From: kbuild test robot <lkp@intel.com>
To: kbuild-all@lists.01.org
Subject: Re: [PATCH v2] kbuild: Enable -Wtautological-compare
Date: Fri, 27 Mar 2020 13:07:58 +0800 [thread overview]
Message-ID: <202003271330.DeDFOBJ8%lkp@intel.com> (raw)
In-Reply-To: <20200326194155.29107-1-natechancellor@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 13217 bytes --]
Hi Nathan,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on kbuild/for-next]
[also build test WARNING on v5.6-rc7 next-20200326]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/Nathan-Chancellor/kbuild-Enable-Wtautological-compare/20200327-072823
base: https://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild.git for-next
config: x86_64-defconfig (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 2a43a1610db335afcccd1a179a33a0886a5a2c4d)
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER=clang make.cross ARCH=x86_64
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
>> kernel//trace/trace.c:9337:33: warning: array comparison always evaluates to true [-Wtautological-compare]
if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
^
1 warning generated.
vim +9337 kernel//trace/trace.c
7e465baa80293e Tom Zanussi 2017-09-22 9312
3928a8a2d98081 Steven Rostedt 2008-09-29 9313 __init static int tracer_alloc_buffers(void)
bc0c38d139ec7f Steven Rostedt 2008-05-12 9314 {
73c5162aa362a5 Steven Rostedt 2009-03-11 9315 int ring_buf_size;
9e01c1b74c9531 Rusty Russell 2009-01-01 9316 int ret = -ENOMEM;
4c11d7aed38937 Steven Rostedt 2008-05-12 9317
a356646a56857c Steven Rostedt (VMware 2019-12-02 9318)
a356646a56857c Steven Rostedt (VMware 2019-12-02 9319) if (security_locked_down(LOCKDOWN_TRACEFS)) {
ee19545220a866 Stephen Rothwell 2019-12-06 9320 pr_warn("Tracing disabled due to lockdown\n");
a356646a56857c Steven Rostedt (VMware 2019-12-02 9321) return -EPERM;
a356646a56857c Steven Rostedt (VMware 2019-12-02 9322) }
a356646a56857c Steven Rostedt (VMware 2019-12-02 9323)
b5e87c05813194 Steven Rostedt (Red Hat 2015-09-29 9324) /*
b5e87c05813194 Steven Rostedt (Red Hat 2015-09-29 9325) * Make sure we don't accidently add more trace options
b5e87c05813194 Steven Rostedt (Red Hat 2015-09-29 9326) * than we have bits for.
b5e87c05813194 Steven Rostedt (Red Hat 2015-09-29 9327) */
9a38a8856f41f9 Steven Rostedt (Red Hat 2015-09-30 9328) BUILD_BUG_ON(TRACE_ITER_LAST_BIT > TRACE_FLAGS_MAX_SIZE);
b5e87c05813194 Steven Rostedt (Red Hat 2015-09-29 9329)
9e01c1b74c9531 Rusty Russell 2009-01-01 9330 if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
9e01c1b74c9531 Rusty Russell 2009-01-01 9331 goto out;
9e01c1b74c9531 Rusty Russell 2009-01-01 9332
ccfe9e42e45123 Alexander Z Lam 2013-08-08 9333 if (!alloc_cpumask_var(&global_trace.tracing_cpumask, GFP_KERNEL))
9e01c1b74c9531 Rusty Russell 2009-01-01 9334 goto out_free_buffer_mask;
a98a3c3fde3ae7 Steven Rostedt 2008-05-12 9335
07d777fe8c3985 Steven Rostedt 2011-09-22 9336 /* Only allocate trace_printk buffers if a trace_printk exists */
07d777fe8c3985 Steven Rostedt 2011-09-22 @9337 if (__stop___trace_bprintk_fmt != __start___trace_bprintk_fmt)
81698831bc462f Steven Rostedt 2012-10-11 9338 /* Must be called before global_trace.buffer is allocated */
07d777fe8c3985 Steven Rostedt 2011-09-22 9339 trace_printk_init_buffers();
07d777fe8c3985 Steven Rostedt 2011-09-22 9340
73c5162aa362a5 Steven Rostedt 2009-03-11 9341 /* To save memory, keep the ring buffer size to its minimum */
73c5162aa362a5 Steven Rostedt 2009-03-11 9342 if (ring_buffer_expanded)
73c5162aa362a5 Steven Rostedt 2009-03-11 9343 ring_buf_size = trace_buf_size;
73c5162aa362a5 Steven Rostedt 2009-03-11 9344 else
73c5162aa362a5 Steven Rostedt 2009-03-11 9345 ring_buf_size = 1;
73c5162aa362a5 Steven Rostedt 2009-03-11 9346
9e01c1b74c9531 Rusty Russell 2009-01-01 9347 cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
ccfe9e42e45123 Alexander Z Lam 2013-08-08 9348 cpumask_copy(global_trace.tracing_cpumask, cpu_all_mask);
9e01c1b74c9531 Rusty Russell 2009-01-01 9349
2b6080f28c7cc3 Steven Rostedt 2012-05-11 9350 raw_spin_lock_init(&global_trace.start_lock);
2b6080f28c7cc3 Steven Rostedt 2012-05-11 9351
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9352 /*
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9353 * The prepare callbacks allocates some memory for the ring buffer. We
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9354 * don't free the buffer if the if the CPU goes down. If we were to free
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9355 * the buffer, then the user would lose any trace that was in the
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9356 * buffer. The memory will be removed once the "instance" is removed.
