From 4c42dc5c69a8f24c467a6c997909d2f1d4efdc7f Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 11 Sep 2020 05:05:38 +0000 Subject: powerpc/kasan: Fix CONFIG_KASAN_VMALLOC for 8xx 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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/8ae4554357da4882612644a74387ae05525b2aaa.1599800716.git.christophe.leroy@csgroup.eu --- arch/powerpc/mm/kasan/kasan_init_32.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'arch/powerpc/mm/kasan') diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c index fb294046e00e..929716ea21e9 100644 --- a/arch/powerpc/mm/kasan/kasan_init_32.c +++ b/arch/powerpc/mm/kasan/kasan_init_32.c @@ -127,8 +127,7 @@ 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) @@ -139,11 +138,11 @@ 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; @@ -153,6 +152,13 @@ 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); -- cgit v1.2.1 From 69a1593abdbcf03a76367320d929a8ae7a5e3d71 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 1 Oct 2020 15:35:38 +0000 Subject: powerpc/32s: Setup the early hash table at all time. At the time being, an early hash table is set up when CONFIG_KASAN is selected. There is nothing wrong with setting such an early hash table all the time, even if it is not used. This is a statically allocated 256 kB table which lies in the init data section. This makes the code simpler and may in the future allow to setup early IO mappings with fixmap instead of hard coding BATs. Put create_hpte() and flush_hash_pages() in the .ref.text section in order to avoid warning for the reference to early_hash[]. This reference is removed by MMU_init_hw_patch() before init memory is freed. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/b8f8101c368b8a6451844a58d7bd7d83c14cf2aa.1601566529.git.christophe.leroy@csgroup.eu --- arch/powerpc/mm/kasan/kasan_init_32.c | 19 ------------------- 1 file changed, 19 deletions(-) (limited to 'arch/powerpc/mm/kasan') diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c index 929716ea21e9..59f61efc43af 100644 --- a/arch/powerpc/mm/kasan/kasan_init_32.c +++ b/arch/powerpc/mm/kasan/kasan_init_32.c @@ -174,22 +174,6 @@ void __init kasan_late_init(void) kasan_unmap_early_shadow_vmalloc(); } -#ifdef CONFIG_PPC_BOOK3S_32 -u8 __initdata early_hash[256 << 10] __aligned(256 << 10) = {0}; - -static void __init kasan_early_hash_table(void) -{ - unsigned int hash = __pa(early_hash); - - modify_instruction_site(&patch__hash_page_A0, 0xffff, hash >> 16); - modify_instruction_site(&patch__flush_hash_A0, 0xffff, hash >> 16); - - Hash = (struct hash_pte *)early_hash; -} -#else -static void __init kasan_early_hash_table(void) {} -#endif - void __init kasan_early_init(void) { unsigned long addr = KASAN_SHADOW_START; @@ -205,7 +189,4 @@ void __init kasan_early_init(void) next = pgd_addr_end(addr, end); pmd_populate_kernel(&init_mm, pmd, kasan_early_shadow_pte); } while (pmd++, addr = next, addr != end); - - if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) - kasan_early_hash_table(); } -- cgit v1.2.1