Commit 6c869e77 authored by Ingo Molnar's avatar Ingo Molnar

Merge branch 'perf/urgent' into perf/core

Conflicts:
	arch/x86/kernel/apic/hw_nmi.c

Merge reason: Resolve conflict, queue up dependent patch.
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parents e4e91ac4 ee6dcfa4
......@@ -21,7 +21,7 @@ config X86
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_IDE
select HAVE_OPROFILE
select HAVE_PERF_EVENTS if (!M386 && !M486)
select HAVE_PERF_EVENTS
select HAVE_IRQ_WORK
select HAVE_IOREMAP_PROT
select HAVE_KPROBES
......
......@@ -17,9 +17,6 @@
#include <linux/nmi.h>
#include <linux/module.h>
/* For reliability, we're prepared to waste bits here. */
static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
#ifdef CONFIG_HARDLOCKUP_DETECTOR
u64 hw_nmi_get_sample_period(void)
{
......@@ -27,6 +24,10 @@ u64 hw_nmi_get_sample_period(void)
}
#endif
/* For reliability, we're prepared to waste bits here. */
static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
#ifdef arch_trigger_all_cpu_backtrace
void arch_trigger_all_cpu_backtrace(void)
{
......
......@@ -372,6 +372,20 @@ static void release_pmc_hardware(void) {}
#endif
static bool check_hw_exists(void)
{
u64 val, val_new = 0;
int ret = 0;
val = 0xabcdUL;
ret |= checking_wrmsrl(x86_pmu.perfctr, val);
ret |= rdmsrl_safe(x86_pmu.perfctr, &val_new);
if (ret || val != val_new)
return false;
return true;
}
static void reserve_ds_buffers(void);
static void release_ds_buffers(void);
......@@ -1363,6 +1377,12 @@ void __init init_hw_perf_events(void)
pmu_check_apic();
/* sanity check that the hardware exists or is emulated */
if (!check_hw_exists()) {
pr_cont("Broken PMU hardware detected, software events only.\n");
return;
}
pr_cont("%s PMU driver.\n", x86_pmu.name);
if (x86_pmu.quirks)
......
......@@ -295,6 +295,7 @@ ENDPROC(native_usergs_sysret64)
.endm
/* save partial stack frame */
.pushsection .kprobes.text, "ax"
ENTRY(save_args)
XCPT_FRAME
cld
......@@ -334,6 +335,7 @@ ENTRY(save_args)
ret
CFI_ENDPROC
END(save_args)
.popsection
ENTRY(save_rest)
PARTIAL_FRAME 1 REST_SKIP+8
......
......@@ -433,6 +433,10 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args)
dr6_p = (unsigned long *)ERR_PTR(args->err);
dr6 = *dr6_p;
/* If it's a single step, TRAP bits are random */
if (dr6 & DR_STEP)
return NOTIFY_DONE;
/* Do an early return if no trap bits are set in DR6 */
if ((dr6 & DR_TRAP_BITS) == 0)
return NOTIFY_DONE;
......
......@@ -33,6 +33,8 @@ enum bp_type_idx {
#ifdef CONFIG_HAVE_HW_BREAKPOINT
extern int __init init_hw_breakpoint(void);
static inline void hw_breakpoint_init(struct perf_event_attr *attr)
{
memset(attr, 0, sizeof(*attr));
......@@ -108,6 +110,8 @@ static inline struct arch_hw_breakpoint *counter_arch_bp(struct perf_event *bp)
#else /* !CONFIG_HAVE_HW_BREAKPOINT */
static inline int __init init_hw_breakpoint(void) { return 0; }
static inline struct perf_event *
register_user_hw_breakpoint(struct perf_event_attr *attr,
perf_overflow_handler_t triggered,
......
......@@ -850,6 +850,7 @@ struct perf_event_context {
int nr_active;
int is_active;
int nr_stat;
int rotate_disable;
atomic_t refcount;
struct task_struct *task;
......@@ -908,20 +909,6 @@ extern int perf_num_counters(void);
extern const char *perf_pmu_name(void);
extern void __perf_event_task_sched_in(struct task_struct *task);
extern void __perf_event_task_sched_out(struct task_struct *task, struct task_struct *next);
extern atomic_t perf_task_events;
static inline void perf_event_task_sched_in(struct task_struct *task)
{
COND_STMT(&perf_task_events, __perf_event_task_sched_in(task));
}
static inline
void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next)
{
COND_STMT(&perf_task_events, __perf_event_task_sched_out(task, next));
}
extern int perf_event_init_task(struct task_struct *child);
extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);
......@@ -1030,6 +1017,21 @@ perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
__perf_sw_event(event_id, nr, nmi, regs, addr);
}
extern atomic_t perf_task_events;
static inline void perf_event_task_sched_in(struct task_struct *task)
{
COND_STMT(&perf_task_events, __perf_event_task_sched_in(task));
}
static inline
void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next)
{
perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0);
COND_STMT(&perf_task_events, __perf_event_task_sched_out(task, next));
}
extern void perf_event_mmap(struct vm_area_struct *vma);
extern struct perf_guest_info_callbacks *perf_guest_cbs;
extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
......
