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-rw-r--r--kernel/trace/Kconfig40
-rw-r--r--kernel/trace/Makefile5
-rw-r--r--kernel/trace/bpf_trace.c160
-rw-r--r--kernel/trace/ftrace.c30
-rw-r--r--kernel/trace/trace.c61
-rw-r--r--kernel/trace/trace.h5
-rw-r--r--kernel/trace/trace_entries.h27
-rw-r--r--kernel/trace/trace_events_trigger.c1
-rw-r--r--kernel/trace/trace_functions_graph.c73
-rw-r--r--kernel/trace/trace_hwlat.c633
-rw-r--r--kernel/trace/trace_kprobe.c4
-rw-r--r--kernel/trace/trace_output.c66
-rw-r--r--kernel/trace/trace_probe.c30
-rw-r--r--kernel/trace/trace_probe.h11
-rw-r--r--kernel/trace/trace_syscalls.c6
-rw-r--r--kernel/trace/trace_uprobe.c8
16 files changed, 1073 insertions, 87 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index f4b86e8ca1e7..2a96b063d659 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -24,11 +24,6 @@ config HAVE_FUNCTION_GRAPH_TRACER
help
See Documentation/trace/ftrace-design.txt
-config HAVE_FUNCTION_GRAPH_FP_TEST
- bool
- help
- See Documentation/trace/ftrace-design.txt
-
config HAVE_DYNAMIC_FTRACE
bool
help
@@ -221,6 +216,41 @@ config SCHED_TRACER
This tracer tracks the latency of the highest priority task
to be scheduled in, starting from the point it has woken up.
+config HWLAT_TRACER
+ bool "Tracer to detect hardware latencies (like SMIs)"
+ select GENERIC_TRACER
+ help
+ This tracer, when enabled will create one or more kernel threads,
+ depening on what the cpumask file is set to, which each thread
+ spinning in a loop looking for interruptions caused by
+ something other than the kernel. For example, if a
+ System Management Interrupt (SMI) takes a noticeable amount of
+ time, this tracer will detect it. This is useful for testing
+ if a system is reliable for Real Time tasks.
+
+ Some files are created in the tracing directory when this
+ is enabled:
+
+ hwlat_detector/width - time in usecs for how long to spin for
+ hwlat_detector/window - time in usecs between the start of each
+ iteration
+
+ A kernel thread is created that will spin with interrupts disabled
+ for "width" microseconds in every "widow" cycle. It will not spin
+ for "window - width" microseconds, where the system can
+ continue to operate.
+
+ The output will appear in the trace and trace_pipe files.
+
+ When the tracer is not running, it has no affect on the system,
+ but when it is running, it can cause the system to be
+ periodically non responsive. Do not run this tracer on a
+ production system.
+
+ To enable this tracer, echo in "hwlat" into the current_tracer
+ file. Every time a latency is greater than tracing_thresh, it will
+ be recorded into the ring buffer.
+
config ENABLE_DEFAULT_TRACERS
bool "Trace process context switches and events"
depends on !GENERIC_TRACER
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index d0a1617b52b4..e57980845549 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -1,8 +1,4 @@
-# We are fully aware of the dangers of __builtin_return_address()
-FRAME_CFLAGS := $(call cc-disable-warning,frame-address)
-KBUILD_CFLAGS += $(FRAME_CFLAGS)
-
# Do not instrument the tracer itself:
ifdef CONFIG_FUNCTION_TRACER
@@ -41,6 +37,7 @@ obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o
obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o
obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
+obj-$(CONFIG_HWLAT_TRACER) += trace_hwlat.o
obj-$(CONFIG_NOP_TRACER) += trace_nop.o
obj-$(CONFIG_STACK_TRACER) += trace_stack.o
obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index b20438fdb029..5dcb99281259 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1,4 +1,5 @@
/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2016 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
@@ -8,6 +9,7 @@
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/bpf.h>
+#include <linux/bpf_perf_event.h>
#include <linux/filter.h>
#include <linux/uaccess.h>
#include <linux/ctype.h>
@@ -59,11 +61,9 @@ unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx)
}
EXPORT_SYMBOL_GPL(trace_call_bpf);
-static u64 bpf_probe_read(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr)
{
- void *dst = (void *) (long) r1;
- int ret, size = (int) r2;
- void *unsafe_ptr = (void *) (long) r3;
+ int ret;
ret = probe_kernel_read(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
@@ -81,12 +81,9 @@ static const struct bpf_func_proto bpf_probe_read_proto = {
.arg3_type = ARG_ANYTHING,
};
-static u64 bpf_probe_write_user(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+BPF_CALL_3(bpf_probe_write_user, void *, unsafe_ptr, const void *, src,
+ u32, size)
{
- void *unsafe_ptr = (void *) (long) r1;
- void *src = (void *) (long) r2;
- int size = (int) r3;
-
/*
* Ensure we're in user context which is safe for the helper to
* run. This helper has no business in a kthread.
