From 179d1600723670dc0d6ae8ce572e0e2c44b64763 Mon Sep 17 00:00:00 2001 From: Chaitanya Kulkarni Date: Sun, 21 Feb 2021 21:29:55 -0800 Subject: block: remove superfluous param in blk_fill_rwbs() The last parameter for the function blk_fill_rwbs() was added in 5782138e47 ("tracing/events: convert block trace points to TRACE_EVENT()") in order to signal read request and use of that parameter was replaced with using switch case REQ_OP_READ with 1b9a9ab78b0 ("blktrace: use op accessors"), but the parameter was never removed. Remove the unused parameter and adjust the respective call sites. Fixes: 1b9a9ab78b0 ("blktrace: use op accessors") Signed-off-by: Chaitanya Kulkarni Reviewed-by: Johannes Thumshirn Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- kernel/trace/blktrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 9e9ee4945043..8a2591c7aa41 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1867,7 +1867,7 @@ void blk_trace_remove_sysfs(struct device *dev) #ifdef CONFIG_EVENT_TRACING -void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes) +void blk_fill_rwbs(char *rwbs, unsigned int op) { int i = 0; -- cgit v1.2.3 From 1f83bb4b491472310ae7aeca505ed3725149906c Mon Sep 17 00:00:00 2001 From: Chaitanya Kulkarni Date: Sun, 21 Feb 2021 21:29:56 -0800 Subject: blktrace: add blk_fill_rwbs documentation comment blk_fill_rwbs() is an expoted function, add kernel style documentation comment. Signed-off-by: Chaitanya Kulkarni Reviewed-by: Johannes Thumshirn Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/blktrace_api.h | 2 +- kernel/trace/blktrace.c | 10 ++++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index 11484f1d19a1..e17d04abf6a3 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -119,7 +119,7 @@ struct compat_blk_user_trace_setup { #endif -extern void blk_fill_rwbs(char *rwbs, unsigned int op); +void blk_fill_rwbs(char *rwbs, unsigned int op); static inline sector_t blk_rq_trace_sector(struct request *rq) { diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 8a2591c7aa41..d7ebef83771c 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1867,6 +1867,16 @@ void blk_trace_remove_sysfs(struct device *dev) #ifdef CONFIG_EVENT_TRACING +/** + * blk_fill_rwbs - Fill the buffer rwbs by mapping op to character string. + * @rwbs buffer to be filled + * @op: REQ_OP_XXX for the tracepoint + * + * Description: + * Maps the REQ_OP_XXX to character and fills the buffer provided by the + * caller with resulting string. + * + **/ void blk_fill_rwbs(char *rwbs, unsigned int op) { int i = 0; -- cgit v1.2.3 From c0ea57608b691d6cde8aff23e11f9858a86b5918 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 16 Feb 2021 16:52:47 +0100 Subject: blktrace: remove debugfs file dentries from struct blk_trace These debugfs dentries do not need to be saved for anything as the whole directory and everything in it is properly cleaned up when the parent directory is removed. So remove them from struct blk_trace and don't save them when created as it's not necessary. Cc: Jens Axboe Cc: Steven Rostedt Cc: Ingo Molnar Cc: linux-block@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Jens Axboe --- include/linux/blktrace_api.h | 2 -- kernel/trace/blktrace.c | 8 ++------ 2 files changed, 2 insertions(+), 8 deletions(-) (limited to 'kernel/trace') diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index e17d04abf6a3..a083e15df608 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -23,8 +23,6 @@ struct blk_trace { u32 pid; u32 dev; struct dentry *dir; - struct dentry *dropped_file; - struct dentry *msg_file; struct list_head running_list; atomic_t dropped; }; diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index d7ebef83771c..0c8690d9f6cd 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -311,8 +311,6 @@ record_it: