/* * tsacct.c - System accounting over taskstats interface * * Copyright (C) Jay Lan, * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #include #include #include #include #include #include /* * fill in basic accounting fields */ void bacct_add_tsk(struct user_namespace *user_ns, struct pid_namespace *pid_ns, struct taskstats *stats, struct task_struct *tsk) { const struct cred *tcred; cputime_t utime, stime, utimescaled, stimescaled; u64 delta; BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN); /* calculate task elapsed time in nsec */ delta = ktime_get_ns() - tsk->start_time; /* Convert to micro seconds */ do_div(delta, NSEC_PER_USEC); stats->ac_etime = delta; /* Convert to seconds for btime */ do_div(delta, USEC_PER_SEC); stats->ac_btime = get_seconds() - delta; if (thread_group_leader(tsk)) { stats->ac_exitcode = tsk->exit_code; if (tsk->flags & PF_FORKNOEXEC) stats->ac_flag |= AFORK; } if (tsk->flags & PF_SUPERPRIV) stats->ac_flag |= ASU; if (tsk->flags & PF_DUMPCORE) stats->ac_flag |= ACORE; if (tsk->flags & PF_SIGNALED) stats->ac_flag |= AXSIG; stats->ac_nice = task_nice(tsk); stats->ac_sched = tsk->policy; stats->ac_pid = task_pid_nr_ns(tsk, pid_ns); rcu_read_lock(); tcred = __task_cred(tsk); stats->ac_uid = from_kuid_munged(user_ns, tcred->uid); stats->ac_gid = from_kgid_munged(user_ns, tcred->gid); stats->ac_ppid = pid_alive(tsk) ? task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0; rcu_read_unlock(); task_cputime(tsk, &utime, &stime); stats->ac_utime = cputime_to_usecs(utime); stats->ac_stime = cputime_to_usecs(stime); task_cputime_scaled(tsk, &utimescaled, &stimescaled); stats->ac_utimescaled = cputime_to_usecs(utimescaled); stats->ac_stimescaled = cputime_to_usecs(stimescaled); stats->ac_minflt = tsk->min_flt; stats->ac_majflt = tsk->maj_flt; strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm)); } #ifdef CONFIG_TASK_XACCT #define KB 1024 #define MB (1024*KB) #define KB_MASK (~(KB-1)) /* * fill in extended accounting fields */ void xacct_add_tsk(struct taskstats *stats, struct task_struct *p) { struct mm_struct *mm; /* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */ stats->coremem = p->acct_rss_mem1 * PAGE_SIZE; do_div(stats->coremem, 1000 * KB); stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE; do_div(stats->virtmem, 1000 * KB); mm = get_task_mm(p); if (mm) { /* adjust to KB unit */ stats->hiwater_rss = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB; stats->hiwater_vm = get_mm_hiwater_vm(mm) * PAGE_SIZE / KB; mmput(mm); } stats->read_char = p->ioac.rchar & KB_MASK; stats->write_char = p->ioac.wchar & KB_MASK; stats->read_syscalls = p->ioac.syscr & KB_MASK; stats->write_syscalls = p->ioac.syscw & KB_MASK; #ifdef CONFIG_TASK_IO_ACCOUNTING stats->read_bytes = p->ioac.read_bytes & KB_MASK; stats->write_bytes = p->ioac.write_bytes & KB_MASK; stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK; #else stats->read_bytes = 0; stats->write_bytes = 0; stats->cancelled_write_bytes = 0; #endif } #undef KB #undef MB static void __acct_update_integrals(struct task_struct *tsk, cputime_t utime, cputime_t stime) { cputime_t time, dtime; u64 delta; if (!likely(tsk->mm)) return; time = stime + utime; dtime = time - tsk->acct_timexpd; /* Avoid division: cputime_t is often in nanoseconds already. */ delta = cputime_to_nsecs(dtime); if (delta < TICK_NSEC) return; tsk->acct_timexpd = time; /* * Divide by 1024 to avoid overflow, and to avoid division. * The final unit reported to userspace is Mbyte-usecs, * the rest of the math is done in xacct_add_tsk. */ tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10; tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10; } /** * acct_update_integrals - update mm integral fields in task_struct * @tsk: task_struct for accounting */ void acct_update_integrals(struct task_struct *tsk) { cputime_t utime, stime; unsigned long flags; local_irq_save(flags); task_cputime(tsk, &utime, &stime); __acct_update_integrals(tsk, utime, stime); local_irq_restore(flags); } /** * acct_account_cputime - update mm integral after cputime update * @tsk: task_struct for accounting */ void acct_account_cputime(struct task_struct *tsk) { __acct_update_integrals(tsk, tsk->utime, tsk->stime); } /** * acct_clear_integrals - clear the mm integral fields in task_struct * @tsk: task_struct whose accounting fields are cleared */ void acct_clear_integrals(struct task_struct *tsk) { tsk->acct_timexpd = 0; tsk->acct_rss_mem1 = 0; tsk->acct_vm_mem1 = 0; } #endif gi/linux/net-next.git/tree/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1 /include/math-emu/op-4.h parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/math-emu/op-4.h')