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-rw-r--r--kernel/trace/Kconfig1
-rw-r--r--kernel/trace/bpf_trace.c27
-rw-r--r--kernel/trace/ring_buffer.c18
-rw-r--r--kernel/trace/trace.c54
-rw-r--r--kernel/trace/trace_stack.c4
5 files changed, 55 insertions, 49 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index af7dad126c13..904c952ac383 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -164,6 +164,7 @@ config PREEMPTIRQ_EVENTS
bool "Enable trace events for preempt and irq disable/enable"
select TRACE_IRQFLAGS
depends on DEBUG_PREEMPT || !PROVE_LOCKING
+ depends on TRACING
default n
help
Enable tracing of disable and enable events for preemption and irqs.
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 27d1f4ffa3de..40207c2a4113 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -343,14 +343,13 @@ static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
.arg4_type = ARG_CONST_SIZE,
};
-static DEFINE_PER_CPU(struct perf_sample_data, bpf_sd);
+static DEFINE_PER_CPU(struct perf_sample_data, bpf_trace_sd);
static __always_inline u64
__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
- u64 flags, struct perf_raw_record *raw)
+ u64 flags, struct perf_sample_data *sd)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
- struct perf_sample_data *sd = this_cpu_ptr(&bpf_sd);
unsigned int cpu = smp_processor_id();
u64 index = flags & BPF_F_INDEX_MASK;
struct bpf_event_entry *ee;
@@ -373,8 +372,6 @@ __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
if (unlikely(event->oncpu != cpu))
return -EOPNOTSUPP;
- perf_sample_data_init(sd, 0, 0);
- sd->raw = raw;
perf_event_output(event, sd, regs);
return 0;
}
@@ -382,6 +379,7 @@ __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
u64, flags, void *, data, u64, size)
{
+ struct perf_sample_data *sd = this_cpu_ptr(&bpf_trace_sd);
struct perf_raw_record raw = {
.frag = {
.size = size,
@@ -392,7 +390,10 @@ BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
return -EINVAL;
- return __bpf_perf_event_output(regs, map, flags, &raw);
+ perf_sample_data_init(sd, 0, 0);
+ sd->raw = &raw;
+
+ return __bpf_perf_event_output(regs, map, flags, sd);
}
static const struct bpf_func_proto bpf_perf_event_output_proto = {
@@ -407,10 +408,12 @@ static const struct bpf_func_proto bpf_perf_event_output_proto = {
};
static DEFINE_PER_CPU(struct pt_regs, bpf_pt_regs);
+static DEFINE_PER_CPU(struct perf_sample_data, bpf_misc_sd);
u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
{
+ struct perf_sample_data *sd = this_cpu_ptr(&bpf_misc_sd);
struct pt_regs *regs = this_cpu_ptr(&bpf_pt_regs);
struct perf_raw_frag frag = {
.copy = ctx_copy,
@@ -428,8 +431,10 @@ u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
};
perf_fetch_caller_regs(regs);
+ perf_sample_data_init(sd, 0, 0);
+ sd->raw = &raw;
- return __bpf_perf_event_output(regs, map, flags, &raw);
+ return __bpf_perf_event_output(regs, map, flags, sd);
}
BPF_CALL_0(bpf_get_current_task)
@@ -759,6 +764,8 @@ const struct bpf_prog_ops perf_event_prog_ops = {
static DEFINE_MUTEX(bpf_event_mutex);
+#define BPF_TRACE_MAX_PROGS 64
+
int perf_event_attach_bpf_prog(struct perf_event *event,
struct bpf_prog *prog)
{
@@ -772,6 +779,12 @@ int perf_event_attach_bpf_prog(struct perf_event *event,
goto unlock;
old_array = event->tp_event->prog_array;
+ if (old_array &&
+ bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
+ ret = -E2BIG;
+ goto unlock;
+ }
+
ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
if (ret < 0)
goto unlock;
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 91874a95060d..9ab18995ff1e 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -280,6 +280,8 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data);
/* Missed count stored at end */
#define RB_MISSED_STORED (1 << 30)
+#define RB_MISSED_FLAGS (RB_MISSED_EVENTS|RB_MISSED_STORED)
+
struct buffer_data_page {
u64 time_stamp; /* page time stamp */
local_t commit; /* write committed index */
@@ -331,7 +333,9 @@ static void rb_init_page(struct buffer_data_page *bpage)
*/
size_t ring_buffer_page_len(void *page)
{
- return local_read(&((struct buffer_data_page *)page)->commit)
+ struct buffer_data_page *bpage = page;
+
+ return (local_read(&bpage->commit) & ~RB_MISSED_FLAGS)
+ BUF_PAGE_HDR_SIZE;
}
@@ -1799,12 +1803,6 @@ void ring_buffer_change_overwrite(struct ring_buffer *buffer, int val)
}
EXPORT_SYMBOL_GPL(ring_buffer_change_overwrite);
-static __always_inline void *
-__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
-{
- return bpage->data + index;
-}
-
static __always_inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
{
return bpage->page->data + index;
@@ -4406,8 +4404,13 @@ void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
{
struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
struct buffer_data_page *bpage = data;
+ struct page *page = virt_to_page(bpage);
unsigned long flags;
+ /* If the page is still in use someplace else, we can't reuse it */
+ if (page_ref_count(page) > 1)
+ goto out;
+
local_irq_save(flags);
arch_spin_lock(&cpu_buffer->lock);
@@ -4419,6 +4422,7 @@ void ring_buffer_free_read_page(struct ring_buffer *buffer, int cpu, void *data)
arch_spin_unlock(&cpu_buffer->lock);
local_irq_restore(flags);
+ out:
free_page((unsigned long)bpage);
}
EXPORT_SYMBOL_GPL(ring_buffer_free_read_page);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 73e67b68c53b..2a8d8a294345 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -362,7 +362,7 @@ trace_ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct
}
/**
- * trace_pid_filter_add_remove - Add or remove a task from a pid_list
+ * trace_pid_filter_add_remove_task - Add or remove a task from a pid_list
* @pid_list: The list to modify
* @self: The current task for fork or NULL for exit
* @task: The task to add or remove
@@ -925,7 +925,7 @@ static void tracing_snapshot_instance(struct trace_array *tr)
}
/**
- * trace_snapshot - take a snapshot of the current buffer.