static void blk_trace_free(struct blk_trace *bt) { - debugfs_remove(bt->msg_file); - debugfs_remove(bt->dropped_file); relay_close(bt->rchan); debugfs_remove(bt->dir); free_percpu(bt->sequence); @@ -544,10 +542,8 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, INIT_LIST_HEAD(&bt->running_list); ret = -EIO; - bt->dropped_file = debugfs_create_file("dropped", 0444, dir, bt, - &blk_dropped_fops); - - bt->msg_file = debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); + debugfs_create_file("dropped", 0444, dir, bt, &blk_dropped_fops); + debugfs_create_file("msg", 0222, dir, bt, &blk_msg_fops); bt->rchan = relay_open("trace", dir, buts->buf_size, buts->buf_nr, &blk_relay_callbacks, bt); -- cgit v1.2.3 From 22c8542d7b220ffc53816d47b371b1fe34341d4a Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Fri, 25 Sep 2020 16:43:53 -0700 Subject: tracing: add support for objtool mcount This change adds build support for using objtool to generate __mcount_loc sections. Signed-off-by: Sami Tolvanen --- Makefile | 7 +++++++ kernel/trace/Kconfig | 13 +++++++++++++ scripts/Makefile.build | 3 +++ 3 files changed, 23 insertions(+) (limited to 'kernel/trace') diff --git a/Makefile b/Makefile index 2233951666f7..3189eacf3185 100644 --- a/Makefile +++ b/Makefile @@ -860,6 +860,9 @@ ifdef CONFIG_FTRACE_MCOUNT_USE_CC endif endif endif +ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL + CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT +endif ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT ifdef CONFIG_HAVE_C_RECORDMCOUNT BUILD_C_RECORDMCOUNT := y @@ -1236,6 +1239,10 @@ uapi-asm-generic: PHONY += prepare-objtool prepare-resolve_btfids prepare-objtool: $(objtool_target) ifeq ($(SKIP_STACK_VALIDATION),1) +ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL + @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 + @false +endif ifdef CONFIG_UNWINDER_ORC @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 @false diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 3985a31a49b7..936ccab1b938 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -60,6 +60,11 @@ config HAVE_NOP_MCOUNT help Arch supports the gcc options -pg with -mrecord-mcount and -nop-mcount +config HAVE_OBJTOOL_MCOUNT + bool + help + Arch supports objtool --mcount + config HAVE_C_RECORDMCOUNT bool help @@ -612,10 +617,18 @@ config FTRACE_MCOUNT_USE_CC depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY depends on FTRACE_MCOUNT_RECORD +config FTRACE_MCOUNT_USE_OBJTOOL + def_bool y + depends on HAVE_OBJTOOL_MCOUNT + depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY + depends on !FTRACE_MCOUNT_USE_CC + depends on FTRACE_MCOUNT_RECORD + config FTRACE_MCOUNT_USE_RECORDMCOUNT def_bool y depends on !FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY depends on !FTRACE_MCOUNT_USE_CC + depends on !FTRACE_MCOUNT_USE_OBJTOOL depends on FTRACE_MCOUNT_RECORD config TRACING_MAP diff --git a/scripts/Makefile.build b/scripts/Makefile.build index d94fc9ab819d..59fabd9685ee 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -238,6 +238,9 @@ endif ifdef CONFIG_X86_SMAP objtool_args += --uaccess endif +ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL + objtool_args += --mcount +endif # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file -- cgit v1.2.3 From 94d4bffdda21baa2c749bc229c41811a7559dd15 Mon Sep 17 00:00:00 2001 From: Chaitanya Kulkarni Date: Tue, 23 Feb 2021 23:16:23 -0800 Subject: blktrace: fix documentation for blk_fill_rw() Add missing ":" after rwbs function parameter documentation that fixes following warning :- ./kernel/trace/blktrace.c:1877: warning: Function parameter or member 'rwbs' not described in 'blk_fill_rwbs' Reported-by: Stephen Rothwell Fixes: 1f83bb4b4914 ("blktrace: add blk_fill_rwbs documentation