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/testing/selftests/ir/.gitignore | 2 + tools/testing/selftests/ir/Makefile | 7 + tools/testing/selftests/ir/ir_loopback.c | 219 ++++++++++++++++++++++++++++++ tools/testing/selftests/ir/ir_loopback.sh | 25 ++++ 4 files changed, 253 insertions(+) create mode 100644 tools/testing/selftests/ir/.gitignore create mode 100644 tools/testing/selftests/ir/Makefile create mode 100644 tools/testing/selftests/ir/ir_loopback.c create mode 100755 tools/testing/selftests/ir/ir_loopback.sh (limited to 'tools/testing/selftests/ir') diff --git a/tools/testing/selftests/ir/.gitignore b/tools/testing/selftests/ir/.gitignore new file mode 100644 index 000000000..0bbada8c1 --- /dev/null +++ b/tools/testing/selftests/ir/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +ir_loopback diff --git a/tools/testing/selftests/ir/Makefile b/tools/testing/selftests/ir/Makefile new file mode 100644 index 000000000..ad06489c2 --- /dev/null +++ b/tools/testing/selftests/ir/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0 +TEST_PROGS := ir_loopback.sh +TEST_GEN_PROGS_EXTENDED := ir_loopback +APIDIR := ../../../include/uapi +CFLAGS += -Wall -O2 -I$(APIDIR) + +include ../lib.mk diff --git a/tools/testing/selftests/ir/ir_loopback.c b/tools/testing/selftests/ir/ir_loopback.c new file mode 100644 index 000000000..adfcf50b1 --- /dev/null +++ b/tools/testing/selftests/ir/ir_loopback.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +// test ir decoder +// +// Copyright (C) 2018 Sean Young + +// When sending LIRC_MODE_SCANCODE, the IR will be encoded. rc-loopback +// will send this IR to the receiver side, where we try to read the decoded +// IR. Decoding happens in a separate kernel thread, so we will need to +// wait until that is scheduled, hence we use poll to check for read +// readiness. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "kselftest.h" + +#define TEST_SCANCODES 10 +#define SYSFS_PATH_MAX 256 +#define DNAME_PATH_MAX 256 + +/* + * Support ancient lirc.h which does not have these values. Can be removed + * once RHEL 8 is no longer a relevant testing platform. + */ +#if RC_PROTO_MAX < 26 +#define RC_PROTO_RCMM12 24 +#define RC_PROTO_RCMM24 25 +#define RC_PROTO_RCMM32 26 +#endif + +static const struct { + enum rc_proto proto; + const char *name; + unsigned int mask; + const char *decoder; +} protocols[] = { + { RC_PROTO_RC5, "rc-5", 0x1f7f, "rc-5" }, + { RC_PROTO_RC5X_20, "rc-5x-20", 0x1f7f3f, "rc-5" }, + { RC_PROTO_RC5_SZ, "rc-5-sz", 0x2fff, "rc-5-sz" }, + { RC_PROTO_JVC, "jvc", 0xffff, "jvc" }, + { RC_PROTO_SONY12, "sony-12", 0x1f007f, "sony" }, + { RC_PROTO_SONY15, "sony-15", 0xff007f, "sony" }, + { RC_PROTO_SONY20, "sony-20", 0x1fff7f, "sony" }, + { RC_PROTO_NEC, "nec", 0xffff, "nec" }, + { RC_PROTO_NECX, "nec-x", 0xffffff, "nec" }, + { RC_PROTO_NEC32, "nec-32", 0xffffffff, "nec" }, + { RC_PROTO_SANYO, "sanyo", 0x1fffff, "sanyo" }, + { RC_PROTO_RC6_0, "rc-6-0", 0xffff, "rc-6" }, + { RC_PROTO_RC6_6A_20, "rc-6-6a-20", 0xfffff, "rc-6" }, + { RC_PROTO_RC6_6A_24, "rc-6-6a-24", 0xffffff, "rc-6" }, + { RC_PROTO_RC6_6A_32, "rc-6-6a-32", 0xffffffff, "rc-6" }, + { RC_PROTO_RC6_MCE, "rc-6-mce", 0x00007fff, "rc-6" }, + { RC_PROTO_SHARP, "sharp", 0x1fff, "sharp" }, + { RC_PROTO_IMON, "imon", 0x7fffffff, "imon" }, + { RC_PROTO_RCMM12, "rcmm-12", 0x00000fff, "rc-mm" }, + { RC_PROTO_RCMM24, "rcmm-24", 0x00ffffff, "rc-mm" }, + { RC_PROTO_RCMM32, "rcmm-32", 0xffffffff, "rc-mm" }, +}; + +int lirc_open(const char *rc) +{ + struct dirent *dent; + char buf[SYSFS_PATH_MAX + DNAME_PATH_MAX]; + DIR *d; + int fd; + + snprintf(buf, sizeof(buf), "/sys/class/rc/%s", rc); + + d = opendir(buf); + if (!d) + ksft_exit_fail_msg("cannot open %s: %m\n", buf); + + while ((dent = readdir(d)) != NULL) { + if (!strncmp(dent->d_name, "lirc", 