August 2019 - Linux-stable-mirror

Re: [PATCH 8/8] ceph: hold i_ceph_lock when removing caps for freeing inode

by Sasha Levin

Hi, [This is an automated email] This commit has been processed because it contains a -stable tag. The stable tag indicates that it's relevant for the following trees: all The bot has tested the following trees: v5.1.4, v5.0.18, v4.19.45, v4.14.121, v4.9.178, v4.4.180, v3.18.140. v5.1.4: Build OK! v5.0.18: Failed to apply! Possible dependencies: e3ec8d6898f71 ("ceph: send cap releases more aggressively") v4.19.45: Failed to apply! Possible dependencies: e3ec8d6898f71 ("ceph: send cap releases more aggressively") v4.14.121: Failed to apply! Possible dependencies: a1c6b8358171c ("ceph: define argument structure for handle_cap_grant") a57d9064e4ee4 ("ceph: flush pending works before shutdown super") e3ec8d6898f71 ("ceph: send cap releases more aggressively") v4.9.178: Failed to apply! Possible dependencies: a1c6b8358171c ("ceph: define argument structure for handle_cap_grant") a57d9064e4ee4 ("ceph: flush pending works before shutdown super") e3ec8d6898f71 ("ceph: send cap releases more aggressively") v4.4.180: Failed to apply! Possible dependencies: 13d1ad16d05ee ("libceph: move message allocation out of ceph_osdc_alloc_request()") 34b759b4a22b0 ("ceph: kill ceph_empty_snapc") 3f1af42ad0fad ("libceph: enable large, variable-sized OSD requests") 5be0389dac662 ("ceph: re-send AIO write request when getting -EOLDSNAP error") 7627151ea30bc ("libceph: define new ceph_file_layout structure") 779fe0fb8e188 ("ceph: rados pool namespace support") 922dab6134178 ("libceph, rbd: ceph_osd_linger_request, watch/notify v2") a1c6b8358171c ("ceph: define argument structure for handle_cap_grant") ae458f5a171ba ("libceph: make r_request msg_size calculation clearer") c41d13a31fefe ("rbd: use header_oid instead of header_name") c8fe9b17d055f ("ceph: Asynchronous IO support") d30291b985d18 ("libceph: variable-sized ceph_object_id") e3ec8d6898f71 ("ceph: send cap releases more aggressively") v3.18.140: Failed to apply! Possible dependencies: 10183a69551f7 ("ceph: check OSD caps before read/write") 28127bdd2f843 ("ceph: convert inline data to normal data before data write") 31c542a199d79 ("ceph: add inline data to pagecache") 5be0389dac662 ("ceph: re-send AIO write request when getting -EOLDSNAP error") 70db4f3629b34 ("ceph: introduce a new inode flag indicating if cached dentries are ordered") 745a8e3bccbc6 ("ceph: don't pre-allocate space for cap release messages") 7627151ea30bc ("libceph: define new ceph_file_layout structure") 779fe0fb8e188 ("ceph: rados pool namespace support") 83701246aee8f ("ceph: sync read inline data") a1c6b8358171c ("ceph: define argument structure for handle_cap_grant") affbc19a68f99 ("ceph: make sure syncfs flushes all cap snaps") c8fe9b17d055f ("ceph: Asynchronous IO support") d30291b985d18 ("libceph: variable-sized ceph_object_id") d3383a8e37f80 ("ceph: avoid block operation when !TASK_RUNNING (ceph_mdsc_sync)") e3ec8d6898f71 ("ceph: send cap releases more aggressively") e96a650a8174e ("ceph, rbd: delete unnecessary checks before two function calls") How should we proceed with this patch? -- Thanks, Sasha

5 years, 3 months

3
2
0 0

[PATCH v5 1/3] [v4.9.y] coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping

