Received-SPF: pass (google.com: domain of linux-kernel+bounces-91073-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.48.161 as permitted sender) client-ip=147.75.48.161;
Sender: Guenter Roeck <groeck7@gmail.com>
Date: Mon, 4 Mar 2024 10:12:23 -0800
From: Guenter Roeck <linux@roeck-us.net>
To: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Dmitry Vyukov <dvyukov@google.com>,
	linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: hw_breakpoint unit test failures with various
 architectures/platforms in qemu
Message-ID: <f477329e-4ecf-4c6c-82b1-1e9b84443902@roeck-us.net>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

Hi,

I see a number of failures and tracebacks when running the hw_breakpoint
unit tests on various architectures in qemu. Some examples are below.

Is this a potential problem with the unit tests, with the hardware,
or with the qemu emulation of that hardware ?

In other words, is it worthwhile to look into this further, or would
it make more sense to just disable those tests if they fail on a
given hardware/platform ?

Thanks,
Guenter

---
arm:smdkc210:

[    9.515572]     ok 2 test_many_cpus
[    9.519425] ########### searching unregister_test_bp
[    9.519989] ------------[ cut here ]------------
[    9.520995] ########### searching test_one_task_on_all_cpus
[    9.521318] WARNING: CPU: 1 PID: 63 at kernel/events/hw_breakpoint_test.c:49 test_one_task_on_all_cpus+0x90/0x1c4
[    9.521921] Modules linked in:
[    9.522532] CPU: 1 PID: 63 Comm: kunit_try_catch Tainted: G                 N 6.8.0-rc7-00028-g624465c9abd6 #1
[    9.523102] Hardware name: Samsung Exynos (Flattened Device Tree)
[    9.523610]  unwind_backtrace from show_stack+0x10/0x14
[    9.523936]  show_stack from dump_stack_lvl+0x68/0x90
[    9.524191]  dump_stack_lvl from __warn+0xbc/0x21c
[    9.524429]  __warn from warn_slowpath_fmt+0x1a8/0x1b0
[    9.524674]  warn_slowpath_fmt from test_one_task_on_all_cpus+0x90/0x1c4
[    9.524971]  test_one_task_on_all_cpus from kunit_try_run_case+0x58/0x18c
[    9.525273]  kunit_try_run_case from kunit_generic_run_threadfn_adapter+0x14/0x20
[    9.525593]  kunit_generic_run_threadfn_adapter from kthread+0x118/0x124
[    9.525889]  kthread from ret_from_fork+0x14/0x28
[    9.526200] Exception stack(0xf0ad5fb0 to 0xf0ad5ff8)
[    9.526663] 5fa0:                                     00000000 00000000 00000000 00000000
[    9.527112] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    9.527449] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[    9.527876] irq event stamp: 113
[    9.528088] hardirqs last  enabled at (121): [<c01adfb4>] console_unlock+0x114/0x130
[    9.529049] hardirqs last disabled at (140): [<c01adfa0>] console_unlock+0x100/0x130
[    9.529501] softirqs last  enabled at (138): [<c010168c>] __do_softirq+0x340/0x520
[    9.529892] softirqs last disabled at (129): [<c012f23c>] irq_exit+0x190/0x1c0
[    9.530227] ---[ end trace 0000000000000000 ]---
[    9.531752]     # test_one_task_on_all_cpus: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[    9.531752]     Expected IS_ERR(bp) to be false, but is true
[    9.537757]     not ok 3 test_one_task_on_all_cpus

---
arm:raspi2b (and others):

[   14.718608]     # Subtest: hw_breakpoint
[   14.719351]     # module: hw_breakpoint_test
[   14.722275]     1..9
[   14.737927]     # test_one_cpu: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   14.737927]     Expected IS_ERR(bp) to be false, but is true
[   14.745960]     not ok 1 test_one_cpu
[   14.750052]     # test_many_cpus: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   14.750052]     Expected IS_ERR(bp) to be false, but is true
[   14.791453]     not ok 2 test_many_cpus
[   14.805964]     # test_one_task_on_all_cpus: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   14.805964]     Expected IS_ERR(bp) to be false, but is true
[   14.822662]     not ok 3 test_one_task_on_all_cpus
[   14.836897]     # test_two_tasks_on_all_cpus: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   14.836897]     Expected IS_ERR(bp) to be false, but is true
[   14.869770]     not ok 4 test_two_tasks_on_all_cpus
[   14.913412]     # test_one_task_on_one_cpu: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   14.913412]     Expected IS_ERR(bp) to be false, but is true
[   14.929852]     not ok 5 test_one_task_on_one_cpu
[   14.939676]     # test_one_task_mixed: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   14.939676]     Expected IS_ERR(bp) to be false, but is true
[   14.953670]     not ok 6 test_one_task_mixed
[   14.964403]     # test_two_tasks_on_one_cpu: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   14.964403]     Expected IS_ERR(bp) to be false, but is true
[   14.997262]     not ok 7 test_two_tasks_on_one_cpu
[   15.012825]     # test_two_tasks_on_one_all_cpus: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   15.012825]     Expected IS_ERR(bp) to be false, but is true
[   15.045472]     not ok 8 test_two_tasks_on_one_all_cpus
[   15.070033]     # test_task_on_all_and_one_cpu: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[   15.070033]     Expected IS_ERR(bp) to be false, but is true
[   15.077092]     not ok 9 test_task_on_all_and_one_cpu

---
arm64:virt:

[    7.753199]     ok 2 test_many_cpus
[    7.766356]     # test_one_task_on_all_cpus: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[    7.766356]     Expected IS_ERR(bp) to be false, but is true
[    7.775897]     not ok 3 test_one_task_on_all_cpus
[    7.786604]     # test_two_tasks_on_all_cpus: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[    7.786604]     Expected IS_ERR(bp) to be false, but is true
[    7.793878]     not ok 4 test_two_tasks_on_all_cpus
[    7.799954]     # test_one_task_on_one_cpu: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[    7.799954]     Expected IS_ERR(bp) to be false, but is true
[    7.811446]     not ok 5 test_one_task_on_one_cpu
[    7.823706]     # test_one_task_mixed: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[    7.823706]     Expected IS_ERR(bp) to be false, but is true
[    7.838892]     not ok 6 test_one_task_mixed
[    7.843594]     # test_two_tasks_on_one_cpu: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[    7.843594]     Expected IS_ERR(bp) to be false, but is true
[    7.862087]     not ok 7 test_two_tasks_on_one_cpu
[    7.869706]     # test_two_tasks_on_one_all_cpus: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[    7.869706]     Expected IS_ERR(bp) to be false, but is true
[    7.874499]     not ok 8 test_two_tasks_on_one_all_cpus
[    7.878321]     # test_task_on_all_and_one_cpu: ASSERTION FAILED at kernel/events/hw_breakpoint_test.c:70
[    7.878321]     Expected IS_ERR(bp) to be false, but is true
[    7.894138]     not ok 9 test_task_on_all_and_one_cpu
[    7.894501] # hw_breakpoint: pass:2 fail:7 skip:0 total:9
[    7.894911] # Totals: pass:2 fail:7 skip:0 total:9

---
loongarch:

[    7.327439]     ok 2 test_many_cpus
[    7.330144] ------------[ cut here ]------------
[    7.330849] WARNING: CPU: 1 PID: 87 at kernel/events/hw_breakpoint_test.c:49 test_one_task_on_all_cpus+0x204/0x210