On Tue, Jan 23, 2018 at 03:07:15PM -0600, Eric W. Biederman wrote:
> The helpers added are:
> send_sig_mceerr
> force_sig_mceerr
> force_sig_bnderr
> force_sig_pkuerr
>
> Filling out siginfo properly can ge tricky. Especially for these
> specialized cases where the temptation is to share code with other
> cases which use a different subset of siginfo fields. Unfortunately
> that code sharing frequently results in bugs with the wrong siginfo
> fields filled in, and makes it harder to verify that the siginfo
> structure was properly initialized.
>
> Provide these helpers instead that get all of the details right, and
> guarantee that siginfo is properly initialized.
>
> send_sig_mceerr and force_sig_mceer are a little special as two si
> codes BUS_MCEERR_AO and BUS_MCEER_AR both use the same extended
> signinfo layout.
nice. i can make use of these helpers in the memory-key implementation.
One small nit-pick below though...
>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
> ---
> include/linux/sched/signal.h | 6 +++++
> kernel/signal.c | 61 ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 67 insertions(+)
>
> diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
...snip..
> +
> +#ifdef SEGV_PKUERR
Should this really be under SEGV_PKUERR ? that macro is defined
unconditionally anyway.
> +int force_sig_pkuerr(void __user *addr, u32 pkey)
> +{
> + struct siginfo info;
> +
> + clear_siginfo(&info);
> + info.si_signo = SIGSEGV;
> + info.si_errno = 0;
> + info.si_code = SEGV_PKUERR;
> + info.si_addr = addr;
> + info.si_pkey = pkey;
> + return force_sig_info(info.si_signo, &info, current);
> +}
> +#endif
