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Date: Thu, 23 May 2019 11:22:54 +0100
From: Ard Biesheuvel <ard.biesheuvel@....com>
To: linux-arm-kernel@...ts.infradead.org
Cc: marc.zyngier@....com, mark.rutland@....com,
linux-kernel@...r.kernel.org,
Ard Biesheuvel <ard.biesheuvel@....com>,
Nadav Amit <namit@...are.com>,
Rick Edgecombe <rick.p.edgecombe@...el.com>,
Peter Zijlstra <peterz@...radead.org>,
Andrew Morton <akpm@...ux-foundation.org>,
Will Deacon <will.deacon@....com>,
Masami Hiramatsu <mhiramat@...nel.org>,
James Morse <james.morse@....com>
Subject: [PATCH 2/4] 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.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@....com>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/cacheflush.h | 3 ++
arch/arm64/mm/pageattr.c | 48 ++++++++++++++++----
mm/vmalloc.c | 11 -----
4 files changed, 44 insertions(+), 19 deletions(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index ca9c175fb949..4ab32180eabd 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -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
diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index 19844211a4e6..b9ee5510067f 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -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
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 6cd645edcf35..9c6b9039ec8f 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -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 */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 233af6936c93..1135dd8f2665 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -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. */
--
2.17.1
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