@@ -128,9 +125,9 @@ static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
* limited trace_printk()
* only %d %u %x %ld %lu %lx %lld %llu %llx %p %s conversion specifiers allowed
*/
-static u64 bpf_trace_printk(u64 r1, u64 fmt_size, u64 r3, u64 r4, u64 r5)
+BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
+ u64, arg2, u64, arg3)
{
- char *fmt = (char *) (long) r1;
bool str_seen = false;
int mod[3] = {};
int fmt_cnt = 0;
@@ -176,16 +173,16 @@ static u64 bpf_trace_printk(u64 r1, u64 fmt_size, u64 r3, u64 r4, u64 r5)
switch (fmt_cnt) {
case 1:
- unsafe_addr = r3;
- r3 = (long) buf;
+ unsafe_addr = arg1;
+ arg1 = (long) buf;
break;
case 2:
- unsafe_addr = r4;
- r4 = (long) buf;
+ unsafe_addr = arg2;
+ arg2 = (long) buf;
break;
case 3:
- unsafe_addr = r5;
- r5 = (long) buf;
+ unsafe_addr = arg3;
+ arg3 = (long) buf;
break;
}
buf[0] = 0;
@@ -207,9 +204,9 @@ static u64 bpf_trace_printk(u64 r1, u64 fmt_size, u64 r3, u64 r4, u64 r5)
}
return __trace_printk(1/* fake ip will not be printed */, fmt,
- mod[0] == 2 ? r3 : mod[0] == 1 ? (long) r3 : (u32) r3,
- mod[1] == 2 ? r4 : mod[1] == 1 ? (long) r4 : (u32) r4,
- mod[2] == 2 ? r5 : mod[2] == 1 ? (long) r5 : (u32) r5);
+ mod[0] == 2 ? arg1 : mod[0] == 1 ? (long) arg1 : (u32) arg1,
+ mod[1] == 2 ? arg2 : mod[1] == 1 ? (long) arg2 : (u32) arg2,
+ mod[2] == 2 ? arg3 : mod[2] == 1 ? (long) arg3 : (u32) arg3);
}
static const struct bpf_func_proto bpf_trace_printk_proto = {
@@ -231,9 +228,8 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
return &bpf_trace_printk_proto;
}
-static u64 bpf_perf_event_read(u64 r1, u64 flags, u64 r3, u64 r4, u64 r5)
+BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
{
- struct bpf_map *map = (struct bpf_map *) (unsigned long) r1;
struct bpf_array *array = container_of(map, struct bpf_array, map);
unsigned int cpu = smp_processor_id();
u64 index = flags & BPF_F_INDEX_MASK;
@@ -310,11 +306,9 @@ __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
return 0;
}
-static u64 bpf_perf_event_output(u64 r1, u64 r2, u64 flags, u64 r4, u64 size)
+BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
+ u64, flags, void *, data, u64, size)
{
- struct pt_regs *regs = (struct pt_regs *)(long) r1;
- struct bpf_map *map = (struct bpf_map *)(long) r2;
- void *data = (void *)(long) r4;
struct perf_raw_record raw = {
.frag = {
.size = size,
@@ -365,7 +359,7 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
return __bpf_perf_event_output(regs, map, flags, &raw);
}
-static u64 bpf_get_current_task(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+BPF_CALL_0(bpf_get_current_task)
{
return (long) current;
}
@@ -376,6 +370,31 @@ static const struct bpf_func_proto bpf_get_current_task_proto = {
.ret_type = RET_INTEGER,
};
+BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
+{
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
+ struct cgroup *cgrp;
+
+ if (unlikely(in_interrupt()))
+ return -EINVAL;
+ if (unlikely(idx >= array->map.max_entries))
+ return -E2BIG;
+
+ cgrp = READ_ONCE(array->ptrs[idx]);
+ if (unlikely(!cgrp))
+ return -EAGAIN;
+
+ return task_under_cgroup_hierarchy(current, cgrp);
+}
+
+static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
+ .func = bpf_current_task_under_cgroup,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_CONST_MAP_PTR,
+ .arg2_type = ARG_ANYTHING,
+};
+
static const struct bpf_func_proto *tracing_func_proto(enum bpf_func_id func_id)
{
switch (func_id) {
@@ -407,6 +426,10 @@ static const struct bpf_func_proto *tracing_func_proto(enum bpf_func_id func_id)
return &bpf_perf_event_read_proto;
case BPF_FUNC_probe_write_user:
return bpf_get_probe_write_proto();
+ case BPF_FUNC_current_task_under_cgroup:
+ return &bpf_current_task_under_cgroup_proto;
+ case BPF_FUNC_get_prandom_u32:
+ return &bpf_get_prandom_u32_proto;
default:
return NULL;
}
@@ -447,16 +470,17 @@ static struct bpf_prog_type_list kprobe_tl = {
.type = BPF_PROG_TYPE_KPROBE,
};
-static u64 bpf_perf_event_output_tp(u64 r1, u64 r2, u64 index, u64 r4, u64 size)
+BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
+ u64, flags, void *, data, u64, size)
{
+ struct pt_regs *regs = *(struct pt_regs **)tp_buff;
+
/*
* r1 points to perf tracepoint buffer where first 8 bytes are hidden
* from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
- * from there and call the same bpf_perf_event_output() helper
+ * from there and call the same bpf_perf_event_output() helper inline.
*/
- u64 ctx = *(long *)(uintptr_t)r1;
-
- return bpf_perf_event_output(ctx, r2, index, r4, size);
+ return ____bpf_perf_event_output(regs, map, flags, data, size);
}
static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
@@ -470,11 +494,18 @@ static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
.arg5_type = ARG_CONST_STACK_SIZE,
};
-static u64 bpf_get_stackid_tp(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
+ u64, flags)
{
- u64 ctx = *(long *)(uintptr_t)r1;
+ struct pt_regs *regs = *(struct pt_regs **)tp_buff;
- return bpf_get_stackid(ctx, r2, r3, r4, r5);
+ /*
+ * Same comment as in bpf_perf_event_output_tp(), only that this time
+ * the other helper's function body cannot be inlined due to being
+ * external, thus we need to call raw helper function.
+ */
+ return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
+ flags, 0, 0);
}
static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
@@ -520,10 +551,69 @@ static struct bpf_prog_type_list tracepoint_tl = {
.type = BPF_PROG_TYPE_TRACEPOINT,
};
+static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
+ enum bpf_reg_type *reg_type)
+{
+ if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
+ return false;
+ if (type != BPF_READ)
+ return false;
+ if (off % size != 0)
+ return false;
+ if (off == offsetof(struct bpf_perf_event_data, sample_period)) {
+ if (size != sizeof(u64))
+ return false;
+ } else {
+ if (size != sizeof(long))
+ return false;
+ }
+ return true;
+}
+
+static u32 pe_prog_convert_ctx_access(enum bpf_access_type type, int dst_reg,
+ int src_reg, int ctx_off,
+ struct bpf_insn *insn_buf,
+ struct bpf_prog *prog)
