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ide: Treat read/write beyond end as invalid

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The block layer fails such reads and writes just fine.  However, they
then get treated like valid operations that fail: the error action
gets executed.  Unwanted; reporting the error to the guest is the only
sensible action.

Reject them before passing them to the block layer.  This bypasses the
error action and I/O accounting.  Not quite correct for DMA, because
DMA can fail after some success, and when that happens, the part that
succeeded isn't counted.  Tolerable, because I/O accounting is an
inconsistent mess anyway.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Markus Armbruster 2014-07-09 19:07:32 +02:00 committed by Kevin Wolf
parent 3c2daac0b9
commit 58ac321135
1 changed files with 28 additions and 0 deletions
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28
hw/ide/core.c
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@ -499,6 +499,18 @@ static void ide_rw_error(IDEState *s) {
ide_set_irq(s->bus);
}
static bool ide_sect_range_ok(IDEState *s,
uint64_t sector, uint64_t nb_sectors)
{
uint64_t total_sectors;
bdrv_get_geometry(s->bs, &total_sectors);
if (sector > total_sectors || nb_sectors > total_sectors - sector) {
return false;
}
return true;
}
static void ide_sector_read_cb(void *opaque, int ret)
{
IDEState *s = opaque;
@ -554,6 +566,11 @@ void ide_sector_read(IDEState *s)
printf("sector=%" PRId64 "\n", sector_num);
#endif
if (!ide_sect_range_ok(s, sector_num, n)) {
ide_rw_error(s);
return;
}
s->iov.iov_base = s->io_buffer;
s->iov.iov_len = n * BDRV_SECTOR_SIZE;
qemu_iovec_init_external(&s->qiov, &s->iov, 1);
@ -671,6 +688,12 @@ void ide_dma_cb(void *opaque, int ret)
sector_num, n, s->dma_cmd);
#endif
if (!ide_sect_range_ok(s, sector_num, n)) {
dma_buf_commit(s);
ide_dma_error(s);
return;
}
switch (s->dma_cmd) {
case IDE_DMA_READ:
s->bus->dma->aiocb = dma_bdrv_read(s->bs, &s->sg, sector_num,
@ -790,6 +813,11 @@ void ide_sector_write(IDEState *s)
n = s->req_nb_sectors;
}
if (!ide_sect_range_ok(s, sector_num, n)) {
ide_rw_error(s);
return;
}
s->iov.iov_base = s->io_buffer;
s->iov.iov_len = n * BDRV_SECTOR_SIZE;
qemu_iovec_init_external(&s->qiov, &s->iov, 1);