From: Akinobu Mita <akinobu.mita@gmail.com>
To: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
linux-fsdevel@vger.kernel.org, corbet@lwn.net, david@redhat.com,
osalvador@suse.de, shuah@kernel.org,
Zhao Gongyi <zhaogongyi@huawei.com>,
Wei Yongjun <weiyongjun1@huawei.com>,
Yicong Yang <yangyicong@hisilicon.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
akpm@linux-foundation.org
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Subject: [PATCH 3/3] debugfs: fix error when writing negative value to atomic_t debugfs file
Date: Tue, 20 Sep 2022 02:24:18 +0900 [thread overview]
Message-ID: <20220919172418.45257-4-akinobu.mita@gmail.com> (raw)
In-Reply-To: <20220919172418.45257-1-akinobu.mita@gmail.com>
The simple attribute files do not accept a negative value since the
commit 488dac0c9237 ("libfs: fix error cast of negative value in
simple_attr_write()"), so we have to use a 64-bit value to write a
negative value for a debugfs file created by debugfs_create_atomic_t().
This restores the previous behaviour by introducing
DEFINE_DEBUGFS_ATTRIBUTE_SIGNED for a signed value.
Fixes: 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()")
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
---
.../fault-injection/fault-injection.rst | 10 +++----
fs/debugfs/file.c | 28 +++++++++++++++----
include/linux/debugfs.h | 19 +++++++++++--
3 files changed, 43 insertions(+), 14 deletions(-)
diff --git a/Documentation/fault-injection/fault-injection.rst b/Documentation/fault-injection/fault-injection.rst
index 17779a2772e5..5f6454b9dbd4 100644
--- a/Documentation/fault-injection/fault-injection.rst
+++ b/Documentation/fault-injection/fault-injection.rst
@@ -83,9 +83,7 @@ configuration of fault-injection capabilities.
- /sys/kernel/debug/fail*/times:
specifies how many times failures may happen at most. A value of -1
- means "no limit". Note, though, that this file only accepts unsigned
- values. So, if you want to specify -1, you better use 'printf' instead
- of 'echo', e.g.: $ printf %#x -1 > times
+ means "no limit".
- /sys/kernel/debug/fail*/space:
@@ -284,7 +282,7 @@ Application Examples
echo Y > /sys/kernel/debug/$FAILTYPE/task-filter
echo 10 > /sys/kernel/debug/$FAILTYPE/probability
echo 100 > /sys/kernel/debug/$FAILTYPE/interval
- printf %#x -1 > /sys/kernel/debug/$FAILTYPE/times
+ echo -1 > /sys/kernel/debug/$FAILTYPE/times
echo 0 > /sys/kernel/debug/$FAILTYPE/space
echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
echo Y > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
@@ -338,7 +336,7 @@ Application Examples
echo N > /sys/kernel/debug/$FAILTYPE/task-filter
echo 10 > /sys/kernel/debug/$FAILTYPE/probability
echo 100 > /sys/kernel/debug/$FAILTYPE/interval
- printf %#x -1 > /sys/kernel/debug/$FAILTYPE/times
+ echo -1 > /sys/kernel/debug/$FAILTYPE/times
echo 0 > /sys/kernel/debug/$FAILTYPE/space
echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
echo Y > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
@@ -369,7 +367,7 @@ Application Examples
echo N > /sys/kernel/debug/$FAILTYPE/task-filter
echo 100 > /sys/kernel/debug/$FAILTYPE/probability
echo 0 > /sys/kernel/debug/$FAILTYPE/interval
- printf %#x -1 > /sys/kernel/debug/$FAILTYPE/times
+ echo -1 > /sys/kernel/debug/$FAILTYPE/times
echo 0 > /sys/kernel/debug/$FAILTYPE/space
echo 1 > /sys/kernel/debug/$FAILTYPE/verbose
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 950c63fa4d0b..38930d9b0bb7 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -378,8 +378,8 @@ ssize_t debugfs_attr_read(struct file *file, char __user *buf,
}
EXPORT_SYMBOL_GPL(debugfs_attr_read);
-ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
- size_t len, loff_t *ppos)
+static ssize_t debugfs_attr_write_xsigned(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos, bool is_signed)
{
struct dentry *dentry = F_DENTRY(file);
ssize_t ret;
@@ -387,12 +387,28 @@ ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
ret = debugfs_file_get(dentry);
if (unlikely(ret))
return ret;
- ret = simple_attr_write(file, buf, len, ppos);
+ if (is_signed)
+ ret = simple_attr_write_signed(file, buf, len, ppos);
+ else
+ ret = simple_attr_write(file, buf, len, ppos);
debugfs_file_put(dentry);
