Re: [PATCH 0/6] Final si_trapno bits

From: ebiederm@xmission.com (Eric W. Biederman)
To: Marco Elver <elver@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Florian Weimer <fweimer@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Collingbourne <pcc@google.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Alexander Potapenko <glider@google.com>,
	sparclinux <sparclinux@vger.kernel.org>,
	linux-arch <linux-arch@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux API <linux-api@vger.kernel.org>,
	kasan-dev <kasan-dev@googlegroups.com>
Subject: Re: [PATCH 0/6] Final si_trapno bits
Date: Fri, 16 Jul 2021 11:08:52 -0500	[thread overview]
Message-ID: <87tukuw8a3.fsf@disp2133> (raw)
In-Reply-To: <YPFybJQ7eviet341@elver.google.com> (Marco Elver's message of "Fri, 16 Jul 2021 13:50:04 +0200")

Marco Elver <elver@google.com> writes:

> On Thu, Jul 15, 2021 at 01:09PM -0500, Eric W. Biederman wrote:
>> As a part of a fix for the ABI of the newly added SIGTRAP TRAP_PERF a
>> si_trapno was reduced to an ordinary extention of the _sigfault case
>> of struct siginfo.
>> 
>> When Linus saw the complete set of changes come in as a fix he requested
>> that the set of changes be trimmed down to just what was necessary to
>> fix the SIGTRAP TRAP_PERF ABI.
>> 
>> I had intended to get the rest of the changes into the merge window for
>> v5.14 but I dropped the ball.
>> 
>> I have made the changes to stop using __ARCH_SI_TRAPNO be per
>> architecture so they are easier to review.  In doing so I found one
>> place on alpha where I used send_sig_fault instead of
>> send_sig_fault_trapno(... si_trapno = 0).  That would not have changed
>> the userspace behavior but it did make the kernel code less clear.
>> 
>> My rule in these patches is everywhere that siginfo layout calls
>> for SIL_FAULT_TRAPNO the code uses either force_sig_fault_trapno
>> or send_sig_fault_trapno.
>> 
>> And of course I have rebased and compile tested Marco's compile time
>> assert patches.
>> 
>> Eric
>> 
>> 
>> Eric W. Biederman (3):
>>       signal/sparc: si_trapno is only used with SIGILL ILL_ILLTRP
>>       signal/alpha: si_trapno is only used with SIGFPE and SIGTRAP TRAP_UNK
>>       signal: Remove the generic __ARCH_SI_TRAPNO support
>> 
>> Marco Elver (3):
>>       sparc64: Add compile-time asserts for siginfo_t offsets
>>       arm: Add compile-time asserts for siginfo_t offsets
>>       arm64: Add compile-time asserts for siginfo_t offsets
>
> Nice, thanks for the respin. If I diffed it right, I see this is almost
> (modulo what you mentioned above) equivalent to:
>   https://lore.kernel.org/linux-api/m1tuni8ano.fsf_-_@fess.ebiederm.org/
> + what's already in mainline. It's only missing:
>
> 	signal: Verify the alignment and size of siginfo_t
> 	signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency
>
> Would this be appropriate for this series, or rather separately, or
> dropped completely?

Appropriate I just overlooked them.

Eric