Re: [PATCH] fixup! signal: factor copy_siginfo_to_external32 from copy_siginfo_to_user32

Christophe Leroy
2020-04-29T06:17:32Z

Le 28/04/2020 à 21:56, Arnd Bergmann a écrit :
> I think I found a way to improve the x32 handling:
>
> This is a simplification over Christoph's "[PATCH 2/7] signal: factor
> copy_siginfo_to_external32 from copy_siginfo_to_user32", reducing the
> x32 specifics in the common code to a single #ifdef/#endif check, in
> order to keep it more readable for everyone else.
>
> Christoph, if you like it, please fold into your patch.
>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
> Cc: Jeremy Kerr <jk@ozlabs.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: "Eric W . Biederman" <ebiederm@xmission.com>
> Cc: linuxppc-dev@lists.ozlabs.org
> Cc: linux-fsdevel@vger.kernel.org
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> arch/x86/include/asm/compat.h | 10 ++++++++++
> arch/x86/kernel/signal.c | 23 +++++++++++++++++++++++
> kernel/signal.c | 15 ++-------------
> 3 files changed, 35 insertions(+), 13 deletions(-)
>

[...]

> diff --git a/kernel/signal.c b/kernel/signal.c
> index 1a81602050b4..935facca4860 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -3318,29 +3318,18 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
> }
> }
>
> +#ifndef CONFIG_X86_X32_ABI

Can it be declared __weak instead of enclosing it in an #ifndef ?

> int copy_siginfo_to_user32(struct compat_siginfo __user *to,
> const struct kernel_siginfo *from)
> -#if defined(CONFIG_X86_X32_ABI) || defined(CONFIG_IA32_EMULATION)
> -{
> - return __copy_siginfo_to_user32(to, from, in_x32_syscall());
> -}
> -int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
> - const struct kernel_siginfo *from, bool x32_ABI)
> -#endif
> {
> struct compat_siginfo new;
>
> copy_siginfo_to_external32(&new, from);
> -#ifdef CONFIG_X86_X32_ABI
> - if (x32_ABI && from->si_signo == SIGCHLD) {
> - new._sifields._sigchld_x32._utime = from->si_utime;
> - new._sifields._sigchld_x32._stime = from->si_stime;
> - }
> -#endif
> if (copy_to_user(to, &new, sizeof(struct compat_siginfo)))
> return -EFAULT;
> return 0;
> }
> +#endif
>
> static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
> const struct compat_siginfo *from)
>

Christophe