linux-stable/kernel/trace
Wonhyuk Yang d8413b16fe tracing: Fix return value of trace_pid_write()
[ Upstream commit b27f266f74 ]

Setting set_event_pid with trailing whitespace lead to endless write
system calls like below.

    $ strace echo "123 " > /sys/kernel/debug/tracing/set_event_pid
    execve("/usr/bin/echo", ["echo", "123 "], ...) = 0
    ...
    write(1, "123 \n", 5)                   = 4
    write(1, "\n", 1)                       = 0
    write(1, "\n", 1)                       = 0
    write(1, "\n", 1)                       = 0
    write(1, "\n", 1)                       = 0
    write(1, "\n", 1)                       = 0
    ....

This is because, the result of trace_get_user's are not returned when it
read at least one pid. To fix it, update read variable even if
parser->idx == 0.

The result of applied patch is below.

    $ strace echo "123 " > /sys/kernel/debug/tracing/set_event_pid
    execve("/usr/bin/echo", ["echo", "123 "], ...) = 0
    ...
    write(1, "123 \n", 5)                   = 5
    close(1)                                = 0

Link: https://lkml.kernel.org/r/20220503050546.288911-1-vvghjk1234@gmail.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Baik Song An <bsahn@etri.re.kr>
Cc: Hong Yeon Kim <kimhy@etri.re.kr>
Cc: Taeung Song <taeung@reallinux.co.kr>
Cc: linuxgeek@linuxgeek.io
Cc: stable@vger.kernel.org
Fixes: 4909010788 ("tracing: Add set_event_pid directory for future use")
Signed-off-by: Wonhyuk Yang <vvghjk1234@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-07-29 17:25:29 +02:00
..
blktrace.c blktrace: fix use after free for struct blk_trace 2022-03-08 19:12:43 +01:00
bpf_trace.c bpf: Add MEM_RDONLY for helper args that are pointers to rdonly mem. 2022-05-01 17:22:26 +02:00
bpf_trace.h
error_report-traces.c tracing: add error_report_end trace point 2021-02-26 09:41:02 -08:00
fgraph.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
ftrace.c tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
ftrace_internal.h
Kconfig tracing: Simplify the Kconfig dependency of FTRACE 2021-08-16 11:37:20 -04:00
kprobe_event_gen_test.c
Makefile tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
pid_list.c tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
pid_list.h tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
power-traces.c
preemptirq_delay_test.c kernel: trace: preemptirq_delay_test: add cpu affinity 2021-02-02 17:02:07 -05:00
ring_buffer.c ring-buffer: Protect ring_buffer_reset() from reentrancy 2021-11-18 19:16:03 +01:00
ring_buffer_benchmark.c
rpm-traces.c
synth_event_gen_test.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace.c tracing: Fix return value of trace_pid_write() 2022-07-29 17:25:29 +02:00
trace.h tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
trace_benchmark.c
trace_benchmark.h
trace_boot.c tracing: Initialize integer variable to prevent garbage return value 2022-06-09 10:23:21 +02:00
trace_branch.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_clock.c tracing: Do no increment trace_clock_global() by one 2021-06-18 09:10:00 -04:00
trace_dynevent.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_dynevent.h tracing: Add DYNAMIC flag for dynamic events 2021-08-18 18:10:32 -04:00
trace_entries.h trace: Add timerlat tracer 2021-06-25 19:57:24 -04:00
trace_eprobe.c tracing: Fix misspelling of "missing" 2021-10-29 09:54:14 -04:00
trace_event_perf.c ftrace: do CPU checking after preemption disabled 2021-11-18 19:16:20 +01:00
trace_events.c tracing: Place trace_pid_list logic into abstract functions 2022-07-29 17:25:29 +02:00
trace_events_filter.c tracing: Add ustring operation to filtering string pointers 2022-03-08 19:12:33 +01:00
trace_events_filter_test.h
trace_events_hist.c tracing/histograms: Fix memory leak problem 2022-07-21 21:24:11 +02:00
trace_events_inject.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_events_synth.c tracing: Do not let synth_events block other dyn_event systems during create 2022-03-08 19:12:35 +01:00
trace_events_trigger.c tracing: Have traceon and traceoff trigger honor the instance 2022-03-02 11:48:03 +01:00
trace_export.c
trace_functions.c tracing: Add "func_no_repeats" option for function tracing 2021-04-15 14:50:02 -04:00
trace_functions_graph.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_hwlat.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_irqsoff.c tracing: Merge irqflags + preempt counter. 2021-02-02 17:02:06 -05:00
trace_kdb.c kdb: Rename members of struct kdbtab_t 2021-07-27 17:05:06 +01:00
trace_kprobe.c tracing/kprobes: Check whether get_kretprobe() returns NULL in kretprobe_dispatcher() 2022-06-29 09:03:20 +02:00
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_mmiotrace.c tracing: Remove definition of DEBUG in trace_mmiotrace.c 2021-02-02 17:02:07 -05:00
trace_nop.c
trace_osnoise.c tracing/osnoise: Force quiescent states while tracing 2022-03-16 14:23:43 +01:00
trace_output.c tracing: Add migrate-disabled counter to tracing output. 2021-09-03 19:42:35 -04:00
trace_output.h
trace_preemptirq.c
trace_printk.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_probe.c tracing/probes: check the return value of kstrndup() for pbuf 2022-03-08 19:12:38 +01:00
trace_probe.h tracing: Add a probe that attaches to trace events 2021-08-20 14:18:40 -04:00
trace_probe_tmpl.h tracing/probes: Have process_fetch_insn() take a void * instead of pt_regs 2021-08-19 09:09:03 -04:00
trace_recursion_record.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_sched_switch.c
trace_sched_wakeup.c tracing: Change variable type as bool for clean-up 2021-06-30 09:19:14 -04:00
trace_selftest.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace_selftest_dynamic.c
trace_seq.c tracing: Fix various typos in comments 2021-03-23 14:08:18 -04:00
trace_stack.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_stat.c tracing: Disable "other" permission bits in the tracefs files 2021-11-18 19:16:15 +01:00
trace_stat.h
trace_synth.h tracing: synth events: increase max fields count 2021-09-08 15:29:16 -04:00
trace_syscalls.c tracing: Make tp_printk work on syscall tracepoints 2022-06-14 18:36:14 +02:00
trace_uprobe.c tracing/uprobes: Check the return value of kstrdup() for tu->filename 2022-03-08 19:12:38 +01:00
tracing_map.c tracing: Fix a kmemleak false positive in tracing_map 2021-12-17 10:30:16 +01:00
tracing_map.h