by Ajay Kaher

From: Andrea Arcangeli <aarcange(a)redhat.com> commit 04f5866e41fb70690e28397487d8bd8eea7d712a upstream. The core dumping code has always run without holding the mmap_sem for writing, despite that is the only way to ensure that the entire vma layout will not change from under it. Only using some signal serialization on the processes belonging to the mm is not nearly enough. This was pointed out earlier. For example in Hugh's post from Jul 2017: https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils "Not strictly relevant here, but a related note: I was very surprised to discover, only quite recently, how handle_mm_fault() may be called without down_read(mmap_sem) - when core dumping. That seems a misguided optimization to me, which would also be nice to correct" In particular because the growsdown and growsup can move the vm_start/vm_end the various loops the core dump does around the vma will not be consistent if page faults can happen concurrently. Pretty much all users calling mmget_not_zero()/get_task_mm() and then taking the mmap_sem had the potential to introduce unexpected side effects in the core dumping code. Adding mmap_sem for writing around the ->core_dump invocation is a viable long term fix, but it requires removing all copy user and page faults and to replace them with get_dump_page() for all binary formats which is not suitable as a short term fix. For the time being this solution manually covers the places that can confuse the core dump either by altering the vma layout or the vma flags while it runs. Once ->core_dump runs under mmap_sem for writing the function mmget_still_valid() can be dropped. Allowing mmap_sem protected sections to run in parallel with the coredump provides some minor parallelism advantage to the swapoff code (which seems to be safe enough by never mangling any vma field and can keep doing swapins in parallel to the core dumping) and to some other corner case. In order to facilitate the backporting I added "Fixes: 86039bd3b4e6" however the side effect of this same race condition in /proc/pid/mem should be reproducible since before 2.6.12-rc2 so I couldn't add any other "Fixes:" because there's no hash beyond the git genesis commit. Because find_extend_vma() is the only location outside of the process context that could modify the "mm" structures under mmap_sem for reading, by adding the mmget_still_valid() check to it, all other cases that take the mmap_sem for reading don't need the new check after mmget_not_zero()/get_task_mm(). The expand_stack() in page fault context also doesn't need the new check, because all tasks under core dumping are frozen. Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com Fixes: 86039bd3b4e6 ("userfaultfd: add new syscall to provide memory externalization") Signed-off-by: Andrea Arcangeli <aarcange(a)redhat.com> Reported-by: Jann Horn <jannh(a)google.com> Suggested-by: Oleg Nesterov <oleg(a)redhat.com> Acked-by: Peter Xu <peterx(a)redhat.com> Reviewed-by: Mike Rapoport <rppt(a)linux.ibm.com> Reviewed-by: Oleg Nesterov <oleg(a)redhat.com> Reviewed-by: Jann Horn <jannh(a)google.com> Acked-by: Jason Gunthorpe <jgg(a)mellanox.com> Acked-by: Michal Hocko <mhocko(a)suse.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> [akaher(a)vmware.com: stable 4.9 backport - handle binder_update_page_range - mhocko(a)suse.com] Signed-off-by: Ajay Kaher <akaher(a)vmware.com> --- drivers/android/binder.c | 6 ++++++ fs/proc/task_mmu.c | 18 ++++++++++++++++++ fs/userfaultfd.c | 9 +++++++++ include/linux/mm.h | 21 +++++++++++++++++++++ mm/mmap.c | 6 +++++- 5 files changed, 59 insertions(+), 1 deletion(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 80499f4..f05ab8f 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -581,6 +581,12 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate, if (mm) { down_write(&mm->mmap_sem); + if (!mmget_still_valid(mm)) { + if (allocate == 0) + goto free_range; + goto err_no_vma; + } + vma = proc->vma; if (vma && mm != proc->vma_vm_mm) { pr_err("%d: vma mm and task mm mismatch\n", diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 5138e78..4b207b1 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1057,6 +1057,24 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, count = -EINTR; goto out_mm; } + /* + * Avoid to modify vma->vm_flags + * without locked ops while the + * coredump reads the vm_flags. + */ + if (!mmget_still_valid(mm)) { + /* + * Silently return "count" + * like if get_task_mm() + * failed. FIXME: should this + * function have returned + * -ESRCH if get_task_mm() + * failed like if + * get_proc_task() fails? + */ + up_write(&mm->mmap_sem); + goto out_mm; + } for (vma = mm->mmap; vma; vma = vma->vm_next) { vma->vm_flags &= ~VM_SOFTDIRTY; vma_set_page_prot(vma); diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 784d667..8bf425a 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -479,6 +479,8 @@ static int userfaultfd_release(struct inode *inode, struct file *file) * taking the mmap_sem for writing. */ down_write(&mm->mmap_sem); + if (!mmget_still_valid(mm)) + goto skip_mm; prev = NULL; for (vma = mm->mmap; vma; vma = vma->vm_next) { cond_resched(); @@ -501,6 +503,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file) vma->vm_flags = new_flags; vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX; } +skip_mm: up_write(&mm->mmap_sem); mmput(mm); wakeup: @@ -802,6 +805,9 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx, goto out; down_write(&mm->mmap_sem); + if (!mmget_still_valid(mm)) + goto out_unlock; + vma = find_vma_prev(mm, start, &prev); if (!vma) goto out_unlock; @@ -947,6 +953,9 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx, goto out; down_write(&mm->mmap_sem); + if (!mmget_still_valid(mm)) + goto out_unlock; + vma = find_vma_prev(mm, start, &prev); if (!vma) goto out_unlock; diff --git a/include/linux/mm.h b/include/linux/mm.h index e3c8d40..c239984 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1189,6 +1189,27 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long address, void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma, unsigned long start, unsigned long end); +/* + * This has to be called after a get_task_mm()/mmget_not_zero() + * followed by taking the mmap_sem for writing before modifying the + * vmas or anything the coredump pretends not to change from under it. + * + * NOTE: find_extend_vma() called from GUP context is the only place + * that can modify the "mm" (notably the vm_start/end) under mmap_sem + * for reading and outside the context of the process, so it is also + * the only case that holds the mmap_sem for reading that must call + * this function. Generally if the mmap_sem is hold for reading + * there's no need of this check after get_task_mm()/mmget_not_zero(). + * + * This function can be obsoleted and the check can be removed, after + * the coredump code will hold the mmap_sem for writing before + * invoking the ->core_dump methods. + */ +static inline bool mmget_still_valid(struct mm_struct *mm) +{ + return likely(!mm->core_state); +} + /** * mm_walk - callbacks for walk_page_range * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry diff --git a/mm/mmap.c b/mm/mmap.c index 3f2314a..19368fb 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2448,7 +2448,8 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr) vma = find_vma_prev(mm, addr, &prev); if (vma && (vma->vm_start <= addr)) return vma; - if (!prev || expand_stack(prev, addr)) + /* don't alter vm_end if the coredump is running */ + if (!prev || !mmget_still_valid(mm) || expand_stack(prev, addr)) return NULL; if (prev->vm_flags & VM_LOCKED) populate_vma_page_range(prev, addr, prev->vm_end, NULL); @@ -2474,6 +2475,9 @@ find_extend_vma(struct mm_struct *mm, unsigned long addr) return vma; if (!(vma->vm_flags & VM_GROWSDOWN)) return NULL; + /* don't alter vm_start if the coredump is running */ + if (!mmget_still_valid(mm)) + return NULL; start = vma->vm_start; if (expand_stack(vma, addr)) return NULL; -- 2.7.4

