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authorLinus Torvalds <torvalds@linux-foundation.org>2020-05-07 15:27:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-05-07 15:27:11 -0700
commit192ffb7515839b1cc8457e0a8c1e09783de019d3 (patch)
treea0c710bd51591401ad466564bea0f5bb819cf6cc /kernel
parent9ecc4d775f61fb3fd26a1b8cc70a56a98b3b40d3 (diff)
parent8842604446d1f005abcbf8c63c12eabdb5695094 (diff)
downloadlwn-192ffb7515839b1cc8457e0a8c1e09783de019d3.tar.gz
lwn-192ffb7515839b1cc8457e0a8c1e09783de019d3.zip
Merge tag 'trace-v5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt: - Fix bootconfig causing kernels to fail with CONFIG_BLK_DEV_RAM enabled - Fix allocation leaks in bootconfig tool - Fix a double initialization of a variable - Fix API bootconfig usage from kprobe boot time events - Reject NULL location for kprobes - Fix crash caused by preempt delay module not cleaning up kthread correctly - Add vmalloc_sync_mappings() to prevent x86_64 page faults from recursively faulting from tracing page faults - Fix comment in gpu/trace kerneldoc header - Fix documentation of how to create a trace event class - Make the local tracing_snapshot_instance_cond() function static * tag 'trace-v5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tools/bootconfig: Fix resource leak in apply_xbc() tracing: Make tracing_snapshot_instance_cond() static tracing: Fix doc mistakes in trace sample gpu/trace: Minor comment updates for gpu_mem_total tracepoint tracing: Add a vmalloc_sync_mappings() for safe measure tracing: Wait for preempt irq delay thread to finish tracing/kprobes: Reject new event if loc is NULL tracing/boottime: Fix kprobe event API usage tracing/kprobes: Fix a double initialization typo bootconfig: Fix to remove bootconfig data from initrd while boot
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/preemptirq_delay_test.c30
-rw-r--r--kernel/trace/trace.c16
-rw-r--r--kernel/trace/trace_boot.c20
-rw-r--r--kernel/trace/trace_kprobe.c8
4 files changed, 54 insertions, 20 deletions
diff --git a/kernel/trace/preemptirq_delay_test.c b/kernel/trace/preemptirq_delay_test.c
index 31c0fad4cb9e..c4c86de63cf9 100644
--- a/kernel/trace/preemptirq_delay_test.c
+++ b/kernel/trace/preemptirq_delay_test.c
@@ -113,22 +113,42 @@ static int preemptirq_delay_run(void *data)
for (i = 0; i < s; i++)
(testfuncs[i])(i);
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ while (!kthread_should_stop()) {
+ schedule();
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+
+ __set_current_state(TASK_RUNNING);
+
return 0;
}
-static struct task_struct *preemptirq_start_test(void)
+static int preemptirq_run_test(void)
{
+ struct task_struct *task;
+
char task_name[50];
snprintf(task_name, sizeof(task_name), "%s_test", test_mode);
- return kthread_run(preemptirq_delay_run, NULL, task_name);
+ task = kthread_run(preemptirq_delay_run, NULL, task_name);
+ if (IS_ERR(task))
+ return PTR_ERR(task);
+ if (task)
+ kthread_stop(task);
+ return 0;
}
static ssize_t trigger_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t count)
{
- preemptirq_start_test();
+ ssize_t ret;
+
+ ret = preemptirq_run_test();
+ if (ret)
+ return ret;
return count;
}
@@ -148,11 +168,9 @@ static struct kobject *preemptirq_delay_kobj;
static int __init preemptirq_delay_init(void)
{
- struct task_struct *test_task;
int retval;
- test_task = preemptirq_start_test();
- retval = PTR_ERR_OR_ZERO(test_task);
+ retval = preemptirq_run_test();
if (retval != 0)
return retval;
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8d2b98812625..29615f15a820 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -947,7 +947,8 @@ int __trace_bputs(unsigned long ip, const char *str)
EXPORT_SYMBOL_GPL(__trace_bputs);
#ifdef CONFIG_TRACER_SNAPSHOT
-void tracing_snapshot_instance_cond(struct trace_array *tr, void *cond_data)
+static void tracing_snapshot_instance_cond(struct trace_array *tr,
+ void *cond_data)
{
struct tracer *tracer = tr->current_trace;
unsigned long flags;
@@ -8525,6 +8526,19 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
*/
allocate_snapshot = false;
#endif
+
+ /*
+ * Because of some magic with the way alloc_percpu() works on
+ * x86_64, we need to synchronize the pgd of all the tables,
+ * otherwise the trace events that happen in x86_64 page fault
+ * handlers can't cope with accessing the chance that a
+ * alloc_percpu()'d memory might be touched in the page fault trace
+ * event. Oh, and we need to audit all other alloc_percpu() and vmalloc()
+ * calls in tracing, because something might get triggered within a
+ * page fault trace event!
+ */
+ vmalloc_sync_mappings();
+
return 0;
}
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 06d7feb5255f..9de29bb45a27 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -95,24 +95,20 @@ trace_boot_add_kprobe_event(struct xbc_node *node, const char *event)
struct xbc_node *anode;
char buf[MAX_BUF_LEN];
const char *val;
- int ret;
+ int ret = 0;
- kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
+ xbc_node_for_each_array_value(node, "probes", anode, val) {
+ kprobe_event_cmd_init(&cmd, buf, MAX_BUF_LEN);
- ret = kprobe_event_gen_cmd_start(&cmd, event, NULL);
- if (ret)
- return ret;
+ ret = kprobe_event_gen_cmd_start(&cmd, event, val);
+ if (ret)
+ break;
- xbc_node_for_each_array_value(node, "probes", anode, val) {
- ret = kprobe_event_add_field(&cmd, val);
+ ret = kprobe_event_gen_cmd_end(&cmd);
if (ret)
- return ret;
+ pr_err("Failed to add probe: %s\n", buf);
}
- ret = kprobe_event_gen_cmd_end(&cmd);
- if (ret)
- pr_err("Failed to add probe: %s\n", buf);
-
return ret;
}
#else
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index d0568af4a0ef..35989383ae11 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -453,7 +453,7 @@ static bool __within_notrace_func(unsigned long addr)
static bool within_notrace_func(struct trace_kprobe *tk)
{
- unsigned long addr = addr = trace_kprobe_address(tk);
+ unsigned long addr = trace_kprobe_address(tk);
char symname[KSYM_NAME_LEN], *p;
if (!__within_notrace_func(addr))
@@ -940,6 +940,9 @@ EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
* complete command or only the first part of it; in the latter case,
* kprobe_event_add_fields() can be used to add more fields following this.
*
+ * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
+ * returns -EINVAL if @loc == NULL.
+ *
* Return: 0 if successful, error otherwise.
*/
int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
@@ -953,6 +956,9 @@ int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
if (cmd->type != DYNEVENT_TYPE_KPROBE)
return -EINVAL;
+ if (!loc)
+ return -EINVAL;
+
if (kretprobe)
snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
else