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

Browse Source 
Pull perf fixes from Ingo Molnar:
 "The biggest chunk of the changes are two regression fixes: a HT
  workaround fix and an event-group scheduling fix.  It's been verified
  with 5 days of fuzzer testing.

  Other fixes:

   - eBPF fix
   - a BIOS breakage detection fix
   - PMU driver fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/pt: Fix a refactoring bug
  perf/x86: Tweak broken BIOS rules during check_hw_exists()
  perf/x86/intel/pt: Untangle pt_buffer_reset_markers()
  perf: Disallow sparse AUX allocations for non-SG PMUs in overwrite mode
  perf/x86: Improve HT workaround GP counter constraint
  perf/x86: Fix event/group validation
  perf: Fix race in BPF program unregister
This commit is contained in:
Linus Torvalds 2015-06-05 10:00:53 -07:00
commit a0e9c6efa5
10 changed files with 139 additions and 84 deletions
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83
arch/x86/kernel/cpu/perf_event.c
View File

@ -190,6 +190,7 @@ static bool check_hw_exists(void)
u64 val, val_fail, val_new= ~0;
int i, reg, reg_fail, ret = 0;
int bios_fail = 0;
int reg_safe = -1;
/*
* Check to see if the BIOS enabled any of the counters, if so
@ -204,6 +205,8 @@ static bool check_hw_exists(void)
bios_fail = 1;
val_fail = val;
reg_fail = reg;
} else {
reg_safe = i;
}
}
@ -221,12 +224,23 @@ static bool check_hw_exists(void)
}
}
/*
* If all the counters are enabled, the below test will always
* fail. The tools will also become useless in this scenario.
* Just fail and disable the hardware counters.
*/
if (reg_safe == -1) {
reg = reg_safe;
goto msr_fail;
}
/*
* Read the current value, change it and read it back to see if it
* matches, this is needed to detect certain hardware emulators
* (qemu/kvm) that don't trap on the MSR access and always return 0s.
*/
reg = x86_pmu_event_addr(0);
reg = x86_pmu_event_addr(reg_safe);
if (rdmsrl_safe(reg, &val))
goto msr_fail;
val ^= 0xffffUL;
@ -611,6 +625,7 @@ struct sched_state {
int event; /* event index */
int counter; /* counter index */
int unassigned; /* number of events to be assigned left */
int nr_gp; /* number of GP counters used */
unsigned long used[BITS_TO_LONGS(X86_PMC_IDX_MAX)];
};
@ -620,27 +635,29 @@ struct sched_state {
struct perf_sched {
int max_weight;
int max_events;
struct perf_event **events;
struct sched_state state;
int max_gp;
int saved_states;
struct event_constraint **constraints;
struct sched_state state;
struct sched_state saved[SCHED_STATES_MAX];
};
/*
* Initialize interator that runs through all events and counters.
*/
static void perf_sched_init(struct perf_sched *sched, struct perf_event **events,
int num, int wmin, int wmax)
static void perf_sched_init(struct perf_sched *sched, struct event_constraint **constraints,
int num, int wmin, int wmax, int gpmax)
{
int idx;
memset(sched, 0, sizeof(*sched));
sched->max_events = num;
sched->max_weight = wmax;
sched->events = events;
sched->max_gp = gpmax;
sched->constraints = constraints;
for (idx = 0; idx < num; idx++) {
if (events[idx]->hw.constraint->weight == wmin)
if (constraints[idx]->weight == wmin)
break;
}
@ -687,7 +704,7 @@ static bool __perf_sched_find_counter(struct perf_sched *sched)
if (sched->state.event >= sched->max_events)
return false;
c = sched->events[sched->state.event]->hw.constraint;
c = sched->constraints[sched->state.event];
/* Prefer fixed purpose counters */
