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authorLinus Torvalds <torvalds@linux-foundation.org>2024-05-17 18:34:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-05-17 18:34:27 -0700
commit594d28157f2d55c4f17f2e18c778da098446e594 (patch)
tree097f046fd99ef03975102e0dfb4f61cccea7b4cf /kernel/trace/ftrace.c
parent70a663205d5085f1d82f7058e9419ff7612e9396 (diff)
parentd4e9a968738bf66d3bb852dd5588d4c7afd6d7f4 (diff)
Merge tag 'trace-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt: - Remove unused ftrace_direct_funcs variables - Fix a possible NULL pointer dereference race in eventfs - Update do_div() usage in trace event benchmark test - Speedup direct function registration with asynchronous RCU callback. The synchronization was done in the registration code and this caused delays when registering direct callbacks. Move the freeing to a call_rcu() that will prevent delaying of the registering. - Replace simple_strtoul() usage with kstrtoul() * tag 'trace-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: eventfs: Fix a possible null pointer dereference in eventfs_find_events() ftrace: Fix possible use-after-free issue in ftrace_location() ftrace: Remove unused global 'ftrace_direct_func_count' ftrace: Remove unused list 'ftrace_direct_funcs' tracing: Improve benchmark test performance by using do_div() ftrace: Use asynchronous grace period for register_ftrace_direct() ftrace: Replaces simple_strtoul in ftrace
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c68
1 files changed, 35 insertions, 33 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d4efdab463b8..65208d3b5ed9 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1595,12 +1595,15 @@ static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end)
unsigned long ftrace_location_range(unsigned long start, unsigned long end)
{
struct dyn_ftrace *rec;
+ unsigned long ip = 0;
+ rcu_read_lock();
rec = lookup_rec(start, end);
if (rec)
- return rec->ip;
+ ip = rec->ip;
+ rcu_read_unlock();
- return 0;
+ return ip;
}
/**
@@ -1614,25 +1617,22 @@ unsigned long ftrace_location_range(unsigned long start, unsigned long end)
*/
unsigned long ftrace_location(unsigned long ip)
{
- struct dyn_ftrace *rec;
+ unsigned long loc;
unsigned long offset;
unsigned long size;
- rec = lookup_rec(ip, ip);
- if (!rec) {
+ loc = ftrace_location_range(ip, ip);
+ if (!loc) {
if (!kallsyms_lookup_size_offset(ip, &size, &offset))
goto out;
/* map sym+0 to __fentry__ */
if (!offset)
- rec = lookup_rec(ip, ip + size - 1);
+ loc = ftrace_location_range(ip, ip + size - 1);
}
- if (rec)
- return rec->ip;
-
out:
- return 0;
+ return loc;
}
/**
@@ -2538,7 +2538,6 @@ ftrace_find_unique_ops(struct dyn_ftrace *rec)
/* Protected by rcu_tasks for reading, and direct_mutex for writing */
static struct ftrace_hash __rcu *direct_functions = EMPTY_HASH;
static DEFINE_MUTEX(direct_mutex);
-int ftrace_direct_func_count;
/*
* Search the direct_functions hash to see if the given instruction pointer
@@ -4201,12 +4200,12 @@ static int
add_rec_by_index(struct ftrace_hash *hash, struct ftrace_glob *func_g,
int clear_filter)
{
- long index = simple_strtoul(func_g->search, NULL, 0);
+ long index;
struct ftrace_page *pg;
struct dyn_ftrace *rec;
/* The index starts at 1 */
- if (--index < 0)
+ if (kstrtoul(func_g->search, 0, &index) || --index < 0)
return 0;
do_for_each_ftrace_rec(pg, rec) {
@@ -5317,14 +5316,6 @@ ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt,
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
-struct ftrace_direct_func {
- struct list_head next;
- unsigned long addr;
- int count;
-};
-
-static LIST_HEAD(ftrace_direct_funcs);
-
static int register_ftrace_function_nolock(struct ftrace_ops *ops);
/*
@@ -5365,6 +5356,13 @@ static void remove_direct_functions_hash(struct ftrace_hash *hash, unsigned long
}
}
+static void register_ftrace_direct_cb(struct rcu_head *rhp)
+{
+ struct ftrace_hash *fhp = container_of(rhp, struct ftrace_hash, rcu);
+
+ free_ftrace_hash(fhp);
+}
+
/**
* register_ftrace_direct - Call a custom trampoline directly
* for multiple functions registered in @ops
@@ -5463,10 +5461,8 @@ int register_ftrace_direct(struct ftrace_ops *ops, unsigned long addr)
out_unlock:
mutex_unlock(&direct_mutex);
- if (free_hash && free_hash != EMPTY_HASH) {
- synchronize_rcu_tasks();
- free_ftrace_hash(free_hash);
- }
+ if (free_hash && free_hash != EMPTY_HASH)
+ call_rcu_tasks(&free_hash->rcu, register_ftrace_direct_cb);
if (new_hash)
free_ftrace_hash(new_hash);
@@ -5816,9 +5812,8 @@ __setup("ftrace_graph_notrace=", set_graph_notrace_function);
static int __init set_graph_max_depth_function(char *str)
{
- if (!str)
+ if (!str || kstrtouint(str, 0, &fgraph_max_depth))
return 0;
- fgraph_max_depth = simple_strtoul(str, NULL, 0);
return 1;
}
__setup("ftrace_graph_max_depth=", set_graph_max_depth_function);
@@ -6595,6 +6590,8 @@ static int ftrace_process_locs(struct module *mod,
/* We should have used all pages unless we skipped some */
if (pg_unuse) {
WARN_ON(!skipped);
+ /* Need to synchronize with ftrace_location_range() */
+ synchronize_rcu();
ftrace_free_pages(pg_unuse);
}
return ret;
@@ -6808,6 +6805,9 @@ void ftrace_release_mod(struct module *mod)
out_unlock:
mutex_unlock(&ftrace_lock);
+ /* Need to synchronize with ftrace_location_range() */
+ if (tmp_page)
+ synchronize_rcu();
for (pg = tmp_page; pg; pg = tmp_page) {
/* Needs to be called outside of ftrace_lock */
@@ -7141,6 +7141,7 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
unsigned long start = (unsigned long)(start_ptr);
unsigned long end = (unsigned long)(end_ptr);
struct ftrace_page **last_pg = &ftrace_pages_start;
+ struct ftrace_page *tmp_page = NULL;
struct ftrace_page *pg;
struct dyn_ftrace *rec;
struct dyn_ftrace key;
@@ -7182,12 +7183,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
ftrace_update_tot_cnt--;
if (!pg->index) {
*last_pg = pg->next;
- if (pg->records) {
- free_pages((unsigned long)pg->records, pg->order);
- ftrace_number_of_pages -= 1 << pg->order;
- }
- ftrace_number_of_groups--;
- kfree(pg);
+ pg->next = tmp_page;
+ tmp_page = pg;
pg = container_of(last_pg, struct ftrace_page, next);
if (!(*last_pg))
ftrace_pages = pg;
@@ -7204,6 +7201,11 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr)
clear_func_from_hashes(func);
kfree(func);
}
+ /* Need to synchronize with ftrace_location_range() */
+ if (tmp_page) {
+ synchronize_rcu();
+ ftrace_free_pages(tmp_page);
+ }
}
void __init ftrace_free_init_mem(void)