This patchset changes files among many subsystems. I don't know which
tree it should be applied to, so I just base it on Linus's tree.
There're many truncated kthreads in the kernel, which may make trouble
for the user, for example, the user can't get detailed device
information from the task comm.
This patchset tries to improve this problem fundamentally by extending
the task comm size from 16 to 24. In order to do that, we have to do
some cleanups first.
1. Make the copy of task comm always safe no matter what the task
comm size is. For example,
Unsafe Safe
strlcpy strscpy_pad
strncpy strscpy_pad
bpf_probe_read_kernel bpf_probe_read_kernel_str
bpf_core_read_str
bpf_get_current_comm
perf_event__prepare_comm
prctl(2)
2. Replace the old hard-coded 16 with a new macro TASK_COMM_LEN_16 to
make it more grepable.
3. Extend the task comm size to 24 for CONFIG_BASE_FULL case and keep it
as 16 for CONFIG_BASE_SMALL.
4. Print a warning if the kthread comm is still truncated.
Changes since v4:
- introduce TASK_COMM_LEN_16 and TASK_COMM_LEN_24 per Steven
- replace hard-coded 16 with TASK_COMM_LEN_16 per Kees
- use strscpy_pad() instead of strlcpy()/strncpy() per Kees
- make perf test adopt to task comm size change per Arnaldo and Mathieu
- fix warning reported by kernel test robot
Changes since v3:
- fixes -Wstringop-truncation warning reported by kernel test robot
Changes since v2:
- avoid change UAPI code per Kees
- remove the description of out of tree code from commit log per Peter
Changes since v1:
- extend task comm to 24bytes, per Petr
- improve the warning per Petr
- make the checkpatch warning a separate patch
Yafang Shao (15):
fs/exec: make __set_task_comm always set a nul ternimated string
fs/exec: make __get_task_comm always get a nul terminated string
sched.h: introduce TASK_COMM_LEN_16
cn_proc: make connector comm always nul ternimated
drivers/infiniband: make setup_ctxt always get a nul terminated task
comm
elfcore: make prpsinfo always get a nul terminated task comm
samples/bpf/kern: use TASK_COMM_LEN instead of hard-coded 16
samples/bpf/user: use TASK_COMM_LEN_16 instead of hard-coded 16
tools/include: introduce TASK_COMM_LEN_16
tools/lib/perf: use TASK_COMM_LEN_16 instead of hard-coded 16
tools/bpf/bpftool: use TASK_COMM_LEN_16 instead of hard-coded 16
tools/perf/test: make perf test adopt to task comm size change
tools/testing/selftests/bpf: use TASK_COMM_LEN_16 instead of
hard-coded 16
sched.h: extend task comm from 16 to 24 for CONFIG_BASE_FULL
kernel/kthread: show a warning if kthread's comm is truncated
drivers/connector/cn_proc.c | 5 +++-
drivers/infiniband/hw/qib/qib.h | 4 +--
drivers/infiniband/hw/qib/qib_file_ops.c | 2 +-
fs/binfmt_elf.c | 2 +-
fs/exec.c | 5 ++--
include/linux/elfcore-compat.h | 3 ++-
include/linux/elfcore.h | 4 +--
include/linux/sched.h | 11 +++++++-
include/uapi/linux/cn_proc.h | 7 ++++-
kernel/kthread.c | 7 ++++-
samples/bpf/offwaketime_kern.c | 10 +++----
samples/bpf/offwaketime_user.c | 6 ++---
samples/bpf/test_overhead_kprobe_kern.c | 11 ++++----
samples/bpf/test_overhead_tp_kern.c | 5 ++--
samples/bpf/tracex2_kern.c | 3 ++-
samples/bpf/tracex2_user.c | 7 ++---
tools/bpf/bpftool/Makefile | 1 +
tools/bpf/bpftool/main.h | 3 ++-
tools/bpf/bpftool/skeleton/pid_iter.bpf.c | 4 +--
tools/bpf/bpftool/skeleton/pid_iter.h | 4 ++-
tools/include/linux/sched/task.h | 3 +++
tools/lib/perf/include/perf/event.h | 5 ++--
tools/perf/tests/evsel-tp-sched.c | 26 ++++++++++++++-----
tools/testing/selftests/bpf/Makefile | 2 +-
.../selftests/bpf/prog_tests/ringbuf.c | 3 ++-
.../selftests/bpf/prog_tests/ringbuf_multi.c | 3 ++-
.../bpf/prog_tests/sk_storage_tracing.c | 3 ++-
.../selftests/bpf/prog_tests/test_overhead.c | 3 ++-
.../bpf/prog_tests/trampoline_count.c | 3 ++-
tools/testing/selftests/bpf/progs/profiler.h | 7 ++---
.../selftests/bpf/progs/profiler.inc.h | 8 +++---
tools/testing/selftests/bpf/progs/pyperf.h | 4 +--
.../testing/selftests/bpf/progs/strobemeta.h | 6 ++---
.../bpf/progs/test_core_reloc_kernel.c | 3 ++-
.../selftests/bpf/progs/test_ringbuf.c | 3 ++-
.../selftests/bpf/progs/test_ringbuf_multi.c | 3 ++-
.../bpf/progs/test_sk_storage_tracing.c | 5 ++--
.../selftests/bpf/progs/test_skb_helpers.c | 5 ++--
.../selftests/bpf/progs/test_stacktrace_map.c | 5 ++--
.../selftests/bpf/progs/test_tracepoint.c | 5 ++--
40 files changed, 135 insertions(+), 74 deletions(-)
--
2.17.1
