Re: [PATCH v5 3/6] uaccess: Add non-pagefault user-space read functions

2019-02-28 Thread Yonghong Song
On 2/28/19 6:29 PM, Masami Hiramatsu wrote: > Hi Yonghong, > > On Thu, 28 Feb 2019 22:49:43 + > Yonghong Song wrote: > >> >> >> On 2/28/19 8:03 AM, Masami Hiramatsu wrote: >>> Add probe_user_read(), strncpy_from_unsafe_user() and >>> strnlen_unsafe_user() which allows caller to access user

Re: [PATCH v5 3/6] uaccess: Add non-pagefault user-space read functions

2019-02-28 Thread Masami Hiramatsu
Hi Yonghong, On Thu, 28 Feb 2019 22:49:43 + Yonghong Song wrote: > > > On 2/28/19 8:03 AM, Masami Hiramatsu wrote: > > 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_

Re: [PATCH v5 3/6] uaccess: Add non-pagefault user-space read functions

2019-02-28 Thread Yonghong Song
On 2/28/19 8:03 AM, Masami Hiramatsu wrote: > 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 s

[PATCH v5 3/6] uaccess: Add non-pagefault user-space read functions

2019-02-28 Thread Masami Hiramatsu
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 add