Thread (11 messages) 11 messages, 4 authors, 2021-12-14
STALE1650d
Revisions (2)
  1. v1 [diff vs current]
  2. v2 current

[PATCH v2 2/2] kdump: crashdump: use copy_to_user_or_kernel() to simplify code

From: Tiezhu Yang <yangtiezhu@loongson.cn>
Date: 2021-12-11 03:33:27
Also in: kexec, linux-fsdevel, linux-mips, linux-riscv, linux-sh, linuxppc-dev, lkml
Subsystem: arm port, arm64 port (aarch64 architecture), filesystems (vfs and infrastructure), kdump, linux for powerpc (32-bit and 64-bit), mips, proc filesystem, risc-v architecture, superh, the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Russell King, Catalin Marinas, Will Deacon, Alexander Viro, Christian Brauner, Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Madhavan Srinivasan, Michael Ellerman, Thomas Bogendoerfer, Paul Walmsley, Palmer Dabbelt, Albert Ou, Yoshinori Sato, Rich Felker, John Paul Adrian Glaubitz, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen 

Use copy_to_user_or_kernel() to simplify the related code about
copy_oldmem_page() in arch/*/kernel/crash_dump*.c files.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 arch/arm/kernel/crash_dump.c     | 12 +++---------
 arch/arm64/kernel/crash_dump.c   | 12 +++---------
 arch/ia64/kernel/crash_dump.c    | 12 +++++-------
 arch/mips/kernel/crash_dump.c    | 11 +++--------
 arch/powerpc/kernel/crash_dump.c | 11 ++++-------
 arch/riscv/kernel/crash_dump.c   | 11 +++--------
 arch/sh/kernel/crash_dump.c      | 11 +++--------
 arch/x86/kernel/crash_dump_32.c  | 11 +++--------
 arch/x86/kernel/crash_dump_64.c  | 15 +++++----------
 fs/proc/vmcore.c                 |  4 ++--
 include/linux/crash_dump.h       |  8 ++++----
 11 files changed, 38 insertions(+), 80 deletions(-)

diff --git a/arch/arm/kernel/crash_dump.c b/arch/arm/kernel/crash_dump.c
index 53cb924..a27c5df 100644
--- a/arch/arm/kernel/crash_dump.c
+++ b/arch/arm/kernel/crash_dump.c
@@ -29,7 +29,7 @@
  */
 ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 			 size_t csize, unsigned long offset,
-			 int userbuf)
+			 bool userbuf)
 {
 	void *vaddr;
 
@@ -40,14 +40,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user(buf, vaddr + offset, csize)) {
-			iounmap(vaddr);
-			return -EFAULT;
-		}
-	} else {
-		memcpy(buf, vaddr + offset, csize);
-	}
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		csize = -EFAULT;
 
 	iounmap(vaddr);
 	return csize;
diff --git a/arch/arm64/kernel/crash_dump.c b/arch/arm64/kernel/crash_dump.c
index 58303a9..d22988f 100644
--- a/arch/arm64/kernel/crash_dump.c
+++ b/arch/arm64/kernel/crash_dump.c
@@ -27,7 +27,7 @@
  */
 ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 			 size_t csize, unsigned long offset,
-			 int userbuf)
+			 bool userbuf)
 {
 	void *vaddr;
 
@@ -38,14 +38,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user((char __user *)buf, vaddr + offset, csize)) {
-			memunmap(vaddr);
-			return -EFAULT;
-		}
-	} else {
-		memcpy(buf, vaddr + offset, csize);
-	}
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		csize = -EFAULT;
 
 	memunmap(vaddr);
 
diff --git a/arch/ia64/kernel/crash_dump.c b/arch/ia64/kernel/crash_dump.c
index 0ed3c3d..12128f8 100644
--- a/arch/ia64/kernel/crash_dump.c
+++ b/arch/ia64/kernel/crash_dump.c
@@ -33,19 +33,17 @@
  */
 ssize_t
 copy_oldmem_page(unsigned long pfn, char *buf,
-		size_t csize, unsigned long offset, int userbuf)
+		size_t csize, unsigned long offset, bool userbuf)
 {
 	void  *vaddr;
 