if (c->idxmsk64 & (~0ULL << INTEL_PMC_IDX_FIXED)) {
idx = INTEL_PMC_IDX_FIXED;
@ -696,11 +713,16 @@ static bool __perf_sched_find_counter(struct perf_sched *sched)
goto done;
}
}
/* Grab the first unused counter starting with idx */
idx = sched->state.counter;
for_each_set_bit_from(idx, c->idxmsk, INTEL_PMC_IDX_FIXED) {
if (!__test_and_set_bit(idx, sched->state.used))
if (!__test_and_set_bit(idx, sched->state.used)) {
if (sched->state.nr_gp++ >= sched->max_gp)
return false;
goto done;
}
}
return false;
@ -745,7 +767,7 @@ static bool perf_sched_next_event(struct perf_sched *sched)
if (sched->state.weight > sched->max_weight)
return false;
}
c = sched->events[sched->state.event]->hw.constraint;
c = sched->constraints[sched->state.event];
} while (c->weight != sched->state.weight);
sched->state.counter = 0; /* start with first counter */
@ -756,12 +778,12 @@ static bool perf_sched_next_event(struct perf_sched *sched)
/*
* Assign a counter for each event.
*/
int perf_assign_events(struct perf_event **events, int n,
int wmin, int wmax, int *assign)
int perf_assign_events(struct event_constraint **constraints, int n,
int wmin, int wmax, int gpmax, int *assign)
{
struct perf_sched sched;
perf_sched_init(&sched, events, n, wmin, wmax);
perf_sched_init(&sched, constraints, n, wmin, wmax, gpmax);
do {
if (!perf_sched_find_counter(&sched))
@ -788,9 +810,9 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
x86_pmu.start_scheduling(cpuc);
for (i = 0, wmin = X86_PMC_IDX_MAX, wmax = 0; i < n; i++) {
hwc = &cpuc->event_list[i]->hw;
cpuc->event_constraint[i] = NULL;
c = x86_pmu.get_event_constraints(cpuc, i, cpuc->event_list[i]);
hwc->constraint = c;
cpuc->event_constraint[i] = c;
wmin = min(wmin, c->weight);
wmax = max(wmax, c->weight);
@ -801,7 +823,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
*/
for (i = 0; i < n; i++) {
hwc = &cpuc->event_list[i]->hw;
c = hwc->constraint;
c = cpuc->event_constraint[i];
/* never assigned */
if (hwc->idx == -1)
@ -821,9 +843,26 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
}
/* slow path */
if (i != n)
unsched = perf_assign_events(cpuc->event_list, n, wmin,
wmax, assign);
if (i != n) {
int gpmax = x86_pmu.num_counters;
/*
* Do not allow scheduling of more than half the available
* generic counters.
*
* This helps avoid counter starvation of sibling thread by
* ensuring at most half the counters cannot be in exclusive
* mode. There is no designated counters for the limits. Any
* N/2 counters can be used. This helps with events with
* specific counter constraints.
*/
if (is_ht_workaround_enabled() && !cpuc->is_fake &&
READ_ONCE(cpuc->excl_cntrs->exclusive_present))
gpmax /= 2;
unsched = perf_assign_events(cpuc->event_constraint, n, wmin,
wmax, gpmax, assign);
}
/*
* In case of success (unsched = 0), mark events as committed,
@ -840,7 +879,7 @@ int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign)
e = cpuc->event_list[i];
e->hw.flags |= PERF_X86_EVENT_COMMITTED;
if (x86_pmu.commit_scheduling)
x86_pmu.commit_scheduling(cpuc, e, assign[i]);
x86_pmu.commit_scheduling(cpuc, i, assign[i]);
}
}
@ -1292,8 +1331,10 @@ static void x86_pmu_del(struct perf_event *event, int flags)
x86_pmu.put_event_constraints(cpuc, event);
/* Delete the array entry. */
while (++i < cpuc->n_events)
while (++i < cpuc->n_events) {
cpuc->event_list[i-1] = cpuc->event_list[i];
cpuc->event_constraint[i-1] = cpuc->event_constraint[i];
}
--cpuc->n_events;
perf_event_update_userpage(event);