5 years, 3 months

2
5
0 0

FAILED: patch "[PATCH] sched/fair: Use RCU accessors consistently for ->numa_group" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From cb361d8cdef69990f6b4504dc1fd9a594d983c97 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 16 Jul 2019 17:20:47 +0200 Subject: [PATCH] sched/fair: Use RCU accessors consistently for ->numa_group The old code used RCU annotations and accessors inconsistently for ->numa_group, which can lead to use-after-frees and NULL dereferences. Let all accesses to ->numa_group use proper RCU helpers to prevent such issues. Signed-off-by: Jann Horn <jannh(a)google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Petr Mladek <pmladek(a)suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Will Deacon <will(a)kernel.org> Fixes: 8c8a743c5087 ("sched/numa: Use {cpu, pid} to create task groups for shared faults") Link: https://lkml.kernel.org/r/20190716152047.14424-3-jannh@google.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> diff --git a/include/linux/sched.h b/include/linux/sched.h index 8dc1811487f5..9f51932bd543 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1092,7 +1092,15 @@ struct task_struct { u64 last_sum_exec_runtime; struct callback_head numa_work; - struct numa_group *numa_group; + /* + * This pointer is only modified for current in syscall and + * pagefault context (and for tasks being destroyed), so it can be read + * from any of the following contexts: + * - RCU read-side critical section + * - current->numa_group from everywhere + * - task's runqueue locked, task not running + */ + struct numa_group __rcu *numa_group; /* * numa_faults is an array split into four regions: diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6adb0e0f5feb..bc9cfeaac8bd 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1086,6 +1086,21 @@ struct numa_group { unsigned long faults[0]; }; +/* + * For functions that can be called in multiple contexts that permit reading + * ->numa_group (see struct task_struct for locking rules). + */ +static struct numa_group *deref_task_numa_group(struct task_struct *p) +{ + return rcu_dereference_check(p->numa_group, p == current || + (lockdep_is_held(&task_rq(p)->lock) && !READ_ONCE(p->on_cpu))); +} + +static struct numa_group *deref_curr_numa_group(struct task_struct *p) +{ + return rcu_dereference_protected(p->numa_group, p == current); +} + static inline unsigned long group_faults_priv(struct numa_group *ng); static inline unsigned long group_faults_shared(struct numa_group *ng); @@ -1129,10 +1144,12 @@ static unsigned int task_scan_start(struct task_struct *p) { unsigned long smin = task_scan_min(p); unsigned long period = smin; + struct numa_group *ng; /* Scale the maximum scan period with the amount of shared memory. */ - if (p->numa_group) { - struct numa_group *ng = p->numa_group; + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); + if (ng) { unsigned long shared = group_faults_shared(ng); unsigned long private = group_faults_priv(ng); @@ -1140,6 +1157,7 @@ static unsigned int task_scan_start(struct task_struct *p) period *= shared + 1; period /= private + shared + 1; } + rcu_read_unlock(); return max(smin, period); } @@ -1148,13 +1166,14 @@ static unsigned int task_scan_max(struct task_struct *p) { unsigned long smin = task_scan_min(p); unsigned long smax; + struct numa_group *ng; /* Watch for min being lower than max due to floor calculations */ smax = sysctl_numa_balancing_scan_period_max / task_nr_scan_windows(p); /* Scale the maximum scan period with the amount of shared memory. */ - if (p->numa_group) { - struct numa_group *ng = p->numa_group; + ng = deref_curr_numa_group(p); + if (ng) { unsigned long shared = group_faults_shared(ng); unsigned long private = group_faults_priv(ng); unsigned long period = smax; @@ -1186,7 +1205,7 @@ void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) p->numa_scan_period = sysctl_numa_balancing_scan_delay; p->numa_work.next = &p->numa_work; p->numa_faults = NULL; - p->numa_group = NULL; + RCU_INIT_POINTER(p->numa_group, NULL); p->last_task_numa_placement = 0; p->last_sum_exec_runtime = 0; @@ -1233,7 +1252,16 @@ static void account_numa_dequeue(struct rq *rq, struct task_struct *p) pid_t task_numa_group_id(struct task_struct *p) { - return p->numa_group ? p->numa_group->gid : 0; + struct numa_group *ng; + pid_t gid = 0; + + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); + if (ng) + gid = ng->gid; + rcu_read_unlock(); + + return gid; } /* @@ -1258,11 +1286,13 @@ static inline unsigned long task_faults(struct task_struct *p, int nid) static inline unsigned long group_faults(struct task_struct *p, int nid) { - if (!p->numa_group) + struct numa_group *ng = deref_task_numa_group(p); + + if (!ng) return 0; - return p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 0)] + - p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 1)]; + return ng->faults[task_faults_idx(NUMA_MEM, nid, 0)] + + ng->faults[task_faults_idx(NUMA_MEM, nid, 1)]; } static inline unsigned long group_faults_cpu(struct numa_group *group, int nid) @@ -1400,12 +1430,13 @@ static inline unsigned long task_weight(struct task_struct *p, int nid, static inline unsigned long group_weight(struct task_struct *p, int nid, int dist) { + struct numa_group *ng = deref_task_numa_group(p); unsigned long faults, total_faults; - if (!p->numa_group) + if (!ng) return 0; - total_faults = p->numa_group->total_faults; + total_faults = ng->total_faults; if (!total_faults) return 0; @@ -1419,7 +1450,7 @@ static inline unsigned long group_weight(struct task_struct *p, int nid, bool should_numa_migrate_memory(struct task_struct *p, struct page * page, int src_nid, int dst_cpu) { - struct numa_group *ng = p->numa_group; + struct numa_group *ng = deref_curr_numa_group(p); int dst_nid = cpu_to_node(dst_cpu); int last_cpupid, this_cpupid; @@ -1600,13 +1631,14 @@ static bool load_too_imbalanced(long src_load, long dst_load, static void task_numa_compare(struct task_numa_env *env, long taskimp, long groupimp, bool maymove) { + struct numa_group *cur_ng, *p_ng = deref_curr_numa_group(env->p); struct