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9357 */
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9358 ret = cpuhp_setup_state_multi(CPUHP_TRACE_RB_PREPARE,
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9359 "trace/RB:preapre", trace_rb_cpu_prepare,
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9360 NULL);
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9361 if (ret < 0)
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9362 goto out_free_cpumask;
2c4a33aba5f9ea Steven Rostedt (Red Hat 2014-03-25 9363) /* Used for event triggers */
147d88e0b5eb90 Dan Carpenter 2017-08-01 9364 ret = -ENOMEM;
2c4a33aba5f9ea Steven Rostedt (Red Hat 2014-03-25 9365) temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
2c4a33aba5f9ea Steven Rostedt (Red Hat 2014-03-25 9366) if (!temp_buffer)
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9367 goto out_rm_hp_state;
2c4a33aba5f9ea Steven Rostedt (Red Hat 2014-03-25 9368)
939c7a4f04fcd2 Yoshihiro YUNOMAE 2014-06-05 9369 if (trace_create_savedcmd() < 0)
939c7a4f04fcd2 Yoshihiro YUNOMAE 2014-06-05 9370 goto out_free_temp_buffer;
939c7a4f04fcd2 Yoshihiro YUNOMAE 2014-06-05 9371
9e01c1b74c9531 Rusty Russell 2009-01-01 9372 /* TODO: make the number of buffers hot pluggable with CPUS */
737223fbca3b1c Steven Rostedt (Red Hat 2013-03-05 9373) if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
24589e3a20876d Steven Rostedt (VMware 2020-01-25 9374) MEM_FAIL(1, "tracer: failed to allocate ring buffer!\n");
939c7a4f04fcd2 Yoshihiro YUNOMAE 2014-06-05 9375 goto out_free_savedcmd;
a98a3c3fde3ae7 Steven Rostedt 2008-05-12 9376 }
a7603ff4b5f7e2 Steven Rostedt 2012-08-06 9377
499e547057f5bb Steven Rostedt 2012-02-22 9378 if (global_trace.buffer_disabled)
499e547057f5bb Steven Rostedt 2012-02-22 9379 tracing_off();
a98a3c3fde3ae7 Steven Rostedt 2008-05-12 9380
e1e232ca6b8faa Steven Rostedt 2014-02-10 9381 if (trace_boot_clock) {
e1e232ca6b8faa Steven Rostedt 2014-02-10 9382 ret = tracing_set_clock(&global_trace, trace_boot_clock);
e1e232ca6b8faa Steven Rostedt 2014-02-10 9383 if (ret < 0)
a395d6a7e3d6e3 Joe Perches 2016-03-22 9384 pr_warn("Trace clock %s not defined, going back to default\n",
e1e232ca6b8faa Steven Rostedt 2014-02-10 9385 trace_boot_clock);
e1e232ca6b8faa Steven Rostedt 2014-02-10 9386 }
e1e232ca6b8faa Steven Rostedt 2014-02-10 9387
ca1643186d3dce Steven Rostedt (Red Hat 2013-05-23 9388) /*
ca1643186d3dce Steven Rostedt (Red Hat 2013-05-23 9389) * register_tracer() might reference current_trace, so it
ca1643186d3dce Steven Rostedt (Red Hat 2013-05-23 9390) * needs to be set before we register anything. This is
ca1643186d3dce Steven Rostedt (Red Hat 2013-05-23 9391) * just a bootstrap of current_trace anyway.
