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/xtensa/mm/init.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 arch/xtensa/mm/init.c (limited to 'arch/xtensa/mm/init.c') diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c new file mode 100644 index 000000000..fe83a6833 --- /dev/null +++ b/arch/xtensa/mm/init.c @@ -0,0 +1,202 @@ +/* + * arch/xtensa/mm/init.c + * + * Derived from MIPS, PPC. + * + * 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) 2001 - 2005 Tensilica Inc. + * Copyright (C) 2014 - 2016 Cadence Design Systems Inc. + * + * Chris Zankel + * Joe Taylor + * Marc Gauthier + * Kevin Chea + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +/* + * Initialize the bootmem system and give it all low memory we have available. + */ + +void __init bootmem_init(void) +{ + /* Reserve all memory below PHYS_OFFSET, as memory + * accounting doesn't work for pages below that address. + * + * If PHYS_OFFSET is zero reserve page at address 0: + * successfull allocations should never return NULL. + */ + memblock_reserve(0, PHYS_OFFSET ? PHYS_OFFSET : 1); + + early_init_fdt_scan_reserved_mem(); + + if (!memblock_phys_mem_size()) + panic("No memory found!\n"); + + min_low_pfn = PFN_UP(memblock_start_of_DRAM()); + min_low_pfn = max(min_low_pfn, PFN_UP(PHYS_OFFSET)); + max_pfn = PFN_DOWN(memblock_end_of_DRAM()); + max_low_pfn = min(max_pfn, MAX_LOW_PFN); + + early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT, + (phys_addr_t)max_low_pfn << PAGE_SHIFT); + + memblock_set_current_limit(PFN_PHYS(max_low_pfn)); + dma_contiguous_reserve(PFN_PHYS(max_low_pfn)); + + memblock_dump_all(); +} + +static void __init print_vm_layout(void) +{ + pr_info("virtual kernel memory layout:\n" +#ifdef CONFIG_KASAN + " kasan : 0x%08lx - 0x%08lx (%5lu MB)\n" +#endif +#ifdef CONFIG_MMU + " vmalloc : 0x%08lx - 0x%08lx (%5lu MB)\n" +#endif +#ifdef CONFIG_HIGHMEM + " pkmap : 0x%08lx - 0x%08lx (%5lu kB)\n" + " fixmap : 0x%08lx - 0x%08lx (%5lu kB)\n" +#endif + " lowmem : 0x%08lx - 0x%08lx (%5lu MB)\n" + " .text : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .rodata : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .data : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .init : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .bss : 0x%08lx - 0x%08lx (%5lu kB)\n", +#ifdef CONFIG_KASAN + KASAN_SHADOW_START, KASAN_SHADOW_START + KASAN_SHADOW_SIZE, + KASAN_SHADOW_SIZE >> 20, +#endif +#ifdef CONFIG_MMU + VMALLOC_START, VMALLOC_END, + (VMALLOC_END - VMALLOC_START) >> 20, +#ifdef CONFIG_HIGHMEM + PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE, + (LAST_PKMAP*PAGE_SIZE) >> 10, + FIXADDR_START, FIXADDR_END, + (FIXADDR_END - FIXADDR_START) >> 10, +#endif + PAGE_OFFSET, PAGE_OFFSET + + (max_low_pfn - min_low_pfn) * PAGE_SIZE, +#else + min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE, +#endif + ((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20, + (unsigned long)_text, (unsigned long)_etext, + (unsigned long)(_etext - _text) >> 10, + (unsigned long)__start_rodata, (unsigned long)__end_rodata, + (unsigned long)(__end_rodata - __start_rodata) >> 10, + (unsigned long)_sdata, (unsigned long)_edata, + (unsigned long)(_edata - _sdata) >> 10, + (unsigned long)__init_begin, (unsigned long)__init_end, + (unsigned long)(__init_end - __init_begin) >> 10, + (unsigned long)__bss_start, (unsigned long)__bss_stop, + (unsigned long)(__bss_stop - __bss_start) >> 10); +} + +void __init arch_zone_limits_init(unsigned long *max_zone_pfns) +{ + max_zone_pfns[ZONE_NORMAL] = max_low_pfn; +#ifdef CONFIG_HIGHMEM + max_zone_pfns[ZONE_HIGHMEM] = max_pfn; +#endif +} + +void __init zones_init(void) +{ + print_vm_layout(); +} + +static void __init parse_memmap_one(char *p) +{ + char *oldp; + unsigned long start_at, mem_size; + + if (!p) + return; + + oldp = p; + mem_size = memparse(p, &p); + if (p == oldp) + return; + + switch (*p) { + case '@': + start_at = memparse(p + 1, &p); + memblock_add(start_at, mem_size); + break; + + case '$': + start_at = memparse(p + 1, &p); + memblock_reserve(start_at, mem_size); + break; + + case 0: + memblock_reserve(mem_size, -mem_size); + break; + + default: + pr_warn("Unrecognized memmap syntax: %s\n", p); + break; + } +} + +static int __init parse_memmap_opt(char *str) +{ + while (str) { + char *k = strchr(str, ','); + + if (k) + *k++ = 0; + + parse_memmap_one(str); + str = k; + } + + return 0; +} +early_param("memmap", parse_memmap_opt); + +#ifdef CONFIG_MMU +static const pgprot_t protection_map[16] = { + [VM_NONE] = PAGE_NONE, + [VM_READ] = PAGE_READONLY, + [VM_WRITE] = PAGE_COPY, + [VM_WRITE | VM_READ] = PAGE_COPY, + [VM_EXEC] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_READ] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC, + [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC, + [VM_SHARED] = PAGE_NONE, + [VM_SHARED | VM_READ] = PAGE_READONLY, + [VM_SHARED | VM_WRITE] = PAGE_SHARED, + [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED, + [VM_SHARED | VM_EXEC] = PAGE_READONLY_EXEC, + [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_EXEC, + [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC, + [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC +}; +DECLARE_VM_GET_PAGE_PROT +#endif -- cgit v1.3.1