pci: Common overflow prevention

Introduce pci_config_read/write_common helpers to prevent passing
accesses down the callback chain that go beyond the config space limits.
Adjust length assertions as they are no longer correct (cutting may
generate valid 3 byte accesses).

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Jan Kiszka 2011-07-22 11:05:01 +02:00 committed by Michael S. Tsirkin
parent 85dde9a90b
commit 42e4126b79
4 changed files with 34 additions and 14 deletions

View file

@ -1108,8 +1108,7 @@ uint32_t pci_default_read_config(PCIDevice *d,
uint32_t address, int len)
{
uint32_t val = 0;
assert(len == 1 || len == 2 || len == 4);
len = MIN(len, pci_config_size(d) - address);
memcpy(&val, d->config + address, len);
return le32_to_cpu(val);
}
@ -1117,9 +1116,8 @@ uint32_t pci_default_read_config(PCIDevice *d,
void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l)
{
int i, was_irq_disabled = pci_irq_disabled(d);
uint32_t config_size = pci_config_size(d);
for (i = 0; i < l && addr + i < config_size; val >>= 8, ++i) {
for (i = 0; i < l; val >>= 8, ++i) {
uint8_t wmask = d->wmask[addr + i];
uint8_t w1cmask = d->w1cmask[addr + i];
assert(!(wmask & w1cmask));