ca1643186d3dce Steven Rostedt (Red Hat 2013-05-23 9392) */
2b6080f28c7cc3 Steven Rostedt 2012-05-11 9393 global_trace.current_trace = &nop_trace;
2b6080f28c7cc3 Steven Rostedt 2012-05-11 9394
0b9b12c1b884eb Steven Rostedt (Red Hat 2014-01-14 9395) global_trace.max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
0b9b12c1b884eb Steven Rostedt (Red Hat 2014-01-14 9396)
4104d326b670c2 Steven Rostedt (Red Hat 2014-01-10 9397) ftrace_init_global_array_ops(&global_trace);
4104d326b670c2 Steven Rostedt (Red Hat 2014-01-10 9398)
9a38a8856f41f9 Steven Rostedt (Red Hat 2015-09-30 9399) init_trace_flags_index(&global_trace);
9a38a8856f41f9 Steven Rostedt (Red Hat 2015-09-30 9400)
ca1643186d3dce Steven Rostedt (Red Hat 2013-05-23 9401) register_tracer(&nop_trace);
ca1643186d3dce Steven Rostedt (Red Hat 2013-05-23 9402)
dbeafd0d6131d0 Steven Rostedt (VMware 2017-03-03 9403) /* Function tracing may start here (via kernel command line) */
dbeafd0d6131d0 Steven Rostedt (VMware 2017-03-03 9404) init_function_trace();
dbeafd0d6131d0 Steven Rostedt (VMware 2017-03-03 9405)
60a11774b38fef Steven Rostedt 2008-05-12 9406 /* All seems OK, enable tracing */
60a11774b38fef Steven Rostedt 2008-05-12 9407 tracing_disabled = 0;
3928a8a2d98081 Steven Rostedt 2008-09-29 9408
3f5a54e371ca20 Steven Rostedt 2008-07-30 9409 atomic_notifier_chain_register(&panic_notifier_list,
3f5a54e371ca20 Steven Rostedt 2008-07-30 9410 &trace_panic_notifier);
3f5a54e371ca20 Steven Rostedt 2008-07-30 9411
3f5a54e371ca20 Steven Rostedt 2008-07-30 9412 register_die_notifier(&trace_die_notifier);
2fc1dfbe17e770 Frederic Weisbecker 2009-03-16 9413
ae63b31e4d0e2e Steven Rostedt 2012-05-03 9414 global_trace.flags = TRACE_ARRAY_FL_GLOBAL;
ae63b31e4d0e2e Steven Rostedt 2012-05-03 9415
ae63b31e4d0e2e Steven Rostedt 2012-05-03 9416 INIT_LIST_HEAD(&global_trace.systems);
ae63b31e4d0e2e Steven Rostedt 2012-05-03 9417 INIT_LIST_HEAD(&global_trace.events);
067fe038e70f6e Tom Zanussi 2018-01-15 9418 INIT_LIST_HEAD(&global_trace.hist_vars);
2f754e771b1a6f Steven Rostedt (VMware 2019-04-01 9419) INIT_LIST_HEAD(&global_trace.err_log);
ae63b31e4d0e2e Steven Rostedt 2012-05-03 9420 list_add(&global_trace.list, &ftrace_trace_arrays);
ae63b31e4d0e2e Steven Rostedt 2012-05-03 9421
a4d1e688230339 Jiaxing Wang 2015-11-04 9422 apply_trace_boot_options();
7bcfaf54f591a0 Steven Rostedt 2012-11-01 9423
77fd5c15e3216b Steven Rostedt (Red Hat 2013-03-12 9424) register_snapshot_cmd();
77fd5c15e3216b Steven Rostedt (Red Hat 2013-03-12 9425)
2fc1dfbe17e770 Frederic Weisbecker 2009-03-16 9426 return 0;
3f5a54e371ca20 Steven Rostedt 2008-07-30 9427
939c7a4f04fcd2 Yoshihiro YUNOMAE 2014-06-05 9428 out_free_savedcmd:
939c7a4f04fcd2 Yoshihiro YUNOMAE 2014-06-05 9429 free_saved_cmdlines_buffer(savedcmd);
2c4a33aba5f9ea Steven Rostedt (Red Hat 2014-03-25 9430) out_free_temp_buffer:
2c4a33aba5f9ea Steven Rostedt (Red Hat 2014-03-25 9431) ring_buffer_free(temp_buffer);
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9432 out_rm_hp_state:
b32614c03413f8 Sebastian Andrzej Siewior 2016-11-27 9433 cpuhp_remove_multi_state(CPUHP_TRACE_RB_PREPARE);
9e01c1b74c9531 Rusty Russell 2009-01-01 9434 out_free_cpumask:
ccfe9e42e45123 Alexander Z Lam 2013-08-08 9435 free_cpumask_var(global_trace.tracing_cpumask);
9e01c1b74c9531 Rusty Russell 2009-01-01 9436 out_free_buffer_mask:
9e01c1b74c9531 Rusty Russell 2009-01-01 9437 free_cpumask_var(tracing_buffer_mask);
9e01c1b74c9531 Rusty Russell 2009-01-01 9438 out:
9e01c1b74c9531 Rusty Russell 2009-01-01 9439 return ret;
bc0c38d139ec7f Steven Rostedt 2008-05-12 9440 }
b2821ae68b1448 Steven Rostedt 2009-02-02 9441
:::::: The code@line 9337 was first introduced by commit
:::::: 07d777fe8c3985bc83428c2866713c2d1b3d4129 tracing: Add percpu buffers for trace_printk()
:::::: TO: Steven Rostedt <srostedt@redhat.com>
:::::: CC: Steven Rostedt <rostedt@goodmis.org>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 29184 bytes --]
next prev parent reply other threads:[~2020-03-27 5:07 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-26 19:41 [PATCH v2] kbuild: Enable -Wtautological-compare Nathan Chancellor
2020-03-27 5:07 ` kbuild test robot [this message]
2020-03-29 11:31 ` Masahiro Yamada
2020-03-31 10:11 ` Nathan Chancellor
2020-03-31 16:02 ` Nick Desaulniers
2020-03-31 19:26 ` Nathan Chancellor
2020-04-02 17:05 ` Masahiro Yamada
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=202003271330.DeDFOBJ8%lkp@intel.com \
--to=lkp@intel.com \
--cc=kbuild-all@lists.01.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.