return ret;
}
+
+ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ return debugfs_attr_write_xsigned(file, buf, len, ppos, false);
+}
EXPORT_SYMBOL_GPL(debugfs_attr_write);
+ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ return debugfs_attr_write_xsigned(file, buf, len, ppos, true);
+}
+EXPORT_SYMBOL_GPL(debugfs_attr_write_signed);
+
static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode,
struct dentry *parent, void *value,
const struct file_operations *fops,
@@ -738,11 +754,11 @@ static int debugfs_atomic_t_get(void *data, u64 *val)
*val = atomic_read((atomic_t *)data);
return 0;
}
-DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
+DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t, debugfs_atomic_t_get,
debugfs_atomic_t_set, "%lld\n");
-DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
+DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
"%lld\n");
-DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set,
+DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_wo, NULL, debugfs_atomic_t_set,
"%lld\n");
/**
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index f60674692d36..ea2d919fd9c7 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -45,7 +45,7 @@ struct debugfs_u32_array {
extern struct dentry *arch_debugfs_dir;
-#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \
+#define DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed) \
static int __fops ## _open(struct inode *inode, struct file *file) \
{ \
__simple_attr_check_format(__fmt, 0ull); \
@@ -56,10 +56,16 @@ static const struct file_operations __fops = { \
.open = __fops ## _open, \
.release = simple_attr_release, \
.read = debugfs_attr_read, \
- .write = debugfs_attr_write, \
+ .write = (__is_signed) ? debugfs_attr_write_signed : debugfs_attr_write, \
.llseek = no_llseek, \
}
+#define DEFINE_DEBUGFS_ATTRIBUTE(__fops, __get, __set, __fmt) \
+ DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false)
+
+#define DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt) \
+ DEFINE_DEBUGFS_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true)
+
typedef struct vfsmount *(*debugfs_automount_t)(struct dentry *, void *);
#if defined(CONFIG_DEBUG_FS)
@@ -102,6 +108,8 @@ ssize_t debugfs_attr_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos);
ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos);
+ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos);
struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
struct dentry *new_dir, const char *new_name);
@@ -254,6 +262,13 @@ static inline ssize_t debugfs_attr_write(struct file *file,
return -ENODEV;
}
+static inline ssize_t debugfs_attr_write_signed(struct file *file,
+ const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ return -ENODEV;
+}
+
static inline struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
struct dentry *new_dir, char *new_name)
{
--
2.34.1
next prev parent reply other threads:[~2022-09-19 17:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-19 17:24 [PATCH 0/3] fix error when writing negative value to simple attribute files Akinobu Mita
2022-09-19 17:24 ` [PATCH 1/3] libfs: add DEFINE_SIMPLE_ATTRIBUTE_SIGNED for signed value Akinobu Mita
2022-09-20 8:14 ` David Hildenbrand
2022-09-19 17:24 ` [PATCH 2/3] lib/notifier-error-inject: fix error when writing -errno to debugfs file Akinobu Mita
2022-09-20 8:15 ` David Hildenbrand
2022-09-19 17:24 ` Akinobu Mita [this message]
2022-09-20 8:19 ` [PATCH 3/3] debugfs: fix error when writing negative value to atomic_t " David Hildenbrand
2022-09-20 7:47 ` [PATCH 0/3] fix error when writing negative value to simple attribute files Greg Kroah-Hartman
2022-09-22 8:06 ` Zhao Gongyi
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=20220919172418.45257-4-akinobu.mita@gmail.com \
--to=akinobu.mita@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=corbet@lwn.net \
--cc=david@redhat.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=osalvador@suse.de \
--cc=rafael@kernel.org \
--cc=shuah@kernel.org \
--cc=viro@zeniv.linux.org.uk \
--cc=weiyongjun1@huawei.com \
--cc=yangyicong@hisilicon.com \
--cc=zhaogongyi@huawei.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.