diff options
| author | Kővágó, Zoltán <dirty.ice.hu@gmail.com> | 2019-10-13 21:58:06 +0200 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2019-10-18 08:14:05 +0200 |
| commit | 670777a91580ec7e34d879c3973927f748be6f47 (patch) | |
| tree | ee9d5c57f38fe689da268b2a1b9712225672e693 | |
| parent | 3e44607e9394ca08f8672bffa045d2462a371bbc (diff) | |
usbaudio: change playback counters to 64 bit
With stereo playback, they need about 375 minutes of continuous audio
playback to overflow, which is usually not a problem (as stopping and
later resuming playback resets the counters). But with 7.1 audio, they
only need about 95 minutes to overflow.
After the overflow, the buf->prod % USBAUDIO_PACKET_SIZE(channels)
assertion no longer holds true, which will result in overflowing the
buffer. With 64 bit variables, it would take about 762000 years to
overflow.
Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Message-id: ff866985ed369f1e18ea7c70da6a7fce8e241deb.1570996490.git.DirtY.iCE.hu@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
| -rw-r--r-- | hw/usb/dev-audio.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/hw/usb/dev-audio.c b/hw/usb/dev-audio.c index e42bdfbdc1..ea604bbb8e 100644 --- a/hw/usb/dev-audio.c +++ b/hw/usb/dev-audio.c @@ -578,9 +578,9 @@ static const USBDesc desc_audio_multi = { struct streambuf { uint8_t *data; - uint32_t size; - uint32_t prod; - uint32_t cons; + size_t size; + uint64_t prod; + uint64_t cons; }; static void streambuf_init(struct streambuf *buf, uint32_t size, @@ -601,7 +601,7 @@ static void streambuf_fini(struct streambuf *buf) static int streambuf_put(struct streambuf *buf, USBPacket *p, uint32_t channels) { - uint32_t free = buf->size - (buf->prod - buf->cons); + int64_t free = buf->size - (buf->prod - buf->cons); if (free < USBAUDIO_PACKET_SIZE(channels)) { return 0; @@ -610,6 +610,8 @@ static int streambuf_put(struct streambuf *buf, USBPacket *p, uint32_t channels) return 0; } + /* can happen if prod overflows */ + assert(buf->prod % USBAUDIO_PACKET_SIZE(channels) == 0); usb_packet_copy(p, buf->data + (buf->prod % buf->size), USBAUDIO_PACKET_SIZE(channels)); buf->prod += USBAUDIO_PACKET_SIZE(channels); @@ -618,10 +620,10 @@ static int streambuf_put(struct streambuf *buf, USBPacket *p, uint32_t channels) static uint8_t *streambuf_get(struct streambuf *buf, size_t *len) { - uint32_t used = buf->prod - buf->cons; + int64_t used = buf->prod - buf->cons; uint8_t *data; - if (!used) { + if (used <= 0) { *len = 0; return NULL; } |