......@@ -620,7 +620,7 @@ static struct pmu perf_breakpoint = {
.read = hw_breakpoint_pmu_read,
};
static int __init init_hw_breakpoint(void)
int __init init_hw_breakpoint(void)
{
unsigned int **task_bp_pinned;
int cpu, err_cpu;
......@@ -655,6 +655,5 @@ static int __init init_hw_breakpoint(void)
return -ENOMEM;
}
core_initcall(init_hw_breakpoint);
......@@ -145,7 +145,9 @@ void irq_work_run(void)
* Clear the BUSY bit and return to the free state if
* no-one else claimed it meanwhile.
*/
cmpxchg(&entry->next, next_flags(NULL, IRQ_WORK_BUSY), NULL);
(void)cmpxchg(&entry->next,
next_flags(NULL, IRQ_WORK_BUSY),
NULL);
}
}
EXPORT_SYMBOL_GPL(irq_work_run);
......
......@@ -31,6 +31,7 @@
#include <linux/kernel_stat.h>
#include <linux/perf_event.h>
#include <linux/ftrace_event.h>
#include <linux/hw_breakpoint.h>
#include <asm/irq_regs.h>
......@@ -1286,8 +1287,6 @@ void __perf_event_task_sched_out(struct task_struct *task,
{
int ctxn;
perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0);
for_each_task_context_nr(ctxn)
perf_event_context_sched_out(task, ctxn, next);
}
......@@ -1621,7 +1620,11 @@ static void rotate_ctx(struct perf_event_context *ctx)
{
raw_spin_lock(&ctx->lock);
/* Rotate the first entry last of non-pinned groups */
/*
* Rotate the first entry last of non-pinned groups. Rotation might be
* disabled by the inheritance code.
*/
if (!ctx->rotate_disable)
list_rotate_left(&ctx->flexible_groups);
raw_spin_unlock(&ctx->lock);
......@@ -2234,11 +2237,6 @@ int perf_event_release_kernel(struct perf_event *event)
raw_spin_unlock_irq(&ctx->lock);
mutex_unlock(&ctx->mutex);
mutex_lock(&event->owner->perf_event_mutex);
list_del_init(&event->owner_entry);
mutex_unlock(&event->owner->perf_event_mutex);
put_task_struct(event->owner);
free_event(event);
return 0;
......@@ -2251,9 +2249,43 @@ EXPORT_SYMBOL_GPL(perf_event_release_kernel);
static int perf_release(struct inode *inode, struct file *file)
{
struct perf_event *event = file->private_data;
struct task_struct *owner;
file->private_data = NULL;
rcu_read_lock();
owner = ACCESS_ONCE(event->owner);
/*
* Matches the smp_wmb() in perf_event_exit_task(). If we observe
* !owner it means the list deletion is complete and we can indeed
* free this event, otherwise we need to serialize on
* owner->perf_event_mutex.
*/
smp_read_barrier_depends();
if (owner) {
/*
* Since delayed_put_task_struct() also drops the last
* task reference we can safely take a new reference
* while holding the rcu_read_lock().
*/
get_task_struct(owner);
}
rcu_read_unlock();
if (owner) {
mutex_lock(&owner->perf_event_mutex);
/*
* We have to re-check the event->owner field, if it is cleared
* we raced with perf_event_exit_task(), acquiring the mutex
* ensured they're done, and we can proceed with freeing the
* event.
