From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- arch/arc/plat-sim/Makefile | 6 ++++++ arch/arc/plat-sim/platform.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) create mode 100644 arch/arc/plat-sim/Makefile create mode 100644 arch/arc/plat-sim/platform.c (limited to 'arch/arc/plat-sim') diff --git a/arch/arc/plat-sim/Makefile b/arch/arc/plat-sim/Makefile new file mode 100644 index 000000000..ea9389bf8 --- /dev/null +++ b/arch/arc/plat-sim/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Copyright (C) 2011-2012 Synopsys, Inc. (www.synopsys.com) +# + +obj-y := platform.o diff --git a/arch/arc/plat-sim/platform.c b/arch/arc/plat-sim/platform.c new file mode 100644 index 000000000..2bde2a6e3 --- /dev/null +++ b/arch/arc/plat-sim/platform.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ARC simulation Platform support code + * + * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com) + */ + +#include +#include + +/*----------------------- Machine Descriptions ------------------------------ + * + * Machine description is simply a set of platform/board specific callbacks + * This is not directly related to DeviceTree based dynamic device creation, + * however as part of early device tree scan, we also select the right + * callback set, by matching the DT compatible name. + */ + +static const char *simulation_compat[] __initconst = { +#ifdef CONFIG_ISA_ARCOMPACT + "snps,nsim", + "snps,nsimosci", +#else + "snps,nsimosci_hs", + "snps,zebu_hs", +#endif + NULL, +}; + +MACHINE_START(SIMULATION, "simulation") + .dt_compat = simulation_compat, +MACHINE_END -- cgit v1.3.1