[PATCH v10 14/17] mm: vmalloc: pass additional vm_flags to __vmalloc_node_range()

[Andrey Ryabinin <a.ryabinin@samsung.com>]

For instrumenting global variables KASan will shadow memory backing
memory for modules. So on module loading we will need to allocate
shadow memory and map it at exact virtual address.
__vmalloc_node_range() seems like the best fit for that purpose,
except it puts a guard hole after allocated area.

Now we have VM_NO_GUARD flag disabling guard page, so we need to
pass into __vmalloc_node_range(). Add new parameter 'vm_flags'
to __vmalloc_node_range() function.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
---
 arch/arm/kernel/module.c       |  2 +-
 arch/arm64/kernel/module.c     |  4 ++--
 arch/mips/kernel/module.c      |  2 +-
 arch/parisc/kernel/module.c    |  2 +-
 arch/s390/kernel/module.c      |  2 +-
 arch/sparc/kernel/module.c     |  2 +-
 arch/unicore32/kernel/module.c |  2 +-
 arch/x86/kernel/module.c       |  2 +-
 include/linux/vmalloc.h        |  4 +++-
 mm/vmalloc.c                   | 10 ++++++----
 10 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index bea7db9..2e11961 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -41,7 +41,7 @@
 void *module_alloc(unsigned long size)
 {
 	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-				GFP_KERNEL, PAGE_KERNEL_EXEC, NUMA_NO_NODE,
+				GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
 				__builtin_return_address(0));
 }
 #endif
diff --git a/arch/arm64/kernel/module.c b/arch/arm64/kernel/module.c
index 9b6f71d..67bf410 100644
--- a/arch/arm64/kernel/module.c
+++ b/arch/arm64/kernel/module.c
@@ -35,8 +35,8 @@
 void *module_alloc(unsigned long size)
 {
 	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-				    GFP_KERNEL, PAGE_KERNEL_EXEC, NUMA_NO_NODE,
-				    __builtin_return_address(0));
+				    GFP_KERNEL, PAGE_KERNEL_EXEC, 0,
+				    NUMA_NO_NODE, __builtin_return_address(0));
 }
 
 enum aarch64_reloc_op {
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index 2a52568..1833f51 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -47,7 +47,7 @@ static DEFINE_SPINLOCK(dbe_lock);
 void *module_alloc(unsigned long size)
 {
 	return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
-				GFP_KERNEL, PAGE_KERNEL, NUMA_NO_NODE,
+				GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
 				__builtin_return_address(0));
 }
 #endif
diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index 5822e8e..3c63a82 100644
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -219,7 +219,7 @@ void *module_alloc(unsigned long size)
 	 * init_data correctly */
 	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
 				    GFP_KERNEL | __GFP_HIGHMEM,
-				    PAGE_KERNEL_RWX, NUMA_NO_NODE,
+				    PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
 				    __builtin_return_address(0));
 }
 
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index 409d152..36154a2 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -50,7 +50,7 @@ void *module_alloc(unsigned long size)
 	if (PAGE_ALIGN(size) > MODULES_LEN)
 		return NULL;
 	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-				    GFP_KERNEL, PAGE_KERNEL, NUMA_NO_NODE,
+				    GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
 				    __builtin_return_address(0));
 }
 #endif
diff --git a/arch/sparc/kernel/module.c b/arch/sparc/kernel/module.c
index 97655e0..192a617 100644
--- a/arch/sparc/kernel/module.c
+++ b/arch/sparc/kernel/module.c
@@ -29,7 +29,7 @@ static void *module_map(unsigned long size)
 	if (PAGE_ALIGN(size) > MODULES_LEN)
 		return NULL;
 	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-				GFP_KERNEL, PAGE_KERNEL, NUMA_NO_NODE,
+				GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
 				__builtin_return_address(0));
 }
 #else
diff --git a/arch/unicore32/kernel/module.c b/arch/unicore32/kernel/module.c
index dc41f6d..e191b34 100644
--- a/arch/unicore32/kernel/module.c
+++ b/arch/unicore32/kernel/module.c
@@ -25,7 +25,7 @@
 void *module_alloc(unsigned long size)
 {
 	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-				GFP_KERNEL, PAGE_KERNEL_EXEC, NUMA_NO_NODE,
+				GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
 				__builtin_return_address(0));
 }
 
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index e69f988..e830e61 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -88,7 +88,7 @@ void *module_alloc(unsigned long size)
 	return __vmalloc_node_range(size, 1,
 				    MODULES_VADDR + get_module_load_offset(),
 				    MODULES_END, GFP_KERNEL | __GFP_HIGHMEM,
-				    PAGE_KERNEL_EXEC, NUMA_NO_NODE,
+				    PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
 				    __builtin_return_address(0));
 }
 
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 1526fe7..7d7acb3 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -76,7 +76,9 @@ extern void *vmalloc_32_user(unsigned long size);
 extern void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot);
 extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
 			unsigned long start, unsigned long end, gfp_t gfp_mask,
-			pgprot_t prot, int node, const void *caller);
+			pgprot_t prot, unsigned long vm_flags, int node,
+			const void *caller);
+
 extern void vfree(const void *addr);
 
 extern void *vmap(struct page **pages, unsigned int count,
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2e74e99..35b25e1 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1619,6 +1619,7 @@ fail:
  *	@end:		vm area range end
  *	@gfp_mask:	flags for the page level allocator
  *	@prot:		protection mask for the allocated pages
+ *	@vm_flags:	additional vm area flags (e.g. %VM_NO_GUARD)
  *	@node:		node to use for allocation or NUMA_NO_NODE
  *	@caller:	caller's return address
  *
@@ -1628,7 +1629,8 @@ fail:
  */
 void *__vmalloc_node_range(unsigned long size, unsigned long align,
 			unsigned long start, unsigned long end, gfp_t gfp_mask,
-			pgprot_t prot, int node, const void *caller)
+			pgprot_t prot, unsigned long vm_flags, int node,
+			const void *caller)
 {
 	struct vm_struct *area;
 	void *addr;
@@ -1638,8 +1640,8 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
 	if (!size || (size >> PAGE_SHIFT) > totalram_pages)
 		goto fail;
 
-	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED,
-				  start, end, node, gfp_mask, caller);
+	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
+				vm_flags, start, end, node, gfp_mask, caller);
 	if (!area)
 		goto fail;
 
@@ -1688,7 +1690,7 @@ static void *__vmalloc_node(unsigned long size, unsigned long align,
 			    int node, const void *caller)
 {
 	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
-				gfp_mask, prot, node, caller);
+				gfp_mask, prot, 0, node, caller);
 }
 
 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
-- 
2.2.2

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