4)) { + snprintf(buf, sizeof(buf), "/dev/%s", dent->d_name); + break; + } + } + + if (!dent) + ksft_exit_skip("cannot find lirc device for %s\n", rc); + + closedir(d); + + fd = open(buf, O_RDWR | O_NONBLOCK); + if (fd == -1) + ksft_exit_fail_msg("cannot open: %s: %m\n", buf); + + return fd; +} + +int main(int argc, char **argv) +{ + unsigned int mode; + char buf[100]; + int rlircfd, wlircfd, protocolfd, i, n; + + srand(time(NULL)); + + if (argc != 3) + ksft_exit_fail_msg("Usage: %s \n", + argv[0]); + + rlircfd = lirc_open(argv[2]); + mode = LIRC_MODE_SCANCODE; + if (ioctl(rlircfd, LIRC_SET_REC_MODE, &mode)) + ksft_exit_fail_msg("failed to set scancode rec mode %s: %m\n", + argv[2]); + + wlircfd = lirc_open(argv[1]); + if (ioctl(wlircfd, LIRC_SET_SEND_MODE, &mode)) + ksft_exit_fail_msg("failed to set scancode send mode %s: %m\n", + argv[1]); + + snprintf(buf, sizeof(buf), "/sys/class/rc/%s/protocols", argv[2]); + protocolfd = open(buf, O_WRONLY); + if (protocolfd == -1) + ksft_exit_fail_msg("failed to open %s: %m\n", buf); + + printf("Sending IR on %s and receiving IR on %s.\n", argv[1], argv[2]); + + for (i = 0; i < ARRAY_SIZE(protocols); i++) { + if (write(protocolfd, protocols[i].decoder, + strlen(protocols[i].decoder)) == -1) + ksft_exit_fail_msg("failed to set write decoder\n"); + + printf("Testing protocol %s for decoder %s (%d/%d)...\n", + protocols[i].name, protocols[i].decoder, + i + 1, (int)ARRAY_SIZE(protocols)); + + for (n = 0; n < TEST_SCANCODES; n++) { + unsigned int scancode = rand() & protocols[i].mask; + unsigned int rc_proto = protocols[i].proto; + + if (rc_proto == RC_PROTO_RC6_MCE) + scancode |= 0x800f0000; + + if (rc_proto == RC_PROTO_NECX && + (((scancode >> 16) ^ ~(scancode >> 8)) & 0xff) == 0) + continue; + + if (rc_proto == RC_PROTO_NEC32 && + (((scancode >> 8) ^ ~scancode) & 0xff) == 0) + continue; + + if (rc_proto == RC_PROTO_RCMM32 && + (scancode & 0x000c0000) != 0x000c0000 && + scancode & 0x00008000) + continue; + + struct lirc_scancode lsc = { + .rc_proto = rc_proto, + .scancode = scancode + }; + + printf("Testing scancode:%x\n", scancode); + + while (write(wlircfd, &lsc, sizeof(lsc)) < 0) { + if (errno == EINTR) + continue; + + ksft_exit_fail_msg("failed to send ir: %m\n"); + } + + struct pollfd pfd = { .fd = rlircfd, .events = POLLIN }; + struct lirc_scancode lsc2; + + poll(&pfd, 1, 1000); + + bool decoded = true; + + while (read(rlircfd, &lsc2, sizeof(lsc2)) < 0) { + if (errno == EINTR) + continue; + + ksft_test_result_error("no scancode decoded: %m\n"); + decoded = false; + break; + } + + if (!decoded) + continue; + + if (lsc.rc_proto != lsc2.rc_proto) + ksft_test_result_error("decoded protocol is different: %d\n", + lsc2.rc_proto); + + else if (lsc.scancode != lsc2.scancode) + ksft_test_result_error("decoded scancode is different: %llx\n", + lsc2.scancode); + else + ksft_inc_pass_cnt(); + } + + printf("OK\n"); + } + + close(rlircfd); + close(wlircfd); + close(protocolfd); + + if (ksft_get_fail_cnt() > 0) + ksft_exit_fail(); + else + ksft_exit_pass(); + + return 0; +} diff --git a/tools/testing/selftests/ir/ir_loopback.sh b/tools/testing/selftests/ir/ir_loopback.sh new file mode 100755 index 000000000..aff9299c9 --- /dev/null +++ b/tools/testing/selftests/ir/ir_loopback.sh @@ -0,0 +1,25 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +# Kselftest framework requirement - SKIP code is 4. +ksft_skip=4 + +if [ $UID != 0 ]; then + echo "Please run ir_loopback test as root [SKIP]" + exit $ksft_skip +fi + +if ! /sbin/modprobe -q -n rc-loopback; then + echo "ir_loopback: module rc-loopback is not found in /lib/modules/`uname -r` [SKIP]" + exit $ksft_skip +fi + +/sbin/modprobe rc-loopback +if [ $? -ne 0 ]; then + exit +fi + +RCDEV=$(grep -l DRV_NAME=rc-loopback /sys/class/rc/rc*/uevent | grep -o 'rc[0-9]\+') + +./ir_loopback $RCDEV $RCDEV +exit -- cgit v1.3.1