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.kis...@siemens.com> --- Now I have to deal with 3 byte config space access for device assignment, but Michael was right, such things are possible, even in PCIe. hw/pci.c | 6 ++---- hw/pci_host.c | 24 ++++++++++++++++++++---- hw/pci_host.h | 6 ++++++ hw/pcie_host.c | 12 ++++++------ 4 files changed, 34 insertions(+), 14 deletions(-) diff --git a/hw/pci.c b/hw/pci.c index b904a4e..ef94739 100644 --- a/hw/pci.c +++ b/hw/pci.c @@ -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)); diff --git a/hw/pci_host.c b/hw/pci_host.c index 728e2d4..bfdc321 100644 --- a/hw/pci_host.c +++ b/hw/pci_host.c @@ -47,17 +47,33 @@ static inline PCIDevice *pci_dev_find_by_addr(PCIBus *bus, uint32_t addr) return pci_find_device(bus, bus_num, devfn); } +void pci_config_write_common(PCIDevice *pci_dev, uint32_t addr, + uint32_t limit, uint32_t val, uint32_t len) +{ + assert(len <= 4); + pci_dev->config_write(pci_dev, addr, val, MIN(len, limit - addr)); +} + +uint32_t pci_config_read_common(PCIDevice *pci_dev, uint32_t addr, + uint32_t limit, uint32_t len) +{ + assert(len <= 4); + return pci_dev->config_read(pci_dev, addr, MIN(len, limit - addr)); +} + void pci_data_write(PCIBus *s, uint32_t addr, uint32_t val, int len) { PCIDevice *pci_dev = pci_dev_find_by_addr(s, addr); uint32_t config_addr = addr & (PCI_CONFIG_SPACE_SIZE - 1); - if (!pci_dev) + if (!pci_dev) { return; + } PCI_DPRINTF("%s: %s: addr=%02" PRIx32 " val=%08" PRIx32 " len=%d\n", __func__, pci_dev->name, config_addr, val, len); - pci_dev->config_write(pci_dev, config_addr, val, len); + pci_config_write_common(pci_dev, config_addr, PCI_CONFIG_SPACE_SIZE, val, + len); } uint32_t pci_data_read(PCIBus *s, uint32_t addr, int len) @@ -66,12 +82,12 @@ uint32_t pci_data_read(PCIBus *s, uint32_t addr, int len) uint32_t config_addr = addr & (PCI_CONFIG_SPACE_SIZE - 1); uint32_t val; - assert(len == 1 || len == 2 || len == 4); if (!pci_dev) { return ~0x0; } - val = pci_dev->config_read(pci_dev, config_addr, len); + val = pci_config_read_common(pci_dev, config_addr, PCI_CONFIG_SPACE_SIZE, + len); PCI_DPRINTF("%s: %s: addr=%02"PRIx32" val=%08"PRIx32" len=%d\n", __func__, pci_dev->name, config_addr, val, len); diff --git a/hw/pci_host.h b/hw/pci_host.h index 0a58595..e95db6c 100644 --- a/hw/pci_host.h +++ b/hw/pci_host.h @@ -39,6 +39,12 @@ struct PCIHostState { PCIBus *bus; }; +/* common internal helpers for PCI/PCIe hosts, cut off overflows */ +void pci_config_write_common(PCIDevice *pci_dev, uint32_t addr, + uint32_t addr_mask, uint32_t val, uint32_t len); +uint32_t pci_config_read_common(PCIDevice *pci_dev, uint32_t addr, + uint32_t addr_mask, uint32_t len); + void pci_data_write(PCIBus *s, uint32_t addr, uint32_t val, int len); uint32_t pci_data_read(PCIBus *s, uint32_t addr, int len); diff --git a/hw/pcie_host.c b/hw/pcie_host.c index b749865..ed6656b 100644 --- a/hw/pcie_host.c +++ b/hw/pcie_host.c @@ -57,22 +57,22 @@ static void pcie_mmcfg_data_write(PCIBus *s, { PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, mmcfg_addr); - if (!pci_dev) + if (!pci_dev) { return; - - pci_dev->config_write(pci_dev, - PCIE_MMCFG_CONFOFFSET(mmcfg_addr), val, len); + } + pci_config_write_common(pci_dev, PCIE_MMCFG_CONFOFFSET(mmcfg_addr), + PCIE_CONFIG_SPACE_SIZE, val, len); } static uint32_t pcie_mmcfg_data_read(PCIBus *s, uint32_t addr, int len) { PCIDevice *pci_dev = pcie_dev_find_by_mmcfg_addr(s, addr); - assert(len == 1 || len == 2 || len == 4); if (!pci_dev) { return ~0x0; } - return pci_dev->config_read(pci_dev, PCIE_MMCFG_CONFOFFSET(addr), len); + return pci_config_read_common(pci_dev, PCIE_MMCFG_CONFOFFSET(addr), + PCIE_CONFIG_SPACE_SIZE, len); } static void pcie_mmcfg_data_writeb(void *opaque, -- 1.7.3.4