Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
tracing/fprobe: Reject registration of a registered fprobe before init
Reject registration of a registered fprobe which is on the fprobe
hash table before initializing fprobe.
The add_fprobe_hash() checks this re-register fprobe, but since
fprobe_init() clears hlist_array field, it is too late to check it.
It has to check the re-registration before touncing fprobe.
Link: https://lore.kernel.org/all/177669364845.132053.18375367916162315835.stgit@mhiramat.tok.corp.google.com/
Fixes: 4346ba160409 ("fprobe: Rewrite fprobe on function-graph tracer")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
+10
-11
+10
-11
kernel/trace/fprobe.c
+10
-11
kernel/trace/fprobe.c
···
4
4
*/
5
5
#define pr_fmt(fmt) "fprobe: " fmt
6
6
7
+
#include <linux/cleanup.h>
7
8
#include <linux/err.h>
8
9
#include <linux/fprobe.h>
9
10
#include <linux/kallsyms.h>
···
108
107
}
109
108
110
109
/* Check existence of the fprobe */
111
-
static bool is_fprobe_still_exist(struct fprobe *fp)
110
+
static bool fprobe_registered(struct fprobe *fp)
112
111
{
113
112
struct hlist_head *head;
114
113
struct fprobe_hlist *fph;
···
121
120
}
122
121
return false;
123
122
}
124
-
NOKPROBE_SYMBOL(is_fprobe_still_exist);
123
+
NOKPROBE_SYMBOL(fprobe_registered);
125
124
126
125
static int add_fprobe_hash(struct fprobe *fp)
127
126
{
···
132
131
133
132
if (WARN_ON_ONCE(!fph))
134
133
return -EINVAL;
135
-
136
-
if (is_fprobe_still_exist(fp))
137
-
return -EEXIST;
138
134
139
135
head = &fprobe_table[hash_ptr(fp, FPROBE_HASH_BITS)];
140
136
hlist_add_head_rcu(&fp->hlist_array->hlist, head);
···
147
149
if (WARN_ON_ONCE(!fph))
148
150
return -EINVAL;
149
151
150
-
if (!is_fprobe_still_exist(fp))
152
+
if (!fprobe_registered(fp))
151
153
return -ENOENT;
152
154
153
155
fph->fp = NULL;
···
478
480
if (!fp)
479
481
break;
480
482
curr += FPROBE_HEADER_SIZE_IN_LONG;
481
-
if (is_fprobe_still_exist(fp) && !fprobe_disabled(fp)) {
483
+
if (fprobe_registered(fp) && !fprobe_disabled(fp)) {
482
484
if (WARN_ON_ONCE(curr + size > size_words))
483
485
break;
484
486
fp->exit_handler(fp, trace->func, ret_ip, fregs,
···
837
839
struct fprobe_hlist *hlist_array;
838
840
int ret, i;
839
841
842
+
guard(mutex)(&fprobe_mutex);
843
+
if (fprobe_registered(fp))
844
+
return -EEXIST;
845
+
840
846
ret = fprobe_init(fp, addrs, num);
841
847
if (ret)
842
848
return ret;
843
-
844
-
mutex_lock(&fprobe_mutex);
845
849
846
850
hlist_array = fp->hlist_array;
847
851
if (fprobe_is_ftrace(fp))
···
864
864
delete_fprobe_node(&hlist_array->array[i]);
865
865
}
866
866
}
867
-
mutex_unlock(&fprobe_mutex);
868
867
869
868
if (ret)
870
869
fprobe_fail_cleanup(fp);
···
925
926
int ret = 0, i, count;
926
927
927
928
mutex_lock(&fprobe_mutex);
928
-
if (!fp || !is_fprobe_still_exist(fp)) {
929
+
if (!fp || !fprobe_registered(fp)) {
929
930
ret = -EINVAL;
930
931
goto out;
931
932
}