v4l2-compliance sends a zeroed struct v4l2_streamparm in
v4l2-test-formats.cpp::testParmType(), and this results in a division by
0 in some gspca subdrivers:
divide error: 0000 [#1] SMP
Modules linked in: gspca_ov534 gspca_main ...
CPU: 0 PID: 17201 Comm: v4l2-compliance Not tainted 4.3.0-rc2-ao2 #1
Hardware name: System manufacturer System Product Name/M2N-E SLI, BIOS
ASUS M2N-E SLI ACPI BIOS Revision 1301 09/16/2010
task: ffff8800818306c0 ti: ffff880095c4c000 task.ti: ffff880095c4c000
RIP: 0010:[<ffffffffa079bd62>] [<ffffffffa079bd62>] sd_set_streamparm+0x12/0x60 [gspca_ov534]
RSP: 0018:ffff880095c4fce8 EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffff8800c9522000 RCX: ffffffffa077a140
RDX: 0000000000000000 RSI: ffff880095e0c100 RDI: ffff8800c9522000
RBP: ffff880095e0c100 R08: ffffffffa077a100 R09: 00000000000000cc
R10: ffff880067ec7740 R11: 0000000000000016 R12: ffffffffa07bb400
R13: 0000000000000000 R14: ffff880081b6a800 R15: 0000000000000000
FS: 00007fda0de78740(0000) GS:ffff88012fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000014630f8 CR3: 00000000cf349000 CR4: 00000000000006f0
Stack:
ffffffffa07a6431 ffff8800c9522000 ffffffffa077656e 00000000c0cc5616
ffff8800c9522000 ffffffffa07a5e20 ffff880095e0c100 0000000000000000
ffff880067ec7740 ffffffffa077a140 ffff880067ec7740 0000000000000016
Call Trace:
[<ffffffffa07a6431>] ? v4l_s_parm+0x21/0x50 [videodev]
[<ffffffffa077656e>] ? vidioc_s_parm+0x4e/0x60 [gspca_main]
[<ffffffffa07a5e20>] ? __video_do_ioctl+0x280/0x2f0 [videodev]
[<ffffffffa07a5ba0>] ? video_ioctl2+0x20/0x20 [videodev]
[<ffffffffa07a59b9>] ? video_usercopy+0x319/0x4e0 [videodev]
[<ffffffff81182dc1>] ? page_add_new_anon_rmap+0x71/0xa0
[<ffffffff811afb92>] ? mem_cgroup_commit_charge+0x52/0x90
[<ffffffff81179b18>] ? handle_mm_fault+0xc18/0x1680
[<ffffffffa07a15cc>] ? v4l2_ioctl+0xac/0xd0 [videodev]
[<ffffffff811c846f>] ? do_vfs_ioctl+0x28f/0x480
[<ffffffff811c86d4>] ? SyS_ioctl+0x74/0x80
[<ffffffff8154a8b6>] ? entry_SYSCALL_64_fastpath+0x16/0x75
Code: c7 93 d9 79 a0 5b 5d e9 f1 f3 9a e0 0f 1f 00 66 2e 0f 1f 84 00
00 00 00 00 66 66 66 66 90 53 31 d2 48 89 fb 48 83 ec 08 8b 46 10 <f7>
76 0c 80 bf ac 0c 00 00 00 88 87 4e 0e 00 00 74 09 80 bf 4f
RIP [<ffffffffa079bd62>] sd_set_streamparm+0x12/0x60 [gspca_ov534]
RSP <ffff880095c4fce8>
---[ end trace 279710c2c6c72080 ]---
Following what the doc says about a zeroed timeperframe (see
http://www.linuxtv.org/downloads/v4l-dvb-apis/vidioc-g-parm.html):
...
To reset manually applications can just set this field to zero.
fix the issue by resetting the frame rate to a default value in case of
an unusable timeperframe.
The fix is done in the subdrivers instead of gspca.c because only the
subdrivers have notion of a default frame rate to reset the camera to.
Signed-off-by: Antonio Ospite <ao2@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
Hi,
I think the problem in the gspca subdrivers has always been there, so the
patch could be applied to any relevant stable releases.
After the fix, v4l2-compliance runs fine but it gets two failures, I'll send
another mail about those.
After this change gets merged I will also send a patch to use defines for the
default framerates used below as the same value is used in multiple places.
Ah, I ran the patch through scripts/checkpatch.pl from 4.3-rc2 and it
complained about the commit message but I think it may be a false positive.
Ciao ciao,
Antonio
drivers/media/usb/gspca/ov534.c | 9 +++++++--
drivers/media/usb/gspca/topro.c | 6 +++++-
2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/media/usb/gspca/ov534.c b/drivers/media/usb/gspca/ov534.c
index 146071b..bfff1d1 100644
--- a/drivers/media/usb/gspca/ov534.c
+++ b/drivers/media/usb/gspca/ov534.c
@@ -1491,8 +1491,13 @@ static void sd_set_streamparm(struct gspca_dev *gspca_dev,
struct v4l2_fract *tpf = &cp->timeperframe;
struct sd *sd = (struct sd *) gspca_dev;
- /* Set requested framerate */
- sd->frame_rate = tpf->denominator / tpf->numerator;
+ if (tpf->numerator == 0 || tpf->denominator == 0)
+ /* Set default framerate */
+ sd->frame_rate = 30;
+ else
+ /* Set requested framerate */
+ sd->frame_rate = tpf->denominator / tpf->numerator;
+
if (gspca_dev->streaming)
set_frame_rate(gspca_dev);
diff --git a/drivers/media/usb/gspca/topro.c b/drivers/media/usb/gspca/topro.c
index c70ff40..c028a5c 100644
--- a/drivers/media/usb/gspca/topro.c
+++ b/drivers/media/usb/gspca/topro.c
@@ -4802,7 +4802,11 @@ static void sd_set_streamparm(struct gspca_dev *gspca_dev,
struct v4l2_fract *tpf = &cp->timeperframe;
int fr, i;
- sd->framerate = tpf->denominator / tpf->numerator;
+ if (tpf->numerator == 0 || tpf->denominator == 0)
+ sd->framerate = 30;
+ else
+ sd->framerate = tpf->denominator / tpf->numerator;
+
if (gspca_dev->streaming)
setframerate(gspca_dev, v4l2_ctrl_g_ctrl(gspca_dev->exposure));
--
2.6.0
--
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