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maccess: remove probe_read_common and probe_write_common

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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>
This commit is contained in:
Christoph Hellwig 2020-06-08 21:34:24 -07:00 committed by Linus Torvalds
parent 02dddb160e
commit cd0309058f
1 changed files with 29 additions and 34 deletions
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63
mm/maccess.c
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@ -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);