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 --- tools/dma/.gitignore | 3 + tools/dma/Makefile | 55 ++++++++++++++++ tools/dma/config | 1 + tools/dma/dma_map_benchmark.c | 144 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 203 insertions(+) create mode 100644 tools/dma/.gitignore create mode 100644 tools/dma/Makefile create mode 100644 tools/dma/config create mode 100644 tools/dma/dma_map_benchmark.c (limited to 'tools/dma') diff --git a/tools/dma/.gitignore b/tools/dma/.gitignore new file mode 100644 index 000000000..94b68cf41 --- /dev/null +++ b/tools/dma/.gitignore @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only +dma_map_benchmark +include/linux/map_benchmark.h diff --git a/tools/dma/Makefile b/tools/dma/Makefile new file mode 100644 index 000000000..e4abf37bf --- /dev/null +++ b/tools/dma/Makefile @@ -0,0 +1,55 @@ +# SPDX-License-Identifier: GPL-2.0 +include ../scripts/Makefile.include + +bindir ?= /usr/bin + +# This will work when dma is built in tools env. where srctree +# isn't set and when invoked from selftests build, where srctree +# is set to ".". building_out_of_srctree is undefined for in srctree +# builds +ifndef building_out_of_srctree +srctree := $(patsubst %/,%,$(dir $(CURDIR))) +srctree := $(patsubst %/,%,$(dir $(srctree))) +endif + +# Do not use make's built-in rules +# (this improves performance and avoids hard-to-debug behaviour); +MAKEFLAGS += -r + +override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include + +ALL_TARGETS := dma_map_benchmark +ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS)) + +all: $(ALL_PROGRAMS) + +export srctree OUTPUT CC LD CFLAGS +include $(srctree)/tools/build/Makefile.include + +# +# We need the following to be outside of kernel tree +# +$(OUTPUT)include/linux/map_benchmark.h: ../../include/uapi/linux/map_benchmark.h + mkdir -p $(OUTPUT)include/linux 2>&1 || true + ln -sf $(CURDIR)/../../include/uapi/linux/map_benchmark.h $@ + +prepare: $(OUTPUT)include/linux/map_benchmark.h + +FORCE: + +DMA_MAP_BENCHMARK = dma_map_benchmark +$(DMA_MAP_BENCHMARK): prepare FORCE + $(CC) $(CFLAGS) $(DMA_MAP_BENCHMARK).c -o $(DMA_MAP_BENCHMARK) + +clean: + rm -f $(ALL_PROGRAMS) + rm -rf $(OUTPUT)include + find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete -o -name '\.*.cmd' -delete + +install: $(ALL_PROGRAMS) + install -d -m 755 $(DESTDIR)$(bindir); \ + for program in $(ALL_PROGRAMS); do \ + install $$program $(DESTDIR)$(bindir); \ + done + +.PHONY: all install clean prepare FORCE diff --git a/tools/dma/config b/tools/dma/config new file mode 100644 index 000000000..6102ee3c4 --- /dev/null +++ b/tools/dma/config @@ -0,0 +1 @@ +CONFIG_DMA_MAP_BENCHMARK=y diff --git a/tools/dma/dma_map_benchmark.c b/tools/dma/dma_map_benchmark.c new file mode 100644 index 000000000..eab0ac611 --- /dev/null +++ b/tools/dma/dma_map_benchmark.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 HiSilicon Limited. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define NSEC_PER_MSEC 1000000L + +static char *directions[] = { + "BIDIRECTIONAL", + "TO_DEVICE", + "FROM_DEVICE", +}; + +static char *mode[] = { + "SINGLE_MODE", + "SG_MODE", +}; + +int main(int argc, char **argv) +{ + struct map_benchmark map; + int fd, opt; + /* default single thread, run 20 seconds on NUMA_NO_NODE */ + int threads = 1, seconds = 20, node = -1; + /* default single map mode */ + int map_mode = DMA_MAP_BENCH_SINGLE_MODE; + /* default dma mask 32bit, bidirectional DMA */ + int bits = 32, xdelay = 0, dir = DMA_MAP_BIDIRECTIONAL; + /* default granule 1 PAGESIZE */ + int granule = 1; + + int cmd = DMA_MAP_BENCHMARK; + + while ((opt = getopt(argc, argv, "t:s:n:b:d:x:g:m:")) != -1) { + switch (opt) { + case 't': + threads = atoi(optarg); + break; + case 's': + seconds = atoi(optarg); + break; + case 'n': + node = atoi(optarg); + break; + case 'b': + bits = atoi(optarg); + break; + case 'd': + dir = atoi(optarg); + break; + case 'x': + xdelay = atoi(optarg); + break; + case 'g': + granule = atoi(optarg); + break; + case 'm': + map_mode = atoi(optarg); + break; + default: + return -1; + } + } + + if (map_mode < 0 || map_mode >= DMA_MAP_BENCH_MODE_MAX) { + fprintf(stderr, "invalid map mode, SINGLE_MODE:%d, SG_MODE: %d\n", + DMA_MAP_BENCH_SINGLE_MODE, DMA_MAP_BENCH_SG_MODE); + exit(1); + } + + if (threads <= 0 || threads > DMA_MAP_MAX_THREADS) { + fprintf(stderr, "invalid number of threads, must be in 1-%d\n", + DMA_MAP_MAX_THREADS); + exit(1); + } + + if (seconds <= 0 || seconds > DMA_MAP_MAX_SECONDS) { + fprintf(stderr, "invalid number of seconds, must be in 1-%d\n", + DMA_MAP_MAX_SECONDS); + exit(1); + } + + if (xdelay < 0 || xdelay > DMA_MAP_MAX_TRANS_DELAY) { + fprintf(stderr, "invalid transmit delay, must be in 0-%ld\n", + DMA_MAP_MAX_TRANS_DELAY); + exit(1); + } + + /* suppose the mininum DMA zone is 1MB in the world */ + if (bits < 20 || bits > 64) { + fprintf(stderr, "invalid dma mask bit, must be in 20-64\n"); + exit(1); + } + + if (dir != DMA_MAP_BIDIRECTIONAL && dir != DMA_MAP_TO_DEVICE && + dir != DMA_MAP_FROM_DEVICE) { + fprintf(stderr, "invalid dma direction\n"); + exit(1); + } + + if (granule < 1 || granule > 1024) { + fprintf(stderr, "invalid granule size\n"); + exit(1); + } + + fd = open("/sys/kernel/debug/dma_map_benchmark", O_RDWR); + if (fd == -1) { + perror("open"); + exit(1); + } + + memset(&map, 0, sizeof(map)); + map.seconds = seconds; + map.threads = threads; + map.node = node; + map.dma_bits = bits; + map.dma_dir = dir; + map.dma_trans_ns = xdelay; + map.granule = granule; + map.map_mode = map_mode; + + if (ioctl(fd, cmd, &map)) { + perror("ioctl"); + exit(1); + } + + printf("dma mapping benchmark(%s): threads:%d seconds:%d node:%d dir:%s granule:%d\n", + mode[map_mode], threads, seconds, node, directions[dir], granule); + printf("average map latency(us):%.1f standard deviation:%.1f\n", + map.avg_map_100ns/10.0, map.map_stddev/10.0); + printf("average unmap latency(us):%.1f standard deviation:%.1f\n", + map.avg_unmap_100ns/10.0, map.unmap_stddev/10.0); + + return 0; +} -- cgit v1.3.1