Commit cd030905 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Linus Torvalds
Browse files

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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew 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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 02dddb16

mm/maccess.c

+29 −34
Original line number Diff line number Diff line
@@ -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);

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