_unlock_irqrestore(&ctx->lock, flags);

return ctx;
}
diff --git a/kernel/irq_work.c b/kernel/irq_work.c
index 23a7a0ba1388..db8c248ebc8c 100644
--- a/kernel/irq_work.c
+++ b/kernel/irq_work.c
@@ -70,9 +70,6 @@ bool irq_work_queue(struct irq_work *work)
if (!irq_work_claim(work))
return false;

- /*record irq_work call stack in order to print it in KASAN reports*/
- kasan_record_aux_stack(work);
-
/* Queue the entry and raise the IPI if needed. */
preempt_disable();
__irq_work_queue_local(work);