 	if (!csize)
 		return 0;
+
 	vaddr = __va(pfn<<PAGE_SHIFT);
-	if (userbuf) {
-		if (copy_to_user(buf, (vaddr + offset), csize)) {
-			return -EFAULT;
-		}
-	} else
-		memcpy(buf, (vaddr + offset), csize);
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		return -EFAULT;
+
 	return csize;
 }
 
diff --git a/arch/mips/kernel/crash_dump.c b/arch/mips/kernel/crash_dump.c
index 2e50f551..7670915 100644
--- a/arch/mips/kernel/crash_dump.c
+++ b/arch/mips/kernel/crash_dump.c
@@ -16,7 +16,7 @@
  * in the current kernel.
  */
 ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-			 size_t csize, unsigned long offset, int userbuf)
+			 size_t csize, unsigned long offset, bool userbuf)
 {
 	void  *vaddr;
 
@@ -24,13 +24,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 		return 0;
 
 	vaddr = kmap_local_pfn(pfn);
-
-	if (!userbuf) {
-		memcpy(buf, vaddr + offset, csize);
-	} else {
-		if (copy_to_user(buf, vaddr + offset, csize))
-			csize = -EFAULT;
-	}
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		csize = -EFAULT;
 
 	kunmap_local(vaddr);
 
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c
index 5693e1c67..e2e9612 100644
--- a/arch/powerpc/kernel/crash_dump.c
+++ b/arch/powerpc/kernel/crash_dump.c
@@ -69,13 +69,10 @@ void __init setup_kdump_trampoline(void)
 #endif /* CONFIG_NONSTATIC_KERNEL */
 
 static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize,
-                               unsigned long offset, int userbuf)
+				unsigned long offset, bool userbuf)
 {
-	if (userbuf) {
-		if (copy_to_user((char __user *)buf, (vaddr + offset), csize))
-			return -EFAULT;
-	} else
-		memcpy(buf, (vaddr + offset), csize);
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		return -EFAULT;
 
 	return csize;
 }
@@ -94,7 +91,7 @@ static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize,
  * in the current kernel. We stitch up a pte, similar to kmap_atomic.
  */
 ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-			size_t csize, unsigned long offset, int userbuf)
+			size_t csize, unsigned long offset, bool userbuf)
 {
 	void  *vaddr;
 	phys_addr_t paddr;
diff --git a/arch/riscv/kernel/crash_dump.c b/arch/riscv/kernel/crash_dump.c
index 86cc0ad..4167437 100644
--- a/arch/riscv/kernel/crash_dump.c
+++ b/arch/riscv/kernel/crash_dump.c
@@ -22,7 +22,7 @@
  */
 ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 			 size_t csize, unsigned long offset,
-			 int userbuf)
+			 bool userbuf)
 {
 	void *vaddr;
 
@@ -33,13 +33,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user((char __user *)buf, vaddr + offset, csize)) {
-			memunmap(vaddr);
-			return -EFAULT;
-		}
-	} else
-		memcpy(buf, vaddr + offset, csize);
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		csize = -EFAULT;
 
 	memunmap(vaddr);
 	return csize;
diff --git a/arch/sh/kernel/crash_dump.c b/arch/sh/kernel/crash_dump.c
index 5b41b59..4bc071a 100644
--- a/arch/sh/kernel/crash_dump.c
+++ b/arch/sh/kernel/crash_dump.c
@@ -24,7 +24,7 @@
  * in the current kernel. We stitch up a pte, similar to kmap_atomic.
  */
 ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-                               size_t csize, unsigned long offset, int userbuf)
+			 size_t csize, unsigned long offset, bool userbuf)
 {
 	void  __iomem *vaddr;
 
@@ -33,13 +33,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 
 	vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
 
