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[Qemu-devel] [PATCH v4 2.1 4/4] ide: Treat read/write beyond end as inva
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH v4 2.1 4/4] ide: Treat read/write beyond end as invalid |
Date: |
Wed, 9 Jul 2014 19:07:32 +0200 |
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 <address@hidden>
---
hw/ide/core.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/hw/ide/core.c b/hw/ide/core.c
index 3a38f1e..db191a6 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -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);
--
1.9.3