diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2019-11-02 00:17:56 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-09 19:04:29 +0200 |
| commit | cfb4721fce554cb596ea86af116d3d68a4d91254 (patch) | |
| tree | 7341a734e01e2f80d800cc2ce0970395ea45db28 /include | |
| parent | 61135a9c74c8f79fce637c28f6109ab58467d5bd (diff) | |
uaccess: Add non-pagefault user-space write function
[ Upstream commit 1d1585ca0f48fe7ed95c3571f3e4a82b2b5045dc ]
Commit 3d7081822f7f ("uaccess: Add non-pagefault user-space read functions")
missed to add probe write function, therefore factor out a probe_write_common()
helper with most logic of probe_kernel_write() except setting KERNEL_DS, and
add a new probe_user_write() helper so it can be used from BPF side.
Again, on some archs, the user address space and kernel address space can
co-exist and be overlapping, so in such case, setting KERNEL_DS would mean
that the given address is treated as being in kernel address space.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/bpf/9df2542e68141bfa3addde631441ee45503856a8.1572649915.git.daniel@iogearbox.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/uaccess.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index db88f36540e9..db9b0dd0a7a3 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -265,6 +265,18 @@ extern long probe_user_read(void *dst, const void __user *src, size_t size); extern long notrace probe_kernel_write(void *dst, const void *src, size_t size); extern long notrace __probe_kernel_write(void *dst, const void *src, size_t size); +/* + * probe_user_write(): safely attempt to write to a location in user space + * @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. + */ +extern long notrace probe_user_write(void __user *dst, const void *src, size_t size); +extern long notrace __probe_user_write(void __user *dst, const void *src, size_t size); + extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count); extern long strncpy_from_unsafe_user(char *dst, const void __user *unsafe_addr, long count); |