-	if (userbuf) {
-		if (copy_to_user((void __user *)buf, (vaddr + offset), csize)) {
-			iounmap(vaddr);
-			return -EFAULT;
-		}
-	} else
-	memcpy(buf, (vaddr + offset), csize);
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		csize = -EFAULT;
 
 	iounmap(vaddr);
 	return csize;
diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c
index 5fcac46..3eff124 100644
--- a/arch/x86/kernel/crash_dump_32.c
+++ b/arch/x86/kernel/crash_dump_32.c
@@ -43,7 +43,7 @@ static inline bool is_crashed_pfn_valid(unsigned long pfn)
  * in the current kernel.
  */
 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
-			 unsigned long offset, int userbuf)
+			 unsigned long offset, bool userbuf)
 {
 	void  *vaddr;
 
@@ -54,13 +54,8 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
 		return -EFAULT;
 
 	vaddr = kmap_local_pfn(pfn);
-
-	if (!userbuf) {
-		memcpy(buf, vaddr + offset, csize);
-	} else {
-		if (copy_to_user(buf, vaddr + offset, csize))
-			csize = -EFAULT;
-	}
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		csize = -EFAULT;
 
 	kunmap_local(vaddr);
 
diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index a7f617a..e8fffdf 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -13,7 +13,7 @@
 #include <linux/cc_platform.h>
 
 static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
-				  unsigned long offset, int userbuf,
+				  unsigned long offset, bool userbuf,
 				  bool encrypted)
 {
 	void  *vaddr;
@@ -29,13 +29,8 @@ static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user((void __user *)buf, vaddr + offset, csize)) {
-			iounmap((void __iomem *)vaddr);
-			return -EFAULT;
-		}
-	} else
-		memcpy(buf, vaddr + offset, csize);
+	if (copy_to_user_or_kernel(buf, vaddr + offset, csize, userbuf))
+		csize = -EFAULT;
 
 	set_iounmap_nonlazy();
 	iounmap((void __iomem *)vaddr);
@@ -56,7 +51,7 @@ static ssize_t __copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
  * mapped in the current kernel. We stitch up a pte, similar to kmap_atomic.
  */
 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
-			 unsigned long offset, int userbuf)
+			 unsigned long offset, bool userbuf)
 {
 	return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, false);
 }
@@ -67,7 +62,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
  * machines.
  */
 ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
-				   unsigned long offset, int userbuf)
+				   unsigned long offset, bool userbuf)
 {
 	return __copy_oldmem_page(pfn, buf, csize, offset, userbuf, true);
 }
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index f67fd77..bba52aa 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -133,7 +133,7 @@ static int open_vmcore(struct inode *inode, struct file *file)
 
 /* Reads a page from the oldmem device from given offset. */
 ssize_t read_from_oldmem(char *buf, size_t count,
-			 u64 *ppos, int userbuf,
+			 u64 *ppos, bool userbuf,
 			 bool encrypted)
 {
 	unsigned long pfn, offset;
@@ -233,7 +233,7 @@ int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
  */
 ssize_t __weak
 copy_oldmem_page_encrypted(unsigned long pfn, char *buf, size_t csize,
-			   unsigned long offset, int userbuf)
+			   unsigned long offset, bool userbuf)
 {
 	return copy_oldmem_page(pfn, buf, csize, offset, userbuf);
 }
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index 6208215..033448b 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -25,10 +25,10 @@ extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
 				  unsigned long size, pgprot_t prot);
 
 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
-						unsigned long, int);
+						unsigned long, bool);
 extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
 					  size_t csize, unsigned long offset,
-					  int userbuf);
+					  bool userbuf);
 
 void vmcore_cleanup(void);
 
@@ -136,11 +136,11 @@ static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
 
 #ifdef CONFIG_PROC_VMCORE
 ssize_t read_from_oldmem(char *buf, size_t count,
-			 u64 *ppos, int userbuf,
+			 u64 *ppos, bool userbuf,
 			 bool encrypted);
 #else
 static inline ssize_t read_from_oldmem(char *buf, size_t count,
-				       u64 *ppos, int userbuf,
+				       u64 *ppos, bool userbuf,
 				       bool encrypted)
 {
 	return -EOPNOTSUPP;
-- 
2.1.0


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