Re: [PATCH 9/9] Consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS

[Ingo Molnar]

* Stephen Boyd <sboyd@xxxxxxxxxxxxxx> wrote:

> The help text for this config is duplicated across the x86,
> parisc, and s390 Kconfig.debug files. Arnd Bergman noted that the
> help text was slightly misleading and should be fixed to state
> that enabling this option isn't a problem when using pre 4.4 gcc.
> 
> To simplify the rewording, consolidate the text into
> lib/Kconfig.debug and modify it there to be more explicit about
> when you should say N to this config.
> 
> Also, make the text a bit more generic by stating that this
> option enables compile time checks so we can cover architectures
> which emit warnings vs. ones which emit errors. The details of
> how an architecture decided to implement the checks isn't as
> important as the concept of compile time checking of
> copy_from_user() calls.
> 
> While we're doing this, remove all the copy_from_user_overflow()
> code that's duplicated many times and place it into lib/ so that
> any architecture supporting this option can get the function for
> free.
> 
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: linux-parisc@xxxxxxxxxxxxxxx
> Cc: linux-s390@xxxxxxxxxxxxxxx
> Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
> Cc: Helge Deller <deller@xxxxxx>
> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
> Cc: Chris Metcalf <cmetcalf@xxxxxxxxxx>
> Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> ---
>  arch/parisc/Kconfig             |    1 +
>  arch/parisc/Kconfig.debug       |   14 --------------
>  arch/s390/Kconfig               |    1 +
>  arch/s390/Kconfig.debug         |   14 --------------
>  arch/s390/lib/Makefile          |    1 -
>  arch/s390/lib/usercopy.c        |    8 --------
>  arch/sparc/lib/Makefile         |    1 -
>  arch/sparc/lib/usercopy.c       |    8 --------
>  arch/tile/Kconfig               |    8 +-------
>  arch/tile/include/asm/uaccess.h |    7 ++++++-
>  arch/tile/lib/uaccess.c         |    8 --------
>  arch/x86/Kconfig                |    1 +
>  arch/x86/Kconfig.debug          |   14 --------------
>  arch/x86/lib/usercopy_32.c      |    6 ------
>  arch/x86/lib/usercopy_64.c      |    6 ------
>  lib/Kconfig.debug               |   18 ++++++++++++++++++
>  lib/Makefile                    |    1 +
>  lib/usercopy.c                  |    8 ++++++++
>  18 files changed, 37 insertions(+), 88 deletions(-)
>  delete mode 100644 arch/s390/lib/usercopy.c
>  delete mode 100644 arch/sparc/lib/usercopy.c
>  create mode 100644 lib/usercopy.c

Very nice!

Acked-by: Ingo Molnar <mingo@xxxxxxx>

	Ingo
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