Christophe Leroy 2807273f5e powerpc/fixmap: fix crash with HIGHMEM ... Commit f2bb86937d ("powerpc/fixmap: don't clear fixmap area in paging_init()") removed the clearing of fixmap area in order to avoid clearing fixmapped areas set earlier. However unlike all other users of fixmap which use __set_fixmap(), HIGHMEM functions directly use __set_pte_at(). This means the page table must pre-exist, otherwise the following crash can be encoutered due to the lack of entry in the PGD. Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=4K MMU=Hash PowerMac Modules linked in: CPU: 0 PID: 1 Comm: swapper Not tainted 5.4.0+ #2528 NIP: c0144ce8 LR: c0144ccc CTR: 00000080 REGS: ef0b5aa0 TRAP: 0300 Not tainted (5.4.0+) MSR: 00009032 <EE,ME,IR,DR,RI> CR: 44282842 XER: 00000000 DAR: fffdf000 DSISR: 42000000 GPR00: c0144ccc ef0b5b58 ef0b0000 fffdf000 fffdf000 00000000 c0000f7c 00000000 GPR08: c0833000 fffdf000 00000000 ef1c53c9 24042842 00000000 00000000 00000000 GPR16: 00000000 00000000 ef7e7358 effe8160 00000000 c08a9660 c0851644 00000004 GPR24: c08c70a8 00002dc2 00000000 00000001 00000201 effe8160 effe8160 00000000 NIP [c0144ce8] prep_new_page+0x138/0x178 LR [c0144ccc] prep_new_page+0x11c/0x178 Call Trace: [ef0b5b58] [c0144ccc] prep_new_page+0x11c/0x178 (unreliable) [ef0b5b88] [c0147218] get_page_from_freelist+0x1fc/0xd88 [ef0b5c38] [c0148328] __alloc_pages_nodemask+0xd4/0xbb4 [ef0b5cf8] [c0142ba8] __vmalloc_node_range+0x1b4/0x2e0 [ef0b5d38] [c0142dd0] vzalloc+0x48/0x58 [ef0b5d58] [c0301c8c] check_partition+0x58/0x244 [ef0b5d78] [c02ffe80] blk_add_partitions+0x44/0x2cc [ef0b5db8] [c01a32d8] bdev_disk_changed+0x68/0xfc [ef0b5de8] [c01a4494] __blkdev_get+0x290/0x460 [ef0b5e28] [c02fdd40] __device_add_disk+0x480/0x4d8 [ef0b5e68] [c0810688] brd_init+0xc0/0x188 [ef0b5e88] [c0005194] do_one_initcall+0x40/0x19c [ef0b5ee8] [c07dd4dc] kernel_init_freeable+0x164/0x230 [ef0b5f28] [c0005408] kernel_init+0x18/0x10c [ef0b5f38] [c0014274] ret_from_kernel_thread+0x14/0x1c Partially revert that commit to still clear the fixmap area dedicated to HIGHMEM. Fixes: f2bb86937d ("powerpc/fixmap: don't clear fixmap area in paging_init()") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d42fa9747df5afa41e67b08e374c98d3b40529c9.1574927918.git.christophe.leroy@c-s.fr		2019-11-29 22:41:15 +11:00
..
book3s32	powerpc/32s: automatically allocate BAT in setbat()	2019-11-19 19:38:38 +11:00
book3s64	powerpc/book3s64/hash: Add cond_resched to avoid soft lockup warning	2019-11-05 22:24:57 +11:00
kasan	powerpc/mm: Fix an Oops in kasan_mmu_init()	2019-09-21 08:36:53 +10:00
nohash	powerpc/32: Don't populate page tables for block mapped pages except on the 8xx.	2019-11-18 22:27:52 +11:00
ptdump	powerpc: use the generic dma coherent remap allocator	2019-08-28 23:19:34 +10:00
copro_fault.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 153	2019-05-30 11:26:32 -07:00
dma-noncoherent.c	powerpc updates for 5.4	2019-09-20 11:48:06 -07:00
drmem.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
fault.c	powerpc/mm: Show if a bad page fault on data is read or write.	2019-11-18 22:27:51 +11:00
highmem.c	powerpc/highmem: Change BUG_ON() to WARN_ON()	2019-04-20 22:02:11 +10:00
hugetlbpage.c	mm: introduce compound_nr()	2019-09-24 15:54:08 -07:00
init-common.c	powerpc: introduce kernstart_virt_addr to store the kernel base	2019-11-13 19:27:32 +11:00
init_32.c	powerpc: move memstart_addr and kernstart_addr to init-common.c	2019-11-13 19:27:28 +11:00
init_64.c	Merge branch 'topic/kaslr-book3e32' into next	2019-11-14 19:23:33 +11:00
ioremap.c	powerpc/mm: split out early ioremap path.	2019-08-27 13:03:35 +10:00
ioremap_32.c	powerpc/ioremap: warn on early use of ioremap()	2019-11-19 19:38:38 +11:00
ioremap_64.c	powerpc/ioremap: warn on early use of ioremap()	2019-11-19 19:38:38 +11:00
Makefile	powerpc/mm: Move ioremap functions out of pgtable_32/64.c	2019-08-27 13:03:35 +10:00
mem.c	powerpc/fixmap: fix crash with HIGHMEM	2019-11-29 22:41:15 +11:00
mmap.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156	2019-05-30 11:26:35 -07:00
mmu_context.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
mmu_decl.h	powerpc/fsl_booke/kaslr: clear the original kernel if randomized	2019-11-13 19:27:44 +11:00
numa.c	powerpc updates for 5.3	2019-07-13 16:08:36 -07:00
pgtable-frag.c	mm: treewide: clarify pgtable_page_{ctor,dtor}() naming	2019-09-26 10:10:44 -07:00
pgtable.c	powerpc updates for 5.3	2019-07-13 16:08:36 -07:00
pgtable_32.c	powerpc/32: Don't populate page tables for block mapped pages except on the 8xx.	2019-11-18 22:27:52 +11:00
pgtable_64.c	powerpc/mm: Move ioremap functions out of pgtable_32/64.c	2019-08-27 13:03:35 +10:00
slice.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156	2019-05-30 11:26:35 -07:00