Commit 670777a9 authored by Kővágó, Zoltán's avatar Kővágó, Zoltán Committed by Gerd Hoffmann
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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: default avatarKővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Message-id: ff866985ed369f1e18ea7c70da6a7fce8e241deb.1570996490.git.DirtY.iCE.hu@gmail.com
Signed-off-by: default avatarGerd Hoffmann <kraxel@redhat.com>
parent 3e44607e

hw/usb/dev-audio.c

+8 −6
Original line number Diff line number Diff line
@@ -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;

    }