Commit 9cbacb83 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc: Don't ignore errors from set_memory_{n}p() in __kernel_map_pages() 

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: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20ef75884aa6a636e8298736f3d1056b0793d3d9.1708078640.git.christophe.leroy@csgroup.eu
parent 3c8016e6

arch/powerpc/mm/book3s64/hash_utils.c

+2 −1
Original line number Diff line number Diff line
@@ -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 */

arch/powerpc/mm/mmu_decl.h

+1 −1
Original line number Diff line number Diff line
@@ -187,4 +187,4 @@ int create_section_mapping(unsigned long start, unsigned long end, 
			   int nid, pgprot_t prot);

#endif



void hash__kernel_map_pages(struct page *page, int numpages, int enable);
 
int hash__kernel_map_pages(struct page *page, int numpages, int enable);

arch/powerpc/mm/pageattr.c

+7 −3
Original line number Diff line number Diff line
@@ -107,17 +107,21 @@ 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: changing memory protections failed\n", __func__);

}

#endif

#endif