comment") Signed-off-by: Chaitanya Kulkarni Signed-off-by: Jens Axboe --- kernel/trace/blktrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 0c8690d9f6cd..ca6f0ceba09b 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1865,7 +1865,7 @@ void blk_trace_remove_sysfs(struct device *dev) /** * blk_fill_rwbs - Fill the buffer rwbs by mapping op to character string. - * @rwbs buffer to be filled + * @rwbs: buffer to be filled * @op: REQ_OP_XXX for the tracepoint * * Description: -- cgit v1.2.3 From 9c0dee54eb91d48cca048bd7bd2c1f4a166e0252 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Thu, 25 Feb 2021 17:19:44 -0800 Subject: tracing: add error_report_end trace point Patch series "Add error_report_end tracepoint to KFENCE and KASAN", v3. This patchset adds a tracepoint, error_repor_end, that is to be used by KFENCE, KASAN, and potentially other bug detection tools, when they print an error report. One of the possible use cases is userspace collection of kernel error reports: interested parties can subscribe to the tracing event via tracefs, and get notified when an error report occurs. This patch (of 3): Introduce error_report_end tracepoint. It can be used in debugging tools like KASAN, KFENCE, etc. to provide extensions to the error reporting mechanisms (e.g. allow tests hook into error reporting, ease error report collection from production kernels). Another benefit would be making use of ftrace for debugging or benchmarking the tools themselves. Should we need it, the tracepoint name leaves us with the possibility to introduce a complementary error_report_start tracepoint in the future. Link: https://lkml.kernel.org/r/20210121131915.1331302-1-glider@google.com Link: https://lkml.kernel.org/r/20210121131915.1331302-2-glider@google.com Signed-off-by: Alexander Potapenko Suggested-by: Marco Elver Cc: Andrey Konovalov Cc: Dmitry Vyukov Cc: Ingo Molnar Cc: Petr Mladek Cc: Steven Rostedt Cc: Sergey Senozhatsky Cc: Greg Kroah-Hartman Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/trace/events/error_report.h | 74 +++++++++++++++++++++++++++++++++++++ kernel/trace/Makefile | 1 + kernel/trace/error_report-traces.c | 11 ++++++ 3 files changed, 86 insertions(+) create mode 100644 include/trace/events/error_report.h create mode 100644 kernel/trace/error_report-traces.c (limited to 'kernel/trace') diff --git a/include/trace/events/error_report.h b/include/trace/events/error_report.h new file mode 100644 index 000000000000..96f64bf218b2 --- /dev/null +++ b/include/trace/events/error_report.h @@ -0,0 +1,74 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Declarations for error reporting tracepoints. + * + * Copyright (C) 2021, Google LLC. + */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM error_report + +#if !defined(_TRACE_ERROR_REPORT_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_ERROR_REPORT_H + +#include + +#ifndef __ERROR_REPORT_DECLARE_TRACE_ENUMS_ONCE_ONLY +#define __ERROR_REPORT_DECLARE_TRACE_ENUMS_ONCE_ONLY + +enum error_detector { + ERROR_DETECTOR_KFENCE, + ERROR_DETECTOR_KASAN +}; + +#endif /* __ERROR_REPORT_DECLARE_TRACE_ENUMS_ONCE_ONLY */ + +#define error_detector_list \ + EM(ERROR_DETECTOR_KFENCE, "kfence") \ + EMe(ERROR_DETECTOR_KASAN, "kasan") +/* Always end the list with an EMe. */ + +#undef EM +#undef EMe + +#define EM(a, b) TRACE_DEFINE_ENUM(a); +#define EMe(a, b) TRACE_DEFINE_ENUM(a); + +error_detector_list + +#undef EM +#undef EMe + +#define EM(a, b) { a, b }, +#define EMe(a, b) { a, b } + +#define show_error_detector_list(val) \ + __print_symbolic(val, error_detector_list) + +DECLARE_EVENT_CLASS(error_report_template, + TP_PROTO(enum error_detector error_detector, unsigned long id), + TP_ARGS(error_detector, id), + TP_STRUCT__entry(__field(enum error_detector, error_detector) + __field(unsigned