[PATCH 09/23] maccess: remove probe_read_common and probe_write_common

Christoph Hellwig
2020-05-21T15:25:40Z

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>
---
mm/maccess.c | 63 ++++++++++++++++++++++++----------------------------
1 file changed, 29 insertions(+), 34 deletions(-)

diff --git a/mm/maccess.c b/mm/maccess.c
index e783ebfccd542..31cf6604e7fff 100644
--- 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
@@ -69,10 +45,15 @@ 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);

@@ -91,11 +72,16 @@ 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);

@@ -114,10 +100,14 @@ 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;
}

/**
@@ -135,11 +125,16 @@ 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;
}

/**
--
2.26.2