24
arch/x86/kernel/cpu/perf_event.h
View File

@ -74,6 +74,7 @@ struct event_constraint {
#define PERF_X86_EVENT_EXCL 0x0040 /* HT exclusivity on counter */
#define PERF_X86_EVENT_DYNAMIC 0x0080 /* dynamic alloc'd constraint */
#define PERF_X86_EVENT_RDPMC_ALLOWED 0x0100 /* grant rdpmc permission */
#define PERF_X86_EVENT_EXCL_ACCT 0x0200 /* accounted EXCL event */
struct amd_nb {
@ -134,8 +135,6 @@ enum intel_excl_state_type {
struct intel_excl_states {
enum intel_excl_state_type init_state[X86_PMC_IDX_MAX];
enum intel_excl_state_type state[X86_PMC_IDX_MAX];
int num_alloc_cntrs;/* #counters allocated */
int max_alloc_cntrs;/* max #counters allowed */
bool sched_started; /* true if scheduling has started */
};
@ -144,6 +143,11 @@ struct intel_excl_cntrs {
struct intel_excl_states states[2];
union {
u16 has_exclusive[2];
u32 exclusive_present;
};
int refcnt; /* per-core: #HT threads */
unsigned core_id; /* per-core: core id */
};
@ -172,7 +176,11 @@ struct cpu_hw_events {
added in the current transaction */
int assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
u64 tags[X86_PMC_IDX_MAX];
struct perf_event *event_list[X86_PMC_IDX_MAX]; /* in enabled order */
struct event_constraint *event_constraint[X86_PMC_IDX_MAX];
int n_excl; /* the number of exclusive events */
unsigned int group_flag;
int is_fake;
@ -519,9 +527,7 @@ struct x86_pmu {
void (*put_event_constraints)(struct cpu_hw_events *cpuc,
struct perf_event *event);
void (*commit_scheduling)(struct cpu_hw_events *cpuc,
struct perf_event *event,
int cntr);
void (*commit_scheduling)(struct cpu_hw_events *cpuc, int idx, int cntr);
void (*start_scheduling)(struct cpu_hw_events *cpuc);
@ -717,8 +723,8 @@ static inline void __x86_pmu_enable_event(struct hw_perf_event *hwc,
void x86_pmu_enable_all(int added);
int perf_assign_events(struct perf_event **events, int n,
int wmin, int wmax, int *assign);
int perf_assign_events(struct event_constraint **constraints, int n,
int wmin, int wmax, int gpmax, int *assign);
int x86_schedule_events(struct cpu_hw_events *cpuc, int n, int *assign);
void x86_pmu_stop(struct perf_event *event, int flags);
@ -929,4 +935,8 @@ static inline struct intel_shared_regs *allocate_shared_regs(int cpu)
return NULL;
}
static inline int is_ht_workaround_enabled(void)
{
return 0;
}
#endif /* CONFIG_CPU_SUP_INTEL */

45
arch/x86/kernel/cpu/perf_event_intel.c
View File

@ -1923,7 +1923,6 @@ intel_start_scheduling(struct cpu_hw_events *cpuc)
xl = &excl_cntrs->states[tid];
xl->sched_started = true;
xl->num_alloc_cntrs = 0;
/*
* lock shared state until we are done scheduling
* in stop_event_scheduling()
@ -2000,6 +1999,11 @@ intel_get_excl_constraints(struct cpu_hw_events *cpuc, struct perf_event *event,
* across HT threads
*/
is_excl = c->flags & PERF_X86_EVENT_EXCL;
if (is_excl && !(event->hw.flags & PERF_X86_EVENT_EXCL_ACCT)) {
event->hw.flags |= PERF_X86_EVENT_EXCL_ACCT;
if (!cpuc->n_excl++)
WRITE_ONCE(excl_cntrs->has_exclusive[tid], 1);
}
/*
* xl = state of current HT
@ -2008,18 +2012,6 @@ intel_get_excl_constraints(struct cpu_hw_events *cpuc, struct perf_event *event,
xl = &excl_cntrs->states[tid];
xlo = &excl_cntrs->states[o_tid];
/*
* do not allow scheduling of more than max_alloc_cntrs
* which is set to half the available generic counters.
* this helps avoid counter starvation of sibling thread
* by ensuring at most half the counters cannot be in
* exclusive mode. There is not designated counters for the
* limits. Any N/2 counters can be used. This helps with
* events with specifix counter constraints
*/
if (xl->num_alloc_cntrs++ == xl->max_alloc_cntrs)
return &emptyconstraint;
cx = c;
/*
@ -2106,7 +2098,7 @@ static struct event_constraint *
intel_get_event_constraints(struct cpu_hw_events *cpuc, int idx,
struct perf_event *event)
{
struct event_constraint *c1 = event->hw.constraint;
struct event_constraint *c1 = cpuc->event_constraint[idx];
struct event_constraint *c2;
/*
@ -2150,6 +2142,11 @@ static void intel_put_excl_constraints(struct cpu_hw_events *cpuc,
xl = &excl_cntrs->states[tid];
xlo = &excl_cntrs->states[o_tid];
if (hwc->flags & PERF_X86_EVENT_EXCL_ACCT) {
hwc->flags &= ~PERF_X86_EVENT_EXCL_ACCT;
if (!--cpuc->n_excl)
WRITE_ONCE(excl_cntrs->has_exclusive[tid], 0);
}
/*
* put_constraint may be called from x86_schedule_events()
@ -2188,8 +2185,6 @@ intel_put_shared_regs_event_constraints(struct cpu_hw_events *cpuc,
static void intel_put_event_constraints(struct cpu_hw_events *cpuc,
struct perf_event *event)
{
struct event_constraint *c = event->hw.constraint;
intel_put_shared_regs_event_constraints(cpuc, event);
/*
@ -2197,19 +2192,14 @@ static void intel_put_event_constraints(struct cpu_hw_events *cpuc,
* all events are subject to and must call the
* put_excl_constraints() routine
*/
if (c && cpuc->excl_cntrs)
if (cpuc->excl_cntrs)
intel_put_excl_constraints(cpuc, event);
/* cleanup dynamic constraint */
if (c && (c->flags & PERF_X86_EVENT_DYNAMIC))
event->hw.constraint = NULL;
}
static void intel_commit_scheduling(struct cpu_hw_events *cpuc,
struct perf_event *event, int cntr)
static void intel_commit_scheduling(struct cpu_hw_events *cpuc, int idx, int cntr)
{
struct intel_excl_cntrs *excl_cntrs = cpuc->excl_cntrs;
struct event_constraint *c = event->hw.constraint;
struct event_constraint *c = cpuc->event_constraint[idx];
struct intel_excl_states *xlo, *xl;
int tid = cpuc->excl_thread_id;
int o_tid = 1 - tid;
@ -2639,8 +2629,6 @@ static void intel_pmu_cpu_starting(int cpu)
cpuc->lbr_sel = &cpuc->shared_regs->regs[EXTRA_REG_LBR];
if (x86_pmu.flags & PMU_FL_EXCL_CNTRS) {
int h = x86_pmu.num_counters >> 1;
for_each_cpu(i, topology_thread_cpumask(cpu)) {
struct intel_excl_cntrs *c;
@ -2654,11 +2642,6 @@ static void intel_pmu_cpu_starting(int cpu)
}
cpuc->excl_cntrs->core_id = core_id;
cpuc->excl_cntrs->refcnt++;
/*
* set hard limit to half the number of generic counters
*/
cpuc->excl_cntrs->states[0].max_alloc_cntrs = h;
cpuc->excl_cntrs->states[1].max_alloc_cntrs = h;
}
}