+ * tracing_snapshot - take a snapshot of the current buffer.
*
* This causes a swap between the snapshot buffer and the current live
* tracing buffer. You can use this to take snapshots of the live
@@ -1004,9 +1004,9 @@ int tracing_alloc_snapshot(void)
EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
/**
- * trace_snapshot_alloc - allocate and take a snapshot of the current buffer.
+ * tracing_snapshot_alloc - allocate and take a snapshot of the current buffer.
*
- * This is similar to trace_snapshot(), but it will allocate the
+ * This is similar to tracing_snapshot(), but it will allocate the
* snapshot buffer if it isn't already allocated. Use this only
* where it is safe to sleep, as the allocation may sleep.
*
@@ -1303,7 +1303,7 @@ unsigned long __read_mostly tracing_thresh;
/*
* Copy the new maximum trace into the separate maximum-trace
* structure. (this way the maximum trace is permanently saved,
- * for later retrieval via /sys/kernel/debug/tracing/latency_trace)
+ * for later retrieval via /sys/kernel/tracing/tracing_max_latency)
*/
static void
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
@@ -2415,7 +2415,7 @@ trace_process_export(struct trace_export *export,
entry = ring_buffer_event_data(event);
size = ring_buffer_event_length(event);
- export->write(entry, size);
+ export->write(export, entry, size);
}
static DEFINE_MUTEX(ftrace_export_lock);
@@ -4178,37 +4178,30 @@ static const struct file_operations show_traces_fops = {
.llseek = seq_lseek,
};
-/*
- * The tracer itself will not take this lock, but still we want
- * to provide a consistent cpumask to user-space:
- */
-static DEFINE_MUTEX(tracing_cpumask_update_lock);
-
-/*
- * Temporary storage for the character representation of the
- * CPU bitmask (and one more byte for the newline):
- */
-static char mask_str[NR_CPUS + 1];
-
static ssize_t
tracing_cpumask_read(struct file *filp, char __user *ubuf,
size_t count, loff_t *ppos)
{
struct trace_array *tr = file_inode(filp)->i_private;
+ char *mask_str;
int len;
- mutex_lock(&tracing_cpumask_update_lock);
+ len = snprintf(NULL, 0, "%*pb\n",
+ cpumask_pr_args(tr->tracing_cpumask)) + 1;
+ mask_str = kmalloc(len, GFP_KERNEL);
+ if (!mask_str)
+ return -ENOMEM;
- len = snprintf(mask_str, count, "%*pb\n",
+ len = snprintf(mask_str, len, "%*pb\n",
cpumask_pr_args(tr->tracing_cpumask));
if (len >= count) {
count = -EINVAL;
goto out_err;
}
- count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
+ count = simple_read_from_buffer(ubuf, count, ppos, mask_str, len);
out_err:
- mutex_unlock(&tracing_cpumask_update_lock);
+ kfree(mask_str);
return count;
}
@@ -4228,8 +4221,6 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
if (err)
goto err_unlock;
- mutex_lock(&tracing_cpumask_update_lock);
-
local_irq_disable();
arch_spin_lock(&tr->max_lock);
for_each_tracing_cpu(cpu) {
@@ -4252,8 +4243,6 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
local_irq_enable();
cpumask_copy(tr->tracing_cpumask, tracing_cpumask_new);
-
- mutex_unlock(&tracing_cpumask_update_lock);
free_cpumask_var(tracing_cpumask_new);
return count;
@@ -6780,7 +6769,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
.spd_release = buffer_spd_release,
};
struct buffer_ref *ref;
- int entries, size, i;
+ int entries, i;
ssize_t ret = 0;
#ifdef CONFIG_TRACER_MAX_TRACE
@@ -6834,14 +6823,6 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
break;
}
- /*
- * zero out any left over data, this is going to
- * user land.
- */
- size = ring_buffer_page_len(ref->page);
- if (size < PAGE_SIZE)
- memset(ref->page + size, 0, PAGE_SIZE - size);
-
page = virt_to_page(ref->page);
spd.pages[i] = page;
@@ -7599,6 +7580,7 @@ allocate_trace_buffer(struct trace_array *tr, struct trace_buffer *buf, int size
buf->data = alloc_percpu(struct trace_array_cpu);
if (!buf->data) {
ring_buffer_free(buf->buffer);
+ buf->buffer = NULL;
return -ENOMEM;
}
@@ -7622,7 +7604,9 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
allocate_snapshot ? size : 1);
if (WARN_ON(ret)) {
ring_buffer_free(tr->trace_buffer.buffer);
+ tr->trace_buffer.buffer = NULL;
free_percpu(tr->trace_buffer.data);
+ tr->trace_buffer.data = NULL;
return -ENOMEM;
}
tr->allocated_snapshot = allocate_snapshot;
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 734accc02418..3c7bfc4bf5e9 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -209,6 +209,10 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip,
if (__this_cpu_read(disable_stack_tracer) != 1)
goto out;
+ /* If rcu is not watching, then save stack trace can fail */
+ if (!rcu_is_watching())
+ goto out;
+
ip += MCOUNT_INSN_SIZE;
check_stack(ip, &stack);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.