lkml.org 
[lkml]   [2009]   [May]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH V3] asm-generic: add a generic uaccess.h
    Arnd Bergmann wrote:
    > On Friday 01 May 2009, Michal Simek wrote:
    >> Arnd Bergmann wrote:
    >>> +
    >>> +#include <asm/segment.h>
    >>> +
    >>> +#ifndef get_fs
    >>> +#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
    >> one line above -> get_fs could be defined in different space
    >> and this arch could use MAKE_MM_SEG too -> for example powerpc.
    >
    > I don't think I understand what you are trying to tell me.
    > How do you think this should look?

    I meant move MAKE_MM_SEG macro to this position because this macro could be use
    with arch which define different get_fs.

    #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
    #ifndef get_fs
    ...


    >
    >>> +
    >>> +#define VERIFY_READ 0
    >>> +#define VERIFY_WRITE 1
    >>> +
    >>
    >> Not sure if any arch do READ/WRITE check but if yes.
    >
    > I could not find any architecture using it either, but the
    > API is defined this way.
    >
    >> #ifndef access_ok
    >>
    >>> +#define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))
    >> #endif
    >
    > right, will change.
    >
    >>> +
    >>> +/*
    >>> + * The architecture should really override this if possible, at least
    >>> + * doing a check on the get_fs()
    >>> + */
    >> If they should really override it but why write it here.
    >
    > Mostly for documentation purposes, so that an architecture maintainer
    > can copy the prototype. I see the asm-generic headers as both fallbacks
    > for architectures and as templates of what should be implemented.
    >
    >>> +#define get_user(x, ptr) \
    >>> +({ \
    >>> + might_sleep(); \
    >>> + __access_ok(ptr, sizeof (*ptr)) ? \
    >>> + __get_user(x, ptr) : \
    >>> + -EFAULT; \
    >>> +})
    >> I am getting here (for put_user macro too) any error on noMMU. :-(
    >
    > What kind of error do you see?

    System is getting crazy with -> I am debugging it.


    >
    >>> +static inline long
    >>> +strncpy_from_user(char *dst, const char __user *src, long count)
    >>> +{
    >>> + if (!__access_ok(src, 1))
    >>> + return -EFAULT;
    >>> + return __strncpy_from_user(dst, src, count);
    >>> +}
    >> Is it a good place to add might_sleep() and unlikely(+ some other cases) too?
    >> We have almost the same code.
    >
    > Yes, I think so. The unlikely() can probably go into __access_ok() though,
    > so we don't have to write it every time.

    ok

    Michal


    >
    > Arnd <><


    --
    Michal Simek, Ing. (M.Eng)
    w: www.monstr.eu p: +42-0-721842854


    \
     
     \ /
      Last update: 2009-05-01 16:15    [W:3.116 / U:0.024 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site