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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6

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* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: ohci: fix race when reading count in AR descriptor
  firewire: ohci: avoid reallocation of AR buffers
  firewire: ohci: fix race in AR split packet handling
  firewire: ohci: fix buffer overflow in AR split packet handling
This commit is contained in:
Linus Torvalds 2010-11-05 14:17:22 -07:00
commit f69fa76482
1 changed files with 65 additions and 23 deletions
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84
drivers/firewire/ohci.c
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@ -577,17 +577,11 @@ static int ohci_update_phy_reg(struct fw_card *card, int addr,
return ret;
}
static int ar_context_add_page(struct ar_context *ctx)
static void ar_context_link_page(struct ar_context *ctx,
struct ar_buffer *ab, dma_addr_t ab_bus)
{
struct device *dev = ctx->ohci->card.device;
struct ar_buffer *ab;
dma_addr_t uninitialized_var(ab_bus);
size_t offset;
ab = dma_alloc_coherent(dev, PAGE_SIZE, &ab_bus, GFP_ATOMIC);
if (ab == NULL)
return -ENOMEM;
ab->next = NULL;
memset(&ab->descriptor, 0, sizeof(ab->descriptor));
ab->descriptor.control = cpu_to_le16(DESCRIPTOR_INPUT_MORE |
@ -606,6 +600,19 @@ static int ar_context_add_page(struct ar_context *ctx)
reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE);
flush_writes(ctx->ohci);
}
static int ar_context_add_page(struct ar_context *ctx)
{
struct device *dev = ctx->ohci->card.device;
struct ar_buffer *ab;
dma_addr_t uninitialized_var(ab_bus);
ab = dma_alloc_coherent(dev, PAGE_SIZE, &ab_bus, GFP_ATOMIC);
if (ab == NULL)
return -ENOMEM;
ar_context_link_page(ctx, ab, ab_bus);
return 0;
}
@ -730,16 +737,17 @@ static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
static void ar_context_tasklet(unsigned long data)
{
struct ar_context *ctx = (struct ar_context *)data;
struct fw_ohci *ohci = ctx->ohci;
struct ar_buffer *ab;
struct descriptor *d;
void *buffer, *end;
__le16 res_count;
ab = ctx->current_buffer;
d = &ab->descriptor;
if (d->res_count == 0) {
size_t size, rest, offset;
res_count = ACCESS_ONCE(d->res_count);
if (res_count == 0) {
size_t size, size2, rest, pktsize, size3, offset;
dma_addr_t start_bus;
void *start;
@ -750,29 +758,63 @@ static void ar_context_tasklet(unsigned long data)
*/
offset = offsetof(struct ar_buffer, data);
start = buffer = ab;
start = ab;
start_bus = le32_to_cpu(ab->descriptor.data_address) - offset;
buffer = ab->data;
ab = ab->next;
d = &ab->descriptor;
size = buffer + PAGE_SIZE - ctx->pointer;
size = start + PAGE_SIZE - ctx->pointer;
/* valid buffer data in the next page */
rest = le16_to_cpu(d->req_count) - le16_to_cpu(d->res_count);
/* what actually fits in this page */
size2 = min(rest, (size_t)PAGE_SIZE - offset - size);
memmove(buffer, ctx->pointer, size);
memcpy(buffer + size, ab->data, rest);
ctx->current_buffer = ab;
ctx->pointer = (void *) ab->data + rest;
end = buffer + size + rest;
memcpy(buffer + size, ab->data, size2);
while (size > 0) {
void *next = handle_ar_packet(ctx, buffer);
pktsize = next - buffer;
if (pktsize >= size) {
/*
* We have handled all the data that was
* originally in this page, so we can now
* continue in the next page.
*/
buffer = next;
break;
}
/* move the next packet to the start of the buffer */
memmove(buffer, next, size + size2 - pktsize);
size -= pktsize;
/* fill up this page again */
size3 = min(rest - size2,
(size_t)PAGE_SIZE - offset - size - size2);
memcpy(buffer + size + size2,
(void *) ab->data + size2, size3);
size2 += size3;
}
if (rest > 0) {
/* handle the packets that are fully in the next page */
buffer = (void *) ab->data +
(buffer - (start + offset + size));
end = (void *) ab->data + rest;
while (buffer < end)
buffer = handle_ar_packet(ctx, buffer);
dma_free_coherent(ohci->card.device, PAGE_SIZE,
start, start_bus);
ar_context_add_page(ctx);
ctx->current_buffer = ab;
ctx->pointer = end;
ar_context_link_page(ctx, start, start_bus);
} else {
ctx->pointer = start + PAGE_SIZE;
}
} else {
buffer = ctx->pointer;
ctx->pointer = end =
(void *) ab + PAGE_SIZE - le16_to_cpu(d->res_count);
(void *) ab + PAGE_SIZE - le16_to_cpu(res_count);
while (buffer < end)
buffer = handle_ar_packet(ctx, buffer);