diff options
| author | Robert Richter | 2022-10-18 15:23:30 +0200 |
|---|---|---|
| committer | Dan Williams | 2022-11-14 10:37:08 -0800 |
| commit | 3bb80da51b1c1dbf31af2226f57cbc258f5e994b (patch) | |
| tree | ae7eec7c7c62a07e7f6b198af38b6a04ab406bd8 /drivers | |
| parent | fa89248e669d589cdb895517e75cdead8d8ba5c0 (diff) | |
cxl/core: Check physical address before mapping it in devm_cxl_iomap_block()
The physical base address of a CXL range can be invalid and is then
set to CXL_RESOURCE_NONE. In general software shall prevent such
situations, but it is hard to proof this may never happen. E.g. in
add_port_attach_ep() there this the following:
component_reg_phys = find_component_registers(uport_dev);
port = devm_cxl_add_port(&parent_port->dev, uport_dev,
component_reg_phys, parent_dport);
find_component_registers() and subsequent functions (e.g.
cxl_regmap_to_base()) may return CXL_RESOURCE_NONE. But it is written
to port without any further check in cxl_port_alloc():
port->component_reg_phys = component_reg_phys;
It is then later directly used in devm_cxl_setup_hdm() to map io
ranges with devm_cxl_iomap_block(). Just an example...
Check this condition. Also do not fail silently like an ioremap()
failure, use a WARN_ON_ONCE() for it.
Signed-off-by: Robert Richter <rrichter@amd.com>
Link: https://lore.kernel.org/r/20221018132341.76259-3-rrichter@amd.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/cxl/core/regs.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c index 6522931df3f7..ec178e69b18f 100644 --- a/drivers/cxl/core/regs.c +++ b/drivers/cxl/core/regs.c @@ -167,6 +167,9 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr, void __iomem *ret_val; struct resource *res; + if (WARN_ON_ONCE(addr == CXL_RESOURCE_NONE)) + return NULL; + res = devm_request_mem_region(dev, addr, length, dev_name(dev)); if (!res) { resource_size_t end = addr + length - 1; |