In arch/*/kernel/crash_dump*.c, there exist many similar code
about copy_oldmem_page(), remove copy_to() in fs/proc/vmcore.c
and add copy_to_user_or_kernel() in lib/usercopy.c, then we can
use copy_to_user_or_kernel() to simplify the related code.
Signed-off-by: Tiezhu Yang <yangtie...@loongson.cn>
---
fs/proc/vmcore.c | 28 +++++++---------------------
include/linux/uaccess.h | 1 +
lib/usercopy.c | 15 +++++++++++++++
3 files changed, 23 insertions(+), 21 deletions(-)
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 509f851..f67fd77 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -238,22 +238,8 @@ copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
size_t csize,
return copy_oldmem_page(pfn, buf, csize, offset, userbuf);
}
-/*
- * Copy to either kernel or user space
- */
-static int copy_to(void *target, void *src, size_t size, int userbuf)
-{
- if (userbuf) {
- if (copy_to_user((char __user *) target, src, size))
- return -EFAULT;
- } else {
- memcpy(target, src, size);
- }
- return 0;
-}
-
#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
-static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, int userbuf)
+static int vmcoredd_copy_dumps(void *dst, u64 start, size_t size, bool userbuf)
{
struct vmcoredd_node *dump;
u64 offset = 0;
@@ -266,7 +252,7 @@ static int vmcoredd_copy_dumps(void *dst, u64 start, size_t
size, int userbuf)
if (start < offset + dump->size) {
tsz = min(offset + (u64)dump->size - start, (u64)size);
buf = dump->buf + start - offset;
- if (copy_to(dst, buf, tsz, userbuf)) {
+ if (copy_to_user_or_kernel(dst, buf, tsz, userbuf)) {
ret = -EFAULT;
goto out_unlock;
}
@@ -330,7 +316,7 @@ static int vmcoredd_mmap_dumps(struct vm_area_struct *vma,
unsigned long dst,
* returned otherwise number of bytes read are returned.
*/
static ssize_t __read_vmcore(char *buffer, size_t buflen, loff_t *fpos,
- int userbuf)
+ bool userbuf)
{
ssize_t acc = 0, tmp;
size_t tsz;
@@ -347,7 +333,7 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen,
loff_t *fpos,
/* Read ELF core header */
if (*fpos < elfcorebuf_sz) {
tsz = min(elfcorebuf_sz - (size_t)*fpos, buflen);
- if (copy_to(buffer, elfcorebuf + *fpos, tsz, userbuf))
+ if (copy_to_user_or_kernel(buffer, elfcorebuf + *fpos, tsz,
userbuf))
return -EFAULT;
buflen -= tsz;
*fpos += tsz;
@@ -395,7 +381,7 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen,
loff_t *fpos,
/* Read remaining elf notes */
tsz = min(elfcorebuf_sz + elfnotes_sz - (size_t)*fpos, buflen);
kaddr = elfnotes_buf + *fpos - elfcorebuf_sz - vmcoredd_orig_sz;
- if (copy_to(buffer, kaddr, tsz, userbuf))
+ if (copy_to_user_or_kernel(buffer, kaddr, tsz, userbuf))
return -EFAULT;
buflen -= tsz;
@@ -435,7 +421,7 @@ static ssize_t __read_vmcore(char *buffer, size_t buflen,
loff_t *fpos,
static ssize_t read_vmcore(struct file *file, char __user *buffer,
size_t buflen, loff_t *fpos)
{
- return __read_vmcore((__force char *) buffer, buflen, fpos, 1);
+ return __read_vmcore((__force char *) buffer, buflen, fpos, true);
}
/*
@@ -461,7 +447,7 @@ static vm_fault_t mmap_vmcore_fault(struct vm_fault *vmf)
if (!PageUptodate(page)) {
offset = (loff_t) index << PAGE_SHIFT;
buf = __va((page_to_pfn(page) << PAGE_SHIFT));
- rc = __read_vmcore(buf, PAGE_SIZE, &offset, 0);
+ rc = __read_vmcore(buf, PAGE_SIZE, &offset, false);
if (rc < 0) {
unlock_page(page);
put_page(page);
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index ac03940..a25e682e 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -283,6 +283,7 @@ __copy_from_user_inatomic_nocache(void *to, const void
__user *from,
#endif /* ARCH_HAS_NOCACHE_UACCESS */
extern __must_check int check_zeroed_user(const void __user *from, size_t
size);
+extern __must_check int copy_to_user_or_kernel(void *target, void *src, size_t
size, bool userbuf);
/**
* copy_struct_from_user: copy a struct from userspace
diff --git a/lib/usercopy.c b/lib/usercopy.c
index 7413dd3..7431b1b 100644
--- a/lib/usercopy.c
+++ b/lib/usercopy.c
@@ -90,3 +90,18 @@ int check_zeroed_user(const void __user *from, size_t size)
return -EFAULT;
}
EXPORT_SYMBOL(check_zeroed_user);
+
+/*
+ * Copy to either user or kernel space
+ */
+int copy_to_user_or_kernel(void *target, void *src, size_t size, bool userbuf)
+{
+ if (userbuf) {
+ if (copy_to_user((char __user *) target, src, size))
+ return -EFAULT;
+ } else {
+ memcpy(target, src, size);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(copy_to_user_or_kernel);
--
2.1.0