+{
+ struct bpf_insn *insn = insn_buf;
+
+ switch (ctx_off) {
+ case offsetof(struct bpf_perf_event_data, sample_period):
+ BUILD_BUG_ON(FIELD_SIZEOF(struct perf_sample_data, period) != sizeof(u64));
+
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
+ data), dst_reg, src_reg,
+ offsetof(struct bpf_perf_event_data_kern, data));
+ *insn++ = BPF_LDX_MEM(BPF_DW, dst_reg, dst_reg,
+ offsetof(struct perf_sample_data, period));
+ break;
+ default:
+ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
+ regs), dst_reg, src_reg,
+ offsetof(struct bpf_perf_event_data_kern, regs));
+ *insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), dst_reg, dst_reg, ctx_off);
+ break;
+ }
+
+ return insn - insn_buf;
+}
+
+static const struct bpf_verifier_ops perf_event_prog_ops = {
+ .get_func_proto = tp_prog_func_proto,
+ .is_valid_access = pe_prog_is_valid_access,
+ .convert_ctx_access = pe_prog_convert_ctx_access,
+};
+
+static struct bpf_prog_type_list perf_event_tl = {
+ .ops = &perf_event_prog_ops,
+ .type = BPF_PROG_TYPE_PERF_EVENT,
+};
+
static int __init register_kprobe_prog_ops(void)
{
bpf_register_prog_type(&kprobe_tl);
bpf_register_prog_type(&tracepoint_tl);
+ bpf_register_prog_type(&perf_event_tl);
return 0;
}
late_initcall(register_kprobe_prog_ops);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 84752c8e28b5..da87b3cba5b3 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -872,7 +872,13 @@ function_profile_call(unsigned long ip, unsigned long parent_ip,
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static int profile_graph_entry(struct ftrace_graph_ent *trace)
{
+ int index = trace->depth;
+
function_profile_call(trace->func, 0, NULL, NULL);
+
+ if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
+ current->ret_stack[index].subtime = 0;
+
return 1;
}
@@ -1856,6 +1862,10 @@ static int __ftrace_hash_update_ipmodify(struct ftrace_ops *ops,
/* Update rec->flags */
do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
/* We need to update only differences of filter_hash */
in_old = !!ftrace_lookup_ip(old_hash, rec->ip);
in_new = !!ftrace_lookup_ip(new_hash, rec->ip);
@@ -1878,6 +1888,10 @@ rollback:
/* Roll back what we did above */
do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
if (rec == end)
goto err_out;
@@ -2391,6 +2405,10 @@ void __weak ftrace_replace_code(int enable)
return;
do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
failed = __ftrace_replace_code(rec, enable);
if (failed) {
ftrace_bug(failed, rec);
@@ -2757,7 +2775,7 @@ static int ftrace_shutdown(struct ftrace_ops *ops, int command)
struct dyn_ftrace *rec;
do_for_each_ftrace_rec(pg, rec) {
- if (FTRACE_WARN_ON_ONCE(rec->flags))
+ if (FTRACE_WARN_ON_ONCE(rec->flags & ~FTRACE_FL_DISABLED))
pr_warn(" %pS flags:%lx\n",
(void *)rec->ip, rec->flags);
} while_for_each_ftrace_rec();
@@ -3592,6 +3610,10 @@ match_records(struct ftrace_hash *hash, char *func, int len, char *mod)
goto out_unlock;
do_for_each_ftrace_rec(pg, rec) {
+
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
if (ftrace_match_record(rec, &func_g, mod_match, exclude_mod)) {
ret = enter_record(hash, rec, clear_filter);
if (ret < 0) {
@@ -3787,6 +3809,9 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
do_for_each_ftrace_rec(pg, rec) {
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
if (!ftrace_match_record(rec, &func_g, NULL, 0))
continue;
@@ -4679,6 +4704,9 @@ ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
do_for_each_ftrace_rec(pg, rec) {
+ if (rec->flags & FTRACE_FL_DISABLED)
+ continue;
+
if (ftrace_match_record(rec, &func_g, NULL, 0)) {
/* if it is in the array */
exists = false;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index dade4c9559cc..8696ce6bf2f6 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1047,7 +1047,7 @@ void disable_trace_on_warning(void)
*
* Shows real state of the ring buffer if it is enabled or not.
*/
-static int tracer_tracing_is_on(struct trace_array *tr)
+int tracer_tracing_is_on(struct trace_array *tr)
{
if (tr->trace_buffer.buffer)
return ring_buffer_record_is_on(tr->trace_buffer.buffer);
@@ -4123,6 +4123,30 @@ static const char readme_msg[] =
"\t\t\t traces\n"
#endif
#endif /* CONFIG_STACK_TRACER */
+#ifdef CONFIG_KPROBE_EVENT
+ " kprobe_events\t\t- Add/remove/show the kernel dynamic events\n"
+ "\t\t\t Write into this file to define/undefine new trace events.\n"
+#endif
+#ifdef CONFIG_UPROBE_EVENT
+ " uprobe_events\t\t- Add/remove/show the userspace dynamic events\n"
+ "\t\t\t Write into this file to define/undefine new trace events.\n"
+#endif
+#if defined(CONFIG_KPROBE_EVENT) || defined(CONFIG_UPROBE_EVENT)
+ "\t accepts: event-definitions (one definition per line)\n"
+ "\t Format: p|r[:[<group>/]<event>] <place> [<args>]\n"
+ "\t -:[<group>/]<event>\n"
+#ifdef CONFIG_KPROBE_EVENT
+ "\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
+#endif
+#ifdef CONFIG_UPROBE_EVENT
+ "\t place: <path>:<offset>\n"
+#endif
+ "\t args: <name>=fetcharg[:type]\n"
+ "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n"
+ "\t $stack<index>, $stack, $retval, $comm\n"
+ "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string,\n"
+ "\t b<bit-width>@<bit-offset>/<container-size>\n"
+#endif
" events/\t\t- Directory containing all trace event subsystems:\n"
" enable\t\t- Write 0/1 to enable/disable tracing of all events\n"
" events/<system>/\t- Directory containing all trace events for <system>:\n"
@@ -4945,7 +4969,7 @@ out:
return ret;
}
-#ifdef CONFIG_TRACER_MAX_TRACE
+#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
static ssize_t
tracing_max_lat_read(struct file *filp, char __user *ubuf,
@@ -5124,19 +5148,20 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
struct trace_iterator *iter = filp->private_data;
ssize_t sret;
- /* return any leftover data */
- sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
- if (sret != -EBUSY)
- return sret;
-
- trace_seq_init(&iter->seq);
-
/*
* Avoid more than one consumer on a single file descriptor
* This is just a matter of traces coherency, the ring buffer itself
* is protected.