rq *dst_rq = cpu_rq(env->dst_cpu); + long imp = p_ng ? groupimp : taskimp; struct task_struct *cur; long src_load, dst_load; - long load; - long imp = env->p->numa_group ? groupimp : taskimp; - long moveimp = imp; int dist = env->dist; + long moveimp = imp; + long load; if (READ_ONCE(dst_rq->numa_migrate_on)) return; @@ -1645,21 +1677,22 @@ static void task_numa_compare(struct task_numa_env *env, * If dst and source tasks are in the same NUMA group, or not * in any group then look only at task weights. */ - if (cur->numa_group == env->p->numa_group) { + cur_ng = rcu_dereference(cur->numa_group); + if (cur_ng == p_ng) { imp = taskimp + task_weight(cur, env->src_nid, dist) - task_weight(cur, env->dst_nid, dist); /* * Add some hysteresis to prevent swapping the * tasks within a group over tiny differences. */ - if (cur->numa_group) + if (cur_ng) imp -= imp / 16; } else { /* * Compare the group weights. If a task is all by itself * (not part of a group), use the task weight instead. */ - if (cur->numa_group && env->p->numa_group) + if (cur_ng && p_ng) imp += group_weight(cur, env->src_nid, dist) - group_weight(cur, env->dst_nid, dist); else @@ -1757,11 +1790,12 @@ static int task_numa_migrate(struct task_struct *p) .best_imp = 0, .best_cpu = -1, }; + unsigned long taskweight, groupweight; struct sched_domain *sd; + long taskimp, groupimp; + struct numa_group *ng; struct rq *best_rq; - unsigned long taskweight, groupweight; int nid, ret, dist; - long taskimp, groupimp; /* * Pick the lowest SD_NUMA domain, as that would have the smallest @@ -1807,7 +1841,8 @@ static int task_numa_migrate(struct task_struct *p) * multiple NUMA nodes; in order to better consolidate the group, * we need to check other locations. */ - if (env.best_cpu == -1 || (p->numa_group && p->numa_group->active_nodes > 1)) { + ng = deref_curr_numa_group(p); + if (env.best_cpu == -1 || (ng && ng->active_nodes > 1)) { for_each_online_node(nid) { if (nid == env.src_nid || nid == p->numa_preferred_nid) continue; @@ -1840,7 +1875,7 @@ static int task_numa_migrate(struct task_struct *p) * A task that migrated to a second choice node will be better off * trying for a better one later. Do not set the preferred node here. */ - if (p->numa_group) { + if (ng) { if (env.best_cpu == -1) nid = env.src_nid; else @@ -2135,6 +2170,7 @@ static void task_numa_placement(struct task_struct *p) unsigned long total_faults; u64 runtime, period; spinlock_t *group_lock = NULL; + struct numa_group *ng; /* * The p->mm->numa_scan_seq field gets updated without @@ -2152,8 +2188,9 @@ static void task_numa_placement(struct task_struct *p) runtime = numa_get_avg_runtime(p, &period); /* If the task is part of a group prevent parallel updates to group stats */ - if (p->numa_group) { - group_lock = &p->numa_group->lock; + ng = deref_curr_numa_group(p); + if (ng) { + group_lock = &ng->lock; spin_lock_irq(group_lock); } @@ -2194,7 +2231,7 @@ static void task_numa_placement(struct task_struct *p) p->numa_faults[cpu_idx] += f_diff; faults += p->numa_faults[mem_idx]; p->total_numa_faults += diff; - if (p->numa_group) { + if (ng) { /* * safe because we can only change our own group * @@ -2202,14 +2239,14 @@ static void task_numa_placement(struct task_struct *p) * nid and priv in a specific region because it * is at the beginning of the numa_faults array. */ - p->numa_group->faults[mem_idx] += diff; - p->numa_group->faults_cpu[mem_idx] += f_diff; - p->numa_group->total_faults += diff; - group_faults += p->numa_group->faults[mem_idx]; + ng->faults[mem_idx] += diff; + ng->faults_cpu[mem_idx] += f_diff; + ng->total_faults += diff; + group_faults += ng->faults[mem_idx]; } } - if (!p->numa_group) { + if (!ng) { if (faults > max_faults) { max_faults = faults; max_nid = nid; @@ -2220,8 +2257,8 @@ static void task_numa_placement(struct task_struct *p) } } - if (p->numa_group) { - numa_group_count_active_nodes(p->numa_group); + if (ng) { + numa_group_count_active_nodes(ng); spin_unlock_irq(group_lock); max_nid = preferred_group_nid(p, max_nid); } @@ -2255,7 +2292,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, int cpu = cpupid_to_cpu(cpupid); int i; - if (unlikely(!p->numa_group)) { + if (unlikely(!deref_curr_numa_group(p))) { unsigned int size = sizeof(struct numa_group) + 4*nr_node_ids*sizeof(unsigned long); @@ -2291,7 +2328,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, if (!grp) goto no_join; - my_grp = p->numa_group; + my_grp = deref_curr_numa_group(p); if (grp == my_grp) goto no_join; @@ -2362,7 +2399,8 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, */ void task_numa_free(struct task_struct *p, bool final) { - struct numa_group *grp = p->numa_group; + /* safe: p either is current or is being freed by current */ + struct numa_group *grp = rcu_dereference_raw(p->numa_group); unsigned long *numa_faults = p->numa_faults; unsigned long flags; int i; @@ -2442,7 +2480,7 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags) * actively using should be counted as local. This allows the * scan rate to slow down when a workload has settled down. */ - ng = p->numa_group; + ng = deref_curr_numa_group(p); if (!priv && !local && ng && ng->active_nodes > 1 && numa_is_active_node(cpu_node, ng) && numa_is_active_node(mem_node, ng)) @@ -10460,18 +10498,22 @@ void show_numa_stats(struct task_struct *p, struct seq_file *m) { int node; unsigned long tsf = 0, tpf = 0, gsf = 0, gpf = 0; + struct numa_group *ng; + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); for_each_online_node(node) { if (p->numa_faults) { tsf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 0)]; tpf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 1)]; } - if (p->numa_group) { - gsf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 0)], - gpf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 1)]; + if (ng) { + gsf = ng->faults[task_faults_idx(NUMA_MEM, node, 0)], + gpf = ng->faults[task_faults_idx(NUMA_MEM, node, 1)]; } print_numa_stats(m, node, tsf, tpf, gsf, gpf); } + rcu_read_unlock(); } #endif /* CONFIG_NUMA_BALANCING */ #endif /* CONFIG_SCHED_DEBUG */