long, id)), + TP_fast_assign(__entry->error_detector = error_detector; + __entry->id = id;), + TP_printk("[%s] %lx", + show_error_detector_list(__entry->error_detector), + __entry->id)); + +/** + * error_report_end - called after printing the error report + * @error_detector: short string describing the error detection tool + * @id: pseudo-unique descriptor identifying the report + * (e.g. the memory access address) + * + * This event occurs right after a debugging tool finishes printing the error + * report. + */ +DEFINE_EVENT(error_report_template, error_report_end, + TP_PROTO(enum error_detector error_detector, unsigned long id), + TP_ARGS(error_detector, id)); + +#endif /* _TRACE_ERROR_REPORT_H */ + +/* This part must be outside protection */ +#include diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 7e44cea89fdc..b28d3e5013cd 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -81,6 +81,7 @@ obj-$(CONFIG_SYNTH_EVENTS) += trace_events_synth.o obj-$(CONFIG_HIST_TRIGGERS) += trace_events_hist.o obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o obj-$(CONFIG_KPROBE_EVENTS) += trace_kprobe.o +obj-$(CONFIG_TRACEPOINTS) += error_report-traces.o obj-$(CONFIG_TRACEPOINTS) += power-traces.o ifeq ($(CONFIG_PM),y) obj-$(CONFIG_TRACEPOINTS) += rpm-traces.o diff --git a/kernel/trace/error_report-traces.c b/kernel/trace/error_report-traces.c new file mode 100644 index 000000000000..f89792c25b11 --- /dev/null +++ b/kernel/trace/error_report-traces.c @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Error reporting trace points. + * + * Copyright (C) 2021, Google LLC. + */ + +#define CREATE_TRACE_POINTS +#include + +EXPORT_TRACEPOINT_SYMBOL_GPL(error_report_end); -- cgit v1.2.3 From 70d443d8463339869f371e77fa594b850f374565 Mon Sep 17 00:00:00 2001 From: "Yordan Karadzhov (VMware)" Date: Thu, 4 Mar 2021 11:23:48 +0200 Subject: tracing: Remove duplicate declaration from trace.h A declaration of function "int trace_empty(struct trace_iterator *iter)" shows up twice in the header file kernel/trace/trace.h Link: https://lkml.kernel.org/r/20210304092348.208033-1-y.karadz@gmail.com Signed-off-by: Yordan Karadzhov (VMware) Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.h | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index dec13ff66077..a6446c03cfbc 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -605,7 +605,6 @@ void trace_graph_function(struct trace_array *tr, void trace_latency_header(struct seq_file *m); void trace_default_header(struct seq_file *m); void print_trace_header(struct seq_file *m, struct trace_iterator *iter); -int trace_empty(struct trace_iterator *iter); void trace_graph_return(struct ftrace_graph_ret *trace); int trace_graph_entry(struct ftrace_graph_ent *trace); -- cgit v1.2.3 From 69268094a1c16f3f44b369f9da78ce98bab5f244 Mon Sep 17 00:00:00 2001 From: Rolf Eike Beer Date: Tue, 2 Mar 2021 09:49:28 +0100 Subject: tracing: Fix help text of TRACEPOINT_BENCHMARK in Kconfig It's "cond_resched()" not "cond_sched()". Link: https://lkml.kernel.org/r/1863065.aFVDpXsuPd@devpool47 Signed-off-by: Rolf Eike Beer Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 9c266b93cbc0..7fa82778c3e6 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -694,7 +694,7 @@ config TRACEPOINT_BENCHMARK help This option creates the tracepoint "benchmark:benchmark_event". When the tracepoint is enabled, it kicks off a kernel thread that - goes into an infinite loop (calling cond_sched() to let other tasks + goes into an infinite loop (calling cond_resched() to let other tasks run), and calls the tracepoint. Each iteration will record the time it took to write to the tracepoint and the next iteration that data will be passed to the tracepoint itself. That is, the tracepoint -- cgit v1.2.3 From 