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| author | Ulf Magnusson <ulfalizer@gmail.com> | 2015-09-07 20:06:14 +0300 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2015-09-13 23:38:51 +0300 |
| commit | 17666497fe631fef483afd38824c5dabdd764b90 (patch) | |
| tree | 58e663e6ca7e2df102005202574b332d0723b6e9 /Documentation | |
| parent | 9ba41327d8d01df54be1e6f1c246b123b009fa55 (diff) | |
| download | linux-17666497fe631fef483afd38824c5dabdd764b90.tar.xz | |
sysfs.txt: mention that store method buffers are null-terminated
Without knowing this, the use of sysfs_streq() becomes puzzling.
The termination happens in kernfs_fop_write().
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
[jc: moved the new text to a different paragraph]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/filesystems/sysfs.txt | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/Documentation/filesystems/sysfs.txt b/Documentation/filesystems/sysfs.txt index 78170ed7bfde..24da7b32c489 100644 --- a/Documentation/filesystems/sysfs.txt +++ b/Documentation/filesystems/sysfs.txt @@ -191,9 +191,10 @@ implementations: be called again, rearmed, to fill the buffer. - On write(2), sysfs expects the entire buffer to be passed during the - first write. Sysfs then passes the entire buffer to the store() - method. - + first write. Sysfs then passes the entire buffer to the store() method. + A terminating null is added after the data on stores. This makes + functions like sysfs_streq() safe to use. + When writing sysfs files, userspace processes should first read the entire file, modify the values it wishes to change, then write the entire buffer back. |