maccess: remove probe_read_common and probe_write_common

Each of the helpers has just two callers, which also different in
dealing with kernel or userspace pointers.  Just open code the logic
in the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200521152301.2587579-10-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/maccess.c b/mm/maccess.c
index 88ab30c054a9776a4790520f594cad10403fbcfe..2526d30739addf7fc6ac8e66e87bead3d5a85f9e 100644 (file)
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -6,30 +6,6 @@
 #include <linux/mm.h>
 #include <linux/uaccess.h>
 
-static __always_inline long
-probe_read_common(void *dst, const void __user *src, size_t size)
-{
-       long ret;
-
-       pagefault_disable();
-       ret = __copy_from_user_inatomic(dst, src, size);
-       pagefault_enable();
-
-       return ret ? -EFAULT : 0;
-}
-
-static __always_inline long
-probe_write_common(void __user *dst, const void *src, size_t size)
-{
-       long ret;
-
-       pagefault_disable();
-       ret = __copy_to_user_inatomic(dst, src, size);
-       pagefault_enable();
-
-       return ret ? -EFAULT : 0;
-}
-
 /**
  * probe_kernel_read(): safely attempt to read from any location
  * @dst: pointer to the buffer that shall take the data
@@ -70,10 +46,15 @@ long __probe_kernel_read(void *dst, const void *src, size_t size)
        mm_segment_t old_fs = get_fs();
 
        set_fs(KERNEL_DS);
-       ret = probe_read_common(dst, (__force const void __user *)src, size);
+       pagefault_disable();
+       ret = __copy_from_user_inatomic(dst, (__force const void __user *)src,
+                       size);
+       pagefault_enable();
        set_fs(old_fs);
 
-       return ret;
+       if (ret)
+               return -EFAULT;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(probe_kernel_read);
 
@@ -92,11 +73,16 @@ long probe_user_read(void *dst, const void __user *src, size_t size)
        mm_segment_t old_fs = get_fs();
 
        set_fs(USER_DS);
-       if (access_ok(src, size))
-               ret = probe_read_common(dst, src, size);
+       if (access_ok(src, size)) {
+               pagefault_disable();
+               ret = __copy_from_user_inatomic(dst, src, size);
+               pagefault_enable();
+       }
        set_fs(old_fs);
 
-       return ret;
+       if (ret)
+               return -EFAULT;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(probe_user_read);
 
@@ -115,10 +101,14 @@ long probe_kernel_write(void *dst, const void *src, size_t size)
        mm_segment_t old_fs = get_fs();
 
        set_fs(KERNEL_DS);
-       ret = probe_write_common((__force void __user *)dst, src, size);
+       pagefault_disable();
+       ret = __copy_to_user_inatomic((__force void __user *)dst, src, size);
+       pagefault_enable();
        set_fs(old_fs);
 
-       return ret;
+       if (ret)
+               return -EFAULT;
+       return 0;
 }
 
 /**
@@ -136,11 +126,16 @@ long probe_user_write(void __user *dst, const void *src, size_t size)
        mm_segment_t old_fs = get_fs();
 
        set_fs(USER_DS);
-       if (access_ok(dst, size))
-               ret = probe_write_common(dst, src, size);
+       if (access_ok(dst, size)) {
+               pagefault_disable();
+               ret = __copy_to_user_inatomic(dst, src, size);
+               pagefault_enable();
+       }
        set_fs(old_fs);
 
-       return ret;
+       if (ret)
+               return -EFAULT;
+       return 0;
 }
 EXPORT_SYMBOL_GPL(probe_user_write);