[GIT PULL] perf fixes

From: Ingo Molnar
Date: Fri Aug 03 2012 - 12:41:21 EST

Linus,

Please pull the latest perf-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf-urgent-for-linus

HEAD: e6dab5ffab59e910ec0e3355f4a6f29f7a7be474 perf/trace: Add ability to set a target task for events

Fix merge window fallout and fix sleep profiling (this was
always broken, so it's not a fix for the merge window - we can
skip this one from the head of the tree).

Thanks,

Ingo

------------------>
Andrew Morton (1):
perf/x86/intel/uncore: Make UNCORE_PMU_HRTIMER_INTERVAL 64-bit

Andrew Vagin (1):
perf/trace: Add ability to set a target task for events

Peter Zijlstra (1):
perf/x86: Fix USER/KERNEL tagging of samples properly


arch/x86/include/asm/perf_event.h | 11 ++-
arch/x86/kernel/cpu/perf_event.c | 89 ++++++++++++++++++++++---
arch/x86/kernel/cpu/perf_event.h | 20 ++++++
arch/x86/kernel/cpu/perf_event_amd_ibs.c | 4 +-
arch/x86/kernel/cpu/perf_event_intel_ds.c | 7 +-
arch/x86/kernel/cpu/perf_event_intel_uncore.h | 2 +-
include/linux/ftrace_event.h | 5 +-
include/linux/perf_event.h | 3 +-
include/trace/events/sched.h | 4 ++
include/trace/ftrace.h | 6 +-
kernel/events/callchain.c | 9 ++-
kernel/events/core.c | 30 ++++++++-
kernel/events/internal.h | 3 +-
kernel/trace/trace_event_perf.c | 2 +-
kernel/trace/trace_kprobe.c | 6 +-
kernel/trace/trace_syscalls.c | 4 +-
kernel/trace/trace_uprobe.c | 2 +-
17 files changed, 175 insertions(+), 32 deletions(-)

diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index dab3935..cb4e43b 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -196,11 +196,16 @@ static inline u32 get_ibs_caps(void) { return 0; }
extern void perf_events_lapic_init(void);

/*
- * Abuse bit 3 of the cpu eflags register to indicate proper PEBS IP fixups.
- * This flag is otherwise unused and ABI specified to be 0, so nobody should
- * care what we do with it.
+ * Abuse bits {3,5} of the cpu eflags register. These flags are otherwise
+ * unused and ABI specified to be 0, so nobody should care what we do with
+ * them.
+ *
+ * EXACT - the IP points to the exact instruction that triggered the
+ * event (HW bugs exempt).
+ * VM - original X86_VM_MASK; see set_linear_ip().
*/
#define PERF_EFLAGS_EXACT (1UL << 3)
+#define PERF_EFLAGS_VM (1UL << 5)

struct pt_regs;
extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 29557aa..915b876 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -32,6 +32,8 @@
#include <asm/smp.h>
#include <asm/alternative.h>
#include <asm/timer.h>
+#include <asm/desc.h>
+#include <asm/ldt.h>

#include "perf_event.h"

@@ -1738,6 +1740,29 @@ valid_user_frame(const void __user *fp, unsigned long size)
return (__range_not_ok(fp, size, TASK_SIZE) == 0);
}

+static unsigned long get_segment_base(unsigned int segment)
+{
+ struct desc_struct *desc;
+ int idx = segment >> 3;
+
+ if ((segment & SEGMENT_TI_MASK) == SEGMENT_LDT) {
+ if (idx > LDT_ENTRIES)
+ return 0;
+
+ if (idx > current->active_mm->context.size)
+ return 0;
+
+ desc = current->active_mm->context.ldt;
+ } else {
+ if (idx > GDT_ENTRIES)
+ return 0;
+
+ desc = __this_cpu_ptr(&gdt_page.gdt[0]);
+ }
+
+ return get_desc_base(desc + idx);
+}
+
#ifdef CONFIG_COMPAT

#include <asm/compat.h>
@@ -1746,13 +1771,17 @@ static inline int
perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
{
/* 32-bit process in 64-bit kernel. */
+ unsigned long ss_base, cs_base;
struct stack_frame_ia32 frame;
const void __user *fp;

if (!test_thread_flag(TIF_IA32))
return 0;

