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Put recycle pointer in own memory area which is not mmap'able.

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This commit is contained in:
hselasky 2015-05-10 12:45:21 +00:00
parent 502d4577e2
commit 6a841c4bb7
1 changed files with 9 additions and 5 deletions
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14
sys/dev/usb/video/udl.c
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@ -203,12 +203,14 @@ udl_buffer_alloc(uint32_t size)
}
mtx_unlock(&udl_buffer_mtx);
if (buf != NULL) {
uint8_t *ptr = ((uint8_t *)buf) - size;
/* wipe and recycle buffer */
memset(buf, 0, size);
return (buf);
memset(ptr, 0, size);
/* return buffer pointer */
return (ptr);
}
/* allocate new buffer */
return (malloc(size, M_USB_DL, M_WAITOK | M_ZERO));
return (malloc(size + sizeof(*buf), M_USB_DL, M_WAITOK | M_ZERO));
}
static void
@ -216,9 +218,11 @@ udl_buffer_free(void *_buf, uint32_t size)
{
struct udl_buffer *buf;
buf = (struct udl_buffer *)_buf;
if (buf == NULL)
/* check for NULL pointer */
if (_buf == NULL)
return;
/* compute pointer to recycle list */
buf = (struct udl_buffer *)(((uint8_t *)_buf) + size);
/*
* Memory mapped buffers should never be freed.