*/
mutex_lock(&iter->mutex);
+
+ /* return any leftover data */
+ sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+ if (sret != -EBUSY)
+ goto out;
+
+ trace_seq_init(&iter->seq);
+
if (iter->trace->read) {
sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
if (sret)
@@ -5867,7 +5892,7 @@ static const struct file_operations tracing_thresh_fops = {
.llseek = generic_file_llseek,
};
-#ifdef CONFIG_TRACER_MAX_TRACE
+#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
static const struct file_operations tracing_max_lat_fops = {
.open = tracing_open_generic,
.read = tracing_max_lat_read,
@@ -6163,9 +6188,6 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
return -EBUSY;
#endif
- if (splice_grow_spd(pipe, &spd))
- return -ENOMEM;
-
if (*ppos & (PAGE_SIZE - 1))
return -EINVAL;
@@ -6175,6 +6197,9 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
len &= PAGE_MASK;
}
+ if (splice_grow_spd(pipe, &spd))
+ return -ENOMEM;
+
again:
trace_access_lock(iter->cpu_file);
entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
@@ -6232,19 +6257,21 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
/* did we read anything? */
if (!spd.nr_pages) {
if (ret)
- return ret;
+ goto out;
+ ret = -EAGAIN;
if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
- return -EAGAIN;
+ goto out;
ret = wait_on_pipe(iter, true);
if (ret)
- return ret;
+ goto out;
goto again;
}
ret = splice_to_pipe(pipe, &spd);
+out:
splice_shrink_spd(&spd);
return ret;
@@ -7195,7 +7222,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
create_trace_options_dir(tr);
-#ifdef CONFIG_TRACER_MAX_TRACE
+#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
trace_create_file("tracing_max_latency", 0644, d_tracer,
&tr->max_latency, &tracing_max_lat_fops);
#endif
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index f783df416726..fd24b1f9ac43 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -38,6 +38,7 @@ enum trace_type {
TRACE_USER_STACK,
TRACE_BLK,
TRACE_BPUTS,
+ TRACE_HWLAT,
__TRACE_LAST_TYPE,
};
@@ -213,6 +214,8 @@ struct trace_array {
*/
struct trace_buffer max_buffer;
bool allocated_snapshot;
+#endif
+#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
unsigned long max_latency;
#endif
struct trace_pid_list __rcu *filtered_pids;
@@ -326,6 +329,7 @@ extern void __ftrace_bad_type(void);
IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \
+ IF_ASSIGN(var, ent, struct hwlat_entry, TRACE_HWLAT); \
IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
TRACE_MMIO_RW); \
IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
@@ -571,6 +575,7 @@ void tracing_reset_current(int cpu);
void tracing_reset_all_online_cpus(void);
int tracing_open_generic(struct inode *inode, struct file *filp);
bool tracing_is_disabled(void);
+int tracer_tracing_is_on(struct trace_array *tr);
struct dentry *trace_create_file(const char *name,
umode_t mode,
struct dentry *parent,
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index 5c30efcda5e6..d1cc37e78f99 100644
--- a/kernel/trace/trace_entries.h
+++ b/kernel/trace/trace_entries.h
@@ -322,3 +322,30 @@ FTRACE_ENTRY(branch, trace_branch,
FILTER_OTHER
);
+
+FTRACE_ENTRY(hwlat, hwlat_entry,
+
+ TRACE_HWLAT,
+
+ F_STRUCT(
+ __field( u64, duration )
+ __field( u64, outer_duration )
+ __field( u64, nmi_total_ts )
+ __field_struct( struct timespec, timestamp )
+ __field_desc( long, timestamp, tv_sec )
+ __field_desc( long, timestamp, tv_nsec )
+ __field( unsigned int, nmi_count )
+ __field( unsigned int, seqnum )
+ ),
+
+ F_printk("cnt:%u\tts:%010lu.%010lu\tinner:%llu\touter:%llunmi-ts:%llu\tnmi-count:%u\n",
+ __entry->seqnum,
+ __entry->tv_sec,
+ __entry->tv_nsec,
+ __entry->duration,
+ __entry->outer_duration,
+ __entry->nmi_total_ts,
+ __entry->nmi_count),
+
+ FILTER_OTHER
+);
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index a975571cde24..6721a1e89f39 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1028,6 +1028,7 @@ static struct event_command trigger_traceon_cmd = {
static struct event_command trigger_traceoff_cmd = {
.name = "traceoff",
.trigger_type = ETT_TRACE_ONOFF,
+ .flags = EVENT_CMD_FL_POST_TRIGGER,
.func = event_trigger_callback,
.reg = register_trigger,
.unreg = unregister_trigger,
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 7363ccf79512..4e480e870474 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -119,7 +119,7 @@ print_graph_duration(struct trace_array *tr, unsigned long long duration,
/* Add a function return address to the trace stack on thread info.*/
int
ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
- unsigned long frame_pointer)
+ unsigned long frame_pointer, unsigned long *retp)
{
unsigned long long calltime;
int index;
@@ -170,8 +170,12 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth,
current->ret_stack[index].ret = ret;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = calltime;
- current->ret_stack[index].subtime = 0;
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
current->ret_stack[index].fp = frame_pointer;
+#endif
+#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+ current->ret_stack[index].retp = retp;
+#endif
*depth = current->curr_ret_stack;
return 0;
@@ -204,7 +208,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret,
return;
}
-#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTRY)
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
/*
* The arch may choose to record the frame pointer used
* and check it here to make sure that it is what we expect it
@@ -279,6 +283,64 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
return ret;
}
+/**
+ * ftrace_graph_ret_addr - convert a potentially modified stack return address
+ * to its original value
+ *
+ * This function can be called by stack unwinding code to convert a found stack
+ * return address ('ret') to its original value, in case the function graph
+ * tracer has modified it to be 'return_to_handler'. If the address hasn't
+ * been modified, the unchanged value of 'ret' is returned.
+ *
+ * 'idx' is a state variable which should be initialized by the caller to zero
+ * before the first call.
+ *
+ * 'retp' is a pointer to the return address on the stack. It's ignored if
+ * the arch doesn't have HAVE_FUNCTION_GRAPH_RET_ADDR_PTR defined.
+ */
+#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
+unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
+ unsigned long ret, unsigned long *retp)
+{
+ int index = task->curr_ret_stack;
+ int i;
+
+ if (ret != (unsigned long)return_to_handler)
+ return ret;
+
+ if (index < -1)
+ index += FTRACE_NOTRACE_DEPTH;
+
+ if (index < 0)
+ return ret;
+
+ for (i = 0; i <= index; i++)
+ if (task->ret_stack[i].retp == retp)
+ return task->ret_stack[i].ret;
+
+ return ret;
+}
+#else /* !HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
+unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
+ unsigned long ret, unsigned long *retp)
+{
+ int task_idx;
+
+ if (ret != (unsigned long)return_to_handler)
+ return ret;
+
+ task_idx = task->curr_ret_stack;
+
+ if (!task->ret_stack || task_idx < *idx)
+ return ret;
+
+ task_idx -= *idx;
+ (*idx)++;
+
+ return task->ret_stack[task_idx].ret;
+}
+#endif /* HAVE_FUNCTION_GRAPH_RET_ADDR_PTR */
+
int __trace_graph_entry(struct trace_array *tr,
struct ftrace_graph_ent *trace,
unsigned long flags,
@@ -1120,6 +1182,11 @@ print_graph_comment(struct trace_seq *s, struct trace_entry *ent,
trace_seq_puts(s, "/* ");
switch (iter->ent->type) {
+ case TRACE_BPUTS:
+ ret = trace_print_bputs_msg_only(iter);
+ if (ret != TRACE_TYPE_HANDLED)
+ return ret;
+ break;
case TRACE_BPRINT:
ret = trace_print_bprintk_msg_only(iter);
if (ret != TRACE_TYPE_HANDLED)
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
new file mode 100644
index 000000000000..b97286c48735
--- /dev/null
+++ b/kernel/trace/trace_hwlat.c
@@ -0,0 +1,633 @@
+/*
+ * trace_hwlatdetect.c - A simple Hardware Latency detector.
+ *
+ * Use this tracer to detect large system latencies induced by the behavior of
+ * certain underlying system hardware or firmware, independent of Linux itself.
+ * The code was developed originally to detect the presence of SMIs on Intel
+ * and AMD systems, although there is no dependency upon x86 herein.