- fp = compat_ptr(regs->bp);
+ cs_base = get_segment_base(regs->cs);
+ ss_base = get_segment_base(regs->ss);
+
+ fp = compat_ptr(ss_base + regs->bp);
while (entry->nr < PERF_MAX_STACK_DEPTH) {
unsigned long bytes;
frame.next_frame = 0;
@@ -1765,8 +1794,8 @@ perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry)
if (!valid_user_frame(fp, sizeof(frame)))
break;

- perf_callchain_store(entry, frame.return_address);
- fp = compat_ptr(frame.next_frame);
+ perf_callchain_store(entry, cs_base + frame.return_address);
+ fp = compat_ptr(ss_base + frame.next_frame);
}
return 1;
}
@@ -1789,6 +1818,12 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
return;
}

+ /*
+ * We don't know what to do with VM86 stacks.. ignore them for now.
+ */
+ if (regs->flags & (X86_VM_MASK | PERF_EFLAGS_VM))
+ return;
+
fp = (void __user *)regs->bp;

perf_callchain_store(entry, regs->ip);
@@ -1816,16 +1851,50 @@ perf_callchain_user(struct perf_callchain_entry *entry, struct pt_regs *regs)
}
}

-unsigned long perf_instruction_pointer(struct pt_regs *regs)
+/*
+ * Deal with code segment offsets for the various execution modes:
+ *
+ * VM86 - the good olde 16 bit days, where the linear address is
+ * 20 bits and we use regs->ip + 0x10 * regs->cs.
+ *
+ * IA32 - Where we need to look at GDT/LDT segment descriptor tables
+ * to figure out what the 32bit base address is.
+ *
+ * X32 - has TIF_X32 set, but is running in x86_64
+ *
+ * X86_64 - CS,DS,SS,ES are all zero based.
+ */
+static unsigned long code_segment_base(struct pt_regs *regs)
{
- unsigned long ip;
+ /*
+ * If we are in VM86 mode, add the segment offset to convert to a
+ * linear address.
+ */
+ if (regs->flags & X86_VM_MASK)
+ return 0x10 * regs->cs;
+
+ /*
+ * For IA32 we look at the GDT/LDT segment base to convert the
+ * effective IP to a linear address.
+ */
+#ifdef CONFIG_X86_32
+ if (user_mode(regs) && regs->cs != __USER_CS)
+ return get_segment_base(regs->cs);
+#else
+ if (test_thread_flag(TIF_IA32)) {
+ if (user_mode(regs) && regs->cs != __USER32_CS)
+ return get_segment_base(regs->cs);
+ }
+#endif
+ return 0;
+}

+unsigned long perf_instruction_pointer(struct pt_regs *regs)
+{
if (perf_guest_cbs && perf_guest_cbs->is_in_guest())
- ip = perf_guest_cbs->get_guest_ip();
- else
- ip = instruction_pointer(regs);
+ return perf_guest_cbs->get_guest_ip();

- return ip;
+ return regs->ip + code_segment_base(regs);
}

unsigned long perf_misc_flags(struct pt_regs *regs)
@@ -1838,7 +1907,7 @@ unsigned long perf_misc_flags(struct pt_regs *regs)
else
misc |= PERF_RECORD_MISC_GUEST_KERNEL;
} else {
- if (!kernel_ip(regs->ip))
+ if (user_mode(regs))
misc |= PERF_RECORD_MISC_USER;
else
misc |= PERF_RECORD_MISC_KERNEL;
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 821d53b..6605a81 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -516,6 +516,26 @@ static inline bool kernel_ip(unsigned long ip)
#endif
}

+/*
+ * Not all PMUs provide the right context information to place the reported IP
+ * into full context. Specifically segment registers are typically not
+ * supplied.
+ *
+ * Assuming the address is a linear address (it is for IBS), we fake the CS and
+ * vm86 mode using the known zero-based code segment and 'fix up' the registers
+ * to reflect this.
+ *
+ * Intel PEBS/LBR appear to typically provide the effective address, nothing
+ * much we can do about that but pray and treat it like a linear address.
+ */
+static inline void set_linear_ip(struct pt_regs *regs, unsigned long ip)
+{
+ regs->cs = kernel_ip(ip) ? __KERNEL_CS : __USER_CS;
+ if (regs->flags & X86_VM_MASK)
+ regs->flags ^= (PERF_EFLAGS_VM | X86_VM_MASK);
+ regs->ip = ip;
+}
+
#ifdef CONFIG_CPU_SUP_AMD

int amd_pmu_init(void);
diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
index da9bcdc..7bfb5be 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
@@ -13,6 +13,8 @@

#include <asm/apic.h>

+#include "perf_event.h"
+
static u32 ibs_caps;

