live-patching.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Petr Mladek <pmladek@suse.com>
To: Jiri Kosina <jikos@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Miroslav Benes <mbenes@suse.cz>
Cc: Joe Lawrence <joe.lawrence@redhat.com>,
	Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
	Nicolai Stange <nstange@suse.de>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
	Petr Mladek <pmladek@suse.com>
Subject: [PATCH 1/4] livepatch/sample: Use the right type for the leaking data pointer
Date: Thu, 16 Jan 2020 16:31:42 +0100	[thread overview]
Message-ID: <20200116153145.2392-2-pmladek@suse.com> (raw)
In-Reply-To: <20200116153145.2392-1-pmladek@suse.com>

The "leak" pointer, in the sample of shadow variable API, is allocated
as sizeof(int). Let's help developers and static analyzers with
understanding the code by using the appropriate pointer type.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
---
 samples/livepatch/livepatch-shadow-fix1.c | 12 ++++++------
 samples/livepatch/livepatch-shadow-fix2.c |  4 ++--
 samples/livepatch/livepatch-shadow-mod.c  |  4 ++--
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/samples/livepatch/livepatch-shadow-fix1.c b/samples/livepatch/livepatch-shadow-fix1.c
index e89ca4546114..bab12bdb753f 100644
--- a/samples/livepatch/livepatch-shadow-fix1.c
+++ b/samples/livepatch/livepatch-shadow-fix1.c
@@ -52,8 +52,8 @@ struct dummy {
  */
 static int shadow_leak_ctor(void *obj, void *shadow_data, void *ctor_data)
 {
-	void **shadow_leak = shadow_data;
-	void *leak = ctor_data;
+	int **shadow_leak = shadow_data;
+	int *leak = ctor_data;
 
 	*shadow_leak = leak;
 	return 0;
@@ -62,7 +62,7 @@ static int shadow_leak_ctor(void *obj, void *shadow_data, void *ctor_data)
 static struct dummy *livepatch_fix1_dummy_alloc(void)
 {
 	struct dummy *d;
-	void *leak;
+	int *leak;
 
 	d = kzalloc(sizeof(*d), GFP_KERNEL);
 	if (!d)
@@ -76,7 +76,7 @@ static struct dummy *livepatch_fix1_dummy_alloc(void)
 	 * variable.  A patched dummy_free routine can later fetch this
 	 * pointer to handle resource release.
 	 */
-	leak = kzalloc(sizeof(int), GFP_KERNEL);
+	leak = kzalloc(sizeof(*leak), GFP_KERNEL);
 	if (!leak) {
 		kfree(d);
 		return NULL;
@@ -94,7 +94,7 @@ static struct dummy *livepatch_fix1_dummy_alloc(void)
 static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data)
 {
 	void *d = obj;
-	void **shadow_leak = shadow_data;
+	int **shadow_leak = shadow_data;
 
 	kfree(*shadow_leak);
 	pr_info("%s: dummy @ %p, prevented leak @ %p\n",
@@ -103,7 +103,7 @@ static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data)
 
 static void livepatch_fix1_dummy_free(struct dummy *d)
 {
-	void **shadow_leak;
+	int **shadow_leak;
 
 	/*
 	 * Patch: fetch the saved SV_LEAK shadow variable, detach and
diff --git a/samples/livepatch/livepatch-shadow-fix2.c b/samples/livepatch/livepatch-shadow-fix2.c
index 50d223b82e8b..29fe5cd42047 100644
--- a/samples/livepatch/livepatch-shadow-fix2.c
+++ b/samples/livepatch/livepatch-shadow-fix2.c
@@ -59,7 +59,7 @@ static bool livepatch_fix2_dummy_check(struct dummy *d, unsigned long jiffies)
 static void livepatch_fix2_dummy_leak_dtor(void *obj, void *shadow_data)
 {
 	void *d = obj;
-	void **shadow_leak = shadow_data;
+	int **shadow_leak = shadow_data;
 
 	kfree(*shadow_leak);
 	pr_info("%s: dummy @ %p, prevented leak @ %p\n",
@@ -68,7 +68,7 @@ static void livepatch_fix2_dummy_leak_dtor(void *obj, void *shadow_data)
 
 static void livepatch_fix2_dummy_free(struct dummy *d)
 {
-	void **shadow_leak;
+	int **shadow_leak;
 	int *shadow_count;
 
 	/* Patch: copy the memory leak patch from the fix1 module. */
diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c
index ecfe83a943a7..7e753b0d2fa6 100644
--- a/samples/livepatch/livepatch-shadow-mod.c
+++ b/samples/livepatch/livepatch-shadow-mod.c
@@ -95,7 +95,7 @@ struct dummy {
 static __used noinline struct dummy *dummy_alloc(void)
 {
 	struct dummy *d;
-	void *leak;
+	int *leak;
 
 	d = kzalloc(sizeof(*d), GFP_KERNEL);
 	if (!d)
@@ -105,7 +105,7 @@ static __used noinline struct dummy *dummy_alloc(void)
 		msecs_to_jiffies(1000 * EXPIRE_PERIOD);
 
 	/* Oops, forgot to save leak! */
-	leak = kzalloc(sizeof(int), GFP_KERNEL);
+	leak = kzalloc(sizeof(*leak), GFP_KERNEL);
 	if (!leak) {
 		kfree(d);
 		return NULL;
-- 
2.16.4


  reply	other threads:[~2020-01-16 15:32 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-16 15:31 [PATCH 0/4] livepatch/samples/selftest: Clean up show variables handling Petr Mladek
2020-01-16 15:31 ` Petr Mladek [this message]
2020-01-16 15:31 ` [PATCH 2/4] livepatch/selftest: Clean up shadow variable names and type Petr Mladek
2020-01-16 15:31 ` [PATCH 3/4] livepatch/samples/selftest: Use klp_shadow_alloc() API correctly Petr Mladek
2020-01-16 15:31 ` [PATCH 4/4] livepatch: Handle allocation failure in the sample of shadow variable API Petr Mladek
2020-01-16 19:29 ` [PATCH 0/4] livepatch/samples/selftest: Clean up show variables handling Joe Lawrence
2020-01-17  8:26 ` Miroslav Benes
2020-01-17  9:41 ` Kamalesh Babulal
2020-01-17 10:13 ` Jiri Kosina

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200116153145.2392-2-pmladek@suse.com \
    --to=pmladek@suse.com \
    --cc=dan.carpenter@oracle.com \
    --cc=jikos@kernel.org \
    --cc=joe.lawrence@redhat.com \
    --cc=jpoimboe@redhat.com \
    --cc=kamalesh@linux.vnet.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=live-patching@vger.kernel.org \
    --cc=mbenes@suse.cz \
    --cc=nstange@suse.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).