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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2014-02-14 14:53:14 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2014-02-14 14:55:37 +0000 |
| commit | 37dbd669415ac82a79b3699da0450aaf68cb1c4c (patch) | |
| tree | 9554ac7c21b0e8b07df81f51503b1b7e8296f698 | |
| parent | 3a893d14cd227454826a9a86cb3ce227d04bc352 (diff) | |
sna: Check that the backlight interface is in sysfs before access
Before we write values into the file, we want to be sure that it is our
sysfs backlight interface, and not some ordinary file we are about to
destroy.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
| -rw-r--r-- | src/sna/sna_display.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c index 521d4ef4..15b27e40 100644 --- a/src/sna/sna_display.c +++ b/src/sna/sna_display.c @@ -445,6 +445,7 @@ sna_output_backlight_get_max(xf86OutputPtr output) { struct sna_output *sna_output = output->driver_private; char path[1024], val[BACKLIGHT_VALUE_LEN]; + struct stat st; int fd, max = 0; /* We are used as an initial check to see if we can @@ -455,6 +456,12 @@ sna_output_backlight_get_max(xf86OutputPtr output) if (access(path, R_OK | W_OK)) return -1; + if (stat(path, &st)) + return -1; + + if (major(st.st_dev)) /* is this a kernel psuedo filesystem? */ + return -1; + sprintf(path, "%s/%s/max_brightness", BACKLIGHT_CLASS, sna_output->backlight_iface); fd = open(path, O_RDONLY); |