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 1/3] siginfo: Move si_trapno inside the union inside _si_fault
Date: Sun, 02 May 2021 13:27:21 -0500 [thread overview]
Message-ID: <m1czu9ng8m.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <CANpmjNOZj-jRfFH365znJGqDAwdXL4Z2QBuHOtdvN_uNJ8WBSA@mail.gmail.com> (Marco Elver's message of "Sat, 1 May 2021 12:31:10 +0200")
Marco Elver <elver@google.com> writes:
> On Sat, 1 May 2021 at 00:50, Eric W. Biederman <ebiederm@xmission.com> wrote:
>>
>> It turns out that linux uses si_trapno very sparingly, and as such it
>> can be considered extra information for a very narrow selection of
>> signals, rather than information that is present with every fault
>> reported in siginfo.
>>
>> As such move si_trapno inside the union inside of _si_fault. This
>> results in no change in placement, and makes it eaiser to extend
>> _si_fault in the future as this reduces the number of special cases.
>> In particular with si_trapno included in the union it is no longer a
>> concern that the union must be pointer alligned on most architectures
>> because the union followes immediately after si_addr which is a
>> pointer.
>>
>
> Maybe add "Link:
> https://lkml.kernel.org/r/CAK8P3a0+uKYwL1NhY6Hvtieghba2hKYGD6hcKx5n8=4Gtt+pHA@mail.gmail.com"
>
>> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
>
> Acked-by: Marco Elver <elver@google.com>
>
> By no longer guarding it with __ARCH_SI_TRAPNO we run the risk that it
> will be used by something else at some point. Is that intentional?
The motivation was letting the code be tested on other architectures.
But once si_trapno falls inside the union instead of being present for
every signal reporting a fault it doesn't really matter.
I think it would be poor taste but harmless to use si_trapno, mostly
because defining a new entry in the union could be more specific and
well defined.
Eric
next prev parent reply other threads:[~2021-05-02 18:27 UTC|newest]
Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-29 7:48 siginfo_t ABI break on sparc64 from si_addr_lsb move 3y ago Marco Elver
2021-04-29 17:23 ` Eric W. Biederman
2021-04-29 18:46 ` Marco Elver
2021-04-29 20:48 ` Arnd Bergmann
2021-04-30 17:08 ` Eric W. Biederman
2021-04-30 19:07 ` Marco Elver
2021-04-30 20:15 ` Eric W. Biederman
2021-04-30 23:50 ` Marco Elver
2021-04-30 22:49 ` [RFC][PATCH 0/3] signal: Move si_trapno into the _si_fault union Eric W. Biederman
2021-04-30 22:50 ` [PATCH 1/3] siginfo: Move si_trapno inside the union inside _si_fault Eric W. Biederman
2021-05-01 10:31 ` Marco Elver
2021-05-02 18:27 ` Eric W. Biederman [this message]
2021-04-30 22:54 ` [PATCH 2/3] signal: Implement SIL_FAULT_TRAPNO Eric W. Biederman
2021-04-30 23:19 ` Eric W. Biederman
2021-05-01 10:33 ` Marco Elver
2021-05-02 18:24 ` Eric W. Biederman
2021-04-30 22:55 ` [PATCH 3/3] signal: Use dedicated helpers to send signals with si_trapno set Eric W. Biederman
2021-05-01 10:33 ` Marco Elver
2021-04-30 22:56 ` [PATCH 4/3] signal: Remove __ARCH_SI_TRAPNO Eric W. Biederman
2021-04-30 23:23 ` Is perf_sigtrap synchronous? Eric W. Biederman
2021-05-01 0:28 ` Marco Elver
2021-04-30 23:42 ` [PATCH 5/3] signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency Eric W. Biederman
