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/mips/mm/pgtable-64.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) create mode 100644 arch/mips/mm/pgtable-64.c (limited to 'arch/mips/mm/pgtable-64.c') diff --git a/arch/mips/mm/pgtable-64.c b/arch/mips/mm/pgtable-64.c new file mode 100644 index 000000000..b24f865de --- /dev/null +++ b/arch/mips/mm/pgtable-64.c @@ -0,0 +1,119 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1999, 2000 by Silicon Graphics + * Copyright (C) 2003 by Ralf Baechle + */ +#include +#include +#include +#include +#include +#include + +void pgd_init(void *addr) +{ + unsigned long *p, *end; + unsigned long entry; + +#if !defined(__PAGETABLE_PUD_FOLDED) + entry = (unsigned long)invalid_pud_table; +#elif !defined(__PAGETABLE_PMD_FOLDED) + entry = (unsigned long)invalid_pmd_table; +#else + entry = (unsigned long)invalid_pte_table; +#endif + + p = (unsigned long *) addr; + end = p + PTRS_PER_PGD; + + do { + p[0] = entry; + p[1] = entry; + p[2] = entry; + p[3] = entry; + p[4] = entry; + p += 8; + p[-3] = entry; + p[-2] = entry; + p[-1] = entry; + } while (p != end); +} + +#ifndef __PAGETABLE_PMD_FOLDED +void pmd_init(void *addr) +{ + unsigned long *p, *end; + unsigned long pagetable = (unsigned long)invalid_pte_table; + + p = (unsigned long *)addr; + end = p + PTRS_PER_PMD; + + do { + p[0] = pagetable; + p[1] = pagetable; + p[2] = pagetable; + p[3] = pagetable; + p[4] = pagetable; + p += 8; + p[-3] = pagetable; + p[-2] = pagetable; + p[-1] = pagetable; + } while (p != end); +} +EXPORT_SYMBOL_GPL(pmd_init); +#endif + +#ifndef __PAGETABLE_PUD_FOLDED +void pud_init(void *addr) +{ + unsigned long *p, *end; + unsigned long pagetable = (unsigned long)invalid_pmd_table; + + p = (unsigned long *)addr; + end = p + PTRS_PER_PUD; + + do { + p[0] = pagetable; + p[1] = pagetable; + p[2] = pagetable; + p[3] = pagetable; + p[4] = pagetable; + p += 8; + p[-3] = pagetable; + p[-2] = pagetable; + p[-1] = pagetable; + } while (p != end); +} +#endif + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +void set_pmd_at(struct mm_struct *mm, unsigned long addr, + pmd_t *pmdp, pmd_t pmd) +{ + *pmdp = pmd; +} +#endif + +void __init pagetable_init(void) +{ + unsigned long vaddr; + pgd_t *pgd_base; + + /* Initialize the entire pgd. */ + pgd_init(swapper_pg_dir); +#ifndef __PAGETABLE_PUD_FOLDED + pud_init(invalid_pud_table); +#endif +#ifndef __PAGETABLE_PMD_FOLDED + pmd_init(invalid_pmd_table); +#endif + pgd_base = swapper_pg_dir; + /* + * Fixed mappings: + */ + vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; + fixrange_init(vaddr, vaddr + FIXADDR_SIZE, pgd_base); +} -- cgit v1.3.1