#if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD)
@@ -536,7 +538,7 @@ static int perf_ibs_handle_irq(struct perf_ibs *perf_ibs, struct pt_regs *iregs)
if (check_rip && (ibs_data.regs[2] & IBS_RIP_INVALID)) {
regs.flags &= ~PERF_EFLAGS_EXACT;
} else {
- instruction_pointer_set(&regs, ibs_data.regs[1]);
+ set_linear_ip(&regs, ibs_data.regs[1]);
regs.flags |= PERF_EFLAGS_EXACT;
}

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 629ae0b..e38d97b 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -499,7 +499,7 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
* We sampled a branch insn, rewind using the LBR stack
*/
if (ip == to) {
- regs->ip = from;
+ set_linear_ip(regs, from);
return 1;
}

@@ -529,7 +529,7 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
} while (to < ip);

if (to == ip) {
- regs->ip = old_to;
+ set_linear_ip(regs, old_to);
return 1;
}

@@ -569,7 +569,8 @@ static void __intel_pmu_pebs_event(struct perf_event *event,
* A possible PERF_SAMPLE_REGS will have to transfer all regs.
*/
regs = *iregs;
- regs.ip = pebs->ip;
+ regs.flags = pebs->flags;
+ set_linear_ip(&regs, pebs->ip);
regs.bp = pebs->bp;
regs.sp = pebs->sp;

diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.h b/arch/x86/kernel/cpu/perf_event_intel_uncore.h
index f385189..c9e5dc5 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.h
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.h
@@ -5,7 +5,7 @@
#include "perf_event.h"

#define UNCORE_PMU_NAME_LEN 32
-#define UNCORE_PMU_HRTIMER_INTERVAL (60 * NSEC_PER_SEC)
+#define UNCORE_PMU_HRTIMER_INTERVAL (60LL * NSEC_PER_SEC)

#define UNCORE_FIXED_EVENT 0xff
#define UNCORE_PMC_IDX_MAX_GENERIC 8
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index af961d6..642928c 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -306,9 +306,10 @@ extern void *perf_trace_buf_prepare(int size, unsigned short type,

static inline void
perf_trace_buf_submit(void *raw_data, int size, int rctx, u64 addr,
- u64 count, struct pt_regs *regs, void *head)
+ u64 count, struct pt_regs *regs, void *head,
+ struct task_struct *task)
{
- perf_tp_event(addr, count, raw_data, size, regs, head, rctx);
+ perf_tp_event(addr, count, raw_data, size, regs, head, rctx, task);
}
#endif

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 76c5c8b..7602ccb 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1272,7 +1272,8 @@ static inline bool perf_paranoid_kernel(void)
extern void perf_event_init(void);
extern void perf_tp_event(u64 addr, u64 count, void *record,
int entry_size, struct pt_regs *regs,
- struct hlist_head *head, int rctx);
+ struct hlist_head *head, int rctx,
+ struct task_struct *task);
extern void perf_bp_event(struct perf_event *event, void *data);

#ifndef perf_misc_flags
diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
index ea7a203..5a8671e 100644
--- a/include/trace/events/sched.h
+++ b/include/trace/events/sched.h
@@ -73,6 +73,9 @@ DECLARE_EVENT_CLASS(sched_wakeup_template,
__entry->prio = p->prio;
__entry->success = success;
__entry->target_cpu = task_cpu(p);
+ )
+ TP_perf_assign(
+ __perf_task(p);
),

TP_printk("comm=%s pid=%d prio=%d success=%d target_cpu=%03d",
@@ -325,6 +328,7 @@ DECLARE_EVENT_CLASS(sched_stat_template,
)
TP_perf_assign(
__perf_count(delay);
+ __perf_task(tsk);
),

TP_printk("comm=%s pid=%d delay=%Lu [ns]",
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index c6bc2fa..a763888 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -712,6 +712,9 @@ __attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
#undef __perf_count
#define __perf_count(c) __count = (c)

+#undef __perf_task
+#define __perf_task(t) __task = (t)
+
#undef TP_perf_assign
#define TP_perf_assign(args...) args

@@ -725,6 +728,7 @@ perf_trace_##call(void *__data, proto) \
struct ftrace_raw_##call *entry; \
struct pt_regs __regs; \
u64 __addr = 0, __count = 1; \
+ struct task_struct *__task = NULL; \
struct hlist_head *head; \
int __entry_size; \
int __data_size; \
@@ -752,7 +756,7 @@ perf_trace_##call(void *__data, proto) \
\
head = this_cpu_ptr(event_call->perf_events); \
perf_trace_buf_submit(entry, __entry_size, rctx, __addr, \
- __count, &__regs, head); \
+ __count, &__regs, head, __task); \
}

