From: "tip-bot2 for Mark Rutland" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
"Paul E. McKenney" <paulmck@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: core/entry] arm64: snapshot thread flags
Date: Fri, 26 Nov 2021 20:22:56 -0000 [thread overview]
Message-ID: <163795817677.11128.14392009886950339362.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20211117163050.53986-7-mark.rutland@arm.com>
The following commit has been merged into the core/entry branch of tip:
Commit-ID: 67c76c3dc0ef46f44715e866c7d4ef81a5a2872d
Gitweb: https://git.kernel.org/tip/67c76c3dc0ef46f44715e866c7d4ef81a5a2872d
Author: Mark Rutland <mark.rutland@arm.com>
AuthorDate: Wed, 17 Nov 2021 16:30:44
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Fri, 26 Nov 2021 21:20:13 +01:00
arm64: snapshot thread flags
Some thread flags can be set remotely, and so even when IRQs are
disabled, the flags can change under our feet. Generally this is
unlikely to cause a problem in practice, but it is somewhat unsound, and
KCSAN will legitimately warn that there is a data race.
To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.
Convert them all to the new flag accessor helpers.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20211117163050.53986-7-mark.rutland@arm.com
---
arch/arm64/kernel/entry-common.c | 2 +-
arch/arm64/kernel/ptrace.c | 4 ++--
arch/arm64/kernel/signal.c | 2 +-
arch/arm64/kernel/syscall.c | 4 ++--
4 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index f7408ed..ef7fcef 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -129,7 +129,7 @@ static __always_inline void prepare_exit_to_user_mode(struct pt_regs *regs)
local_daif_mask();
- flags = READ_ONCE(current_thread_info()->flags);
+ flags = read_thread_flags();
if (unlikely(flags & _TIF_WORK_MASK))
do_notify_resume(regs, flags);
}
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 88a9034..33cac3d 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1839,7 +1839,7 @@ static void tracehook_report_syscall(struct pt_regs *regs,
int syscall_trace_enter(struct pt_regs *regs)
{
- unsigned long flags = READ_ONCE(current_thread_info()->flags);
+ unsigned long flags = read_thread_flags();
if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
tracehook_report_syscall(regs, PTRACE_SYSCALL_ENTER);
@@ -1862,7 +1862,7 @@ int syscall_trace_enter(struct pt_regs *regs)
void syscall_trace_exit(struct pt_regs *regs)
{
- unsigned long flags = READ_ONCE(current_thread_info()->flags);
+ unsigned long flags = read_thread_flags();
audit_syscall_exit(regs);
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 8f6372b..d8aaf4b 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -948,7 +948,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_flags)
}
local_daif_mask();
- thread_flags = READ_ONCE(current_thread_info()->flags);
+ thread_flags = read_thread_flags();
} while (thread_flags & _TIF_WORK_MASK);
}
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index 50a0f1a..c938603 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -81,7 +81,7 @@ void syscall_trace_exit(struct pt_regs *regs);
static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
const syscall_fn_t syscall_table[])
{
- unsigned long flags = current_thread_info()->flags;
+ unsigned long flags = read_thread_flags();
regs->orig_x0 = regs->regs[0];
regs->syscallno = scno;
@@ -148,7 +148,7 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
*/
if (!has_syscall_work(flags) && !IS_ENABLED(CONFIG_DEBUG_RSEQ)) {
local_daif_mask();
- flags = current_thread_info()->flags;
+ flags = read_thread_flags();
if (!has_syscall_work(flags) && !(flags & _TIF_SINGLESTEP))
return;
local_daif_restore(DAIF_PROCCTX);
next prev parent reply other threads:[~2021-11-26 20:25 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-17 16:30 [PATCHv7 00/11] thread_info: use helpers to snapshot thread flags Mark Rutland
2021-11-17 16:30 ` [PATCHv7 01/11] thread_info: add " Mark Rutland
2021-11-26 20:23 ` [tip: core/entry] thread_info: Add " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 02/11] entry: " Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] entry: Snapshot " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 03/11] sched: snapshot " Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] sched: Snapshot " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 04/11] alpha: snapshot " Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] alpha: Snapshot " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 05/11] arm: snapshot " Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] ARM: Snapshot " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 06/11] arm64: snapshot " Mark Rutland
2021-11-26 20:22 ` tip-bot2 for Mark Rutland [this message]
2021-11-17 16:30 ` [PATCHv7 07/11] microblaze: " Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] microblaze: Snapshot " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 08/11] openrisc: snapshot " Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] openrisc: Snapshot " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 09/11] powerpc: avoid discarding flags in system_call_exception() Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] powerpc: Avoid " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 10/11] powerpc: snapshot thread flags Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] powerpc: Snapshot " tip-bot2 for Mark Rutland
2021-11-17 16:30 ` [PATCHv7 11/11] x86: snapshot " Mark Rutland
2021-11-26 20:22 ` [tip: core/entry] x86: Snapshot " tip-bot2 for Mark Rutland
2021-11-29 13:06 [PATCH v8 06/11] arm64: snapshot " Mark Rutland
2021-11-30 23:08 ` [tip: core/entry] arm64: Snapshot " tip-bot2 for Mark Rutland
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