[GIT PULL] tracing: A few fixes for 5.2-rc4

From: Steven Rostedt
Date: Sat Jun 15 2019 - 08:53:56 EST



Linus,

This includes the following fixes:

- Out of range read of stack trace output
- Fix for NULL pointer dereference in trace_uprobe_create()
- Fix to a livepatching / ftrace permission race in the module code
- Fix for NULL pointer dereference in free_ftrace_func_mapper()
- A couple of build warning clean ups


Please pull the latest trace-v5.2-rc4 tree, which can be found at:


git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-v5.2-rc4

Tag SHA1: 2aca81205fbb41cbe4a9cfb017f0cddc08773d00
Head SHA1: 04e03d9a616c19a47178eaca835358610e63a1dd


Eiichi Tsukata (3):
tracing: Fix out-of-range read in trace_stack_print()
tracing/uprobe: Fix NULL pointer dereference in trace_uprobe_create()
tracing/uprobe: Fix obsolete comment on trace_uprobe_create()

Josh Poimboeuf (1):
module: Fix livepatch/ftrace module text permissions race

Vasily Gorbik (1):
tracing: avoid build warning with HAVE_NOP_MCOUNT

Wei Li (1):
ftrace: Fix NULL pointer dereference in free_ftrace_func_mapper()

YueHaibing (1):
tracing: Make two symbols static

----
kernel/livepatch/core.c | 6 ++++++
kernel/trace/ftrace.c | 22 ++++++++++++++++------
kernel/trace/trace.c | 4 ++--
kernel/trace/trace_output.c | 2 +-
kernel/trace/trace_uprobe.c | 15 ++++++++++-----
5 files changed, 35 insertions(+), 14 deletions(-)
---------------------------
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 91cd519756d3..2d17e6e364b5 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -30,6 +30,7 @@
#include <linux/elf.h>
#include <linux/moduleloader.h>
#include <linux/completion.h>
+#include <linux/memory.h>
#include <asm/cacheflush.h>
#include "core.h"
#include "patch.h"
@@ -730,16 +731,21 @@ static int klp_init_object_loaded(struct klp_patch *patch,
struct klp_func *func;
int ret;

+ mutex_lock(&text_mutex);
+
module_disable_ro(patch->mod);
ret = klp_write_object_relocations(patch->mod, obj);
if (ret) {
module_enable_ro(patch->mod, true);
+ mutex_unlock(&text_mutex);
return ret;
}

arch_klp_init_object_loaded(patch, obj);
module_enable_ro(patch->mod, true);

+ mutex_unlock(&text_mutex);
+
klp_for_each_func(obj, func) {
ret = klp_find_object_symbol(obj->name, func->old_name,
func->old_sympos,
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a12aff849c04..38277af44f5c 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -34,6 +34,7 @@
#include <linux/hash.h>
#include <linux/rcupdate.h>
#include <linux/kprobes.h>
+#include <linux/memory.h>

#include <trace/events/sched.h>

@@ -2610,10 +2611,12 @@ static void ftrace_run_update_code(int command)
{
int ret;

+ mutex_lock(&text_mutex);
+
ret = ftrace_arch_code_modify_prepare();
FTRACE_WARN_ON(ret);
if (ret)
- return;
+ goto out_unlock;

/*
* By default we use stop_machine() to modify the code.
@@ -2625,6 +2628,9 @@ static void ftrace_run_update_code(int command)

ret = ftrace_arch_code_modify_post_process();
FTRACE_WARN_ON(ret);
+
+out_unlock:
+ mutex_unlock(&text_mutex);
}

static void ftrace_run_modify_code(struct ftrace_ops *ops, int command,
@@ -2935,14 +2941,13 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)
p = &pg->records[i];
p->flags = rec_flags;

-#ifndef CC_USING_NOP_MCOUNT
/*
* Do the initial record conversion from mcount jump
* to the NOP instructions.
*/
- if (!ftrace_code_disable(mod, p))
+ if (!__is_defined(CC_USING_NOP_MCOUNT) &&
+ !ftrace_code_disable(mod, p))
break;
-#endif

update_cnt++;
}
@@ -4221,10 +4226,13 @@ void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
struct ftrace_func_entry *entry;
struct ftrace_func_map *map;
struct hlist_head *hhd;
- int size = 1 << mapper->hash.size_bits;
- int i;
+ int size, i;
+
+ if (!mapper)
+ return;

if (free_func && mapper->hash.count) {
+ size = 1 << mapper->hash.size_bits;
for (i = 0; i < size; i++) {
hhd = &mapper->hash.buckets[i];
hlist_for_each_entry(entry, hhd, hlist) {
@@ -5776,6 +5784,7 @@ void ftrace_module_enable(struct module *mod)
struct ftrace_page *pg;

mutex_lock(&ftrace_lock);
+ mutex_lock(&text_mutex);

if (ftrace_disabled)
goto out_unlock;
@@ -5837,6 +5846,7 @@ void ftrace_module_enable(struct module *mod)
ftrace_arch_code_modify_post_process();

out_unlock:
+ mutex_unlock(&text_mutex);
mutex_unlock(&ftrace_lock);

process_cached_mods(mod->name);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1c80521fd436..83e08b78dbee 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6923,7 +6923,7 @@ struct tracing_log_err {

static DEFINE_MUTEX(tracing_err_log_lock);

-struct tracing_log_err *get_tracing_log_err(struct trace_array *tr)
+static struct tracing_log_err *get_tracing_log_err(struct trace_array *tr)
{
struct tracing_log_err *err;

@@ -8192,7 +8192,7 @@ static const struct file_operations buffer_percent_fops = {
.llseek = default_llseek,
};

-struct dentry *trace_instance_dir;
+static struct dentry *trace_instance_dir;

static void
init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 54373d93e251..ba751f993c3b 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1057,7 +1057,7 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,

trace_seq_puts(s, "<stack trace>\n");

- for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
+ for (p = field->caller; p && p < end && *p != ULONG_MAX; p++) {

if (trace_seq_has_overflowed(s))
break;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index eb7e06b54741..b55906c77ce0 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -426,8 +426,6 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
/*
* Argument syntax:
* - Add uprobe: p|r[:[GRP/]EVENT] PATH:OFFSET [FETCHARGS]
- *
- * - Remove uprobe: -:[GRP/]EVENT
*/
static int trace_uprobe_create(int argc, const char **argv)
{
@@ -443,10 +441,17 @@ static int trace_uprobe_create(int argc, const char **argv)
ret = 0;
ref_ctr_offset = 0;

- /* argc must be >= 1 */
- if (argv[0][0] == 'r')
+ switch (argv[0][0]) {
+ case 'r':
is_return = true;
- else if (argv[0][0] != 'p' || argc < 2)
+ break;
+ case 'p':
+ break;
+ default:
+ return -ECANCELED;
+ }
+
+ if (argc < 2)
return -ECANCELED;

if (argv[0][1] == ':')