From patchwork series 421895

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=421895

Author: Fox Snowpatch

arch/arm/mm/fault.c

@@ -27,7 +27,7 @@
 
 #ifdef CONFIG_MMU
 
-bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+bool copy_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 {
 	unsigned long addr = (unsigned long)unsafe_src;
 

arch/loongarch/mm/maccess.c

@@ -3,7 +3,7 @@
 #include <linux/uaccess.h>
 #include <linux/kernel.h>
 
-bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+bool copy_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 {
 	/* highest bit set means kernel space */
 	return (unsigned long)unsafe_src >> (BITS_PER_LONG - 1);

arch/mips/mm/maccess.c

@@ -3,7 +3,7 @@
 #include <linux/uaccess.h>
 #include <linux/kernel.h>
 
-bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+bool copy_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 {
 	/* highest bit set means kernel space */
 	return (unsigned long)unsafe_src >> (BITS_PER_LONG - 1);

arch/parisc/lib/memcpy.c

@@ -48,7 +48,7 @@ void * memcpy(void * dst,const void *src, size_t count)
 
 EXPORT_SYMBOL(memcpy);
 
-bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+bool copy_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 {
 	if ((unsigned long)unsafe_src < PAGE_SIZE)
 		return false;

arch/powerpc/mm/maccess.c

@@ -7,7 +7,7 @@
 #include <asm/inst.h>
 #include <asm/ppc-opcode.h>
 
-bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+bool copy_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 {
 	return is_kernel_addr((unsigned long)unsafe_src);
 }

arch/um/kernel/maccess.c

@@ -7,7 +7,7 @@
 #include <linux/kernel.h>
 #include <os.h>
 
-bool copy_from_kernel_nofault_allowed(const void *src, size_t size)
+bool copy_kernel_nofault_allowed(const void *src, size_t size)
 {
 	void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE);
 

arch/x86/mm/maccess.c

@@ -6,7 +6,7 @@
 #include <asm/vsyscall.h>
 
 #ifdef CONFIG_X86_64
-bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+bool copy_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 {
 	unsigned long vaddr = (unsigned long)unsafe_src;
 
@@ -36,7 +36,7 @@ bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 	return __is_canonical_address(vaddr, boot_cpu_data.x86_virt_bits);
 }
 #else
-bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
+bool copy_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 {
 	return (unsigned long)unsafe_src >= TASK_SIZE_MAX;
 }

include/linux/uaccess.h

@@ -387,7 +387,7 @@ copy_struct_from_user(void *dst, size_t ksize, const void __user *src,
 	return 0;
 }
 
-bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size);
+bool copy_kernel_nofault_allowed(const void *unsafe_src, size_t size);
 
 long copy_from_kernel_nofault(void *dst, const void *src, size_t size);
 long notrace copy_to_kernel_nofault(void *dst, const void *src, size_t size);

mm/maccess.c

@@ -7,8 +7,7 @@
 #include <linux/uaccess.h>
 #include <asm/tlb.h>
 
-bool __weak copy_from_kernel_nofault_allowed(const void *unsafe_src,
-		size_t size)
+bool __weak copy_kernel_nofault_allowed(const void *unsafe_src, size_t size)
 {
 	return true;
 }
@@ -28,7 +27,7 @@ long copy_from_kernel_nofault(void *dst, const void *src, size_t size)
 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
 		align = (unsigned long)dst | (unsigned long)src;
 
-	if (!copy_from_kernel_nofault_allowed(src, size))
+	if (!copy_kernel_nofault_allowed(src, size))
 		return -ERANGE;
 
 	pagefault_disable();
@@ -62,6 +61,9 @@ long copy_to_kernel_nofault(void *dst, const void *src, size_t size)
 	if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS))
 		align = (unsigned long)dst | (unsigned long)src;
 
+	if (!copy_kernel_nofault_allowed(dst, size))
+		return -ERANGE;
+
 	pagefault_disable();
 	if (!(align & 7))
 		copy_to_kernel_nofault_loop(dst, src, size, u64, Efault);
@@ -83,7 +85,7 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
 
 	if (unlikely(count <= 0))
 		return 0;
-	if (!copy_from_kernel_nofault_allowed(unsafe_addr, count))
+	if (!copy_kernel_nofault_allowed(unsafe_addr, count))
 		return -ERANGE;
 
 	pagefault_disable();