On 2/2/24 5:31 PM, Greg KH wrote:
On Thu, Feb 01, 2024 at 07:45:45PM -0800, Samasth Norway Ananda wrote:From: Yonghong Song <yonghong.song@xxxxxxxxx> [ Upstream commit 56925f389e152dcb8d093435d43b78a310539c23 ] With previous patch, one of subtests in test_btf_id becomes flaky and may fail. The following is a failing example: Error: #26 btf Error: #26/174 btf/BTF ID Error: #26/174 btf/BTF ID btf_raw_create:PASS:check 0 nsec btf_raw_create:PASS:check 0 nsec test_btf_id:PASS:check 0 nsec ... test_btf_id:PASS:check 0 nsec test_btf_id:FAIL:check BTF lingersdo_test_get_info:FAIL:check failed: -1 The test tries to prove a btf_id not available after the map is closed. But btf_id is freed only after workqueue and a rcu grace period, compared to previous case just after a rcu grade period. Depending on system workload, workqueue could take quite some time to execute function bpf_map_free_deferred() which may cause the test failure. Instead of adding arbitrary delays, let us remove the logic to check btf_id availability after map is closed. Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx> Link: https://urldefense.com/v3/__https://lore.kernel.org/r/20231214203820.1469402-1-yonghong.song@linux.dev__;!!ACWV5N9M2RV99hQ!I-3G5NyOo-Xom0b0NmUHYWm_hs6Ai1qD4A9smNew_5_8jyyEXbISpxoAPa4wSD_eXQr-IOAd4_TM2NBscejS$ Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> [Samasth: backport for 6.6.y] Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@xxxxxxxxxx> --- Above patch is a fix for 59e5791f59dd ("bpf: Fix a race condition between btf_put() and map_free()"). While the commit causing the error is present in 6.6.y the fix is not present. --- tools/testing/selftests/bpf/prog_tests/btf.c | 5 ----- 1 file changed, 5 deletions(-)What about 6.7 as well? Shouldn't this change be there too?
Yes, it should be there on 6.7 as well. Sorry, I should have mentioned that. Thanks, Samasth.
thanks, greg k-h