4
arch/x86/kernel/cpu/perf_event_intel_ds.c
View File

@ -706,9 +706,9 @@ void intel_pmu_pebs_disable(struct perf_event *event)
cpuc->pebs_enabled &= ~(1ULL << hwc->idx);
if (event->hw.constraint->flags & PERF_X86_EVENT_PEBS_LDLAT)
if (event->hw.flags & PERF_X86_EVENT_PEBS_LDLAT)
cpuc->pebs_enabled &= ~(1ULL << (hwc->idx + 32));
else if (event->hw.constraint->flags & PERF_X86_EVENT_PEBS_ST)
else if (event->hw.flags & PERF_X86_EVENT_PEBS_ST)
cpuc->pebs_enabled &= ~(1ULL << 63);
if (cpuc->enabled)

36
arch/x86/kernel/cpu/perf_event_intel_pt.c
View File

@ -151,7 +151,7 @@ static int __init pt_pmu_hw_init(void)
de_attr->attr.attr.name = pt_caps[i].name;
sysfs_attr_init(&de_attrs->attr.attr);
sysfs_attr_init(&de_attr->attr.attr);
de_attr->attr.attr.mode = S_IRUGO;
de_attr->attr.show = pt_cap_show;
@ -615,7 +615,8 @@ static int pt_buffer_reset_markers(struct pt_buffer *buf,
struct perf_output_handle *handle)
{
unsigned long idx, npages, end;
unsigned long head = local64_read(&buf->head);
unsigned long idx, npages, wakeup;
if (buf->snapshot)
return 0;
@ -634,17 +635,26 @@ static int pt_buffer_reset_markers(struct pt_buffer *buf,
buf->topa_index[buf->stop_pos]->stop = 0;
buf->topa_index[buf->intr_pos]->intr = 0;
if (pt_cap_get(PT_CAP_topa_multiple_entries)) {
npages = (handle->size + 1) >> PAGE_SHIFT;
end = (local64_read(&buf->head) >> PAGE_SHIFT) + npages;
/*if (end > handle->wakeup >> PAGE_SHIFT)
end = handle->wakeup >> PAGE_SHIFT;*/
idx = end & (buf->nr_pages - 1);
buf->stop_pos = idx;
idx = (local64_read(&buf->head) >> PAGE_SHIFT) + npages - 1;
idx &= buf->nr_pages - 1;
buf->intr_pos = idx;
}
/* how many pages till the STOP marker */
npages = handle->size >> PAGE_SHIFT;
/* if it's on a page boundary, fill up one more page */
if (!offset_in_page(head + handle->size + 1))
npages++;
idx = (head >> PAGE_SHIFT) + npages;
idx &= buf->nr_pages - 1;
buf->stop_pos = idx;
wakeup = handle->wakeup >> PAGE_SHIFT;
/* in the worst case, wake up the consumer one page before hard stop */
idx = (head >> PAGE_SHIFT) + npages - 1;
if (idx > wakeup)
idx = wakeup;
idx &= buf->nr_pages - 1;
buf->intr_pos = idx;
buf->topa_index[buf->stop_pos]->stop = 1;
buf->topa_index[buf->intr_pos]->intr = 1;

