set_memory_p() and set_memory_np() can fail. As mentioned in linux/mm.h:
/* * To support DEBUG_PAGEALLOC architecture must ensure that * __kernel_map_pages() never fails */ So panic in case set_memory_p() or set_memory_np() fail in __kernel_map_pages(). Link: https://github.com/KSPP/linux/issues/7 Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu> --- arch/powerpc/include/asm/book3s/64/hash.h | 2 +- arch/powerpc/mm/book3s64/hash_utils.c | 3 ++- arch/powerpc/mm/pageattr.c | 10 +++++++--- 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h index 6e70ae511631..8f47ae79f2a6 100644 --- a/arch/powerpc/include/asm/book3s/64/hash.h +++ b/arch/powerpc/include/asm/book3s/64/hash.h @@ -269,7 +269,7 @@ int hash__create_section_mapping(unsigned long start, unsigned long end, int nid, pgprot_t prot); int hash__remove_section_mapping(unsigned long start, unsigned long end); -void hash__kernel_map_pages(struct page *page, int numpages, int enable); +int hash__kernel_map_pages(struct page *page, int numpages, int enable); #endif /* !__ASSEMBLY__ */ #endif /* __KERNEL__ */ diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index 0626a25b0d72..01c3b4b65241 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -2172,7 +2172,7 @@ static void kernel_unmap_linear_page(unsigned long vaddr, unsigned long lmi) mmu_kernel_ssize, 0); } -void hash__kernel_map_pages(struct page *page, int numpages, int enable) +int hash__kernel_map_pages(struct page *page, int numpages, int enable) { unsigned long flags, vaddr, lmi; int i; @@ -2189,6 +2189,7 @@ void hash__kernel_map_pages(struct page *page, int numpages, int enable) kernel_unmap_linear_page(vaddr, lmi); } local_irq_restore(flags); + return 0; } #endif /* CONFIG_DEBUG_PAGEALLOC || CONFIG_KFENCE */ diff --git a/arch/powerpc/mm/pageattr.c b/arch/powerpc/mm/pageattr.c index 16b8d20d6ca8..62b678585878 100644 --- a/arch/powerpc/mm/pageattr.c +++ b/arch/powerpc/mm/pageattr.c @@ -106,17 +106,21 @@ int change_memory_attr(unsigned long addr, int numpages, long action) #ifdef CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC void __kernel_map_pages(struct page *page, int numpages, int enable) { + int err; unsigned long addr = (unsigned long)page_address(page); if (PageHighMem(page)) return; if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !radix_enabled()) - hash__kernel_map_pages(page, numpages, enable); + err = hash__kernel_map_pages(page, numpages, enable); else if (enable) - set_memory_p(addr, numpages); + err = set_memory_p(addr, numpages); else - set_memory_np(addr, numpages); + err = set_memory_np(addr, numpages); + + if (err) + panic("%s: set_memory_%sp() failed\n", enable ? "" : "n"); } #endif #endif -- 2.43.0