+ *
+ * The classical example usage of this tracer is in detecting the presence of
+ * SMIs or System Management Interrupts on Intel and AMD systems. An SMI is a
+ * somewhat special form of hardware interrupt spawned from earlier CPU debug
+ * modes in which the (BIOS/EFI/etc.) firmware arranges for the South Bridge
+ * LPC (or other device) to generate a special interrupt under certain
+ * circumstances, for example, upon expiration of a special SMI timer device,
+ * due to certain external thermal readings, on certain I/O address accesses,
+ * and other situations. An SMI hits a special CPU pin, triggers a special
+ * SMI mode (complete with special memory map), and the OS is unaware.
+ *
+ * Although certain hardware-inducing latencies are necessary (for example,
+ * a modern system often requires an SMI handler for correct thermal control
+ * and remote management) they can wreak havoc upon any OS-level performance
+ * guarantees toward low-latency, especially when the OS is not even made
+ * aware of the presence of these interrupts. For this reason, we need a
+ * somewhat brute force mechanism to detect these interrupts. In this case,
+ * we do it by hogging all of the CPU(s) for configurable timer intervals,
+ * sampling the built-in CPU timer, looking for discontiguous readings.
+ *
+ * WARNING: This implementation necessarily introduces latencies. Therefore,
+ * you should NEVER use this tracer while running in a production
+ * environment requiring any kind of low-latency performance
+ * guarantee(s).
+ *
+ * Copyright (C) 2008-2009 Jon Masters, Red Hat, Inc. <jcm@redhat.com>
+ * Copyright (C) 2013-2016 Steven Rostedt, Red Hat, Inc. <srostedt@redhat.com>
+ *
+ * Includes useful feedback from Clark Williams <clark@redhat.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/kthread.h>
+#include <linux/tracefs.h>
+#include <linux/uaccess.h>
+#include <linux/cpumask.h>
+#include <linux/delay.h>
+#include "trace.h"
+
+static struct trace_array *hwlat_trace;
+
+#define U64STR_SIZE 22 /* 20 digits max */
+
+#define BANNER "hwlat_detector: "
+#define DEFAULT_SAMPLE_WINDOW 1000000 /* 1s */
+#define DEFAULT_SAMPLE_WIDTH 500000 /* 0.5s */
+#define DEFAULT_LAT_THRESHOLD 10 /* 10us */
+
+/* sampling thread*/
+static struct task_struct *hwlat_kthread;
+
+static struct dentry *hwlat_sample_width; /* sample width us */
+static struct dentry *hwlat_sample_window; /* sample window us */
+
+/* Save the previous tracing_thresh value */
+static unsigned long save_tracing_thresh;
+
+/* NMI timestamp counters */
+static u64 nmi_ts_start;
+static u64 nmi_total_ts;
+static int nmi_count;
+static int nmi_cpu;
+
+/* Tells NMIs to call back to the hwlat tracer to record timestamps */
+bool trace_hwlat_callback_enabled;
+
+/* If the user changed threshold, remember it */
+static u64 last_tracing_thresh = DEFAULT_LAT_THRESHOLD * NSEC_PER_USEC;
+
+/* Individual latency samples are stored here when detected. */
+struct hwlat_sample {
+ u64 seqnum; /* unique sequence */
+ u64 duration; /* delta */
+ u64 outer_duration; /* delta (outer loop) */
+ u64 nmi_total_ts; /* Total time spent in NMIs */
+ struct timespec timestamp; /* wall time */
+ int nmi_count; /* # NMIs during this sample */
+};
+
+/* keep the global state somewhere. */
+static struct hwlat_data {
+
+ struct mutex lock; /* protect changes */
+
+ u64 count; /* total since reset */
+
+ u64 sample_window; /* total sampling window (on+off) */
+ u64 sample_width; /* active sampling portion of window */
+
+} hwlat_data = {
+ .sample_window = DEFAULT_SAMPLE_WINDOW,
+ .sample_width = DEFAULT_SAMPLE_WIDTH,
+};
+
+static void trace_hwlat_sample(struct hwlat_sample *sample)
+{
+ struct trace_array *tr = hwlat_trace;
+ struct trace_event_call *call = &event_hwlat;
+ struct ring_buffer *buffer = tr->trace_buffer.buffer;
+ struct ring_buffer_event *event;
+ struct hwlat_entry *entry;
+ unsigned long flags;
+ int pc;
+
+ pc = preempt_count();
+ local_save_flags(flags);
+
+ event = trace_buffer_lock_reserve(buffer, TRACE_HWLAT, sizeof(*entry),
+ flags, pc);
+ if (!event)
+ return;
+ entry = ring_buffer_event_data(event);
+ entry->seqnum = sample->seqnum;
+ entry->duration = sample->duration;
+ entry->outer_duration = sample->outer_duration;
+ entry->timestamp = sample->timestamp;
+ entry->nmi_total_ts = sample->nmi_total_ts;
+ entry->nmi_count = sample->nmi_count;
+
+ if (!call_filter_check_discard(call, entry, buffer, event))
+ __buffer_unlock_commit(buffer, event);
+}
+
+/* Macros to encapsulate the time capturing infrastructure */
+#define time_type u64
+#define time_get() trace_clock_local()
+#define time_to_us(x) div_u64(x, 1000)
+#define time_sub(a, b) ((a) - (b))
+#define init_time(a, b) (a = b)
+#define time_u64(a) a
+
+void trace_hwlat_callback(bool enter)
+{
+ if (smp_processor_id() != nmi_cpu)
+ return;
+
+ /*
+ * Currently trace_clock_local() calls sched_clock() and the
+ * generic version is not NMI safe.
+ */
+ if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK)) {
+ if (enter)
+ nmi_ts_start = time_get();
+ else
+ nmi_total_ts = time_get() - nmi_ts_start;
+ }
+
+ if (enter)
+ nmi_count++;
+}
+
+/**
+ * get_sample - sample the CPU TSC and look for likely hardware latencies
+ *
+ * Used to repeatedly capture the CPU TSC (or similar), looking for potential
+ * hardware-induced latency. Called with interrupts disabled and with
+ * hwlat_data.lock held.
