From: Helge Deller <deller@gmx.de>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Oleg Nesterov <oleg@redhat.com>,
Andrei Vagin <avagin@virtuozzo.com>,
Thomas Gleixner <tglx@linutronix.de>, Greg KH <greg@kroah.com>,
Andrey Vagin <avagin@openvz.org>, Serge Hallyn <serge@hallyn.com>,
Pavel Emelyanov <xemul@virtuozzo.com>,
Cyrill Gorcunov <gorcunov@openvz.org>,
Peter Zijlstra <peterz@infradead.org>, Willy Tarreau <w@1wt.eu>,
linux-arch@vger.kernel.org, linux-api@vger.kernel.org,
Linux Containers <containers@lists.linux-foundation.org>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Richard Henderson <rth@twiddle.net>,
Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
Matt Turner <mattst88@gmail.com>
Subject: Re: [PATCH 1/8] signal/alpha: Document a conflict with SI_USER for SIGTRAP
Date: Sun, 2 Jul 2017 16:13:20 +0200 [thread overview]
Message-ID: <20170702141320.GA32254@ls3530.fritz.box> (raw)
In-Reply-To: <20170630123906.8865-1-ebiederm@xmission.com>
* Eric W. Biederman <ebiederm@xmission.com>:
> Setting si_code to __SI_FAULT results in a userspace seeing
> an si_code of 0. This is the same si_code as SI_USER. Posix
> and common sense requires that SI_USER not be a signal specific
> si_code. As such this use of 0 for the si_code is a pretty
> horribly broken ABI.
>
> Given that alpha is on it's last legs I don't know that it is worth
> fixing this, but it is worth documenting what is going on so that
> no one decides to copy this bad decision.
The ABI was already broken, so IMHO I think it's better to somehow "fix"
it instead. Agreed, alpha and some other architectures are already aged,
but nevertheless most of them build in debian-ports. Below is a
suggested fix which reuses/misuses other existing trap codes instead.
Helge
Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c
index 65bb102..2ed37dd 100644
--- a/arch/alpha/kernel/traps.c
+++ b/arch/alpha/kernel/traps.c
@@ -278,7 +278,7 @@ do_entIF(unsigned long type, struct pt_regs *regs)
case 1: /* bugcheck */
info.si_signo = SIGTRAP;
info.si_errno = 0;
- info.si_code = __SI_FAULT;
+ info.si_code = TRAP_HWBKPT;
info.si_addr = (void __user *) regs->pc;
info.si_trapno = 0;
send_sig_info(SIGTRAP, &info, current);
@@ -318,7 +318,7 @@ do_entIF(unsigned long type, struct pt_regs *regs)
break;
case GEN_ROPRAND:
signo = SIGFPE;
- code = __SI_FAULT;
+ code = FPE_FLTSUB;
break;
case GEN_DECOVF:
@@ -340,7 +340,7 @@ do_entIF(unsigned long type, struct pt_regs *regs)
case GEN_SUBRNG7:
default:
signo = SIGTRAP;
- code = __SI_FAULT;
+ code = TRAP_HWBKPT;
break;
}
next prev parent reply other threads:[~2017-07-02 14:13 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87efu22set.fsf@xmission.com>
2017-06-30 12:38 ` [PATCH 1/8] signal/alpha: Document a conflict with SI_USER for SIGTRAP Eric W. Biederman
2017-07-02 14:13 ` Helge Deller [this message]
[not found] ` <20170702141320.GA32254-PwtjyNU/e7vkVFMGpb/cPg@public.gmane.org>
2017-07-14 10:59 ` Eric W. Biederman
2017-07-17 8:14 ` Michael Cree
2017-07-18 13:37 ` Eric W. Biederman
2017-06-30 12:39 ` [PATCH 2/8] signal/ia64: Document a conflict with SI_USER with SIGFPE Eric W. Biederman
2017-06-30 12:39 ` [PATCH 3/8] signal/sparc: " Eric W. Biederman
2017-06-30 16:45 ` David Miller
[not found] ` <20170630.124505.736865959393416284.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2017-06-30 18:13 ` Eric W. Biederman
[not found] ` <8737ahwdgr.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-07-18 13:43 ` Eric W. Biederman
[not found] ` <87efu22set.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-06-30 12:39 ` [PATCH 4/8] signal/mips: " Eric W. Biederman
2017-06-30 12:39 ` [PATCH 5/8] signal/testing: Don't look for __SI_FAULT in userspace Eric W. Biederman
2017-06-30 12:39 ` [PATCH 6/8] signal/x86: Fix SIGSYS handling in copy_siginfo_to_user32 Eric W. Biederman
2017-06-30 12:39 ` [PATCH 7/8] fcntl: Don't use ambiguous SIG_POLL si_codes Eric W. Biederman
2017-06-30 12:39 ` [PATCH 8/8] signal: Remove kernel interal si_code magic Eric W. Biederman
[not found] ` <20170630123906.8865-8-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2017-07-12 22:36 ` Andrei Vagin
2017-07-12 23:08 ` Eric W. Biederman
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