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/perf/util/cs-etm-base.c | 195 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 tools/perf/util/cs-etm-base.c (limited to 'tools/perf/util/cs-etm-base.c') diff --git a/tools/perf/util/cs-etm-base.c b/tools/perf/util/cs-etm-base.c new file mode 100644 index 000000000..aebef71d3 --- /dev/null +++ b/tools/perf/util/cs-etm-base.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * File for any parts of the Coresight decoding that don't require + * OpenCSD. + */ + +#include +#include + +#include "cs-etm.h" + +static const char * const cs_etm_global_header_fmts[] = { + [CS_HEADER_VERSION] = " Header version %llx\n", + [CS_PMU_TYPE_CPUS] = " PMU type/num cpus %llx\n", + [CS_ETM_SNAPSHOT] = " Snapshot %llx\n", +}; + +static const char * const cs_etm_priv_fmts[] = { + [CS_ETM_MAGIC] = " Magic number %llx\n", + [CS_ETM_CPU] = " CPU %lld\n", + [CS_ETM_NR_TRC_PARAMS] = " NR_TRC_PARAMS %llx\n", + [CS_ETM_ETMCR] = " ETMCR %llx\n", + [CS_ETM_ETMTRACEIDR] = " ETMTRACEIDR %llx\n", + [CS_ETM_ETMCCER] = " ETMCCER %llx\n", + [CS_ETM_ETMIDR] = " ETMIDR %llx\n", +}; + +static const char * const cs_etmv4_priv_fmts[] = { + [CS_ETM_MAGIC] = " Magic number %llx\n", + [CS_ETM_CPU] = " CPU %lld\n", + [CS_ETM_NR_TRC_PARAMS] = " NR_TRC_PARAMS %llx\n", + [CS_ETMV4_TRCCONFIGR] = " TRCCONFIGR %llx\n", + [CS_ETMV4_TRCTRACEIDR] = " TRCTRACEIDR %llx\n", + [CS_ETMV4_TRCIDR0] = " TRCIDR0 %llx\n", + [CS_ETMV4_TRCIDR1] = " TRCIDR1 %llx\n", + [CS_ETMV4_TRCIDR2] = " TRCIDR2 %llx\n", + [CS_ETMV4_TRCIDR8] = " TRCIDR8 %llx\n", + [CS_ETMV4_TRCAUTHSTATUS] = " TRCAUTHSTATUS %llx\n", + [CS_ETMV4_TS_SOURCE] = " TS_SOURCE %lld\n", +}; + +static const char * const cs_ete_priv_fmts[] = { + [CS_ETM_MAGIC] = " Magic number %llx\n", + [CS_ETM_CPU] = " CPU %lld\n", + [CS_ETM_NR_TRC_PARAMS] = " NR_TRC_PARAMS %llx\n", + [CS_ETE_TRCCONFIGR] = " TRCCONFIGR %llx\n", + [CS_ETE_TRCTRACEIDR] = " TRCTRACEIDR %llx\n", + [CS_ETE_TRCIDR0] = " TRCIDR0 %llx\n", + [CS_ETE_TRCIDR1] = " TRCIDR1 %llx\n", + [CS_ETE_TRCIDR2] = " TRCIDR2 %llx\n", + [CS_ETE_TRCIDR8] = " TRCIDR8 %llx\n", + [CS_ETE_TRCAUTHSTATUS] = " TRCAUTHSTATUS %llx\n", + [CS_ETE_TRCDEVARCH] = " TRCDEVARCH %llx\n", + [CS_ETE_TS_SOURCE] = " TS_SOURCE %lld\n", +}; + +static const char * const param_unk_fmt = + " Unknown parameter [%d] %"PRIx64"\n"; +static const char * const magic_unk_fmt = + " Magic number Unknown %"PRIx64"\n"; + +static int cs_etm__print_cpu_metadata_v0(u64 *val, int *offset) +{ + int i = *offset, j, nr_params = 0, fmt_offset; + u64 magic; + + /* check magic value */ + magic = val[i + CS_ETM_MAGIC]; + if ((magic != __perf_cs_etmv3_magic) && + (magic != __perf_cs_etmv4_magic)) { + /* failure - note bad magic value */ + fprintf(stdout, magic_unk_fmt, magic); + return -EINVAL; + } + + /* print common header block */ + fprintf(stdout, cs_etm_priv_fmts[CS_ETM_MAGIC], val[i++]); + fprintf(stdout, cs_etm_priv_fmts[CS_ETM_CPU], val[i++]); + + if (magic == __perf_cs_etmv3_magic) { + nr_params = CS_ETM_NR_TRC_PARAMS_V0; + fmt_offset = CS_ETM_ETMCR; + /* after common block, offset format index past NR_PARAMS */ + for (j = fmt_offset; j < nr_params + fmt_offset; j++, i++) + fprintf(stdout, cs_etm_priv_fmts[j], val[i]); + } else if (magic == __perf_cs_etmv4_magic) { + nr_params = CS_ETMV4_NR_TRC_PARAMS_V0; + fmt_offset = CS_ETMV4_TRCCONFIGR; + /* after common block, offset format index past NR_PARAMS */ + for (j = fmt_offset; j < nr_params + fmt_offset; j++, i++) + fprintf(stdout, cs_etmv4_priv_fmts[j], val[i]); + } + *offset = i; + return 0; +} + +static int cs_etm__print_cpu_metadata_v1(u64 *val, int *offset) +{ + int i = *offset, j, total_params = 0; + u64 magic; + + magic = val[i + CS_ETM_MAGIC]; + /* total params to print is NR_PARAMS + common block size for v1 */ + total_params = val[i + CS_ETM_NR_TRC_PARAMS] + CS_ETM_COMMON_BLK_MAX_V1; + + if (magic == __perf_cs_etmv3_magic) { + for (j = 0; j < total_params; j++, i++) { + /* if newer record - could be excess params */ + if (j >= CS_ETM_PRIV_MAX) + fprintf(stdout, param_unk_fmt, j, val[i]); + else + fprintf(stdout, cs_etm_priv_fmts[j], val[i]); + } + } else if (magic == __perf_cs_etmv4_magic) { + for (j = 0; j < total_params; j++, i++) { + /* if newer record - could be excess params */ + if (j >= CS_ETMV4_PRIV_MAX) + fprintf(stdout, param_unk_fmt, j, val[i]); + else + fprintf(stdout, cs_etmv4_priv_fmts[j], val[i]); + } + } else if (magic == __perf_cs_ete_magic) { + for (j = 0; j < total_params; j++, i++) { + /* if newer record - could be excess params */ + if (j >= CS_ETE_PRIV_MAX) + fprintf(stdout, param_unk_fmt, j, val[i]); + else + fprintf(stdout, cs_ete_priv_fmts[j], val[i]); + } + } else { + /* failure - note bad magic value and error out */ + fprintf(stdout, magic_unk_fmt, magic); + return -EINVAL; + } + *offset = i; + return 0; +} + +static void cs_etm__print_auxtrace_info(u64 *val, int num) +{ + int i, cpu = 0, version, err; + + version = val[0]; + + for (i = 0; i < CS_HEADER_VERSION_MAX; i++) + fprintf(stdout, cs_etm_global_header_fmts[i], val[i]); + + for (i = CS_HEADER_VERSION_MAX; cpu < num; cpu++) { + if (version == 0) + err = cs_etm__print_cpu_metadata_v0(val, &i); + /* printing same for both, but value bit flags added on v2 */ + else if ((version == 1) || (version == 2)) + err = cs_etm__print_cpu_metadata_v1(val, &i); + if (err) + return; + } +} + +/* + * Do some basic checks and print the auxtrace info header before calling + * into cs_etm__process_auxtrace_info_full() which requires OpenCSD to be + * linked in. This allows some basic debugging if OpenCSD is missing. + */ +int cs_etm__process_auxtrace_info(union perf_event *event, + struct perf_session *session) +{ + struct perf_record_auxtrace_info *auxtrace_info = &event->auxtrace_info; + int event_header_size = sizeof(struct perf_event_header); + int num_cpu; + u64 *ptr = NULL; + u64 hdr_version; + + /* Ensure priv[] is large enough for the global header entries */ + if (auxtrace_info->header.size < (event_header_size + INFO_HEADER_SIZE + + CS_ETM_HEADER_SIZE)) + return -EINVAL; + + /* First the global part */ + ptr = (u64 *) auxtrace_info->priv; + + /* Look for version of the header */ + hdr_version = ptr[0]; + if (hdr_version > CS_HEADER_CURRENT_VERSION) { + pr_err("\nCS ETM Trace: Unknown Header Version = %#" PRIx64, hdr_version); + pr_err(", version supported <= %x\n", CS_HEADER_CURRENT_VERSION); + return -EINVAL; + } + + if (dump_trace) { + num_cpu = ptr[CS_PMU_TYPE_CPUS] & 0xffffffff; + cs_etm__print_auxtrace_info(ptr, num_cpu); + } + + return cs_etm__process_auxtrace_info_full(event, session); +} -- cgit v1.3.1