6f6be606e763f2da9fc21de00538c97fe4ca1492 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 3 Mar 2021 18:03:52 -0500 Subject: ring-buffer: Force before_stamp and write_stamp to be different on discard Part of the logic of the new time stamp code depends on the before_stamp and the write_stamp to be different if the write_stamp does not match the last event on the buffer, as it will be used to calculate the delta of the next event written on the buffer. The discard logic depends on this, as the next event to come in needs to inject a full timestamp as it can not rely on the last event timestamp in the buffer because it is unknown due to events after it being discarded. But by changing the write_stamp back to the time before it, it forces the next event to use a full time stamp, instead of relying on it. The issue came when a full time stamp was used for the event, and rb_time_delta() returns zero in that case. The update to the write_stamp (which subtracts delta) made it not change. Then when the event is removed from the buffer, because the before_stamp and write_stamp still match, the next event written would calculate its delta from the write_stamp, but that would be wrong as the write_stamp is of the time of the event that was discarded. In the case that the delta change being made to write_stamp is zero, set the before_stamp to zero as well, and this will force the next event to inject a full timestamp and not use the current write_stamp. Cc: stable@vger.kernel.org Fixes: a389d86f7fd09 ("ring-buffer: Have nested events still record running time stamp") Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ring_buffer.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index b9dad3500041..342f49c3ccc5 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2814,6 +2814,17 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer, write_stamp, write_stamp - delta)) return 0; + /* + * It's possible that the event time delta is zero + * (has the same time stamp as the previous event) + * in which case write_stamp and before_stamp could + * be the same. In such a case, force before_stamp + * to be different than write_stamp. It doesn't + * matter what it is, as long as its different. + */ + if (!delta) + rb_time_set(&cpu_buffer->before_stamp, 0); + /* * If an event were to come in now, it would see that the * write_stamp and the before_stamp are different, and assume -- cgit v1.2.3 From 6549de1fe34162d7ace8b870ae11ca6cae5b8609 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 3 Mar 2021 18:23:40 -0500 Subject: ring-buffer: Add a little more information and a WARN when time stamp going backwards is detected When the CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS is enabled, and the time stamps are detected as not being valid, it reports information about the write stamp, but does not show the before_stamp which is still useful information. Also, it should give a warning once, such that tests detect this happening. Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/ring_buffer.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 342f49c3ccc5..68744c51517e 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3318,9 +3318,13 @@ static void check_buffer(struct ring_buffer_per_cpu *cpu_buffer, goto out; } atomic_inc(&cpu_buffer->record_disabled); - pr_warn("[CPU: %d]TIME DOES NOT MATCH expected:%lld actual:%lld delta:%lld after:%lld\n", - cpu_buffer->cpu, - ts + info->delta, info->ts, info->delta, info->after); + /* There's some cases in boot up that this can happen */ + WARN_ON_ONCE(system_state != SYSTEM_BOOTING); + pr_warn("[CPU: %d]TIME DOES NOT MATCH expected:%lld actual:%lld delta:%lld before:%lld after:%lld%s\n", + cpu_buffer->cpu, + ts + info->delta, info->ts, info->delta, + info->before, info->after, + full ? " (full)" : ""); dump_buffer_page(bpage, info, tail); atomic_dec(&ts_dump); /* Do not re-enable checking */ -- cgit v1.2.3 From f40fc799afc598b3d130d5a0ada994c9d4fb6cf8 Mon Sep 17 00:00:00 2001 From: Vamshi K Sthambamkadi Date: Thu, 4 Mar 2021 15:15:24 +0530 Subject: tracing: Fix memory leak in __create_synth_event() kmemleak report: unreferenced object 0xc5a6f708 (size 8): comm "ftracetest", pid 1209, jiffies 4294911500 (age 6.816s) hex dump (first 8 bytes): 00 c1 3d 60 14 83 1f 8a ..