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author | Masami Hiramatsu <mhiramat@kernel.org> | 2019-05-15 14:38:18 +0900 |
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committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-05-25 23:04:42 -0400 |
commit | 3d7081822f7f9eab867d9bcc8fd635208ec438e0 (patch) | |
tree | 8afb5e61c1f23305996d4a8e03dedd7c048de01d /kernel | |
parent | 2d8d8fac3b4eab035dcd0068e1f5a746a697fbb3 (diff) |
uaccess: Add non-pagefault user-space read functions
Add probe_user_read(), strncpy_from_unsafe_user() and
strnlen_unsafe_user() which allows caller to access user-space
in IRQ context.
Current probe_kernel_read() and strncpy_from_unsafe() are
not available for user-space memory, because it sets
KERNEL_DS while accessing data. On some arch, user address
space and kernel address space can be co-exist, but others
can not. In that case, setting KERNEL_DS means given
address is treated as a kernel address space.
Also strnlen_user() is only available from user context since
it can sleep if pagefault is enabled.
To access user-space memory without pagefault, we need
these new functions which sets USER_DS while accessing
the data.
Link: http://lkml.kernel.org/r/155789869802.26965.4940338412595759063.stgit@devnote2
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
0 files changed, 0 insertions, 0 deletions