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author | Christoph Hellwig <hch@lst.de> | 2020-06-09 06:34:55 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 18:39:15 +0200 |
commit | fc3562d79456bf1740b44d84b8726d20de8d39bd (patch) | |
tree | 13ad665dbf181c2d03f47244604a53fd604e34c6 /mm | |
parent | maccess: always use strict semantics for probe_kernel_read (diff) | |
download | linux-fc3562d79456bf1740b44d84b8726d20de8d39bd.tar.xz linux-fc3562d79456bf1740b44d84b8726d20de8d39bd.zip |
maccess: move user access routines together
Move kernel access vs user access routines together to ease upcoming
ifdefs.
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/20200521152301.2587579-18-hch@lst.de
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/maccess.c | 112 |
1 files changed, 56 insertions, 56 deletions
diff --git a/mm/maccess.c b/mm/maccess.c index 253b786b2bf1..17b26bceb716 100644 --- a/mm/maccess.c +++ b/mm/maccess.c @@ -47,34 +47,6 @@ long probe_kernel_read(void *dst, const void *src, size_t size) EXPORT_SYMBOL_GPL(probe_kernel_read); /** - * probe_user_read(): safely attempt to read from a user-space location - * @dst: pointer to the buffer that shall take the data - * @src: address to read from. This must be a user address. - * @size: size of the data chunk - * - * Safely read from user address @src to the buffer at @dst. If a kernel fault - * happens, handle that and return -EFAULT. - */ -long probe_user_read(void *dst, const void __user *src, size_t size) -{ - long ret = -EFAULT; - mm_segment_t old_fs = get_fs(); - - set_fs(USER_DS); - if (access_ok(src, size)) { - pagefault_disable(); - ret = __copy_from_user_inatomic(dst, src, size); - pagefault_enable(); - } - set_fs(old_fs); - - if (ret) - return -EFAULT; - return 0; -} -EXPORT_SYMBOL_GPL(probe_user_read); - -/** * probe_kernel_write(): safely attempt to write to a location * @dst: address to write to * @src: pointer to the data that shall be written @@ -100,34 +72,6 @@ long probe_kernel_write(void *dst, const void *src, size_t size) } /** - * probe_user_write(): safely attempt to write to a user-space location - * @dst: address to write to - * @src: pointer to the data that shall be written - * @size: size of the data chunk - * - * Safely write to address @dst from the buffer at @src. If a kernel fault - * happens, handle that and return -EFAULT. - */ -long probe_user_write(void __user *dst, const void *src, size_t size) -{ - long ret = -EFAULT; - mm_segment_t old_fs = get_fs(); - - set_fs(USER_DS); - if (access_ok(dst, size)) { - pagefault_disable(); - ret = __copy_to_user_inatomic(dst, src, size); - pagefault_enable(); - } - set_fs(old_fs); - - if (ret) - return -EFAULT; - return 0; -} -EXPORT_SYMBOL_GPL(probe_user_write); - -/** * strncpy_from_kernel_nofault: - Copy a NUL terminated string from unsafe * address. * @dst: Destination address, in kernel space. This buffer must be at @@ -171,6 +115,62 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count) } /** + * probe_user_read(): safely attempt to read from a user-space location + * @dst: pointer to the buffer that shall take the data + * @src: address to read from. This must be a user address. + * @size: size of the data chunk + * + * Safely read from user address @src to the buffer at @dst. If a kernel fault + * happens, handle that and return -EFAULT. + */ +long probe_user_read(void *dst, const void __user *src, size_t size) +{ + long ret = -EFAULT; + mm_segment_t old_fs = get_fs(); + + set_fs(USER_DS); + if (access_ok(src, size)) { + pagefault_disable(); + ret = __copy_from_user_inatomic(dst, src, size); + pagefault_enable(); + } + set_fs(old_fs); + + if (ret) + return -EFAULT; + return 0; +} +EXPORT_SYMBOL_GPL(probe_user_read); + +/** + * probe_user_write(): safely attempt to write to a user-space location + * @dst: address to write to + * @src: pointer to the data that shall be written + * @size: size of the data chunk + * + * Safely write to address @dst from the buffer at @src. If a kernel fault + * happens, handle that and return -EFAULT. + */ +long probe_user_write(void __user *dst, const void *src, size_t size) +{ + long ret = -EFAULT; + mm_segment_t old_fs = get_fs(); + + set_fs(USER_DS); + if (access_ok(dst, size)) { + pagefault_disable(); + ret = __copy_to_user_inatomic(dst, src, size); + pagefault_enable(); + } + set_fs(old_fs); + + if (ret) + return -EFAULT; + return 0; +} +EXPORT_SYMBOL_GPL(probe_user_write); + +/** * strncpy_from_user_nofault: - Copy a NUL terminated string from unsafe user * address. * @dst: Destination address, in kernel space. This buffer must be at |