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Commit 8676a5e7 authored by Ricardo Ribalda's avatar Ricardo Ribalda Committed by Laurent Pinchart
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media: uvcvideo: Fix integer overflow calculating timestamp 

The function uvc_video_clock_update() supports a single SOF overflow. Or
in other words, the maximum difference between the first ant the last
timestamp can be 4096 ticks or 4.096 seconds.

This results in a maximum value for y2 of: 0x12FBECA00, that overflows
32bits.
y2 = (u32)ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1;

Extend the size of y2 to u64 to support all its values.

Without this patch:
 # yavta -s 1920x1080 -f YUYV -t 1/5 -c /dev/video0
Device /dev/v4l/by-id/usb-Shine-Optics_Integrated_Camera_0001-video-index0 opened.
Device `Integrated Camera: Integrated C' on `usb-0000:00:14.0-6' (driver 'uvcvideo') supports video, capture, without mplanes.
Video format set: YUYV (56595559) 1920x1080 (stride 3840) field none buffer size 4147200d
Video format: YUYV (56595559) 1920x1080 (stride 3840) field none buffer size 4147200d
Current frame rate: 1/5
Setting frame rate to: 1/5
Frame rate set: 1/5
8 buffers requested.
length: 4147200d offset: 0 timestamp type/source: mono/SoE
Buffer 0/0 mapped at address 0x7947ea94c000.
length: 4147200d offset: 4149248 timestamp type/source: mono/SoE
Buffer 1/0 mapped at address 0x7947ea557000.
length: 4147200d offset: 8298496 timestamp type/source: mono/SoE
Buffer 2/0 mapped at address 0x7947ea162000.
length: 4147200d offset: 12447744 timestamp type/source: mono/SoE
Buffer 3/0 mapped at address 0x7947e9d6d000.
length: 4147200d offset: 16596992 timestamp type/source: mono/SoE
Buffer 4/0 mapped at address 0x7947e9978000.
length: 4147200d offset: 20746240 timestamp type/source: mono/SoE
Buffer 5/0 mapped at address 0x7947e9583000.
length: 4147200d offset: 24895488 timestamp type/source: mono/SoE
Buffer 6/0 mapped at address 0x7947e918e000.
length: 4147200d offset: 29044736 timestamp type/source: mono/SoE
Buffer 7/0 mapped at address 0x7947e8d99000.
0 (0) [-] none 0 4147200d B 507.554210 508.874282 242.836 fps ts mono/SoE
1 (1) [-] none 2 4147200d B 508.886298 509.074289 0.751 fps ts mono/SoE
2 (2) [-] none 3 4147200d B 509.076362 509.274307 5.261 fps ts mono/SoE
3 (3) [-] none 4 4147200d B 509.276371 509.474336 5.000 fps ts mono/SoE
4 (4) [-] none 5 4147200d B 509.476394 509.674394 4.999 fps ts mono/SoE
5 (5) [-] none 6 4147200d B 509.676506 509.874345 4.997 fps ts mono/SoE
6 (6) [-] none 7 4147200d B 509.876430 510.074370 5.002 fps ts mono/SoE
7 (7) [-] none 8 4147200d B 510.076434 510.274365 5.000 fps ts mono/SoE
8 (0) [-] none 9 4147200d B 510.276421 510.474333 5.000 fps ts mono/SoE
9 (1) [-] none 10 4147200d B 510.476391 510.674429 5.001 fps ts mono/SoE
10 (2) [-] none 11 4147200d B 510.676434 510.874283 4.999 fps ts mono/SoE
11 (3) [-] none 12 4147200d B 510.886264 511.074349 4.766 fps ts mono/SoE
12 (4) [-] none 13 4147200d B 511.070577 511.274304 5.426 fps ts mono/SoE
13 (5) [-] none 14 4147200d B 511.286249 511.474301 4.637 fps ts mono/SoE
14 (6) [-] none 15 4147200d B 511.470542 511.674251 5.426 fps ts mono/SoE
15 (7) [-] none 16 4147200d B 511.672651 511.874337 4.948 fps ts mono/SoE
16 (0) [-] none 17 4147200d B 511.873988 512.074462 4.967 fps ts mono/SoE
17 (1) [-] none 18 4147200d B 512.075982 512.278296 4.951 fps ts mono/SoE
18 (2) [-] none 19 4147200d B 512.282631 512.482423 4.839 fps ts mono/SoE
19 (3) [-] none 20 4147200d B 518.986637 512.686333 0.149 fps ts mono/SoE
20 (4) [-] none 21 4147200d B 518.342709 512.886386 -1.553 fps ts mono/SoE
21 (5) [-] none 22 4147200d B 517.909812 513.090360 -2.310 fps ts mono/SoE
22 (6) [-] none 23 4147200d B 517.590775 513.294454 -3.134 fps ts mono/SoE
23 (7) [-] none 24 4147200d B 513.298465 513.494335 -0.233 fps ts mono/SoE
24 (0) [-] none 25 4147200d B 513.510273 513.698375 4.721 fps ts mono/SoE
25 (1) [-] none 26 4147200d B 513.698904 513.902327 5.301 fps ts mono/SoE
26 (2) [-] none 27 4147200d B 513.895971 514.102348 5.074 fps ts mono/SoE
27 (3) [-] none 28 4147200d B 514.099091 514.306337 4.923 fps ts mono/SoE
28 (4) [-] none 29 4147200d B 514.310348 514.510567 4.734 fps ts mono/SoE
29 (5) [-] none 30 4147200d B 514.509295 514.710367 5.026 fps ts mono/SoE
30 (6) [-] none 31 4147200d B 521.532513 514.914398 0.142 fps ts mono/SoE
31 (7) [-] none 32 4147200d B 520.885277 515.118385 -1.545 fps ts mono/SoE
32 (0) [-] none 33 4147200d B 520.411140 515.318336 -2.109 fps ts mono/SoE
33 (1) [-] none 34 4147200d B 515.325425 515.522278 -0.197 fps ts mono/SoE
34 (2) [-] none 35 4147200d B 515.538276 515.726423 4.698 fps ts mono/SoE
35 (3) [-] none 36 4147200d B 515.720767 515.930373 5.480 fps ts mono/SoE

