From: Christophe Leroy christophe.leroy@csgroup.eu
[ Upstream commit 4c42dc5c69a8f24c467a6c997909d2f1d4efdc7f ]
Before the commit identified below, pages tables allocation was performed after the allocation of final shadow area for linear memory. But that commit switched the order, leading to page tables being already allocated at the time 8xx kasan_init_shadow_8M() is called. Due to this, kasan_init_shadow_8M() doesn't map the needed shadow entries because there are already page tables.
kasan_init_shadow_8M() installs huge PMD entries instead of page tables. We could at that time free the page tables, but there is no point in creating page tables that get freed before being used.
Only book3s/32 hash needs early allocation of page tables. For other variants, we can keep the initial order and create remaining page tables after the allocation of final shadow memory for linear mem.
Move back the allocation of shadow page tables for CONFIG_KASAN_VMALLOC into kasan_init() after the loop which creates final shadow memory for linear mem.
Fixes: 41ea93cf7ba4 ("powerpc/kasan: Fix shadow pages allocation failure") Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/8ae4554357da4882612644a74387ae05525b2aaa.159980071... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/mm/kasan/kasan_init_32.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c index 019b0c0bbbf31..ca91d04d0a7ae 100644 --- a/arch/powerpc/mm/kasan/kasan_init_32.c +++ b/arch/powerpc/mm/kasan/kasan_init_32.c @@ -121,8 +121,7 @@ void __init kasan_mmu_init(void) { int ret;
- if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE) || - IS_ENABLED(CONFIG_KASAN_VMALLOC)) { + if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) { ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END);
if (ret) @@ -133,11 +132,11 @@ void __init kasan_mmu_init(void) void __init kasan_init(void) { struct memblock_region *reg; + int ret;
for_each_memblock(memory, reg) { phys_addr_t base = reg->base; phys_addr_t top = min(base + reg->size, total_lowmem); - int ret;
if (base >= top) continue; @@ -147,6 +146,13 @@ void __init kasan_init(void) panic("kasan: kasan_init_region() failed"); }
+ if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) { + ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END); + + if (ret) + panic("kasan: kasan_init_shadow_page_tables() failed"); + } + kasan_remap_early_shadow_ro();
clear_page(kasan_early_shadow_page);