9
arch/x86/kernel/cpu/perf_event_intel_uncore.c
View File

@ -365,9 +365,8 @@ static int uncore_assign_events(struct intel_uncore_box *box, int assign[], int
bitmap_zero(used_mask, UNCORE_PMC_IDX_MAX);
for (i = 0, wmin = UNCORE_PMC_IDX_MAX, wmax = 0; i < n; i++) {
hwc = &box->event_list[i]->hw;
c = uncore_get_event_constraint(box, box->event_list[i]);
hwc->constraint = c;
box->event_constraint[i] = c;
wmin = min(wmin, c->weight);
wmax = max(wmax, c->weight);
}
@ -375,7 +374,7 @@ static int uncore_assign_events(struct intel_uncore_box *box, int assign[], int
/* fastpath, try to reuse previous register */
for (i = 0; i < n; i++) {
hwc = &box->event_list[i]->hw;
c = hwc->constraint;
c = box->event_constraint[i];
/* never assigned */
if (hwc->idx == -1)
@ -395,8 +394,8 @@ static int uncore_assign_events(struct intel_uncore_box *box, int assign[], int
}
/* slow path */
if (i != n)
ret = perf_assign_events(box->event_list, n,
wmin, wmax, assign);
ret = perf_assign_events(box->event_constraint, n,
wmin, wmax, n, assign);
if (!assign || ret) {
for (i = 0; i < n; i++)

1
arch/x86/kernel/cpu/perf_event_intel_uncore.h
View File

@ -97,6 +97,7 @@ struct intel_uncore_box {
atomic_t refcnt;
struct perf_event *events[UNCORE_PMC_IDX_MAX];
struct perf_event *event_list[UNCORE_PMC_IDX_MAX];
struct event_constraint *event_constraint[UNCORE_PMC_IDX_MAX];
unsigned long active_mask[BITS_TO_LONGS(UNCORE_PMC_IDX_MAX)];
u64 tags[UNCORE_PMC_IDX_MAX];
struct pci_dev *pci_dev;

4
include/linux/perf_event.h
View File

@ -92,8 +92,6 @@ struct hw_perf_event_extra {
int idx; /* index in shared_regs->regs[] */
};
struct event_constraint;
/**
* struct hw_perf_event - performance event hardware details:
*/
@ -112,8 +110,6 @@ struct hw_perf_event {
struct hw_perf_event_extra extra_reg;
struct hw_perf_event_extra branch_reg;
struct event_constraint *constraint;
};
struct { /* software */
struct hrtimer hrtimer;

3
kernel/events/core.c
View File

@ -3442,7 +3442,6 @@ static void free_event_rcu(struct rcu_head *head)
if (event->ns)
put_pid_ns(event->ns);
perf_event_free_filter(event);
perf_event_free_bpf_prog(event);
kfree(event);
}
@ -3573,6 +3572,8 @@ static void __free_event(struct perf_event *event)
put_callchain_buffers();
}
perf_event_free_bpf_prog(event);
if (event->destroy)
event->destroy(event);

14
kernel/events/ring_buffer.c
View File

@ -493,6 +493,20 @@ int rb_alloc_aux(struct ring_buffer *rb, struct perf_event *event,
rb->aux_pages[rb->aux_nr_pages] = page_address(page++);
}
/*
* In overwrite mode, PMUs that don't support SG may not handle more
* than one contiguous allocation, since they rely on PMI to do double
* buffering. In this case, the entire buffer has to be one contiguous
* chunk.
*/
if ((event->pmu->capabilities & PERF_PMU_CAP_AUX_NO_SG) &&
overwrite) {
struct page *page = virt_to_page(rb->aux_pages[0]);
if (page_private(page) != max_order)
goto out;
}
rb->aux_priv = event->pmu->setup_aux(event->cpu, rb->aux_pages, nr_pages,
overwrite);
if (!rb->aux_priv)