bisecting fixing commit since 768292d053619b2725b846ed2bf556bf40f43de2 building syzkaller on ea2f400664b9a9695d642509056f973b827bae41 testing commit 768292d053619b2725b846ed2bf556bf40f43de2 with gcc (GCC) 8.1.0 kernel signature: f8875c5300a1da48163436bab34779827fcfe4b4 all runs: crashed: INFO: task hung in synchronize_rcu testing current HEAD db5b9190ff8202b609fe802ccde41cb28669389f testing commit db5b9190ff8202b609fe802ccde41cb28669389f with gcc (GCC) 8.1.0 kernel signature: 50fd8dfaf2d2d228283bff0cb1e8b9bed51d46ad all runs: OK # git bisect start db5b9190ff8202b609fe802ccde41cb28669389f 768292d053619b2725b846ed2bf556bf40f43de2 Bisecting: 2693 revisions left to test after this (roughly 11 steps) [e5641f02dc9e28e6710cf53d218bfa209a7718de] wil6210: fix freeing of rx buffers in EDMA mode testing commit e5641f02dc9e28e6710cf53d218bfa209a7718de with gcc (GCC) 8.1.0 kernel signature: 8df765893a34978d9dde318a60c081cb5f05171a all runs: crashed: INFO: task hung in synchronize_rcu # git bisect good e5641f02dc9e28e6710cf53d218bfa209a7718de Bisecting: 1346 revisions left to test after this (roughly 10 steps) [49ade064ea4b2836e1933fb8aa4c152ebecab6ab] clk: sunxi: Fix operator precedence in sunxi_divs_clk_setup testing commit 49ade064ea4b2836e1933fb8aa4c152ebecab6ab with gcc (GCC) 8.1.0 kernel signature: 294aaf7d741540465cd44e7a319061328f8fe3a4 run #0: crashed: INFO: task hung in synchronize_rcu run #1: crashed: INFO: task hung in synchronize_rcu run #2: crashed: INFO: task hung in synchronize_rcu run #3: crashed: INFO: task hung in synchronize_rcu run #4: crashed: INFO: task hung in synchronize_rcu run #5: crashed: INFO: task hung in synchronize_rcu run #6: crashed: INFO: task hung in synchronize_rcu run #7: crashed: INFO: task hung in synchronize_rcu run #8: crashed: INFO: task hung in synchronize_rcu run #9: OK # git bisect good 49ade064ea4b2836e1933fb8aa4c152ebecab6ab Bisecting: 673 revisions left to test after this (roughly 9 steps) [27d591844035ea8fd3908a3d1a592e6e4aaf6e02] drbd: Change drbd_request_detach_interruptible's return type to int testing commit 27d591844035ea8fd3908a3d1a592e6e4aaf6e02 with gcc (GCC) 8.1.0 kernel signature: fb311ec7f20224f875b22a5120eec70c2ddfa53e all runs: crashed: INFO: task hung in synchronize_rcu # git bisect good 27d591844035ea8fd3908a3d1a592e6e4aaf6e02 Bisecting: 336 revisions left to test after this (roughly 8 steps) [0af1ad3b1ce50fdcb0996c0cd918ce08dc82c14c] ext4: update direct I/O read lock pattern for IOCB_NOWAIT testing commit 0af1ad3b1ce50fdcb0996c0cd918ce08dc82c14c with gcc (GCC) 8.1.0 kernel signature: ebb80c807bb74818d2af489e49d74ea73f2626ae all runs: OK # git bisect bad 0af1ad3b1ce50fdcb0996c0cd918ce08dc82c14c Bisecting: 168 revisions left to test after this (roughly 7 steps) [45a6c3fb4c0b97881dba13d5894575c69ce97cef] extcon: sm5502: Reset registers during initialization testing commit 45a6c3fb4c0b97881dba13d5894575c69ce97cef with gcc (GCC) 8.1.0 kernel signature: dec65afaace38c02f579be3e99f56e67f7bcc353 all runs: OK # git bisect bad 45a6c3fb4c0b97881dba13d5894575c69ce97cef Bisecting: 83 revisions left to test after this (roughly 6 steps) [e8b26877c4290c84b493075ed515c2e3265c1e47] CIFS: Close open handle after interrupted close testing commit e8b26877c4290c84b493075ed515c2e3265c1e47 with gcc (GCC) 8.1.0 kernel signature: 4f72a14e2c8a7425edf695e68371a31aa278d2c0 all runs: OK # git bisect bad e8b26877c4290c84b493075ed515c2e3265c1e47 Bisecting: 41 revisions left to test after this (roughly 5 steps) [a40982c7e1f9d0a528bc32c17974f95b8ed5c40c] raid5: need to set STRIPE_HANDLE for batch head testing commit a40982c7e1f9d0a528bc32c17974f95b8ed5c40c with gcc (GCC) 8.1.0 kernel signature: f8f2ea97a32e8eb44c178d1a148eecd100ebf32f all runs: OK # git bisect bad a40982c7e1f9d0a528bc32c17974f95b8ed5c40c