/*
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 6581a04..98d4597 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -153,7 +153,8 @@ put_callchain_entry(int rctx)
put_recursion_context(__get_cpu_var(callchain_recursion), rctx);
}

-struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
+struct perf_callchain_entry *
+perf_callchain(struct perf_event *event, struct pt_regs *regs)
{
int rctx;
struct perf_callchain_entry *entry;
@@ -178,6 +179,12 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
}

if (regs) {
+ /*
+ * Disallow cross-task user callchains.
+ */
+ if (event->ctx->task && event->ctx->task != current)
+ goto exit_put;
+
perf_callchain_store(entry, PERF_CONTEXT_USER);
perf_callchain_user(entry, regs);
}
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f1cf0ed..b7935fc 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4039,7 +4039,7 @@ void perf_prepare_sample(struct perf_event_header *header,
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
int size = 1;

- data->callchain = perf_callchain(regs);
+ data->callchain = perf_callchain(event, regs);

if (data->callchain)
size += data->callchain->nr;
@@ -5209,7 +5209,8 @@ static int perf_tp_event_match(struct perf_event *event,
}

void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
- struct pt_regs *regs, struct hlist_head *head, int rctx)
+ struct pt_regs *regs, struct hlist_head *head, int rctx,
+ struct task_struct *task)
{
struct perf_sample_data data;
struct perf_event *event;
@@ -5228,6 +5229,31 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
perf_swevent_event(event, count, &data, regs);
}

+ /*
+ * If we got specified a target task, also iterate its context and
+ * deliver this event there too.
+ */
+ if (task && task != current) {
+ struct perf_event_context *ctx;
+ struct trace_entry *entry = record;
+
+ rcu_read_lock();
+ ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
+ if (!ctx)
+ goto unlock;
+
+ list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+ if (event->attr.type != PERF_TYPE_TRACEPOINT)
+ continue;
+ if (event->attr.config != entry->type)
+ continue;
+ if (perf_tp_event_match(event, &data, regs))
+ perf_swevent_event(event, count, &data, regs);
+ }
+unlock:
+ rcu_read_unlock();
+ }
+
perf_swevent_put_recursion_context(rctx);
}
EXPORT_SYMBOL_GPL(perf_tp_event);
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index b0b107f..a096c19 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -101,7 +101,8 @@ __output_copy(struct perf_output_handle *handle,
}

/* Callchain handling */
-extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
+extern struct perf_callchain_entry *
+perf_callchain(struct perf_event *event, struct pt_regs *regs);
extern int get_callchain_buffers(void);
extern void put_callchain_buffers(void);

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index fee3752..8a6d2ee 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -281,7 +281,7 @@ perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip)

head = this_cpu_ptr(event_function.perf_events);
perf_trace_buf_submit(entry, ENTRY_SIZE, rctx, 0,
- 1, &regs, head);
+ 1, &regs, head, NULL);

#undef ENTRY_SIZE
}
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index b31d3d5..1a21170 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1002,7 +1002,8 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);

head = this_cpu_ptr(call->perf_events);
- perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
+ perf_trace_buf_submit(entry, size, rctx,
+ entry->ip, 1, regs, head, NULL);
}

/* Kretprobe profile handler */
@@ -1033,7 +1034,8 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);

head = this_cpu_ptr(call->perf_events);
- perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
+ perf_trace_buf_submit(entry, size, rctx,
+ entry->ret_ip, 1, regs, head, NULL);
}
#endif /* CONFIG_PERF_EVENTS */

diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 96fc733..60e4d78 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -532,7 +532,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
(unsigned long *)&rec->args);

head = this_cpu_ptr(sys_data->enter_event->perf_events);
- perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
+ perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
}

int perf_sysenter_enable(struct ftrace_event_call *call)
@@ -608,7 +608,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
rec->ret = syscall_get_return_value(current, regs);

head = this_cpu_ptr(sys_data->exit_event->perf_events);
- perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
+ perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
}

int perf_sysexit_enable(struct ftrace_event_call *call)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 2b36ac6..03003cd 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -670,7 +670,7 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);

head = this_cpu_ptr(call->perf_events);
- perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
+ perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head, NULL);

out:
preempt_enable();
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