Hi Feng Tang,
On Tue, 18 Jul 2023 13:28:11 +0800 Feng Tang <feng.tang@xxxxxxxxx> wrote:
> Running kunit test for 6.5-rc1 hits one bug:
>
> ok 10 damon_test_update_monitoring_result
> general protection fault, probably for non-canonical address 0x1bffa5c419cfb81: 0000 [#1] PREEMPT SMP NOPTI
> CPU: 1 PID: 110 Comm: kunit_try_catch Tainted: G N 6.5.0-rc2 #15
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
> RIP: 0010:damon_set_attrs+0xb9/0x120
> Code: f8 00 00 00 4c 8d 58 e0 48 39 c3 74 ba 41 ba 59 17 b7 d1 49 8b 43 10 4d
> 8d 4b 10 48 8d 70 e0 49 39 c1 74 50 49 8b 40 08 31 d2 <69> 4e 18 10 27 00 00
> 49 f7 30 31 d2 48 89 c5 89 c8 f7 f5 31 d2 89
> RSP: 0000:ffffc900005bfd40 EFLAGS: 00010246
> RAX: ffffffff81159fc0 RBX: ffffc900005bfeb8 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 01bffa5c419cfb69 RDI: ffffc900005bfd70
> RBP: ffffc90000013c10 R08: ffffc900005bfdc0 R09: ffffffff81ff10ed
> R10: 00000000d1b71759 R11: ffffffff81ff10dd R12: ffffc90000013a78
> R13: ffff88810eb78180 R14: ffffffff818297c0 R15: ffffc90000013c28
> FS: 0000000000000000(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000000000 CR3: 0000000002a1c001 CR4: 0000000000370ee0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> damon_test_set_attrs+0x63/0x1f0
> kunit_generic_run_threadfn_adapter+0x17/0x30
> kthread+0xfd/0x130
Great. But it would be even greater if you could this kind of output after
decoding the addreses using 'scripts/decode_stacktrace.sh` or
'scripts/faddr2line' from next time if possible.
>
> The problem seems to be related with the damon_ctx was used without
> being initialized. Fix it by adding the initialization.
Somehow the test always passed on my test machine, but maybe that's due to some
different behavior of my compiler. I agree that could be the root cause
because 'damon_set_attrs()' calls 'damon_update_monitoring_results()', which
accesses the context's fields including the targets list. Since the list is
not initialized in this test code, it would cause such error.
>
> Fixes: aa13779be6b7 ("mm/damon/core-test: add a test for damon_set_attrs()")
> Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
Thanks,
SJ
> ---
> mm/damon/core-test.h | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/mm/damon/core-test.h b/mm/damon/core-test.h
> index c11210124344..bb07721909e1 100644
> --- a/mm/damon/core-test.h
> +++ b/mm/damon/core-test.h
> @@ -320,25 +320,25 @@ static void damon_test_update_monitoring_result(struct kunit *test)
>
> static void damon_test_set_attrs(struct kunit *test)
> {
> - struct damon_ctx ctx;
> + struct damon_ctx *c = damon_new_ctx();
> struct damon_attrs valid_attrs = {
> .min_nr_regions = 10, .max_nr_regions = 1000,
> .sample_interval = 5000, .aggr_interval = 100000,};
> struct damon_attrs invalid_attrs;
>
> - KUNIT_EXPECT_EQ(test, damon_set_attrs(&ctx, &valid_attrs), 0);
> + KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &valid_attrs), 0);
>
> invalid_attrs = valid_attrs;
> invalid_attrs.min_nr_regions = 1;
> - KUNIT_EXPECT_EQ(test, damon_set_attrs(&ctx, &invalid_attrs), -EINVAL);
> + KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &invalid_attrs), -EINVAL);
>
> invalid_attrs = valid_attrs;
> invalid_attrs.max_nr_regions = 9;
> - KUNIT_EXPECT_EQ(test, damon_set_attrs(&ctx, &invalid_attrs), -EINVAL);
> + KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &invalid_attrs), -EINVAL);
>
> invalid_attrs = valid_attrs;
> invalid_attrs.aggr_interval = 4999;
> - KUNIT_EXPECT_EQ(test, damon_set_attrs(&ctx, &invalid_attrs), -EINVAL);
> + KUNIT_EXPECT_EQ(test, damon_set_attrs(c, &invalid_attrs), -EINVAL);
> }
>
> static struct kunit_case damon_test_cases[] = {
> --
> 2.34.1
>
>
>
