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/m68k/mm/init.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 arch/m68k/mm/init.c (limited to 'arch/m68k/mm/init.c') diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c new file mode 100644 index 000000000..3b88c0dd1 --- /dev/null +++ b/arch/m68k/mm/init.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/arch/m68k/mm/init.c + * + * Copyright (C) 1995 Hamish Macdonald + * + * Contains common initialization routines, specific init code moved + * to motorola.c and sun3mmu.c + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_ATARI +#include +#endif +#include +#include + +void __init arch_zone_limits_init(unsigned long *max_zone_pfns) +{ + max_zone_pfns[ZONE_DMA] = PFN_DOWN(memblock_end_of_DRAM()); +} + +#ifdef CONFIG_MMU + +int m68k_virt_to_node_shift; + +void __init m68k_setup_node(int node) +{ + node_set_online(node); +} + +#else /* CONFIG_MMU */ + +/* + * paging_init() continues the virtual memory environment setup which + * was begun by the code in arch/head.S. + * The parameters are pointers to where to stick the starting and ending + * addresses of available kernel virtual memory. + */ +void __init paging_init(void) +{ + /* + * Make sure start_mem is page aligned, otherwise bootmem and + * page_alloc get different views of the world. + */ + unsigned long end_mem = memory_end & PAGE_MASK; + + high_memory = (void *) end_mem; +} + +#endif /* CONFIG_MMU */ + +void free_initmem(void) +{ +#ifndef CONFIG_MMU_SUN3 + free_initmem_default(-1); +#endif /* CONFIG_MMU_SUN3 */ +} + +#if defined(CONFIG_MMU) && !defined(CONFIG_COLDFIRE) +#define VECTORS &vectors[0] +#else +#define VECTORS _ramvec +#endif + +static inline void init_pointer_tables(void) +{ +#if defined(CONFIG_MMU) && !defined(CONFIG_SUN3) && !defined(CONFIG_COLDFIRE) + int i, j; + + /* insert pointer tables allocated so far into the tablelist */ + init_pointer_table(kernel_pg_dir, TABLE_PGD); + for (i = 0; i < PTRS_PER_PGD; i++) { + pud_t *pud = (pud_t *)&kernel_pg_dir[i]; + pmd_t *pmd_dir; + + if (!pud_present(*pud)) + continue; + + pmd_dir = (pmd_t *)pgd_page_vaddr(kernel_pg_dir[i]); + init_pointer_table(pmd_dir, TABLE_PMD); + + for (j = 0; j < PTRS_PER_PMD; j++) { + pmd_t *pmd = &pmd_dir[j]; + pte_t *pte_dir; + + if (!pmd_present(*pmd)) + continue; + + pte_dir = (pte_t *)pmd_page_vaddr(*pmd); + init_pointer_table(pte_dir, TABLE_PTE); + } + } +#endif +} + +void __init mem_init(void) +{ + init_pointer_tables(); +} -- cgit v1.3.1