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/arm/mm/cache-v4.S | 148 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 arch/arm/mm/cache-v4.S (limited to 'arch/arm/mm/cache-v4.S') diff --git a/arch/arm/mm/cache-v4.S b/arch/arm/mm/cache-v4.S new file mode 100644 index 000000000..001d7042b --- /dev/null +++ b/arch/arm/mm/cache-v4.S @@ -0,0 +1,148 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/mm/cache-v4.S + * + * Copyright (C) 1997-2002 Russell king + */ +#include +#include +#include +#include +#include +#include "proc-macros.S" + +/* + * flush_icache_all() + * + * Unconditionally clean and invalidate the entire icache. + */ +SYM_TYPED_FUNC_START(v4_flush_icache_all) + ret lr +SYM_FUNC_END(v4_flush_icache_all) + +/* + * flush_user_cache_all() + * + * Invalidate all cache entries in a particular address + * space. + * + * - mm - mm_struct describing address space + */ +SYM_FUNC_ALIAS(v4_flush_user_cache_all, v4_flush_kern_cache_all) + +/* + * flush_kern_cache_all() + * + * Clean and invalidate the entire cache. + */ +SYM_TYPED_FUNC_START(v4_flush_kern_cache_all) +#ifdef CONFIG_CPU_CP15 + mov r0, #0 + mcr p15, 0, r0, c7, c7, 0 @ flush ID cache + ret lr +#else + ret lr +#endif +SYM_FUNC_END(v4_flush_kern_cache_all) + +/* + * flush_user_cache_range(start, end, flags) + * + * Invalidate a range of cache entries in the specified + * address space. + * + * - start - start address (may not be aligned) + * - end - end address (exclusive, may not be aligned) + * - flags - vma_area_struct flags describing address space + */ +SYM_TYPED_FUNC_START(v4_flush_user_cache_range) +#ifdef CONFIG_CPU_CP15 + mov ip, #0 + mcr p15, 0, ip, c7, c7, 0 @ flush ID cache + ret lr +#else + ret lr +#endif +SYM_FUNC_END(v4_flush_user_cache_range) + +/* + * coherent_kern_range(start, end) + * + * Ensure coherency between the Icache and the Dcache in the + * region described by start. If you have non-snooping + * Harvard caches, you need to implement this function. + * + * - start - virtual start address + * - end - virtual end address + */ +SYM_TYPED_FUNC_START(v4_coherent_kern_range) + ret lr +SYM_FUNC_END(v4_coherent_kern_range) + +/* + * coherent_user_range(start, end) + * + * Ensure coherency between the Icache and the Dcache in the + * region described by start. If you have non-snooping + * Harvard caches, you need to implement this function. + * + * - start - virtual start address + * - end - virtual end address + */ +SYM_TYPED_FUNC_START(v4_coherent_user_range) + mov r0, #0 + ret lr +SYM_FUNC_END(v4_coherent_user_range) + +/* + * flush_kern_dcache_area(void *addr, size_t size) + * + * Ensure no D cache aliasing occurs, either with itself or + * the I cache + * + * - addr - kernel address + * - size - region size + */ +SYM_TYPED_FUNC_START(v4_flush_kern_dcache_area) +#ifdef CONFIG_CFI /* Fallthrough if !CFI */ + b v4_dma_flush_range +#endif +SYM_FUNC_END(v4_flush_kern_dcache_area) + +/* + * dma_flush_range(start, end) + * + * Clean and invalidate the specified virtual address range. + * + * - start - virtual start address + * - end - virtual end address + */ +SYM_TYPED_FUNC_START(v4_dma_flush_range) +#ifdef CONFIG_CPU_CP15 + mov r0, #0 + mcr p15, 0, r0, c7, c7, 0 @ flush ID cache +#endif + ret lr +SYM_FUNC_END(v4_dma_flush_range) + +/* + * dma_unmap_area(start, size, dir) + * - start - kernel virtual start address + * - size - size of region + * - dir - DMA direction + */ +SYM_TYPED_FUNC_START(v4_dma_unmap_area) + teq r2, #DMA_TO_DEVICE + bne v4_dma_flush_range + ret lr +SYM_FUNC_END(v4_dma_unmap_area) + +/* + * dma_map_area(start, size, dir) + * - start - kernel virtual start address + * - size - size of region + * - dir - DMA direction + */ +SYM_TYPED_FUNC_START(v4_dma_map_area) + ret lr +SYM_FUNC_END(v4_dma_map_area) -- cgit v1.3.1