Cc: stable@vger.kernel.org
Fixes: 66847ef0 ("[media] uvcvideo: Add UVC timestamps support")
Signed-off-by: default avatarRicardo Ribalda <ribalda@chromium.org>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20240610-hwtimestamp-followup-v1-2-f9eaed7be7f0@chromium.orgSigned-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
parent 53d79953
Show whitespace changes
Inline Side-by-side
Showing with 5 additions and 5 deletions
drivers/media/usb/uvc/uvc_video.c
View file @ 8676a5e7
...@@ -760,11 +760,11 @@ void uvc_video_clock_update(struct uvc_streaming *stream, ...@@ -760,11 +760,11 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
unsigned long flags; unsigned long flags;
u64 timestamp; u64 timestamp;
u32 delta_stc; u32 delta_stc;
u32 y1, y2; u32 y1;
u32 x1, x2; u32 x1, x2;
u32 mean; u32 mean;
u32 sof; u32 sof;
u64 y; u64 y, y2;
if (!uvc_hw_timestamps_param) if (!uvc_hw_timestamps_param)
return; return;
...@@ -816,7 +816,7 @@ void uvc_video_clock_update(struct uvc_streaming *stream, ...@@ -816,7 +816,7 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
sof = y; sof = y;
uvc_dbg(stream->dev, CLOCK, uvc_dbg(stream->dev, CLOCK,
"%s: PTS %u y %llu.%06llu SOF %u.%06llu (x1 %u x2 %u y1 %u y2 %u SOF offset %u)\n", "%s: PTS %u y %llu.%06llu SOF %u.%06llu (x1 %u x2 %u y1 %u y2 %llu SOF offset %u)\n",
stream->dev->name, buf->pts, stream->dev->name, buf->pts,
y >> 16, div_u64((y & 0xffff) * 1000000, 65536), y >> 16, div_u64((y & 0xffff) * 1000000, 65536),
sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536), sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),
...@@ -831,7 +831,7 @@ void uvc_video_clock_update(struct uvc_streaming *stream, ...@@ -831,7 +831,7 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
goto done; goto done;
y1 = NSEC_PER_SEC; y1 = NSEC_PER_SEC;
y2 = (u32)ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1; y2 = ktime_to_ns(ktime_sub(last->host_time, first->host_time)) + y1;
/* /*
* Interpolated and host SOF timestamps can wrap around at slightly * Interpolated and host SOF timestamps can wrap around at slightly
...@@ -852,7 +852,7 @@ void uvc_video_clock_update(struct uvc_streaming *stream, ...@@ -852,7 +852,7 @@ void uvc_video_clock_update(struct uvc_streaming *stream,
timestamp = ktime_to_ns(first->host_time) + y - y1; timestamp = ktime_to_ns(first->host_time) + y - y1;
uvc_dbg(stream->dev, CLOCK, uvc_dbg(stream->dev, CLOCK,
"%s: SOF %u.%06llu y %llu ts %llu buf ts %llu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n", "%s: SOF %u.%06llu y %llu ts %llu buf ts %llu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %llu)\n",
stream->dev->name, stream->dev->name,
sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536), sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536),
y, timestamp, vbuf->vb2_buf.timestamp, y, timestamp, vbuf->vb2_buf.timestamp,
......
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