+ */
+static int get_sample(void)
+{
+ struct trace_array *tr = hwlat_trace;
+ time_type start, t1, t2, last_t2;
+ s64 diff, total, last_total = 0;
+ u64 sample = 0;
+ u64 thresh = tracing_thresh;
+ u64 outer_sample = 0;
+ int ret = -1;
+
+ do_div(thresh, NSEC_PER_USEC); /* modifies interval value */
+
+ nmi_cpu = smp_processor_id();
+ nmi_total_ts = 0;
+ nmi_count = 0;
+ /* Make sure NMIs see this first */
+ barrier();
+
+ trace_hwlat_callback_enabled = true;
+
+ init_time(last_t2, 0);
+ start = time_get(); /* start timestamp */
+
+ do {
+
+ t1 = time_get(); /* we'll look for a discontinuity */
+ t2 = time_get();
+
+ if (time_u64(last_t2)) {
+ /* Check the delta from outer loop (t2 to next t1) */
+ diff = time_to_us(time_sub(t1, last_t2));
+ /* This shouldn't happen */
+ if (diff < 0) {
+ pr_err(BANNER "time running backwards\n");
+ goto out;
+ }
+ if (diff > outer_sample)
+ outer_sample = diff;
+ }
+ last_t2 = t2;
+
+ total = time_to_us(time_sub(t2, start)); /* sample width */
+
+ /* Check for possible overflows */
+ if (total < last_total) {
+ pr_err("Time total overflowed\n");
+ break;
+ }
+ last_total = total;
+
+ /* This checks the inner loop (t1 to t2) */
+ diff = time_to_us(time_sub(t2, t1)); /* current diff */
+
+ /* This shouldn't happen */
+ if (diff < 0) {
+ pr_err(BANNER "time running backwards\n");
+ goto out;
+ }
+
+ if (diff > sample)
+ sample = diff; /* only want highest value */
+
+ } while (total <= hwlat_data.sample_width);
+
+ barrier(); /* finish the above in the view for NMIs */
+ trace_hwlat_callback_enabled = false;
+ barrier(); /* Make sure nmi_total_ts is no longer updated */
+
+ ret = 0;
+
+ /* If we exceed the threshold value, we have found a hardware latency */
+ if (sample > thresh || outer_sample > thresh) {
+ struct hwlat_sample s;
+
+ ret = 1;
+
+ /* We read in microseconds */
+ if (nmi_total_ts)
+ do_div(nmi_total_ts, NSEC_PER_USEC);
+
+ hwlat_data.count++;
+ s.seqnum = hwlat_data.count;
+ s.duration = sample;
+ s.outer_duration = outer_sample;
+ s.timestamp = CURRENT_TIME;
+ s.nmi_total_ts = nmi_total_ts;
+ s.nmi_count = nmi_count;
+ trace_hwlat_sample(&s);
+
+ /* Keep a running maximum ever recorded hardware latency */
+ if (sample > tr->max_latency)
+ tr->max_latency = sample;
+ }
+
+out:
+ return ret;
+}
+
+static struct cpumask save_cpumask;
+static bool disable_migrate;
+
+static void move_to_next_cpu(void)
+{
+ static struct cpumask *current_mask;
+ int next_cpu;
+
+ if (disable_migrate)
+ return;
+
+ /* Just pick the first CPU on first iteration */
+ if (!current_mask) {
+ current_mask = &save_cpumask;
+ get_online_cpus();
+ cpumask_and(current_mask, cpu_online_mask, tracing_buffer_mask);
+ put_online_cpus();
+ next_cpu = cpumask_first(current_mask);
+ goto set_affinity;
+ }
+
+ /*
+ * If for some reason the user modifies the CPU affinity
+ * of this thread, than stop migrating for the duration
+ * of the current test.
+ */
+ if (!cpumask_equal(current_mask, &current->cpus_allowed))
+ goto disable;
+
+ get_online_cpus();
+ cpumask_and(current_mask, cpu_online_mask, tracing_buffer_mask);
+ next_cpu = cpumask_next(smp_processor_id(), current_mask);
+ put_online_cpus();
+
+ if (next_cpu >= nr_cpu_ids)
+ next_cpu = cpumask_first(current_mask);
+
+ set_affinity:
+ if (next_cpu >= nr_cpu_ids) /* Shouldn't happen! */
+ goto disable;
+
+ cpumask_clear(current_mask);
+ cpumask_set_cpu(next_cpu, current_mask);
+
+ sched_setaffinity(0, current_mask);
+ return;
+
+ disable:
+ disable_migrate = true;
+}
+
+/*
+ * kthread_fn - The CPU time sampling/hardware latency detection kernel thread
+ *
+ * Used to periodically sample the CPU TSC via a call to get_sample. We
+ * disable interrupts, which does (intentionally) introduce latency since we
+ * need to ensure nothing else might be running (and thus preempting).
+ * Obviously this should never be used in production environments.
+ *
+ * Currently this runs on which ever CPU it was scheduled on, but most
+ * real-world hardware latency situations occur across several CPUs,
+ * but we might later generalize this if we find there are any actualy
+ * systems with alternate SMI delivery or other hardware latencies.
+ */
+static int kthread_fn(void *data)
+{
+ u64 interval;
+
+ while (!kthread_should_stop()) {
+
+ move_to_next_cpu();
+
+ local_irq_disable();
+ get_sample();
+ local_irq_enable();
+
+ mutex_lock(&hwlat_data.lock);
+ interval = hwlat_data.sample_window - hwlat_data.sample_width;
+ mutex_unlock(&hwlat_data.lock);
+
+ do_div(interval, USEC_PER_MSEC); /* modifies interval value */
+
+ /* Always sleep for at least 1ms */
+ if (interval < 1)
+ interval = 1;
+
+ if (msleep_interruptible(interval))
+ break;
+ }
+
+ return 0;
+}
+
+/**
+ * start_kthread - Kick off the hardware latency sampling/detector kthread
+ *
+ * This starts the kernel thread that will sit and sample the CPU timestamp
+ * counter (TSC or similar) and look for potential hardware latencies.
+ */
+static int start_kthread(struct trace_array *tr)
+{
+ struct task_struct *kthread;
+
+ kthread = kthread_create(kthread_fn, NULL, "hwlatd");
+ if (IS_ERR(kthread)) {
+ pr_err(BANNER "could not start sampling thread\n");
+ return -ENOMEM;
+ }
+ hwlat_kthread = kthread;
+ wake_up_process(kthread);
+
+ return 0;
+}
+
+/**
+ * stop_kthread - Inform the hardware latency samping/detector kthread to stop
+ *
+ * This kicks the running hardware latency sampling/detector kernel thread and
+ * tells it to stop sampling now. Use this on unload and at system shutdown.
+ */
+static void stop_kthread(void)
+{
+ if (!hwlat_kthread)
+ return;
+ kthread_stop(hwlat_kthread);
+ hwlat_kthread = NULL;
+}
+
+/*
+ * hwlat_read - Wrapper read function for reading both window and width
+ * @filp: The active open file structure
+ * @ubuf: The userspace provided buffer to read value into
+ * @cnt: The maximum number of bytes to read
+ * @ppos: The current "file" position
+ *
+ * This function provides a generic read implementation for the global state
+ * "hwlat_data" structure filesystem entries.
