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    Subject[PATCH v3 2/5] uaccess: Use user_access_ok() in user_access_begin()
    Date
    Use user_access_ok() instead of access_ok() in user_access_begin()
    to validate the access context is user. This also allow us to
    use (generic) strncpy_from_user() and strnlen_user() in atomic
    state with setting USER_DS and disable pagefaults.

    Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
    ---
    arch/x86/include/asm/uaccess.h | 2 +-
    include/linux/uaccess.h | 2 +-
    2 files changed, 2 insertions(+), 2 deletions(-)

    diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
    index 3125d129d3b6..3b7502a34114 100644
    --- a/arch/x86/include/asm/uaccess.h
    +++ b/arch/x86/include/asm/uaccess.h
    @@ -715,7 +715,7 @@ extern struct movsl_mask {
    */
    static __must_check inline bool user_access_begin(const void __user *ptr, size_t len)
    {
    - if (unlikely(!access_ok(ptr,len)))
    + if (unlikely(!user_access_ok(ptr, len)))
    return 0;
    __uaccess_begin_nospec();
    return 1;
    diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
    index bf762689658b..1afd9dfabe67 100644
    --- a/include/linux/uaccess.h
    +++ b/include/linux/uaccess.h
    @@ -282,7 +282,7 @@ extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count);
    probe_kernel_read(&retval, addr, sizeof(retval))

    #ifndef user_access_begin
    -#define user_access_begin(ptr,len) access_ok(ptr, len)
    +#define user_access_begin(ptr, len) user_access_ok(ptr, len)
    #define user_access_end() do { } while (0)
    #define unsafe_get_user(x, ptr, err) do { if (unlikely(__get_user(x, ptr))) goto err; } while (0)
    #define unsafe_put_user(x, ptr, err) do { if (unlikely(__put_user(x, ptr))) goto err; } while (0)
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