From: Mark Rutland <mark.rutland@arm.com>
To: linux-kernel@vger.kernel.org
Cc: benh@kernel.crashing.org, boqun.feng@gmail.com, bp@alien8.de,
catalin.marinas@arm.com, dvyukov@google.com, elver@google.com,
ink@jurassic.park.msu.ru, jonas@southpole.se,
juri.lelli@redhat.com, linux@armlinux.org.uk, luto@kernel.org,
mark.rutland@arm.com, mattst88@gmail.com, mingo@redhat.com,
monstr@monstr.eu, mpe@ellerman.id.au, paulmck@kernel.org,
paulus@samba.org, peterz@infradead.org, rth@twiddle.net,
shorne@gmail.com, stefan.kristiansson@saunalahti.fi,
tglx@linutronix.de, vincent.guittot@linaro.org, will@kernel.org
Subject: [RFC PATCH 00/10] thread_info: use helpers to snapshot thread flags
Date: Wed, 9 Jun 2021 13:19:51 +0100 [thread overview]
Message-ID: <20210609122001.18277-1-mark.rutland@arm.com> (raw)
As thread_info::flags scan be manipulated by remote threads, it is necessary to
use atomics or READ_ONCE() to ensure that code manipulates a consistent
snapshot, but we open-code plain accesses to thread_info::flags across the kernel tree.
Generally we get away with this, but tools like KCSAN legitimately warn that
there is a data-race, and this is potentially fragile with compiler
optimizations, LTO, etc.
These patches introduce new helpers to snahpshot the thread flags, with the
intent being that these should replace all plain accesses.
I'm sending this as an RFC as I'm certain I've missed places that need to be
moved over to the helpers, and I want to check that this has the right shape
before digging deeper.
Thanks,
Mark.
Mark Rutland (10):
thread_info: add helpers to snapshot thread flags
entry: snapshot thread flags
sched: snapshot thread flags
alpha: snapshot thread flags
arm: snapshot thread flags
arm64: read thread flags
microblaze: snapshot thread flags
openrisc: snapshot thread flags
powerpc: snapshot thread flags
x86: snapshot thread flags
arch/alpha/kernel/signal.c | 2 +-
arch/arm/kernel/signal.c | 2 +-
arch/arm/mm/alignment.c | 2 +-
arch/arm64/kernel/ptrace.c | 4 ++--
arch/arm64/kernel/signal.c | 2 +-
arch/arm64/kernel/syscall.c | 4 ++--
arch/microblaze/kernel/signal.c | 2 +-
arch/openrisc/kernel/signal.c | 2 +-
arch/powerpc/kernel/interrupt.c | 16 ++++++++--------
arch/powerpc/kernel/ptrace/ptrace.c | 3 +--
arch/x86/kernel/process.c | 8 ++++----
arch/x86/kernel/process.h | 6 +++---
arch/x86/mm/tlb.c | 2 +-
include/linux/entry-kvm.h | 2 +-
include/linux/thread_info.h | 10 ++++++++++
kernel/entry/common.c | 4 ++--
kernel/entry/kvm.c | 4 ++--
kernel/sched/core.c | 2 +-
18 files changed, 43 insertions(+), 34 deletions(-)
--
2.11.0
next reply other threads:[~2021-06-09 12:20 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-09 12:19 Mark Rutland [this message]
2021-06-09 12:19 ` [RFC PATCH 01/10] thread_info: add helpers to snapshot thread flags Mark Rutland
2021-06-10 9:01 ` Marco Elver
2021-06-11 9:17 ` Mark Rutland
2021-06-19 22:28 ` Thomas Gleixner
2021-06-21 8:29 ` Mark Rutland
2021-06-09 12:19 ` [RFC PATCH 02/10] entry: " Mark Rutland
2021-06-09 12:19 ` [RFC PATCH 03/10] sched: " Mark Rutland
2021-06-09 12:19 ` [RFC PATCH 04/10] alpha: " Mark Rutland
2021-06-09 12:19 ` [RFC PATCH 05/10] arm: " Mark Rutland
2021-06-09 12:19 ` [RFC PATCH 06/10] arm64: read " Mark Rutland
2021-06-09 12:19 ` [RFC PATCH 07/10] microblaze: snapshot " Mark Rutland
2021-06-09 12:19 ` [RFC PATCH 08/10] openrisc: " Mark Rutland
2021-06-10 19:14 ` Stafford Horne
2021-06-09 12:20 ` [RFC PATCH 09/10] powerpc: " Mark Rutland
2021-06-15 13:18 ` Michael Ellerman
2021-06-21 8:46 ` Mark Rutland
2021-06-09 12:20 ` [RFC PATCH 10/10] x86: " Mark Rutland
2021-06-19 22:30 ` Thomas Gleixner
2021-06-21 8:35 ` Mark Rutland
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