*/
if (event->owner)
list_del_init(&event->owner_entry);
mutex_unlock(&owner->perf_event_mutex);
put_task_struct(owner);
}
return perf_event_release_kernel(event);
}
......@@ -5668,7 +5700,7 @@ SYSCALL_DEFINE5(perf_event_open,
mutex_unlock(&ctx->mutex);
event->owner = current;
get_task_struct(current);
mutex_lock(&current->perf_event_mutex);
list_add_tail(&event->owner_entry, &current->perf_event_list);
mutex_unlock(&current->perf_event_mutex);
......@@ -5736,12 +5768,6 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
++ctx->generation;
mutex_unlock(&ctx->mutex);
event->owner = current;
get_task_struct(current);
mutex_lock(&current->perf_event_mutex);
list_add_tail(&event->owner_entry, &current->perf_event_list);
mutex_unlock(&current->perf_event_mutex);
return event;
err_free:
......@@ -5892,8 +5918,24 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
*/
void perf_event_exit_task(struct task_struct *child)
{
struct perf_event *event, *tmp;
int ctxn;
mutex_lock(&child->perf_event_mutex);
list_for_each_entry_safe(event, tmp, &child->perf_event_list,
owner_entry) {
list_del_init(&event->owner_entry);
/*
* Ensure the list deletion is visible before we clear
* the owner, closes a race against perf_release() where
* we need to serialize on the owner->perf_event_mutex.
*/
smp_wmb();
event->owner = NULL;
}
mutex_unlock(&child->perf_event_mutex);
for_each_task_context_nr(ctxn)
perf_event_exit_task_context(child, ctxn);
}
......@@ -6113,6 +6155,7 @@ int perf_event_init_context(struct task_struct *child, int ctxn)
struct perf_event *event;
struct task_struct *parent = current;
int inherited_all = 1;
unsigned long flags;
int ret = 0;
child->perf_event_ctxp[ctxn] = NULL;
......@@ -6153,6 +6196,15 @@ int perf_event_init_context(struct task_struct *child, int ctxn)
break;
}
/*
* We can't hold ctx->lock when iterating the ->flexible_group list due
* to allocations, but we need to prevent rotation because
* rotate_ctx() will change the list from interrupt context.
*/
raw_spin_lock_irqsave(&parent_ctx->lock, flags);
parent_ctx->rotate_disable = 1;
raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
list_for_each_entry(event, &parent_ctx->flexible_groups, group_entry) {
ret = inherit_task_group(event, parent, parent_ctx,
child, ctxn, &inherited_all);
......@@ -6160,6 +6212,10 @@ int perf_event_init_context(struct task_struct *child, int ctxn)
break;
}
raw_spin_lock_irqsave(&parent_ctx->lock, flags);
parent_ctx->rotate_disable = 0;
raw_spin_unlock_irqrestore(&parent_ctx->lock, flags);
child_ctx = child->perf_event_ctxp[ctxn];
if (child_ctx && inherited_all) {
......@@ -6312,6 +6368,8 @@ perf_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
void __init perf_event_init(void)
{
int ret;
perf_event_init_all_cpus();
init_srcu_struct(&pmus_srcu);
perf_pmu_register(&perf_swevent);
......@@ -6319,4 +6377,7 @@ void __init perf_event_init(void)
perf_pmu_register(&perf_task_clock);
perf_tp_register();
perf_cpu_notifier(perf_cpu_notify);
ret = init_hw_breakpoint();
WARN(ret, "hw_breakpoint initialization failed with: %d", ret);
}
......@@ -697,17 +697,18 @@ static int __cmd_record(int argc, const char **argv)
if (err < 0)
err = event__synthesize_kernel_mmap(process_synthesized_event,
session, machine, "_stext");
if (err < 0) {
pr_err("Couldn't record kernel reference relocation symbol.\n");
return err;
}
if (err < 0)
pr_err("Couldn't record kernel reference relocation symbol\n"
"Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
"Check /proc/kallsyms permission or run as root.\n");
err = event__synthesize_modules(process_synthesized_event,
session, machine);
if (err < 0) {
pr_err("Couldn't record kernel reference relocation symbol.\n");
return err;
}
if (err < 0)
pr_err("Couldn't record kernel module information.\n"
"Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
"Check /proc/modules permission or run as root.\n");
if (perf_guest)
perf_session__process_machines(session, event__synthesize_guest_os);
......
......@@ -295,7 +295,9 @@ static void symbols__insert_by_name(struct rb_root *self, struct symbol *sym)
{
struct rb_node **p = &self->rb_node;
struct rb_node *parent = NULL;
struct symbol_name_rb_node *symn = ((void *)sym) - sizeof(*parent), *s;
struct symbol_name_rb_node *symn, *s;
symn = container_of(sym, struct symbol_name_rb_node, sym);
while (*p != NULL) {
parent = *p;
......
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