Date: Thu, 24 May 2012 19:28:58 +0200 From: Clemens Ladisch Subject: firewire: core: allocate the low memory region 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 Signed-off-by: Stefan Richter --- drivers/firewire/core-transaction.c | 23 +++++++++++++++++++++-- 1 files changed, 21 insertions(+), 2 deletions(-) --- a/drivers/firewire/core-transaction.c +++ b/drivers/firewire/core-transaction.c @@ -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 "); MODULE_DESCRIPTION("Core IEEE1394 transaction logic"); MODULE_LICENSE("GPL"); @@ -1279,6 +1297,7 @@ static int __init fw_core_init(void) set_text_desc(&model_id_descriptor, model); fw_core_add_address_handler(&topology_map, &topology_map_region); fw_core_add_address_handler(®isters, ®isters_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);