Add check to validate whether requested page is part of system RAM or not before mmap() and error out if its not part of system RAM.
cat /proc/iomem: ----------------- 00000000-27ffffffff : System RAM 2800000000-2fffffffff : namespace0.0 200000000000-2027ffffffff : System RAM 202800000000-202fffffffff : namespace1.0 6000000000000-6003fbfffffff : pciex@600c3c0000000 6004000000000-6007f7fffffff : pciex@600c3c0100000 .... .... Sample dmesg output with this fix: ---------------------------------- [ 160.371911] opal-prd: mmap: Requested page is not part of system RAM (addr : 0x0000202ffcfc0000, size : 0x0000000000570000) [ 160.665366] opal-prd: mmap: Requested page is not part of system RAM (addr : 0x0000202ffcfc0000, size : 0x0000000000570000) [ 160.914627] opal-prd: mmap: Requested page is not part of system RAM (addr : 0x0000202ffcfc0000, size : 0x0000000000570000) [ 161.165253] opal-prd: mmap: Requested page is not part of system RAM (addr : 0x0000202ffcfc0000, size : 0x0000000000570000) [ 161.414604] opal-prd: mmap: Requested page is not part of system RAM (addr : 0x0000202ffcfc0000, size : 0x0000000000570000) CC: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com> CC: Jeremy Kerr <j...@ozlabs.org> CC: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com> Signed-off-by: Vasant Hegde <hegdevas...@linux.vnet.ibm.com> --- arch/powerpc/platforms/powernv/opal-prd.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/platforms/powernv/opal-prd.c b/arch/powerpc/platforms/powernv/opal-prd.c index 45f4223a790f..0f88752302a2 100644 --- a/arch/powerpc/platforms/powernv/opal-prd.c +++ b/arch/powerpc/platforms/powernv/opal-prd.c @@ -3,7 +3,7 @@ * OPAL Runtime Diagnostics interface driver * Supported on POWERNV platform * - * Copyright IBM Corporation 2015 + * Copyright IBM Corporation 2015-2019 */ #define pr_fmt(fmt) "opal-prd: " fmt @@ -47,6 +47,20 @@ static bool opal_prd_range_is_valid(uint64_t addr, uint64_t size) if (addr + size < addr) return false; + /* + * Check if region is in system RAM and error out if the address + * belongs to special devices like NVDIMM. phys_mem_access_prot() + * routine will change ATT bits to non cachable if page is not in + * RAM, causing HBRT to not fetch and execute in the mapped memory + * and fail. Page permissions can be left at default since all + * firmware component should be in system RAM only. + */ + if (!page_is_ram(addr >> PAGE_SHIFT)) { + pr_warn("mmap: Requested page is not part of system RAM " + "(addr : 0x%016llx, size : 0x%016llx)\n", addr, size); + return false; + } + parent = of_find_node_by_path("/reserved-memory"); if (!parent) return false; -- 2.21.0