Messages in this thread Patch in this message | | | Date | Mon, 23 Jul 2007 03:02:29 -0700 (PDT) | From | Trent Piepho <> | Subject | Re: [v4l-dvb-maintainer] [2.6.23 regression fix] usbvision: don't return an uninitialized value |
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On Mon, 23 Jul 2007, Adrian Bunk wrote: > Commit c5f48367fe54c46805774eeea8e828de54a5ad7b introduced this return > of an uninitialized variable. > > Spotted by the Coverity checker.
It spotted that, but it seems it missed the bigger bug, reg->val is unsigned. Since reg->val can't be less than 0, it will never actually return the unitialized variable.
This patch should fix it correctly. The vidioc_g_register function was broken too, it wasn't actually setting reg->val to the register value it read.
-------------------------------------------------------------------- usbvision: fix bugs in vidioc_[sg]_register functions
From: Trent Piepho <xyzzy@speakeasy.org>
s_register was assigning the return code to (unsigned)reg->val, rather than errCode, which it what it would return. Except reg->val can't be < 0, so it would never actually return an error.
g_register never actually put the value it read into reg->val.
Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
diff -r 8e72fe5675b3 -r d5c4fffbbad3 linux/drivers/media/video/usbvision/usbvision-video.c --- a/linux/drivers/media/video/usbvision/usbvision-video.c Sat Jul 21 17:26:40 2007 -0700 +++ b/linux/drivers/media/video/usbvision/usbvision-video.c Mon Jul 23 02:58:31 2007 -0700 @@ -550,6 +550,7 @@ static int vidioc_g_register (struct fil __FUNCTION__, errCode); return errCode; } + reg->val = errCode; return 0; }
@@ -564,8 +565,8 @@ static int vidioc_s_register (struct fil if (!v4l2_chip_match_host(reg->match_type, reg->match_chip)) return -EINVAL; /* NT100x has a 8-bit register space */ - reg->val = (u8)usbvision_write_reg(usbvision, reg->reg&0xff, reg->val); - if (reg->val < 0) { + errCode = usbvision_write_reg(usbvision, reg->reg&0xff, reg->val); + if (errCode < 0) { err("%s: VIDIOC_DBG_S_REGISTER failed: error %d", __FUNCTION__, errCode); return errCode; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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