+ */
+static ssize_t hwlat_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[U64STR_SIZE];
+ u64 *entry = filp->private_data;
+ u64 val;
+ int len;
+
+ if (!entry)
+ return -EFAULT;
+
+ if (cnt > sizeof(buf))
+ cnt = sizeof(buf);
+
+ val = *entry;
+
+ len = snprintf(buf, sizeof(buf), "%llu\n", val);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
+}
+
+/**
+ * hwlat_width_write - Write function for "width" entry
+ * @filp: The active open file structure
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in @file
+ *
+ * This function provides a write implementation for the "width" interface
+ * to the hardware latency detector. It can be used to configure
+ * for how many us of the total window us we will actively sample for any
+ * hardware-induced latency periods. Obviously, it is not possible to
+ * sample constantly and have the system respond to a sample reader, or,
+ * worse, without having the system appear to have gone out to lunch. It
+ * is enforced that width is less that the total window size.
+ */
+static ssize_t
+hwlat_width_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ u64 val;
+ int err;
+
+ err = kstrtoull_from_user(ubuf, cnt, 10, &val);
+ if (err)
+ return err;
+
+ mutex_lock(&hwlat_data.lock);
+ if (val < hwlat_data.sample_window)
+ hwlat_data.sample_width = val;
+ else
+ err = -EINVAL;
+ mutex_unlock(&hwlat_data.lock);
+
+ if (err)
+ return err;
+
+ return cnt;
+}
+
+/**
+ * hwlat_window_write - Write function for "window" entry
+ * @filp: The active open file structure
+ * @ubuf: The user buffer that contains the value to write
+ * @cnt: The maximum number of bytes to write to "file"
+ * @ppos: The current position in @file
+ *
+ * This function provides a write implementation for the "window" interface
+ * to the hardware latency detetector. The window is the total time
+ * in us that will be considered one sample period. Conceptually, windows
+ * occur back-to-back and contain a sample width period during which
+ * actual sampling occurs. Can be used to write a new total window size. It
+ * is enfoced that any value written must be greater than the sample width
+ * size, or an error results.
+ */
+static ssize_t
+hwlat_window_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ u64 val;
+ int err;
+
+ err = kstrtoull_from_user(ubuf, cnt, 10, &val);
+ if (err)
+ return err;
+
+ mutex_lock(&hwlat_data.lock);
+ if (hwlat_data.sample_width < val)
+ hwlat_data.sample_window = val;
+ else
+ err = -EINVAL;
+ mutex_unlock(&hwlat_data.lock);
+
+ if (err)
+ return err;
+
+ return cnt;
+}
+
+static const struct file_operations width_fops = {
+ .open = tracing_open_generic,
+ .read = hwlat_read,
+ .write = hwlat_width_write,
+};
+
+static const struct file_operations window_fops = {
+ .open = tracing_open_generic,
+ .read = hwlat_read,
+ .write = hwlat_window_write,
+};
+
+/**
+ * init_tracefs - A function to initialize the tracefs interface files
+ *
+ * This function creates entries in tracefs for "hwlat_detector".
+ * It creates the hwlat_detector directory in the tracing directory,
+ * and within that directory is the count, width and window files to
+ * change and view those values.
+ */
+static int init_tracefs(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *top_dir;
+
+ d_tracer = tracing_init_dentry();
+ if (IS_ERR(d_tracer))
+ return -ENOMEM;
+
+ top_dir = tracefs_create_dir("hwlat_detector", d_tracer);
+ if (!top_dir)
+ return -ENOMEM;
+
+ hwlat_sample_window = tracefs_create_file("window", 0640,
+ top_dir,
+ &hwlat_data.sample_window,
+ &window_fops);
+ if (!hwlat_sample_window)
+ goto err;
+
+ hwlat_sample_width = tracefs_create_file("width", 0644,
+ top_dir,
+ &hwlat_data.sample_width,
+ &width_fops);
+ if (!hwlat_sample_width)
+ goto err;
+
+ return 0;
+
+ err:
+ tracefs_remove_recursive(top_dir);
+ return -ENOMEM;
+}
+
+static void hwlat_tracer_start(struct trace_array *tr)
+{
+ int err;
+
+ err = start_kthread(tr);
+ if (err)
+ pr_err(BANNER "Cannot start hwlat kthread\n");
+}
+
+static void hwlat_tracer_stop(struct trace_array *tr)
+{
+ stop_kthread();
+}
+
+static bool hwlat_busy;
+
+static int hwlat_tracer_init(struct trace_array *tr)
+{
+ /* Only allow one instance to enable this */
+ if (hwlat_busy)
+ return -EBUSY;
+
+ hwlat_trace = tr;
+
+ disable_migrate = false;
+ hwlat_data.count = 0;
+ tr->max_latency = 0;
+ save_tracing_thresh = tracing_thresh;
+
+ /* tracing_thresh is in nsecs, we speak in usecs */
+ if (!tracing_thresh)
+ tracing_thresh = last_tracing_thresh;
+
+ if (tracer_tracing_is_on(tr))
+ hwlat_tracer_start(tr);
+
+ hwlat_busy = true;
+
+ return 0;
+}
+
+static void hwlat_tracer_reset(struct trace_array *tr)
+{
+ stop_kthread();
+
+ /* the tracing threshold is static between runs */
+ last_tracing_thresh = tracing_thresh;
+
+ tracing_thresh = save_tracing_thresh;
+ hwlat_busy = false;
+}
+
+static struct tracer hwlat_tracer __read_mostly =
+{
+ .name = "hwlat",
+ .init = hwlat_tracer_init,
+ .reset = hwlat_tracer_reset,
+ .start = hwlat_tracer_start,
+ .stop = hwlat_tracer_stop,
+ .allow_instances = true,
+};
+
+__init static int init_hwlat_tracer(void)
+{
+ int ret;
+
+ mutex_init(&hwlat_data.lock);
+
+ ret = register_tracer(&hwlat_tracer);
+ if (ret)
+ return ret;
+
+ init_tracefs();
+
+ return 0;
+}
+late_initcall(init_hwlat_tracer);
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 9aedb0b06683..eb6c9f1d3a93 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -253,6 +253,10 @@ static const struct fetch_type kprobes_fetch_type_table[] = {
ASSIGN_FETCH_TYPE(s16, u16, 1),
ASSIGN_FETCH_TYPE(s32, u32, 1),
ASSIGN_FETCH_TYPE(s64, u64, 1),
+ ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
+ ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
+ ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
+ ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
ASSIGN_FETCH_TYPE_END
};
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 0bb9cf2d53e6..3fc20422c166 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1098,6 +1098,71 @@ static struct trace_event trace_user_stack_event = {
.funcs = &trace_user_stack_funcs,
};
+/* TRACE_HWLAT */
+static enum print_line_t
+trace_hwlat_print(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct trace_entry *entry = iter->ent;
+ struct trace_seq *s = &iter->seq;
+ struct hwlat_entry *field;
+
+ trace_assign_type(field, entry);
+
+ trace_seq_printf(s, "#%-5u inner/outer(us): %4llu/%-5llu ts:%ld.%09ld",
+ field->seqnum,
+ field->duration,
+ field->outer_duration,
+ field->timestamp.tv_sec,
+ field->timestamp.tv_nsec);
+
+ if (field->nmi_count) {
+ /*
+ * The generic sched_clock() is not NMI safe, thus
+ * we only record the count and not the time.