2021-05-01 10:35 ` Marco Elver
2021-04-30 23:43 ` [PATCH 6/3] signal: Factor force_sig_perf out of perf_sigtrap Eric W. Biederman
2021-05-01 10:45 ` Marco Elver
2021-04-30 23:43 ` [PATCH 7/3] signal: Deliver all of the perf_data in si_perf Eric W. Biederman
2021-05-01 10:47 ` Marco Elver
2021-05-02 18:39 ` Eric W. Biederman
2021-05-02 19:13 ` Marco Elver
2021-05-03 12:44 ` Peter Zijlstra
2021-05-03 19:38 ` Eric W. Biederman
2021-05-03 19:53 ` Marco Elver
2021-04-30 23:47 ` [RFC][PATCH 0/3] signal: Move si_trapno into the _si_fault union Eric W. Biederman
2021-05-01 0:37 ` Marco Elver
2021-05-01 15:16 ` Eric W. Biederman
2021-05-01 16:24 ` Marco Elver
2021-05-03 20:25 ` [PATCH 00/12] signal: sort out si_trapno and si_perf Eric W. Biederman
2021-05-03 20:38 ` [PATCH 01/12] sparc64: Add compile-time asserts for siginfo_t offsets Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 02/12] arm: " Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 03/12] arm64: " Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 04/12] siginfo: Move si_trapno inside the union inside _si_fault Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 05/12] signal: Implement SIL_FAULT_TRAPNO Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 06/12] signal: Use dedicated helpers to send signals with si_trapno set Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 07/12] signal: Remove __ARCH_SI_TRAPNO Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 08/12] signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 09/12] signal: Factor force_sig_perf out of perf_sigtrap Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 10/12] signal: Redefine signinfo so 64bit fields are possible Eric W. Beiderman
2021-05-03 21:04 ` Eric W. Biederman
2021-05-03 22:47 ` Marco Elver
2021-05-04 3:42 ` Eric W. Biederman
2021-05-04 4:03 ` Peter Collingbourne
2021-05-04 9:52 ` Marco Elver
2021-05-04 16:16 ` Eric W. Biederman
2021-05-03 20:38 ` [PATCH 11/12] signal: Deliver all of the siginfo perf data in _perf Eric W. Beiderman
2021-05-03 20:38 ` [PATCH 12/12] signalfd: Remove SIL_FAULT_PERF_EVENT fields from signalfd_siginfo Eric W. Beiderman
2021-05-04 21:13 ` [PATCH v3 00/12] signal: sort out si_trapno and si_perf Eric W. Biederman
2021-05-04 22:05 ` Marco Elver
2021-05-05 14:12 ` Eric W. Biederman
2021-05-05 14:10 ` [PATCH v3 01/12] sparc64: Add compile-time asserts for siginfo_t offsets Eric W. Beiderman
2021-05-05 14:10 ` [PATCH v3 02/12] arm: " Eric W. Beiderman
2021-05-05 14:10 ` [PATCH v3 03/12] arm64: " Eric W. Beiderman
2021-05-05 14:10 ` [PATCH v3 04/12] signal: Verify the alignment and size of siginfo_t Eric W. Beiderman
2021-05-05 17:24 ` Marco Elver
2021-05-05 14:10 ` [PATCH v3 05/12] siginfo: Move si_trapno inside the union inside _si_fault Eric W. Beiderman
2021-05-05 14:10 ` [PATCH v3 06/12] signal: Implement SIL_FAULT_TRAPNO Eric W. Beiderman
2021-05-05 17:25 ` Marco Elver
2021-05-05 14:10 ` [PATCH v3 07/12] signal: Use dedicated helpers to send signals with si_trapno set Eric W. Beiderman
2021-05-05 17:25 ` Marco Elver
2021-05-05 14:10 ` [PATCH v3 08/12] signal: Remove __ARCH_SI_TRAPNO Eric W. Beiderman
2021-05-05 17:25 ` Marco Elver
