Re: [uml-devel] [PATCH 1/4] um: Fix _FORTIFY_SOURCE=2 support for kernel modules

[Vitaliy I. <vit...@gm...>]

On Tue, Jun 28, 2011 at 1:15 AM, Richard Weinberger <ri...@no...> wrote:
> When UML is compiled with _FORTIFY_SOURCE we have to
> export all _chk() functions which are used in modules.
> For now it's only the case for __sprintf_chk().
>
> Tested-by: Florian Fainelli <fl...@op...>
> Reported-by: Florian Fainelli <fl...@op...>
> Signed-off-by: Richard Weinberger <ri...@no...>
> ---
>  arch/um/os-Linux/user_syms.c |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/arch/um/os-Linux/user_syms.c b/arch/um/os-Linux/user_syms.c
> index 05f5ea8..45ffe46 100644
> --- a/arch/um/os-Linux/user_syms.c
> +++ b/arch/um/os-Linux/user_syms.c
> @@ -113,3 +113,8 @@ EXPORT_SYMBOL(__stack_smash_handler);
>
>  extern long __guard __attribute__((weak));
>  EXPORT_SYMBOL(__guard);
> +
> +#ifdef _FORTIFY_SOURCE
> +extern int __sprintf_chk(char *str, int flag, size_t strlen, const char *format);
> +EXPORT_SYMBOL(__sprintf_chk);
> +#endif
> --

Can you please clarify why it's needed? I use FORTIFY_SOURCES on
Linus' tree UML on Ubuntu w/ no problems and w/o this patch...

Thanks,
Vitaliy