From: Mike Rapoport rppt@linux.ibm.com
commit 79e482e9c3ae86e849c701c846592e72baddda5a upstream.
Commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") didn't take into account that when there is movable_node parameter in the kernel command line, for_each_mem_range() would skip ranges marked with MEMBLOCK_HOTPLUG.
The page table setup code in POWER uses for_each_mem_range() to create the linear mapping of the physical memory and since the regions marked as MEMORY_HOTPLUG are skipped, they never make it to the linear map.
A later access to the memory in those ranges will fail:
BUG: Unable to handle kernel data access on write at 0xc000000400000000 Faulting instruction address: 0xc00000000008a3c0 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 53 Comm: kworker/u2:0 Not tainted 5.13.0 #7 NIP: c00000000008a3c0 LR: c0000000003c1ed8 CTR: 0000000000000040 REGS: c000000008a57770 TRAP: 0300 Not tainted (5.13.0) MSR: 8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 84222202 XER: 20040000 CFAR: c0000000003c1ed4 DAR: c000000400000000 DSISR: 42000000 IRQMASK: 0 GPR00: c0000000003c1ed8 c000000008a57a10 c0000000019da700 c000000400000000 GPR04: 0000000000000280 0000000000000180 0000000000000400 0000000000000200 GPR08: 0000000000000100 0000000000000080 0000000000000040 0000000000000300 GPR12: 0000000000000380 c000000001bc0000 c0000000001660c8 c000000006337e00 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000040000000 0000000020000000 c000000001a81990 c000000008c30000 GPR24: c000000008c20000 c000000001a81998 000fffffffff0000 c000000001a819a0 GPR28: c000000001a81908 c00c000001000000 c000000008c40000 c000000008a64680 NIP clear_user_page+0x50/0x80 LR __handle_mm_fault+0xc88/0x1910 Call Trace: __handle_mm_fault+0xc44/0x1910 (unreliable) handle_mm_fault+0x130/0x2a0 __get_user_pages+0x248/0x610 __get_user_pages_remote+0x12c/0x3e0 get_arg_page+0x54/0xf0 copy_string_kernel+0x11c/0x210 kernel_execve+0x16c/0x220 call_usermodehelper_exec_async+0x1b0/0x2f0 ret_from_kernel_thread+0x5c/0x70 Instruction dump: 79280fa4 79271764 79261f24 794ae8e2 7ca94214 7d683a14 7c893a14 7d893050 7d4903a6 60000000 60000000 60000000 <7c001fec> 7c091fec 7c081fec 7c051fec ---[ end trace 490b8c67e6075e09 ]---
Making for_each_mem_range() include MEMBLOCK_HOTPLUG regions in the traversal fixes this issue.
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1976100 Link: https://lkml.kernel.org/r/20210712071132.20902-1-rppt@kernel.org Fixes: b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") Signed-off-by: Mike Rapoport rppt@linux.ibm.com Tested-by: Greg Kurz groug@kaod.org Reviewed-by: David Hildenbrand david@redhat.com Cc: stable@vger.kernel.org [5.10+] Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/memblock.h | 4 ++-- mm/memblock.c | 3 ++- 2 files changed, 4 insertions(+), 3 deletions(-)
--- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -207,7 +207,7 @@ static inline void __next_physmem_range( */ #define for_each_mem_range(i, p_start, p_end) \ __for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, \ - MEMBLOCK_NONE, p_start, p_end, NULL) + MEMBLOCK_HOTPLUG, p_start, p_end, NULL)
/** * for_each_mem_range_rev - reverse iterate through memblock areas from @@ -218,7 +218,7 @@ static inline void __next_physmem_range( */ #define for_each_mem_range_rev(i, p_start, p_end) \ __for_each_mem_range_rev(i, &memblock.memory, NULL, NUMA_NO_NODE, \ - MEMBLOCK_NONE, p_start, p_end, NULL) + MEMBLOCK_HOTPLUG, p_start, p_end, NULL)
/** * for_each_reserved_mem_range - iterate over all reserved memblock areas --- a/mm/memblock.c +++ b/mm/memblock.c @@ -940,7 +940,8 @@ static bool should_skip_region(struct me return true;
/* skip hotpluggable memory regions if needed */ - if (movable_node_is_enabled() && memblock_is_hotpluggable(m)) + if (movable_node_is_enabled() && memblock_is_hotpluggable(m) && + !(flags & MEMBLOCK_HOTPLUG)) return true;
/* if we want mirror memory skip non-mirror memory regions */