+ */
+ if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK))
+ trace_seq_printf(s, " nmi-total:%llu",
+ field->nmi_total_ts);
+ trace_seq_printf(s, " nmi-count:%u",
+ field->nmi_count);
+ }
+
+ trace_seq_putc(s, '\n');
+
+ return trace_handle_return(s);
+}
+
+
+static enum print_line_t
+trace_hwlat_raw(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct hwlat_entry *field;
+ struct trace_seq *s = &iter->seq;
+
+ trace_assign_type(field, iter->ent);
+
+ trace_seq_printf(s, "%llu %lld %ld %09ld %u\n",
+ field->duration,
+ field->outer_duration,
+ field->timestamp.tv_sec,
+ field->timestamp.tv_nsec,
+ field->seqnum);
+
+ return trace_handle_return(s);
+}
+
+static struct trace_event_functions trace_hwlat_funcs = {
+ .trace = trace_hwlat_print,
+ .raw = trace_hwlat_raw,
+};
+
+static struct trace_event trace_hwlat_event = {
+ .type = TRACE_HWLAT,
+ .funcs = &trace_hwlat_funcs,
+};
+
/* TRACE_BPUTS */
static enum print_line_t
trace_bputs_print(struct trace_iterator *iter, int flags,
@@ -1233,6 +1298,7 @@ static struct trace_event *events[] __initdata = {
&trace_bputs_event,
&trace_bprint_event,
&trace_print_event,
+ &trace_hwlat_event,
NULL
};
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 74e80a582c28..8c0553d9afd3 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -36,24 +36,28 @@ const char *reserved_field_names[] = {
};
/* Printing in basic type function template */
-#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt) \
-int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \
+#define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt) \
+int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name, \
void *data, void *ent) \
{ \
trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \
return !trace_seq_has_overflowed(s); \
} \
-const char PRINT_TYPE_FMT_NAME(type)[] = fmt; \
-NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(type));
-
-DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "0x%x")
-DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "0x%x")
-DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "0x%x")
-DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "0x%Lx")
-DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d")
-DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
-DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
-DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
+const char PRINT_TYPE_FMT_NAME(tname)[] = fmt; \
+NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname));
+
+DEFINE_BASIC_PRINT_TYPE_FUNC(u8, u8, "%u")
+DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")
+DEFINE_BASIC_PRINT_TYPE_FUNC(u32, u32, "%u")
+DEFINE_BASIC_PRINT_TYPE_FUNC(u64, u64, "%Lu")
+DEFINE_BASIC_PRINT_TYPE_FUNC(s8, s8, "%d")
+DEFINE_BASIC_PRINT_TYPE_FUNC(s16, s16, "%d")
+DEFINE_BASIC_PRINT_TYPE_FUNC(s32, s32, "%d")
+DEFINE_BASIC_PRINT_TYPE_FUNC(s64, s64, "%Ld")
+DEFINE_BASIC_PRINT_TYPE_FUNC(x8, u8, "0x%x")
+DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
+DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
+DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
/* Print type function for string type */
int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name,
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 45400ca5ded1..0c0ae54d44c6 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -149,6 +149,11 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(s8);
DECLARE_BASIC_PRINT_TYPE_FUNC(s16);
DECLARE_BASIC_PRINT_TYPE_FUNC(s32);
DECLARE_BASIC_PRINT_TYPE_FUNC(s64);
+DECLARE_BASIC_PRINT_TYPE_FUNC(x8);
+DECLARE_BASIC_PRINT_TYPE_FUNC(x16);
+DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
+DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
+
DECLARE_BASIC_PRINT_TYPE_FUNC(string);
#define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
@@ -203,7 +208,7 @@ DEFINE_FETCH_##method(u32) \
DEFINE_FETCH_##method(u64)
/* Default (unsigned long) fetch type */
-#define __DEFAULT_FETCH_TYPE(t) u##t
+#define __DEFAULT_FETCH_TYPE(t) x##t
#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)
#define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
#define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
@@ -234,6 +239,10 @@ ASSIGN_FETCH_FUNC(file_offset, ftype), \
#define ASSIGN_FETCH_TYPE(ptype, ftype, sign) \
__ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
+/* If ptype is an alias of atype, use this macro (show atype in format) */
+#define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign) \
+ __ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #atype)
+
#define ASSIGN_FETCH_TYPE_END {}
#define FETCH_TYPE_STRING 0
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index b2b6efc083a4..5e10395da88e 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -610,8 +610,7 @@ static int perf_sysenter_enable(struct trace_event_call *call)
if (!sys_perf_refcount_enter)
ret = register_trace_sys_enter(perf_syscall_enter, NULL);
if (ret) {
- pr_info("event trace: Could not activate"
- "syscall entry trace point");
+ pr_info("event trace: Could not activate syscall entry trace point");
} else {
set_bit(num, enabled_perf_enter_syscalls);
sys_perf_refcount_enter++;
@@ -682,8 +681,7 @@ static int perf_sysexit_enable(struct trace_event_call *call)
if (!sys_perf_refcount_exit)
ret = register_trace_sys_exit(perf_syscall_exit, NULL);
if (ret) {
- pr_info("event trace: Could not activate"
- "syscall exit trace point");
+ pr_info("event trace: Could not activate syscall exit trace point");
} else {
set_bit(num, enabled_perf_exit_syscalls);
sys_perf_refcount_exit++;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index c53485441c88..0913693caf6e 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -211,6 +211,10 @@ static const struct fetch_type uprobes_fetch_type_table[] = {
ASSIGN_FETCH_TYPE(s16, u16, 1),
ASSIGN_FETCH_TYPE(s32, u32, 1),
ASSIGN_FETCH_TYPE(s64, u64, 1),
+ ASSIGN_FETCH_TYPE_ALIAS(x8, u8, u8, 0),
+ ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
+ ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
+ ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
ASSIGN_FETCH_TYPE_END
};
@@ -427,10 +431,6 @@ static int create_trace_uprobe(int argc, char **argv)
pr_info("Probe point is not specified.\n");
return -EINVAL;
}
- if (isdigit(argv[1][0])) {
- pr_info("probe point must be have a filename.\n");
- return -EINVAL;
- }
arg = strchr(argv[1], ':');
if (!arg) {
ret = -EINVAL;
generated by cgit v1.2.3-70-g09d2 (git 2.48.1) at 2025-04-09 03:59:34 +0000