=`.... backtrace: [] __kmalloc_track_caller+0x2a6/0x460 [<7d3d60a6>] kstrndup+0x37/0x70 [<45a0e739>] argv_split+0x1c/0x120 [] __create_synth_event+0x192/0xb00 [<0708b8a3>] create_synth_event+0xbb/0x150 [<3d1941e1>] create_dyn_event+0x5c/0xb0 [<5cf8b9e3>] trace_parse_run_command+0xa7/0x140 [<04deb2ef>] dyn_event_write+0x10/0x20 [<8779ac95>] vfs_write+0xa9/0x3c0 [] ksys_write+0x89/0xc0 [] __ia32_sys_write+0x15/0x20 [<7ce02d85>] __do_fast_syscall_32+0x45/0x80 [] do_fast_syscall_32+0x29/0x60 [<2467454a>] do_SYSENTER_32+0x15/0x20 [<9beaa61d>] entry_SYSENTER_32+0xa9/0xfc unreferenced object 0xc5a6f078 (size 8): comm "ftracetest", pid 1209, jiffies 4294911500 (age 6.816s) hex dump (first 8 bytes): 08 f7 a6 c5 00 00 00 00 ........ backtrace: [] __kmalloc+0x2b6/0x470 [] argv_split+0x82/0x120 [] __create_synth_event+0x192/0xb00 [<0708b8a3>] create_synth_event+0xbb/0x150 [<3d1941e1>] create_dyn_event+0x5c/0xb0 [<5cf8b9e3>] trace_parse_run_command+0xa7/0x140 [<04deb2ef>] dyn_event_write+0x10/0x20 [<8779ac95>] vfs_write+0xa9/0x3c0 [] ksys_write+0x89/0xc0 [] __ia32_sys_write+0x15/0x20 [<7ce02d85>] __do_fast_syscall_32+0x45/0x80 [] do_fast_syscall_32+0x29/0x60 [<2467454a>] do_SYSENTER_32+0x15/0x20 [<9beaa61d>] entry_SYSENTER_32+0xa9/0xfc In __create_synth_event(), while iterating field/type arguments, the argv_split() will return array of atleast 2 elements even when zero arguments(argc=0) are passed. for e.g. when there is double delimiter or string ends with delimiter To fix call argv_free() even when argc=0. Link: https://lkml.kernel.org/r/20210304094521.GA1826@cosmos Signed-off-by: Vamshi K Sthambamkadi Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_events_synth.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 2979a96595b4..8d71e6c83f10 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -1225,8 +1225,10 @@ static int __create_synth_event(const char *name, const char *raw_fields) goto err; } - if (!argc) + if (!argc) { + argv_free(argv); continue; + } n_fields_this_loop = 0; consumed = 0; -- cgit v1.2.3 From ee666a185558ac9a929e53b902a568442ed62416 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Mon, 1 Mar 2021 10:49:35 -0500 Subject: tracing: Skip selftests if tracing is disabled If tracing is disabled for some reason (traceoff_on_warning, command line, etc), the ftrace selftests are guaranteed to fail, as their results are defined by trace data in the ring buffers. If the ring buffers are turned off, the tests will fail, due to lack of data. Because tracing being disabled is for a specific reason (warning, user decided to, etc), it does not make sense to enable tracing to run the self tests, as the test output may corrupt the reason for the tracing to be disabled. Instead, simply skip the self tests and report that they are being skipped due to tracing being disabled. Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e295c413580e..eccb4e1187cc 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1929,6 +1929,12 @@ static int run_tracer_selftest(struct tracer *type) if (!selftests_can_run) return save_selftest(type); + if (!tracing_is_on()) { + pr_warn("Selftest for tracer %s skipped due to tracing disabled\n", + type->name); + return 0; + } + /* * Run a selftest on this tracer. * Here we reset the trace buffer, and set the current -- cgit v1.2.3