From 78cb0945f7141961781f815168f6873ad2b7ed29 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Sat, 16 Mar 2024 12:18:21 +0100 Subject: powerpc: Handle error in mark_rodata_ro() and mark_initmem_nx() mark_rodata_ro() and mark_initmem_nx() use functions that can fail like set_memory_nx() and set_memory_ro(), leading to a not protected kernel. In case of failure, panic. Link: https://github.com/KSPP/linux/issues/7 Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/b16329611deb89e1af505d43f0e2a91310584d26.1710587887.git.christophe.leroy@csgroup.eu --- arch/powerpc/mm/nohash/8xx.c | 33 +++++++++++++++++++++------------ arch/powerpc/mm/nohash/e500.c | 10 +++++++--- 2 files changed, 28 insertions(+), 15 deletions(-) (limited to 'arch/powerpc/mm/nohash') diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c index 6be6421086ed..43d4842bb1c7 100644 --- a/arch/powerpc/mm/nohash/8xx.c +++ b/arch/powerpc/mm/nohash/8xx.c @@ -119,23 +119,26 @@ void __init mmu_mapin_immr(void) PAGE_KERNEL_NCG, MMU_PAGE_512K, true); } -static void mmu_mapin_ram_chunk(unsigned long offset, unsigned long top, - pgprot_t prot, bool new) +static int mmu_mapin_ram_chunk(unsigned long offset, unsigned long top, + pgprot_t prot, bool new) { unsigned long v = PAGE_OFFSET + offset; unsigned long p = offset; + int err = 0; WARN_ON(!IS_ALIGNED(offset, SZ_512K) || !IS_ALIGNED(top, SZ_512K)); - for (; p < ALIGN(p, SZ_8M) && p < top; p += SZ_512K, v += SZ_512K) - __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_512K, new); - for (; p < ALIGN_DOWN(top, SZ_8M) && p < top; p += SZ_8M, v += SZ_8M) - __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_8M, new); - for (; p < ALIGN_DOWN(top, SZ_512K) && p < top; p += SZ_512K, v += SZ_512K) - __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_512K, new); + for (; p < ALIGN(p, SZ_8M) && p < top && !err; p += SZ_512K, v += SZ_512K) + err = __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_512K, new); + for (; p < ALIGN_DOWN(top, SZ_8M) && p < top && !err; p += SZ_8M, v += SZ_8M) + err = __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_8M, new); + for (; p < ALIGN_DOWN(top, SZ_512K) && p < top && !err; p += SZ_512K, v += SZ_512K) + err = __early_map_kernel_hugepage(v, p, prot, MMU_PAGE_512K, new); if (!new) flush_tlb_kernel_range(PAGE_OFFSET + v, PAGE_OFFSET + top); + + return err; } unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) @@ -166,27 +169,33 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) return top; } -void mmu_mark_initmem_nx(void) +int mmu_mark_initmem_nx(void) { unsigned long etext8 = ALIGN(__pa(_etext), SZ_8M); unsigned long sinittext = __pa(_sinittext); unsigned long boundary = strict_kernel_rwx_enabled() ? sinittext : etext8; unsigned long einittext8 = ALIGN(__pa(_einittext), SZ_8M); + int err = 0; if (!debug_pagealloc_enabled_or_kfence()) - mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL, false); + err = mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL, false); mmu_pin_tlb(block_mapped_ram, false); + + return err; } #ifdef CONFIG_STRICT_KERNEL_RWX -void mmu_mark_rodata_ro(void) +int mmu_mark_rodata_ro(void) { unsigned long sinittext = __pa(_sinittext); + int err; - mmu_mapin_ram_chunk(0, sinittext, PAGE_KERNEL_ROX, false); + err = mmu_mapin_ram_chunk(0, sinittext, PAGE_KERNEL_ROX, false); if (IS_ENABLED(CONFIG_PIN_TLB_DATA)) mmu_pin_tlb(block_mapped_ram, true); + + return err; } #endif diff --git a/arch/powerpc/mm/nohash/e500.c b/arch/powerpc/mm/nohash/e500.c index 921c3521ec11..266fb22131fc 100644 --- a/arch/powerpc/mm/nohash/e500.c +++ b/arch/powerpc/mm/nohash/e500.c @@ -285,19 +285,23 @@ void __init adjust_total_lowmem(void) } #ifdef CONFIG_STRICT_KERNEL_RWX -void mmu_mark_rodata_ro(void) +int mmu_mark_rodata_ro(void) { unsigned long remapped; remapped = map_mem_in_cams(__max_low_memory, CONFIG_LOWMEM_CAM_NUM, false, false); - WARN_ON(__max_low_memory != remapped); + if (WARN_ON(__max_low_memory != remapped)) + return -EINVAL; + + return 0; } #endif -void mmu_mark_initmem_nx(void) +int mmu_mark_initmem_nx(void) { /* Everything is done in mmu_mark_rodata_ro() */ + return 0; } void setup_initial_memory_limit(phys_addr_t first_memblock_base, -- cgit v1.2.3