5 years, 3 months

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FAILED: patch "[PATCH] sched/fair: Use RCU accessors consistently for ->numa_group" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From cb361d8cdef69990f6b4504dc1fd9a594d983c97 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 16 Jul 2019 17:20:47 +0200 Subject: [PATCH] sched/fair: Use RCU accessors consistently for ->numa_group The old code used RCU annotations and accessors inconsistently for ->numa_group, which can lead to use-after-frees and NULL dereferences. Let all accesses to ->numa_group use proper RCU helpers to prevent such issues. Signed-off-by: Jann Horn <jannh(a)google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Petr Mladek <pmladek(a)suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Will Deacon <will(a)kernel.org> Fixes: 8c8a743c5087 ("sched/numa: Use {cpu, pid} to create task groups for shared faults") Link: https://lkml.kernel.org/r/20190716152047.14424-3-jannh@google.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> diff --git a/include/linux/sched.h b/include/linux/sched.h index 8dc1811487f5..9f51932bd543 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1092,7 +1092,15 @@ struct task_struct { u64 last_sum_exec_runtime; struct callback_head numa_work; - struct numa_group *numa_group; + /* + * This pointer is only modified for current in syscall and + * pagefault context (and for tasks being destroyed), so it can be read + * from any of the following contexts: + * - RCU read-side critical section + * - current->numa_group from everywhere + * - task's runqueue locked, task not running + */ + struct numa_group __rcu *numa_group; /* * numa_faults is an array split into four regions: diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6adb0e0f5feb..bc9cfeaac8bd 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1086,6 +1086,21 @@ struct numa_group { unsigned long faults[0]; }; +/* + * For functions that can be called in multiple contexts that permit reading + * ->numa_group (see struct task_struct for locking rules). + */ +static struct numa_group *deref_task_numa_group(struct task_struct *p) +{ + return rcu_dereference_check(p->numa_group, p == current || + (lockdep_is_held(&task_rq(p)->lock) && !READ_ONCE(p->on_cpu))); +} + +static struct numa_group *deref_curr_numa_group(struct task_struct *p) +{ + return rcu_dereference_protected(p->numa_group, p == current); +} + static inline unsigned long group_faults_priv(struct numa_group *ng); static inline unsigned long group_faults_shared(struct numa_group *ng); @@ -1129,10 +1144,12 @@ static unsigned int task_scan_start(struct task_struct *p) { unsigned long smin = task_scan_min(p); unsigned long period = smin; + struct numa_group *ng; /* Scale the maximum scan period with the amount of shared memory. */ - if (p->numa_group) { - struct numa_group *ng = p->numa_group; + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); + if (ng) { unsigned long shared = group_faults_shared(ng); unsigned long private = group_faults_priv(ng); @@ -1140,6 +1157,7 @@ static unsigned int task_scan_start(struct task_struct *p) period *= shared + 1; period /= private + shared + 1; } + rcu_read_unlock(); return max(smin, period); } @@ -1148,13 +1166,14 @@ static unsigned int task_scan_max(struct task_struct *p) { unsigned long smin = task_scan_min(p); unsigned long smax; + struct numa_group *ng; /* Watch for min being lower than max due to floor calculations */ smax = sysctl_numa_balancing_scan_period_max / task_nr_scan_windows(p); /* Scale the maximum scan period with the amount of shared memory. */ - if (p->numa_group) { - struct numa_group *ng = p->numa_group; + ng = deref_curr_numa_group(p); + if (ng) { unsigned long shared = group_faults_shared(ng); unsigned long private = group_faults_priv(ng); unsigned long period = smax; @@ -1186,7 +1205,7 @@ void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) p->numa_scan_period = sysctl_numa_balancing_scan_delay; p->numa_work.next = &p->numa_work; p->numa_faults = NULL; - p->numa_group = NULL; + RCU_INIT_POINTER(p->numa_group, NULL); p->last_task_numa_placement = 0; p->last_sum_exec_runtime = 0; @@ -1233,7 +1252,16 @@ static void account_numa_dequeue(struct rq *rq, struct task_struct *p) pid_t task_numa_group_id(struct task_struct *p) { - return p->numa_group ? p->numa_group->gid : 0; + struct numa_group *ng; + pid_t gid = 0; + + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); + if (ng) + gid = ng->gid; + rcu_read_unlock(); + + return gid; } /* @@ -1258,11 +1286,13 @@ static inline unsigned long task_faults(struct task_struct *p, int nid) static inline unsigned long group_faults(struct task_struct *p, int nid) { - if (!p->numa_group) + struct numa_group *ng = deref_task_numa_group(p); + + if (!ng) return 0; - return p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 0)] + - p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 1)]; + return ng->faults[task_faults_idx(NUMA_MEM, nid, 0)] + + ng->faults[task_faults_idx(NUMA_MEM, nid, 1)]; } static inline unsigned long group_faults_cpu(struct numa_group *group, int nid) @@ -1400,12 +1430,13 @@ static inline unsigned long task_weight(struct task_struct *p, int nid, static inline unsigned long group_weight(struct task_struct *p, int nid, int dist) { + struct numa_group *ng = deref_task_numa_group(p); unsigned long faults, total_faults; - if (!p->numa_group) + if (!ng) return 0; - total_faults = p->numa_group->total_faults; + total_faults = ng->total_faults; if (!total_faults) return 0; @@ -1419,7 +1450,7 @@ static inline unsigned long group_weight(struct task_struct *p, int nid, bool should_numa_migrate_memory(struct task_struct *p, struct page * page, int src_nid, int dst_cpu) { - struct numa_group *ng = p->numa_group; + struct numa_group *ng = deref_curr_numa_group(p); int dst_nid = cpu_to_node(dst_cpu); int last_cpupid, this_cpupid; @@ -1600,13 +1631,14 @@ static bool load_too_imbalanced(long src_load, long dst_load, static void task_numa_compare(struct task_numa_env *env, long taskimp, long groupimp, bool maymove) { + struct numa_group *cur_ng, *p_ng = deref_curr_numa_group(env->p); struct rq *dst_rq = cpu_rq(env->dst_cpu); + long imp = p_ng ? groupimp : taskimp; struct task_struct *cur; long src_load, dst_load; - long load; - long imp = env->p->numa_group ? groupimp : taskimp; - long moveimp = imp; int dist = env->dist; + long moveimp = imp; + long load; if (READ_ONCE(dst_rq->numa_migrate_on)) return; @@ -1645,21 +1677,22 @@ static void task_numa_compare(struct task_numa_env *env, * If dst and source tasks are in the same NUMA group, or not * in any group then look only at task weights. */ - if (cur->numa_group == env->p->numa_group) { + cur_ng = rcu_dereference(cur->numa_group); + if (cur_ng == p_ng) { imp = taskimp + task_weight(cur, env->src_nid, dist) - task_weight(cur, env->dst_nid, dist); /* * Add some hysteresis to prevent swapping the * tasks within a group over tiny differences. */ - if (cur->numa_group) + if (cur_ng) imp -= imp / 16; } else { /* * Compare the group weights. If a task is all by itself * (not part of a group), use the task weight instead. */ - if (cur->numa_group && env->p->numa_group) + if (cur_ng && p_ng) imp += group_weight(cur, env->src_nid, dist) - group_weight(cur, env->dst_nid, dist); else @@ -1757,11 +1790,12 @@ static int task_numa_migrate(struct task_struct *p) .best_imp = 0, .best_cpu = -1, }; + unsigned long taskweight, groupweight; struct sched_domain *sd; + long taskimp, groupimp; + struct numa_group *ng; struct rq *best_rq; - unsigned long taskweight, groupweight; int nid, ret, dist; - long taskimp, groupimp; /* * Pick the lowest SD_NUMA domain, as that would have the smallest @@ -1807,7 +1841,8 @@ static int task_numa_migrate(struct task_struct *p) * multiple NUMA nodes; in order to better consolidate the group, * we need to check other locations. */ - if (env.best_cpu == -1 || (p->numa_group && p->numa_group->active_nodes > 1)) { + ng = deref_curr_numa_group(p); + if (env.best_cpu == -1 || (ng && ng->active_nodes > 1)) { for_each_online_node(nid) { if (nid == env.src_nid || nid == p->numa_preferred_nid) continue; @@ -1840,7 +1875,7 @@ static int task_numa_migrate(struct task_struct *p) * A task that migrated to a second choice node will be better off * trying for a better one later. Do not set the preferred node here. */ - if (p->numa_group) { + if (ng) { if (env.best_cpu == -1) nid = env.src_nid; else @@ -2135,6 +2170,7 @@ static void task_numa_placement(struct task_struct *p) unsigned long total_faults; u64 runtime, period; spinlock_t *group_lock = NULL; + struct numa_group *ng; /* * The p->mm->numa_scan_seq field gets updated without @@ -2152,8 +2188,9 @@ static void task_numa_placement(struct task_struct *p) runtime = numa_get_avg_runtime(p, &period); /* If the task is part of a group prevent parallel updates to group stats */ - if (p->numa_group) { - group_lock = &p->numa_group->lock; + ng = deref_curr_numa_group(p); + if (ng) { + group_lock = &ng->lock; spin_lock_irq(group_lock); } @@ -2194,7 +2231,7 @@ static void task_numa_placement(struct task_struct *p) p->numa_faults[cpu_idx] += f_diff; faults += p->numa_faults[mem_idx]; p->total_numa_faults += diff; - if (p->numa_group) { + if (ng) { /* * safe because we can only change our own group * @@ -2202,14 +2239,14 @@ static void task_numa_placement(struct task_struct *p) * nid and priv in a specific region because it * is at the beginning of the numa_faults array. */ - p->numa_group->faults[mem_idx] += diff; - p->numa_group->faults_cpu[mem_idx] += f_diff; - p->numa_group->total_faults += diff; - group_faults += p->numa_group->faults[mem_idx]; + ng->faults[mem_idx] += diff; + ng->faults_cpu[mem_idx] += f_diff; + ng->total_faults += diff; + group_faults += ng->faults[mem_idx]; } } - if (!p->numa_group) { + if (!ng) { if (faults > max_faults) { max_faults = faults; max_nid = nid; @@ -2220,8 +2257,8 @@ static void task_numa_placement(struct task_struct *p) } } - if (p->numa_group) { - numa_group_count_active_nodes(p->numa_group); + if (ng) { + numa_group_count_active_nodes(ng); spin_unlock_irq(group_lock); max_nid = preferred_group_nid(p, max_nid); } @@ -2255,7 +2292,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, int cpu = cpupid_to_cpu(cpupid); int i; - if (unlikely(!p->numa_group)) { + if (unlikely(!deref_curr_numa_group(p))) { unsigned int size = sizeof(struct numa_group) + 4*nr_node_ids*sizeof(unsigned long); @@ -2291,7 +2328,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, if (!grp) goto no_join; - my_grp = p->numa_group; + my_grp = deref_curr_numa_group(p); if (grp == my_grp) goto no_join; @@ -2362,7 +2399,8 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, */ void task_numa_free(struct task_struct *p, bool final) { - struct numa_group *grp = p->numa_group; + /* safe: p either is current or is being freed by current */ + struct numa_group *grp = rcu_dereference_raw(p->numa_group); unsigned long *numa_faults = p->numa_faults; unsigned long flags; int i; @@ -2442,7 +2480,7 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags) * actively using should be counted as local. This allows the * scan rate to slow down when a workload has settled down. */ - ng = p->numa_group; + ng = deref_curr_numa_group(p); if (!priv && !local && ng && ng->active_nodes > 1 && numa_is_active_node(cpu_node, ng) && numa_is_active_node(mem_node, ng)) @@ -10460,18 +10498,22 @@ void show_numa_stats(struct task_struct *p, struct seq_file *m) { int node; unsigned long tsf = 0, tpf = 0, gsf = 0, gpf = 0; + struct numa_group *ng; + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); for_each_online_node(node) { if (p->numa_faults) { tsf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 0)]; tpf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 1)]; } - if (p->numa_group) { - gsf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 0)], - gpf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 1)]; + if (ng) { + gsf = ng->faults[task_faults_idx(NUMA_MEM, node, 0)], + gpf = ng->faults[task_faults_idx(NUMA_MEM, node, 1)]; } print_numa_stats(m, node, tsf, tpf, gsf, gpf); } + rcu_read_unlock(); } #endif /* CONFIG_NUMA_BALANCING */ #endif /* CONFIG_SCHED_DEBUG */