Bisecting: 20 revisions left to test after this (roughly 4 steps) [32b02bfd467f79a55eab70e29baa08d04cbb8683] mm/shmem.c: cast the type of unmap_start to u64 testing commit 32b02bfd467f79a55eab70e29baa08d04cbb8683 with gcc (GCC) 8.1.0 kernel signature: e66ebc29fcc75f5b4512b02d3a322b25841d5be4 all runs: crashed: INFO: task hung in synchronize_rcu # git bisect good 32b02bfd467f79a55eab70e29baa08d04cbb8683 Bisecting: 10 revisions left to test after this (roughly 3 steps) [f7654ebe928d46bd540e0305dbdcc57752de424c] gre: refetch erspan header from skb->data after pskb_may_pull() testing commit f7654ebe928d46bd540e0305dbdcc57752de424c with gcc (GCC) 8.1.0 kernel signature: 1223c750b44a69b0f0c379dd36fae44db4d30c56 all runs: OK # git bisect bad f7654ebe928d46bd540e0305dbdcc57752de424c Bisecting: 4 revisions left to test after this (roughly 2 steps) [c76adee3471f7fe0553904be7ab13c33eda64a19] mm, thp, proc: report THP eligibility for each vma testing commit c76adee3471f7fe0553904be7ab13c33eda64a19 with gcc (GCC) 8.1.0 kernel signature: 55e6240ab9aaee418a0b01092821e9fda9897c2b all runs: OK # git bisect bad c76adee3471f7fe0553904be7ab13c33eda64a19 Bisecting: 2 revisions left to test after this (roughly 1 step) [326ba910fa716dfcc721d7fd30889e4b1f85b1e0] splice: only read in as much information as there is pipe buffer space testing commit 326ba910fa716dfcc721d7fd30889e4b1f85b1e0 with gcc (GCC) 8.1.0 kernel signature: 2e7f1ce82b40d3a25e3342693d833a8066018cb0 all runs: OK # git bisect bad 326ba910fa716dfcc721d7fd30889e4b1f85b1e0 Bisecting: 0 revisions left to test after this (roughly 0 steps) [42a929edf5674aa5c9e2883dafca7eff2013729e] rtc: disable uie before setting time and enable after testing commit 42a929edf5674aa5c9e2883dafca7eff2013729e with gcc (GCC) 8.1.0 kernel signature: d4f242b8585dfd7ce7dbe059ad18175a63a451fb run #0: boot failed: failed to create instance: googleapi: Error 503: Internal error. Please try again or contact Google Support. (Code: '9011745606262495115'), backendError run #1: OK run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK # git bisect bad 42a929edf5674aa5c9e2883dafca7eff2013729e 42a929edf5674aa5c9e2883dafca7eff2013729e is the first bad commit commit 42a929edf5674aa5c9e2883dafca7eff2013729e Author: Alexandre Belloni Date: Mon Oct 21 01:13:20 2019 +0200 rtc: disable uie before setting time and enable after commit 7e7c005b4b1f1f169bcc4b2c3a40085ecc663df2 upstream. When setting the time in the future with the uie timer enabled, rtc_timer_do_work will loop for a while because the expiration of the uie timer was way before the current RTC time and a new timer will be enqueued until the current rtc time is reached. If the uie timer is enabled, disable it before setting the time and enable it after expiring current timers (which may actually be an alarm). This is the safest thing to do to ensure the uie timer is still synchronized with the RTC, especially in the UIE emulation case. Reported-by: syzbot+08116743f8ad6f9a6de7@syzkaller.appspotmail.com Fixes: 6610e0893b8b ("RTC: Rework RTC code to use timerqueue for events") Link: https://lore.kernel.org/r/20191020231320.8191-1-alexandre.belloni@bootlin.com Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman drivers/rtc/interface.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) culprit signature: d4f242b8585dfd7ce7dbe059ad18175a63a451fb parent signature: e66ebc29fcc75f5b4512b02d3a322b25841d5be4 revisions tested: 14, total time: 4h10m0.247950126s (build: 1h59m28.709889379s, test: 2h9m12.906123131s) first good commit: 42a929edf5674aa5c9e2883dafca7eff2013729e rtc: disable uie before setting time and enable after cc: ["a.zummo@towertech.it" "alexandre.belloni@bootlin.com" "gregkh@linuxfoundation.org" "linux-kernel@vger.kernel.org" "linux-rtc@vger.kernel.org"]