On 09/16/2013 02:40 PM, Dave Jones wrote: > On a slow machine (with debugging enabled), upgrading selinux policy may take > a considerable amount of time. Long enough that the softlockup detector > gets triggered. > > The backtrace looks like this.. > > > BUG: soft lockup - CPU#2 stuck for 23s! [load_policy:19045] > > Call Trace: > > [<ffffffff81221ddf>] symcmp+0xf/0x20 > > [<ffffffff81221c27>] hashtab_search+0x47/0x80 > > [<ffffffff8122e96c>] mls_convert_context+0xdc/0x1c0 > > [<ffffffff812294e8>] convert_context+0x378/0x460 > > [<ffffffff81229170>] ? security_context_to_sid_core+0x240/0x240 > > [<ffffffff812221b5>] sidtab_map+0x45/0x80 > > [<ffffffff8122bb9f>] security_load_policy+0x3ff/0x580 > > [<ffffffff810788a8>] ? sched_clock_cpu+0xa8/0x100 > > [<ffffffff810786dd>] ? sched_clock_local+0x1d/0x80 > > [<ffffffff810788a8>] ? sched_clock_cpu+0xa8/0x100 > > [<ffffffff8103096a>] ? __change_page_attr_set_clr+0x82a/0xa50 > > [<ffffffff810786dd>] ? sched_clock_local+0x1d/0x80 > > [<ffffffff810788a8>] ? sched_clock_cpu+0xa8/0x100 > > [<ffffffff8103096a>] ? __change_page_attr_set_clr+0x82a/0xa50 > > [<ffffffff810788a8>] ? sched_clock_cpu+0xa8/0x100 > > [<ffffffff81534ddc>] ? retint_restore_args+0xe/0xe > > [<ffffffff8109c82d>] ? trace_hardirqs_on_caller+0xfd/0x1c0 > > [<ffffffff81279a2e>] ? trace_hardirqs_on_thunk+0x3a/0x3f > > [<ffffffff810d28a8>] ? rcu_irq_exit+0x68/0xb0 > > [<ffffffff81534ddc>] ? retint_restore_args+0xe/0xe > > [<ffffffff8121e947>] sel_write_load+0xa7/0x770 > > [<ffffffff81139633>] ? vfs_write+0x1c3/0x200 > > [<ffffffff81210e8e>] ? security_file_permission+0x1e/0xa0 > > [<ffffffff8113952b>] vfs_write+0xbb/0x200 > > [<ffffffff811581c7>] ? fget_light+0x397/0x4b0 > > [<ffffffff81139c27>] SyS_write+0x47/0xa0 > > [<ffffffff8153bde4>] tracesys+0xdd/0xe2 > > Stephen Smalley suggested: > > > Maybe put a cond_resched() within the ebitmap_for_each_positive_bit() > > loop in mls_convert_context()? > > That seems to do the trick. Tested by downgrading and re-upgrading > selinux-policy-targeted. > > Signed-off-by: Dave Jones <da...@fedoraproject.org>
Acked-by: Stephen Smalley <s...@tycho.nsa.gov> > > diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c > index 40de8d3..9ef8e51 100644 > --- a/security/selinux/ss/mls.c > +++ b/security/selinux/ss/mls.c > @@ -500,6 +500,8 @@ int mls_convert_context(struct policydb *oldp, > rc = ebitmap_set_bit(&bitmap, catdatum->value - 1, 1); > if (rc) > return rc; > + > + cond_resched(); > } > ebitmap_destroy(&c->range.level[l].cat); > c->range.level[l].cat = bitmap; > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