5 years, 3 months

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FAILED: patch "[PATCH] sched/fair: Use RCU accessors consistently for ->numa_group" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From cb361d8cdef69990f6b4504dc1fd9a594d983c97 Mon Sep 17 00:00:00 2001 From: Jann Horn <jannh(a)google.com> Date: Tue, 16 Jul 2019 17:20:47 +0200 Subject: [PATCH] sched/fair: Use RCU accessors consistently for ->numa_group The old code used RCU annotations and accessors inconsistently for ->numa_group, which can lead to use-after-frees and NULL dereferences. Let all accesses to ->numa_group use proper RCU helpers to prevent such issues. Signed-off-by: Jann Horn <jannh(a)google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Petr Mladek <pmladek(a)suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Will Deacon <will(a)kernel.org> Fixes: 8c8a743c5087 ("sched/numa: Use {cpu, pid} to create task groups for shared faults") Link: https://lkml.kernel.org/r/20190716152047.14424-3-jannh@google.com Signed-off-by: Ingo Molnar <mingo(a)kernel.org> diff --git a/include/linux/sched.h b/include/linux/sched.h index 8dc1811487f5..9f51932bd543 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1092,7 +1092,15 @@ struct task_struct { u64 last_sum_exec_runtime; struct callback_head numa_work; - struct numa_group *numa_group; + /* + * This pointer is only modified for current in syscall and + * pagefault context (and for tasks being destroyed), so it can be read + * from any of the following contexts: + * - RCU read-side critical section + * - current->numa_group from everywhere + * - task's runqueue locked, task not running + */ + struct numa_group __rcu *numa_group; /* * numa_faults is an array split into four regions: diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 6adb0e0f5feb..bc9cfeaac8bd 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1086,6 +1086,21 @@ struct numa_group { unsigned long faults[0]; }; +/* + * For functions that can be called in multiple contexts that permit reading + * ->numa_group (see struct task_struct for locking rules). + */ +static struct numa_group *deref_task_numa_group(struct task_struct *p) +{ + return rcu_dereference_check(p->numa_group, p == current || + (lockdep_is_held(&task_rq(p)->lock) && !READ_ONCE(p->on_cpu))); +} + +static struct numa_group *deref_curr_numa_group(struct task_struct *p) +{ + return rcu_dereference_protected(p->numa_group, p == current); +} + static inline unsigned long group_faults_priv(struct numa_group *ng); static inline unsigned long group_faults_shared(struct numa_group *ng); @@ -1129,10 +1144,12 @@ static unsigned int task_scan_start(struct task_struct *p) { unsigned long smin = task_scan_min(p); unsigned long period = smin; + struct numa_group *ng; /* Scale the maximum scan period with the amount of shared memory. */ - if (p->numa_group) { - struct numa_group *ng = p->numa_group; + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); + if (ng) { unsigned long shared = group_faults_shared(ng); unsigned long private = group_faults_priv(ng); @@ -1140,6 +1157,7 @@ static unsigned int task_scan_start(struct task_struct *p) period *= shared + 1; period /= private + shared + 1; } + rcu_read_unlock(); return max(smin, period); } @@ -1148,13 +1166,14 @@ static unsigned int task_scan_max(struct task_struct *p) { unsigned long smin = task_scan_min(p); unsigned long smax; + struct numa_group *ng; /* Watch for min being lower than max due to floor calculations */ smax = sysctl_numa_balancing_scan_period_max / task_nr_scan_windows(p); /* Scale the maximum scan period with the amount of shared memory. */ - if (p->numa_group) { - struct numa_group *ng = p->numa_group; + ng = deref_curr_numa_group(p); + if (ng) { unsigned long shared = group_faults_shared(ng); unsigned long private = group_faults_priv(ng); unsigned long period = smax; @@ -1186,7 +1205,7 @@ void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) p->numa_scan_period = sysctl_numa_balancing_scan_delay; p->numa_work.next = &p->numa_work; p->numa_faults = NULL; - p->numa_group = NULL; + RCU_INIT_POINTER(p->numa_group, NULL); p->last_task_numa_placement = 0; p->last_sum_exec_runtime = 0; @@ -1233,7 +1252,16 @@ static void account_numa_dequeue(struct rq *rq, struct task_struct *p) pid_t task_numa_group_id(struct task_struct *p) { - return p->numa_group ? p->numa_group->gid : 0; + struct numa_group *ng; + pid_t gid = 0; + + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); + if (ng) + gid = ng->gid; + rcu_read_unlock(); + + return gid; } /* @@ -1258,11 +1286,13 @@ static inline unsigned long task_faults(struct task_struct *p, int nid) static inline unsigned long group_faults(struct task_struct *p, int nid) { - if (!p->numa_group) + struct numa_group *ng = deref_task_numa_group(p); + + if (!ng) return 0; - return p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 0)] + - p->numa_group->faults[task_faults_idx(NUMA_MEM, nid, 1)]; + return ng->faults[task_faults_idx(NUMA_MEM, nid, 0)] + + ng->faults[task_faults_idx(NUMA_MEM, nid, 1)]; } static inline unsigned long group_faults_cpu(struct numa_group *group, int nid) @@ -1400,12 +1430,13 @@ static inline unsigned long task_weight(struct task_struct *p, int nid, static inline unsigned long group_weight(struct task_struct *p, int nid, int dist) { + struct numa_group *ng = deref_task_numa_group(p); unsigned long faults, total_faults; - if (!p->numa_group) + if (!ng) return 0; - total_faults = p->numa_group->total_faults; + total_faults = ng->total_faults; if (!total_faults) return 0; @@ -1419,7 +1450,7 @@ static inline unsigned long group_weight(struct task_struct *p, int nid, bool should_numa_migrate_memory(struct task_struct *p, struct page * page, int src_nid, int dst_cpu) { - struct numa_group *ng = p->numa_group; + struct numa_group *ng = deref_curr_numa_group(p); int dst_nid = cpu_to_node(dst_cpu); int last_cpupid, this_cpupid; @@ -1600,13 +1631,14 @@ static bool load_too_imbalanced(long src_load, long dst_load, static void task_numa_compare(struct task_numa_env *env, long taskimp, long groupimp, bool maymove) { + struct numa_group *cur_ng, *p_ng = deref_curr_numa_group(env->p); struct rq *dst_rq = cpu_rq(env->dst_cpu); + long imp = p_ng ? groupimp : taskimp; struct task_struct *cur; long src_load, dst_load; - long load; - long imp = env->p->numa_group ? groupimp : taskimp; - long moveimp = imp; int dist = env->dist; + long moveimp = imp; + long load; if (READ_ONCE(dst_rq->numa_migrate_on)) return; @@ -1645,21 +1677,22 @@ static void task_numa_compare(struct task_numa_env *env, * If dst and source tasks are in the same NUMA group, or not * in any group then look only at task weights. */ - if (cur->numa_group == env->p->numa_group) { + cur_ng = rcu_dereference(cur->numa_group); + if (cur_ng == p_ng) { imp = taskimp + task_weight(cur, env->src_nid, dist) - task_weight(cur, env->dst_nid, dist); /* * Add some hysteresis to prevent swapping the * tasks within a group over tiny differences. */ - if (cur->numa_group) + if (cur_ng) imp -= imp / 16; } else { /* * Compare the group weights. If a task is all by itself * (not part of a group), use the task weight instead. */ - if (cur->numa_group && env->p->numa_group) + if (cur_ng && p_ng) imp += group_weight(cur, env->src_nid, dist) - group_weight(cur, env->dst_nid, dist); else @@ -1757,11 +1790,12 @@ static int task_numa_migrate(struct task_struct *p) .best_imp = 0, .best_cpu = -1, }; + unsigned long taskweight, groupweight; struct sched_domain *sd; + long taskimp, groupimp; + struct numa_group *ng; struct rq *best_rq; - unsigned long taskweight, groupweight; int nid, ret, dist; - long taskimp, groupimp; /* * Pick the lowest SD_NUMA domain, as that would have the smallest @@ -1807,7 +1841,8 @@ static int task_numa_migrate(struct task_struct *p) * multiple NUMA nodes; in order to better consolidate the group, * we need to check other locations. */ - if (env.best_cpu == -1 || (p->numa_group && p->numa_group->active_nodes > 1)) { + ng = deref_curr_numa_group(p); + if (env.best_cpu == -1 || (ng && ng->active_nodes > 1)) { for_each_online_node(nid) { if (nid == env.src_nid || nid == p->numa_preferred_nid) continue; @@ -1840,7 +1875,7 @@ static int task_numa_migrate(struct task_struct *p) * A task that migrated to a second choice node will be better off * trying for a better one later. Do not set the preferred node here. */ - if (p->numa_group) { + if (ng) { if (env.best_cpu == -1) nid = env.src_nid; else @@ -2135,6 +2170,7 @@ static void task_numa_placement(struct task_struct *p) unsigned long total_faults; u64 runtime, period; spinlock_t *group_lock = NULL; + struct numa_group *ng; /* * The p->mm->numa_scan_seq field gets updated without @@ -2152,8 +2188,9 @@ static void task_numa_placement(struct task_struct *p) runtime = numa_get_avg_runtime(p, &period); /* If the task is part of a group prevent parallel updates to group stats */ - if (p->numa_group) { - group_lock = &p->numa_group->lock; + ng = deref_curr_numa_group(p); + if (ng) { + group_lock = &ng->lock; spin_lock_irq(group_lock); } @@ -2194,7 +2231,7 @@ static void task_numa_placement(struct task_struct *p) p->numa_faults[cpu_idx] += f_diff; faults += p->numa_faults[mem_idx]; p->total_numa_faults += diff; - if (p->numa_group) { + if (ng) { /* * safe because we can only change our own group * @@ -2202,14 +2239,14 @@ static void task_numa_placement(struct task_struct *p) * nid and priv in a specific region because it * is at the beginning of the numa_faults array. */ - p->numa_group->faults[mem_idx] += diff; - p->numa_group->faults_cpu[mem_idx] += f_diff; - p->numa_group->total_faults += diff; - group_faults += p->numa_group->faults[mem_idx]; + ng->faults[mem_idx] += diff; + ng->faults_cpu[mem_idx] += f_diff; + ng->total_faults += diff; + group_faults += ng->faults[mem_idx]; } } - if (!p->numa_group) { + if (!ng) { if (faults > max_faults) { max_faults = faults; max_nid = nid; @@ -2220,8 +2257,8 @@ static void task_numa_placement(struct task_struct *p) } } - if (p->numa_group) { - numa_group_count_active_nodes(p->numa_group); + if (ng) { + numa_group_count_active_nodes(ng); spin_unlock_irq(group_lock); max_nid = preferred_group_nid(p, max_nid); } @@ -2255,7 +2292,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, int cpu = cpupid_to_cpu(cpupid); int i; - if (unlikely(!p->numa_group)) { + if (unlikely(!deref_curr_numa_group(p))) { unsigned int size = sizeof(struct numa_group) + 4*nr_node_ids*sizeof(unsigned long); @@ -2291,7 +2328,7 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, if (!grp) goto no_join; - my_grp = p->numa_group; + my_grp = deref_curr_numa_group(p); if (grp == my_grp) goto no_join; @@ -2362,7 +2399,8 @@ static void task_numa_group(struct task_struct *p, int cpupid, int flags, */ void task_numa_free(struct task_struct *p, bool final) { - struct numa_group *grp = p->numa_group; + /* safe: p either is current or is being freed by current */ + struct numa_group *grp = rcu_dereference_raw(p->numa_group); unsigned long *numa_faults = p->numa_faults; unsigned long flags; int i; @@ -2442,7 +2480,7 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags) * actively using should be counted as local. This allows the * scan rate to slow down when a workload has settled down. */ - ng = p->numa_group; + ng = deref_curr_numa_group(p); if (!priv && !local && ng && ng->active_nodes > 1 && numa_is_active_node(cpu_node, ng) && numa_is_active_node(mem_node, ng)) @@ -10460,18 +10498,22 @@ void show_numa_stats(struct task_struct *p, struct seq_file *m) { int node; unsigned long tsf = 0, tpf = 0, gsf = 0, gpf = 0; + struct numa_group *ng; + rcu_read_lock(); + ng = rcu_dereference(p->numa_group); for_each_online_node(node) { if (p->numa_faults) { tsf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 0)]; tpf = p->numa_faults[task_faults_idx(NUMA_MEM, node, 1)]; } - if (p->numa_group) { - gsf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 0)], - gpf = p->numa_group->faults[task_faults_idx(NUMA_MEM, node, 1)]; + if (ng) { + gsf = ng->faults[task_faults_idx(NUMA_MEM, node, 0)], + gpf = ng->faults[task_faults_idx(NUMA_MEM, node, 1)]; } print_numa_stats(m, node, tsf, tpf, gsf, gpf); } + rcu_read_unlock(); } #endif /* CONFIG_NUMA_BALANCING */ #endif /* CONFIG_SCHED_DEBUG */

