maccess,probe_kernel: Allow arch specific override probe_kernel_(read…

…|write) Some archs such as blackfin, would like to have an arch specific probe_kernel_read() and probe_kernel_write() implementation which can fall back to the generic implementation if no special operations are needed. CC: Thomas Gleixner <[email protected]> CC: Ingo Molnar <[email protected]> Signed-off-by: Jason Wessel <[email protected]> Signed-off-by: Mike Frysinger <[email protected]>
akeromi · Jan 7, 2010 · 6144a85 · 6144a85
1 parent 2c1f189
commit 6144a85
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
@@ -94,6 +94,7 @@ static inline unsigned long __copy_from_user_nocache(void *to,
  * happens, handle that and return -EFAULT.
  */
 extern long probe_kernel_read(void *dst, void *src, size_t size);
+extern long __probe_kernel_read(void *dst, void *src, size_t size);
 
 /*
  * probe_kernel_write(): safely attempt to write to a location
@@ -104,6 +105,7 @@ extern long probe_kernel_read(void *dst, void *src, size_t size);
  * Safely write to address @dst from the buffer at @src.  If a kernel fault
  * happens, handle that and return -EFAULT.
  */
-extern long probe_kernel_write(void *dst, void *src, size_t size);
+extern long notrace probe_kernel_write(void *dst, void *src, size_t size);
+extern long notrace __probe_kernel_write(void *dst, void *src, size_t size);
 
 #endif		/* __LINUX_UACCESS_H__ */
diff --git a/mm/maccess.c b/mm/maccess.c
@@ -14,7 +14,11 @@
  * Safely read from address @src to the buffer at @dst.  If a kernel fault
  * happens, handle that and return -EFAULT.
  */
-long probe_kernel_read(void *dst, void *src, size_t size)
+
+long __weak probe_kernel_read(void *dst, void *src, size_t size)
+    __attribute__((alias("__probe_kernel_read")));
+
+long __probe_kernel_read(void *dst, void *src, size_t size)
 {
 	long ret;
 	mm_segment_t old_fs = get_fs();
@@ -39,7 +43,10 @@ EXPORT_SYMBOL_GPL(probe_kernel_read);
  * Safely write to address @dst from the buffer at @src.  If a kernel fault
  * happens, handle that and return -EFAULT.
  */
-long notrace __weak probe_kernel_write(void *dst, void *src, size_t size)
+long __weak probe_kernel_write(void *dst, void *src, size_t size)
+    __attribute__((alias("__probe_kernel_write")));
+
+long __probe_kernel_write(void *dst, void *src, size_t size)
 {
 	long ret;
 	mm_segment_t old_fs = get_fs();