From: Marco Elver <elver@google.com>
To: "Eric W. Beiderman" <ebiederm@xmission.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 v3 12/12] signalfd: Remove SIL_FAULT_PERF_EVENT fields from signalfd_siginfo
Date: Wed, 5 May 2021 19:27:00 +0200 [thread overview]
Message-ID: <CANpmjNPcYS9F+mgFP_DnO5c7kmMs28cdMBWN+ZxE7YNe_oK=_w@mail.gmail.com> (raw)
In-Reply-To: <20210505141101.11519-12-ebiederm@xmission.com>
On Wed, 5 May 2021 at 16:11, Eric W. Beiderman <ebiederm@xmission.com> wrote:
> From: "Eric W. Biederman" <ebiederm@xmission.com>
>
> With the addition of ssi_perf_data and ssi_perf_type struct signalfd_siginfo
> is dangerously close to running out of space. All that remains is just
> enough space for two additional 64bit fields. A practice of adding all
> possible siginfo_t fields into struct singalfd_siginfo can not be supported
> as adding the missing fields ssi_lower, ssi_upper, and ssi_pkey would
> require two 64bit fields and one 32bit fields. In practice the fields
> ssi_perf_data and ssi_perf_type can never be used by signalfd as the signal
> that generates them always delivers them synchronously to the thread that
> triggers them.
>
> Therefore until someone actually needs the fields ssi_perf_data and
> ssi_perf_type in signalfd_siginfo remove them. This leaves a bit more room
> for future expansion.
>
> v1: https://lkml.kernel.org/r/20210503203814.25487-12-ebiederm@xmission.com
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Marco Elver <elver@google.com>
> ---
> fs/signalfd.c | 16 ++++++----------
> include/uapi/linux/signalfd.h | 4 +---
> 2 files changed, 7 insertions(+), 13 deletions(-)
>
> diff --git a/fs/signalfd.c b/fs/signalfd.c
> index 335ad39f3900..040e1cf90528 100644
> --- a/fs/signalfd.c
> +++ b/fs/signalfd.c
> @@ -114,12 +114,13 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
> break;
> case SIL_FAULT_BNDERR:
> case SIL_FAULT_PKUERR:
> + case SIL_FAULT_PERF_EVENT:
> /*
> - * Fall through to the SIL_FAULT case. Both SIL_FAULT_BNDERR
> - * and SIL_FAULT_PKUERR are only generated by faults that
> - * deliver them synchronously to userspace. In case someone
> - * injects one of these signals and signalfd catches it treat
> - * it as SIL_FAULT.
> + * Fall through to the SIL_FAULT case. SIL_FAULT_BNDERR,
> + * SIL_FAULT_PKUERR, and SIL_FAULT_PERF_EVENT are only
> + * generated by faults that deliver them synchronously to
> + * userspace. In case someone injects one of these signals
> + * and signalfd catches it treat it as SIL_FAULT.
> */
> case SIL_FAULT:
> new.ssi_addr = (long) kinfo->si_addr;
> @@ -132,11 +133,6 @@ static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo,
> new.ssi_addr = (long) kinfo->si_addr;
> new.ssi_addr_lsb = (short) kinfo->si_addr_lsb;
> break;
> - case SIL_FAULT_PERF_EVENT:
> - new.ssi_addr = (long) kinfo->si_addr;
> - new.ssi_perf_type = kinfo->si_perf_type;
> - new.ssi_perf_data = kinfo->si_perf_data;
> - break;
> case SIL_CHLD:
> new.ssi_pid = kinfo->si_pid;
> new.ssi_uid = kinfo->si_uid;
> diff --git a/include/uapi/linux/signalfd.h b/include/uapi/linux/signalfd.h
> index e78dddf433fc..83429a05b698 100644
> --- a/include/uapi/linux/signalfd.h
> +++ b/include/uapi/linux/signalfd.h
> @@ -39,8 +39,6 @@ struct signalfd_siginfo {
> __s32 ssi_syscall;
> __u64 ssi_call_addr;
> __u32 ssi_arch;
> - __u32 ssi_perf_type;
> - __u64 ssi_perf_data;
>
> /*
> * Pad strcture to 128 bytes. Remember to update the
> @@ -51,7 +49,7 @@ struct signalfd_siginfo {
> * comes out of a read(2) and we really don't want to have
> * a compat on read(2).
> */
> - __u8 __pad[16];
> + __u8 __pad[28];
> };
>
>
> --
> 2.30.1
next prev parent reply other threads:[~2021-05-05 17:56 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
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 [this message]
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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