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authorAkinobu Mita <akinobu.mita@gmail.com>2022-09-19 20:24:18 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-12-01 03:13:16 +0300
commitd472cf797c4e268613dbce5ec9b95d0bcae19ecb (patch)
tree6b6a908b74655875df07ff720829ed217bfacfe7 /fs/debugfs
parentf883c3edd2c432a2931ec8773c70a570115a50fe (diff)
downloadlinux-d472cf797c4e268613dbce5ec9b95d0bcae19ecb.tar.xz
debugfs: fix error when writing negative value to atomic_t debugfs file
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. Link: https://lkml.kernel.org/r/20220919172418.45257-4-akinobu.mita@gmail.com Fixes: 488dac0c9237 ("libfs: fix error cast of negative value in simple_attr_write()") Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reported-by: Zhao Gongyi <zhaogongyi@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Wei Yongjun <weiyongjun1@huawei.com> Cc: Yicong Yang <yangyicong@hisilicon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/debugfs')
-rw-r--r--fs/debugfs/file.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index ddb3fc258df9..b54f470e0d03 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");
/**