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Commit 4739d53f authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas
Browse files

arm64/mm: wire up CONFIG_ARCH_HAS_SET_DIRECT_MAP 



Wire up the special helper functions to manipulate aliases of vmalloc
regions in the linear map.

Acked-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 7dfac3c5

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ config ARM64 
	select ARCH_HAS_MEMBARRIER_SYNC_CORE

	select ARCH_HAS_PTE_SPECIAL

	select ARCH_HAS_SETUP_DMA_OPS

	select ARCH_HAS_SET_DIRECT_MAP

	select ARCH_HAS_SET_MEMORY

	select ARCH_HAS_STRICT_KERNEL_RWX

	select ARCH_HAS_STRICT_MODULE_RWX

arch/arm64/include/asm/cacheflush.h

+3 −0
Original line number Diff line number Diff line
@@ -187,4 +187,7 @@ static inline void flush_cache_vunmap(unsigned long start, unsigned long end) 


int set_memory_valid(unsigned long addr, int numpages, int enable);



int set_direct_map_invalid_noflush(struct page *page);

int set_direct_map_default_noflush(struct page *page);



#endif

arch/arm64/mm/pageattr.c

+40 −8
Original line number Diff line number Diff line
@@ -159,17 +159,48 @@ int set_memory_valid(unsigned long addr, int numpages, int enable) 
					__pgprot(PTE_VALID));

}



#ifdef CONFIG_DEBUG_PAGEALLOC

int set_direct_map_invalid_noflush(struct page *page)

{

	struct page_change_data data = {

		.set_mask = __pgprot(0),

		.clear_mask = __pgprot(PTE_VALID),

	};



	if (!rodata_full)

		return 0;



	return apply_to_page_range(&init_mm,

				   (unsigned long)page_address(page),

				   PAGE_SIZE, change_page_range, &data);

}



int set_direct_map_default_noflush(struct page *page)

{

	struct page_change_data data = {

		.set_mask = __pgprot(PTE_VALID | PTE_WRITE),

		.clear_mask = __pgprot(PTE_RDONLY),

	};



	if (!rodata_full)

		return 0;



	return apply_to_page_range(&init_mm,

				   (unsigned long)page_address(page),

				   PAGE_SIZE, change_page_range, &data);

}



void __kernel_map_pages(struct page *page, int numpages, int enable)

{

	if (!debug_pagealloc_enabled() && !rodata_full)

		return;



	set_memory_valid((unsigned long)page_address(page), numpages, enable);

}

#ifdef CONFIG_HIBERNATION



/*

 * When built with CONFIG_DEBUG_PAGEALLOC and CONFIG_HIBERNATION, this function

 * is used to determine if a linear map page has been marked as not-valid by

 * CONFIG_DEBUG_PAGEALLOC. Walk the page table and check the PTE_VALID bit.

 * This is based on kern_addr_valid(), which almost does what we need.

 * This function is used to determine if a linear map page has been marked as

 * not-valid. Walk the page table and check the PTE_VALID bit. This is based

 * on kern_addr_valid(), which almost does what we need.

 *

 * Because this is only called on the kernel linear map,  p?d_sect() implies

 * p?d_present(). When debug_pagealloc is enabled, sections mappings are
@@ -183,6 +214,9 @@ bool kernel_page_present(struct page *page) 
	pte_t *ptep;

	unsigned long addr = (unsigned long)page_address(page);



	if (!debug_pagealloc_enabled() && !rodata_full)

		return true;



	pgdp = pgd_offset_k(addr);

	if (pgd_none(READ_ONCE(*pgdp)))

		return false;
@@ -204,5 +238,3 @@ bool kernel_page_present(struct page *page) 
	ptep = pte_offset_kernel(pmdp, addr);

	return pte_valid(READ_ONCE(*ptep));

}
 
#endif /* CONFIG_HIBERNATION */

#endif /* CONFIG_DEBUG_PAGEALLOC */

mm/vmalloc.c

+0 −11
Original line number Diff line number Diff line
@@ -2128,17 +2128,6 @@ static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) 
	int flush_reset = area->flags & VM_FLUSH_RESET_PERMS;

	int i;



	/*

	 * The below block can be removed when all architectures that have

	 * direct map permissions also have set_direct_map_() implementations.

	 * This is concerned with resetting the direct map any an vm alias with

	 * execute permissions, without leaving a RW+X window.

	 */

	if (flush_reset && !IS_ENABLED(CONFIG_ARCH_HAS_SET_DIRECT_MAP)) {

		set_memory_nx(addr, area->nr_pages);

		set_memory_rw(addr, area->nr_pages);

	}



	remove_vm_area(area->addr);



	/* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */