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firewire: core: allocate the low memory region

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Prevent userspace applications from allocating low memory address
ranges.  Otherwise, if some application happens to allocate such
a range and intends for a remote node to access it, and if that node
also implements SBP-2 (which will become more likely with the upcoming
SBP-2 target support), these accesses would be routed by the physical
DMA unit to some wrong memory address.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This commit is contained in:
Clemens Ladisch 2012-05-24 19:28:58 +02:00 committed by Stefan Richter
parent 188726ecb6
commit f07d42ac7f
1 changed files with 21 additions and 2 deletions
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23
drivers/firewire/core-transaction.c
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@ -525,9 +525,10 @@ const struct fw_address_region fw_high_memory_region =
{ .start = 0x000100000000ULL, .end = 0xffffe0000000ULL, };
EXPORT_SYMBOL(fw_high_memory_region);
#if 0
const struct fw_address_region fw_low_memory_region =
static const struct fw_address_region low_memory_region =
{ .start = 0x000000000000ULL, .end = 0x000100000000ULL, };
#if 0
const struct fw_address_region fw_private_region =
{ .start = 0xffffe0000000ULL, .end = 0xfffff0000000ULL, };
const struct fw_address_region fw_csr_region =
@ -1189,6 +1190,23 @@ static struct fw_address_handler registers = {
.address_callback = handle_registers,
};
static void handle_low_memory(struct fw_card *card, struct fw_request *request,
int tcode, int destination, int source, int generation,
unsigned long long offset, void *payload, size_t length,
void *callback_data)
{
/*
* This catches requests not handled by the physical DMA unit,
* i.e., wrong transaction types or unauthorized source nodes.
*/
fw_send_response(card, request, RCODE_TYPE_ERROR);
}
static struct fw_address_handler low_memory = {
.length = 0x000100000000ULL,
.address_callback = handle_low_memory,
};
MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
MODULE_DESCRIPTION("Core IEEE1394 transaction logic");
MODULE_LICENSE("GPL");
@ -1250,6 +1268,7 @@ static int __init fw_core_init(void)
fw_core_add_address_handler(&topology_map, &topology_map_region);
fw_core_add_address_handler(&registers, &registers_region);
fw_core_add_address_handler(&low_memory, &low_memory_region);
fw_core_add_descriptor(&vendor_id_descriptor);
fw_core_add_descriptor(&model_id_descriptor);