2021-05-05 14:10 ` [PATCH v3 09/12] signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency Eric W. Beiderman
2021-05-05 17:26 ` Marco Elver
2021-05-05 14:10 ` [PATCH v3 10/12] signal: Factor force_sig_perf out of perf_sigtrap Eric W. Beiderman
2021-05-05 17:26 ` Marco Elver
2021-05-06 10:54 ` Peter Zijlstra
2021-05-05 14:11 ` [PATCH v3 11/12] signal: Deliver all of the siginfo perf data in _perf Eric W. Beiderman
2021-05-05 17:27 ` Marco Elver
2021-05-05 14:11 ` [PATCH v3 12/12] signalfd: Remove SIL_FAULT_PERF_EVENT fields from signalfd_siginfo Eric W. Beiderman
2021-05-05 17:27 ` Marco Elver
2021-05-05 17:28 ` [PATCH v3 00/12] signal: sort out si_trapno and si_perf Marco Elver
2021-05-06 7:00 ` Geert Uytterhoeven
2021-05-06 10:43 ` Marco Elver
2021-05-06 15:28 ` Eric W. Biederman
2021-05-06 15:14 ` Eric W. Biederman
2021-05-14 4:54 ` [GIT PULL] siginfo: ABI fixes for v5.13-rc2 Eric W. Biederman
2021-05-14 19:14 ` Linus Torvalds
2021-05-14 21:15 ` Eric W. Biederman
2021-05-14 22:38 ` Eric W. Biederman
2021-05-16 7:40 ` Ingo Molnar
2021-05-17 15:29 ` Eric W. Biederman
2021-05-21 14:59 ` [GIT PULL] siginfo: ABI fixes for v5.13-rc3 Eric W. Biederman
2021-05-21 16:34 ` pr-tracker-bot
2021-05-17 19:56 ` [PATCH v4 0/5] siginfo: ABI fixes for TRAP_PERF Eric W. Biederman
2021-05-17 19:57 ` [PATCH v4 1/5] siginfo: Move si_trapno inside the union inside _si_fault Eric W. Beiderman
2021-05-17 19:57 ` [PATCH v4 2/5] signal: Implement SIL_FAULT_TRAPNO Eric W. Beiderman
2021-05-17 19:57 ` [PATCH v4 3/5] signal: Factor force_sig_perf out of perf_sigtrap Eric W. Beiderman
2021-05-17 19:57 ` [PATCH v4 4/5] signal: Deliver all of the siginfo perf data in _perf Eric W. Beiderman
2021-05-17 19:57 ` [PATCH v4 5/5] signalfd: Remove SIL_PERF_EVENT fields from signalfd_siginfo Eric W. Beiderman
2021-05-17 20:53 ` [PATCH v4 0/5] siginfo: ABI fixes for TRAP_PERF Marco Elver
2021-05-18 3:46 ` Eric W. Biederman
2021-05-18 6:44 ` Marco Elver
2021-05-01 16:26 ` [RFC][PATCH 0/3] signal: Move si_trapno into the _si_fault union Marco Elver
2021-07-15 18:09 ` [PATCH 0/6] Final si_trapno bits Eric W. Biederman
2021-07-15 18:11 ` [PATCH 1/6] sparc64: Add compile-time asserts for siginfo_t offsets Eric W. Biederman
2021-07-15 18:11 ` [PATCH 2/6] arm: " Eric W. Biederman
2021-07-15 18:11 ` [PATCH 3/6] arm64: " Eric W. Biederman
2021-07-15 18:12 ` [PATCH 4/6] signal/sparc: si_trapno is only used with SIGILL ILL_ILLTRP Eric W. Biederman
2021-07-16 11:49 ` Marco Elver
2021-07-15 18:12 ` [PATCH 5/6] signal/alpha: si_trapno is only used with SIGFPE and SIGTRAP TRAP_UNK Eric W. Biederman
2021-07-16 11:48 ` Marco Elver
2021-07-15 18:13 ` [PATCH 6/6] signal: Remove the generic __ARCH_SI_TRAPNO support Eric W. Biederman
2021-07-16 11:48 ` Marco Elver
2021-07-16 11:50 ` [PATCH 0/6] Final si_trapno bits Marco Elver
2021-07-16 16:08 ` Eric W. Biederman
2021-07-16 17:15 ` Marco Elver
2021-07-16 16:06 ` [PATCH 7/7] signal: Verify the alignment and size of siginfo_t Eric W. Biederman
2021-07-16 16:07 ` [PATCH 8/6] signal: Rename SIL_PERF_EVENT SIL_FAULT_PERF_EVENT for consistency Eric W. Biederman
2021-04-30 20:43 ` siginfo_t ABI break on sparc64 from si_addr_lsb move 3y ago Arnd Bergmann
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