Last section of memory block is always initialized to mem->start_section_nr + sections_per_block - 1
which will not be true for a section that doesn't contain sections_per_block sections due to the memory size specified. This causes the following kernel crash when memory blocks under a node are registered during reboot that follows a memory hotplug operation on pseries guest. Unable to handle kernel paging request for data at address 0xf0000000003f0020 Faulting instruction address: 0xc0000000007657cc Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=1024 NUMA pSeries Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.2.0-rc6+ #48 task: c0000000ba3c0000 ti: c00000013c580000 task.ti: c00000013c580000 NIP: c0000000007657cc LR: c000000000592dbc CTR: 0000000000000400 REGS: c00000013c5836f0 TRAP: 0300 Not tainted (4.2.0-rc6+) MSR: 8000000000009032 MSR: 8000000000009032 <<SFSF,EE,EE,ME,ME,IR,IR,DR,DR,RI,RI>> CR: 48000048 XER: 00000000 CR: 48000048 XER: 00000000 CFAR: 00003fff990f50ec CFAR: 00003fff990f50ec DAR: f0000000003f0020 DSISR: 40000000 DAR: f0000000003f0020 DSISR: 40000000 SOFTE: 1 SOFTE: 1 GPR00: c000000000592dbc c000000000592dbc c00000013c583970 c00000013c583970 c0000000014f0300 c0000000014f0300 00000000003f0000 00000000003f0000 GPR04: 0000000000000000 0000000000000000 c0000000f43b2900 c0000000f43b2900 c0000000ba324668 c0000000ba324668 0000000000000001 0000000000000001 GPR08: c000000001540300 c000000001540300 f000000000000000 f000000000000000 f0000000003f0000 f0000000003f0000 0000000000000001 0000000000000001 GPR12: 0000000024000084 0000000024000084 c00000000ff20000 c00000000ff20000 c00000000000b5b0 c00000000000b5b0 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR24: c00000000188c380 c00000000188c380 0000000000000000 0000000000000000 0000000000014000 0000000000014000 c0000000018b54e8 c0000000018b54e8 GPR28: c00000013c06e800 c00000013c06e800 000000000000ffff 000000000000ffff 0000000000000000 0000000000000000 000000000000fc00 000000000000fc00 NIP [c0000000007657cc] .get_nid_for_pfn+0x2c/0x60 LR [c000000000592dbc] .register_mem_sect_under_node+0x8c/0x150 Call Trace: [c00000013c583970] [c00000000056e44c] .put_device+0x2c/0x50 [c00000013c5839f0] [c000000000592dbc] .register_mem_sect_under_node+0x8c/0x150 [c00000013c583a80] [c0000000005932b4] .register_one_node+0x2c4/0x380 [c00000013c583b30] [c000000000c882b8] .topology_init+0x44/0x1e0 [c00000013c583bf0] [c00000000000ad30] .do_one_initcall+0x110/0x270 [c00000013c583ce0] [c000000000c845d4] .kernel_init_freeable+0x278/0x360 [c00000013c583db0] [c00000000000b5d4] .kernel_init+0x24/0x130 [c00000013c583e30] [c0000000000094e8] .ret_from_kernel_thread+0x58/0x70 Fix this by updating the memory block to always contain the right number of sections instead of assuming sections_per_block. Signed-off-by: Bharata B Rao <bhar...@linux.vnet.ibm.com> Cc: Nathan Fontenot <nf...@linux.vnet.ibm.com> --- drivers/base/memory.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 2804aed..7f3ce2e 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -645,6 +645,7 @@ static int add_memory_block(int base_section_nr) if (ret) return ret; mem->section_count = section_count; + mem->end_section_nr = mem->start_section_nr + section_count -1; return 0; } -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/