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/powerpc/lib/pmem.c | 88 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 arch/powerpc/lib/pmem.c (limited to 'arch/powerpc/lib/pmem.c') diff --git a/arch/powerpc/lib/pmem.c b/arch/powerpc/lib/pmem.c new file mode 100644 index 000000000..0f0f2d851 --- /dev/null +++ b/arch/powerpc/lib/pmem.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright(c) 2017 IBM Corporation. All rights reserved. + */ + +#include +#include +#include +#include + +#include + +static inline void __clean_pmem_range(unsigned long start, unsigned long stop) +{ + unsigned long shift = l1_dcache_shift(); + unsigned long bytes = l1_dcache_bytes(); + void *addr = (void *)(start & ~(bytes - 1)); + unsigned long size = stop - (unsigned long)addr + (bytes - 1); + unsigned long i; + + for (i = 0; i < size >> shift; i++, addr += bytes) + asm volatile(PPC_DCBSTPS(%0, %1): :"i"(0), "r"(addr): "memory"); +} + +static inline void __flush_pmem_range(unsigned long start, unsigned long stop) +{ + unsigned long shift = l1_dcache_shift(); + unsigned long bytes = l1_dcache_bytes(); + void *addr = (void *)(start & ~(bytes - 1)); + unsigned long size = stop - (unsigned long)addr + (bytes - 1); + unsigned long i; + + for (i = 0; i < size >> shift; i++, addr += bytes) + asm volatile(PPC_DCBFPS(%0, %1): :"i"(0), "r"(addr): "memory"); +} + +static inline void clean_pmem_range(unsigned long start, unsigned long stop) +{ + if (cpu_has_feature(CPU_FTR_ARCH_207S)) + return __clean_pmem_range(start, stop); +} + +static inline void flush_pmem_range(unsigned long start, unsigned long stop) +{ + if (cpu_has_feature(CPU_FTR_ARCH_207S)) + return __flush_pmem_range(start, stop); +} + +/* + * CONFIG_ARCH_HAS_PMEM_API symbols + */ +void arch_wb_cache_pmem(void *addr, size_t size) +{ + unsigned long start = (unsigned long) addr; + clean_pmem_range(start, start + size); +} +EXPORT_SYMBOL_GPL(arch_wb_cache_pmem); + +void arch_invalidate_pmem(void *addr, size_t size) +{ + unsigned long start = (unsigned long) addr; + flush_pmem_range(start, start + size); +} +EXPORT_SYMBOL_GPL(arch_invalidate_pmem); + +/* + * CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE symbols + */ +size_t copy_from_user_flushcache(void *dest, const void __user *src, + size_t size) +{ + unsigned long not_copied, start = (unsigned long) dest; + + src = mask_user_address(src); + not_copied = __copy_from_user(dest, src, size); + clean_pmem_range(start, start + size); + + return not_copied; +} + +void memcpy_flushcache(void *dest, const void *src, size_t size) +{ + unsigned long start = (unsigned long) dest; + + memcpy(dest, src, size); + clean_pmem_range(start, start + size); +} +EXPORT_SYMBOL(memcpy_flushcache); -- cgit v1.3.1