[GIT PULL] tracing: Fixes for v5.7

From: Steven Rostedt
Date: Thu May 07 2020 - 14:33:57 EST


Linus,

This includes the following tracing fixes:

- 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


Please pull the latest trace-v5.7-rc3 tree, which can be found at:


git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-v5.7-rc3

Tag SHA1: e3d5e831583d2024b49104aa791e699974ccfe09
Head SHA1: 8842604446d1f005abcbf8c63c12eabdb5695094


Masami Hiramatsu (4):
bootconfig: Fix to remove bootconfig data from initrd while boot
tracing/kprobes: Fix a double initialization typo
tracing/boottime: Fix kprobe event API usage
tracing/kprobes: Reject new event if loc is NULL

Steven Rostedt (VMware) (2):
tracing: Wait for preempt irq delay thread to finish
tracing: Add a vmalloc_sync_mappings() for safe measure

Wei Yang (1):
tracing: Fix doc mistakes in trace sample

Yiwei Zhang (1):
gpu/trace: Minor comment updates for gpu_mem_total tracepoint

Yunfeng Ye (1):
tools/bootconfig: Fix resource leak in apply_xbc()

Zou Wei (1):
tracing: Make tracing_snapshot_instance_cond() static

----
include/trace/events/gpu_mem.h | 2 +-
init/main.c | 69 ++++++++++++++++++++++--------
kernel/trace/preemptirq_delay_test.c | 30 ++++++++++---
kernel/trace/trace.c | 16 ++++++-
kernel/trace/trace_boot.c | 20 ++++-----
kernel/trace/trace_kprobe.c | 8 +++-
samples/trace_events/trace-events-sample.h | 2 +-
tools/bootconfig/main.c | 9 ++--
8 files changed, 114 insertions(+), 42 deletions(-)
---------------------------
diff --git a/include/trace/events/gpu_mem.h b/include/trace/events/gpu_mem.h
index 1897822a9150..26d871f96e94 100644
--- a/include/trace/events/gpu_mem.h
+++ b/include/trace/events/gpu_mem.h
@@ -24,7 +24,7 @@
*
* @pid: Put 0 for global total, while positive pid for process total.
*
- * @size: Virtual size of the allocation in bytes.
+ * @size: Size of the allocation in bytes.
*
*/
TRACE_EVENT(gpu_mem_total,
diff --git a/init/main.c b/init/main.c
index a48617f2e5e5..1a5da2c2660c 100644
--- a/init/main.c
+++ b/init/main.c
@@ -257,6 +257,47 @@ static int __init loglevel(char *str)

early_param("loglevel", loglevel);

+#ifdef CONFIG_BLK_DEV_INITRD
+static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
+{
+ u32 size, csum;
+ char *data;
+ u32 *hdr;
+
+ if (!initrd_end)
+ return NULL;
+
+ data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
+ if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
+ return NULL;
+
+ hdr = (u32 *)(data - 8);
+ size = hdr[0];
+ csum = hdr[1];
+
+ data = ((void *)hdr) - size;
+ if ((unsigned long)data < initrd_start) {
+ pr_err("bootconfig size %d is greater than initrd size %ld\n",
+ size, initrd_end - initrd_start);
+ return NULL;
+ }
+
+ /* Remove bootconfig from initramfs/initrd */
+ initrd_end = (unsigned long)data;
+ if (_size)
+ *_size = size;
+ if (_csum)
+ *_csum = csum;
+
+ return data;
+}
+#else
+static void * __init get_boot_config_from_initrd(u32 *_size, u32 *_csum)
+{
+ return NULL;
+}
+#endif
+
#ifdef CONFIG_BOOT_CONFIG

char xbc_namebuf[XBC_KEYLEN_MAX] __initdata;
@@ -357,9 +398,12 @@ static void __init setup_boot_config(const char *cmdline)
int pos;
u32 size, csum;
char *data, *copy;
- u32 *hdr;
int ret;

+ data = get_boot_config_from_initrd(&size, &csum);
+ if (!data)
+ goto not_found;
+
strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
parse_args("bootconfig", tmp_cmdline, NULL, 0, 0, 0, NULL,
bootconfig_params);
@@ -367,27 +411,12 @@ static void __init setup_boot_config(const char *cmdline)
if (!bootconfig_found)
return;

- if (!initrd_end)
- goto not_found;
-
- data = (char *)initrd_end - BOOTCONFIG_MAGIC_LEN;
- if (memcmp(data, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN))
- goto not_found;
-
- hdr = (u32 *)(data - 8);
- size = hdr[0];
- csum = hdr[1];
-
if (size >= XBC_DATA_MAX) {
pr_err("bootconfig size %d greater than max size %d\n",
size, XBC_DATA_MAX);
return;
}

- data = ((void *)hdr) - size;
- if ((unsigned long)data < initrd_start)
- goto not_found;
-
if (boot_config_checksum((unsigned char *)data, size) != csum) {
pr_err("bootconfig checksum failed\n");
return;
@@ -420,8 +449,14 @@ static void __init setup_boot_config(const char *cmdline)
not_found:
pr_err("'bootconfig' found on command line, but no bootconfig found\n");
}
+
#else
-#define setup_boot_config(cmdline) do { } while (0)
+
+static void __init setup_boot_config(const char *cmdline)
+{
+ /* Remove bootconfig data from initrd */
+ get_boot_config_from_initrd(NULL, NULL);
+}

static int __init warn_bootconfig(char *str)
{
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
diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h
index 80b4a70315b6..13a35f7cbe66 100644
--- a/samples/trace_events/trace-events-sample.h
+++ b/samples/trace_events/trace-events-sample.h
@@ -416,7 +416,7 @@ TRACE_EVENT_FN(foo_bar_with_fn,
* Note, TRACE_EVENT() itself is simply defined as:
*
* #define TRACE_EVENT(name, proto, args, tstruct, assign, printk) \
- * DEFINE_EVENT_CLASS(name, proto, args, tstruct, assign, printk); \
+ * DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, printk); \
* DEFINE_EVENT(name, name, proto, args)
*
* The DEFINE_EVENT() also can be declared with conditions and reg functions:
diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
index 16b9a420e6fd..001076c51712 100644
--- a/tools/bootconfig/main.c
+++ b/tools/bootconfig/main.c
@@ -314,6 +314,7 @@ int apply_xbc(const char *path, const char *xbc_path)
ret = delete_xbc(path);
if (ret < 0) {
pr_err("Failed to delete previous boot config: %d\n", ret);
+ free(data);
return ret;
}

@@ -321,24 +322,26 @@ int apply_xbc(const char *path, const char *xbc_path)
fd = open(path, O_RDWR | O_APPEND);
if (fd < 0) {
pr_err("Failed to open %s: %d\n", path, fd);
+ free(data);
return fd;
}
/* TODO: Ensure the @path is initramfs/initrd image */
ret = write(fd, data, size + 8);
if (ret < 0) {
pr_err("Failed to apply a boot config: %d\n", ret);
- return ret;
+ goto out;
}
/* Write a magic word of the bootconfig */
ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
if (ret < 0) {
pr_err("Failed to apply a boot config magic: %d\n", ret);
- return ret;
+ goto out;
}
+out:
close(fd);
free(data);

- return 0;
+ return ret;
}

int usage(void)