Files
linux_media/arch/riscv/include/asm/patch.h
Conor Dooley 2a8db5ec4a RISC-V: Don't check text_mutex during stop_machine
We're currently using stop_machine() to update ftrace & kprobes, which
means that the thread that takes text_mutex during may not be the same
as the thread that eventually patches the code.  This isn't actually a
race because the lock is still held (preventing any other concurrent
accesses) and there is only one thread running during stop_machine(),
but it does trigger a lockdep failure.

This patch just elides the lockdep check during stop_machine.

Fixes: c15ac4fd60 ("riscv/ftrace: Add dynamic function tracer support")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230303143754.4005217-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-09 14:58:51 -08:00

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C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2020 SiFive
*/
#ifndef _ASM_RISCV_PATCH_H
#define _ASM_RISCV_PATCH_H
int patch_text_nosync(void *addr, const void *insns, size_t len);
int patch_text(void *addr, u32 *insns, int ninsns);
extern int riscv_patch_in_stop_machine;
#endif /* _ASM_RISCV_PATCH_H */