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/powerpc/sysdev/dart.h | 64 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 arch/powerpc/sysdev/dart.h (limited to 'arch/powerpc/sysdev/dart.h') diff --git a/arch/powerpc/sysdev/dart.h b/arch/powerpc/sysdev/dart.h new file mode 100644 index 000000000..7f5df03d3 --- /dev/null +++ b/arch/powerpc/sysdev/dart.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2004 Olof Johansson , IBM Corporation + */ + +#ifndef _POWERPC_SYSDEV_DART_H +#define _POWERPC_SYSDEV_DART_H + + +/* Offset from base to control register */ +#define DART_CNTL 0 + +/* Offset from base to exception register */ +#define DART_EXCP_U3 0x10 +/* Offset from base to TLB tag registers */ +#define DART_TAGS_U3 0x1000 + +/* U4 registers */ +#define DART_BASE_U4 0x10 +#define DART_SIZE_U4 0x20 +#define DART_EXCP_U4 0x30 +#define DART_TAGS_U4 0x1000 + +/* Control Register fields */ + +/* U3 registers */ +#define DART_CNTL_U3_BASE_MASK 0xfffff +#define DART_CNTL_U3_BASE_SHIFT 12 +#define DART_CNTL_U3_FLUSHTLB 0x400 +#define DART_CNTL_U3_ENABLE 0x200 +#define DART_CNTL_U3_SIZE_MASK 0x1ff +#define DART_CNTL_U3_SIZE_SHIFT 0 + +/* U4 registers */ +#define DART_BASE_U4_BASE_MASK 0xffffff +#define DART_BASE_U4_BASE_SHIFT 0 +#define DART_CNTL_U4_ENABLE 0x80000000 +#define DART_CNTL_U4_IONE 0x40000000 +#define DART_CNTL_U4_FLUSHTLB 0x20000000 +#define DART_CNTL_U4_IDLE 0x10000000 +#define DART_CNTL_U4_PAR_EN 0x08000000 +#define DART_CNTL_U4_IONE_MASK 0x07ffffff +#define DART_SIZE_U4_SIZE_MASK 0x1fff +#define DART_SIZE_U4_SIZE_SHIFT 0 + +#define DART_REG(r) (dart + ((r) >> 2)) +#define DART_IN(r) (in_be32(DART_REG(r))) +#define DART_OUT(r,v) (out_be32(DART_REG(r), (v))) + + +/* size of table in pages */ + + +/* DART table fields */ + +#define DARTMAP_VALID 0x80000000 +#define DARTMAP_RPNMASK 0x00ffffff + + +#define DART_PAGE_SHIFT 12 +#define DART_PAGE_SIZE (1 << DART_PAGE_SHIFT) + + +#endif /* _POWERPC_SYSDEV_DART_H */ -- cgit v1.3.1