5 years, 3 months

1
0
0 0

[stable-4.19 0/4] CVE-2019-3900 fixes

by Jack Wang

Hi, Greg, hi Sasha, I noticed the fixes for CVE-2019-3900 are only backported to 4.14.133+, but not to 4.19, also 5.1, fixes have been included in 5.2. So I backported to 4.19, only compiles fine, no functional tests. Please review, and consider to include in next release. Regards, Jack Wang 1 & 1 IONOS Cloud GmbH Jason Wang (4): vhost: introduce vhost_exceeds_weight() vhost_net: fix possible infinite loop vhost: vsock: add weight support vhost: scsi: add weight support drivers/vhost/net.c | 41 ++++++++++++++--------------------------- drivers/vhost/scsi.c | 15 +++++++++++---- drivers/vhost/vhost.c | 20 +++++++++++++++++++- drivers/vhost/vhost.h | 5 ++++- drivers/vhost/vsock.c | 28 +++++++++++++++++++++------- 5 files changed, 69 insertions(+), 40 deletions(-) -- 2.17.1

5 years, 3 months

6
10
0 0

[PATCH] crypto: qat - Silence smp_processor_id() warning

by Sverdlin, Alexander (Nokia - DE/Ulm)

From: Alexander Sverdlin <alexander.sverdlin(a)nokia.com> It seems that smp_processor_id() is only used for a best-effort load-balancing, refer to qat_crypto_get_instance_node(). It's not feasible to disable preemption for the duration of the crypto requests. Therefore, just silence the warning. This commit is similar to e7a9b05ca4 ("crypto: cavium - Fix smp_processor_id() warnings"). Silences the following splat: BUG: using smp_processor_id() in preemptible [00000000] code: cryptomgr_test/2904 caller is qat_alg_ablkcipher_setkey+0x300/0x4a0 [intel_qat] CPU: 1 PID: 2904 Comm: cryptomgr_test Tainted: P O 4.14.69 #1 ... Call Trace: dump_stack+0x5f/0x86 check_preemption_disabled+0xd3/0xe0 qat_alg_ablkcipher_setkey+0x300/0x4a0 [intel_qat] skcipher_setkey_ablkcipher+0x2b/0x40 __test_skcipher+0x1f3/0xb20 ? cpumask_next_and+0x26/0x40 ? find_busiest_group+0x10e/0x9d0 ? preempt_count_add+0x49/0xa0 ? try_module_get+0x61/0xf0 ? crypto_mod_get+0x15/0x30 ? __kmalloc+0x1df/0x1f0 ? __crypto_alloc_tfm+0x116/0x180 ? crypto_skcipher_init_tfm+0xa6/0x180 ? crypto_create_tfm+0x4b/0xf0 test_skcipher+0x21/0xa0 alg_test_skcipher+0x3f/0xa0 alg_test.part.6+0x126/0x2a0 ? finish_task_switch+0x21b/0x260 ? __schedule+0x1e9/0x800 ? __wake_up_common+0x8d/0x140 cryptomgr_test+0x40/0x50 kthread+0xff/0x130 ? cryptomgr_notify+0x540/0x540 ? kthread_create_on_node+0x70/0x70 ret_from_fork+0x24/0x50 Fixes: ed8ccaef52 ("crypto: qat - Add support for SRIOV") Cc: stable(a)vger.kernel.org Signed-off-by: Alexander Sverdlin <alexander.sverdlin(a)nokia.com> --- drivers/crypto/qat/qat_common/adf_common_drv.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/crypto/qat/qat_common/adf_common_drv.h b/drivers/crypto/qat/qat_common/adf_common_drv.h index 5c4c0a2..d78f8d5 100644 --- a/drivers/crypto/qat/qat_common/adf_common_drv.h +++ b/drivers/crypto/qat/qat_common/adf_common_drv.h @@ -95,7 +95,7 @@ struct service_hndl { static inline int get_current_node(void) { - return topology_physical_package_id(smp_processor_id()); + return topology_physical_package_id(raw_smp_processor_id()); } int adf_service_register(struct service_hndl *service); -- 2.4.6

5 years, 3 months

3
4
0 0

[PATCH] drm/nouveau: Only release VCPI slots on mode changes

by Lyude Paul

Looks like a regression got introduced into nv50_mstc_atomic_check() that somehow didn't get found until now. If userspace changes crtc_state->active to false but leaves the CRTC enabled, we end up calling drm_dp_atomic_find_vcpi_slots() using the PBN calculated in asyh->dp.pbn. However, if the display is inactive we end up calculating a PBN of 0, which inadvertently causes us to have an allocation of 0. >From there, if userspace then disables the CRTC afterwards we end up accidentally attempting to free the VCPI twice: WARNING: CPU: 0 PID: 1484 at drivers/gpu/drm/drm_dp_mst_topology.c:3336 drm_dp_atomic_release_vcpi_slots+0x87/0xb0 [drm_kms_helper] RIP: 0010:drm_dp_atomic_release_vcpi_slots+0x87/0xb0 [drm_kms_helper] Call Trace: drm_atomic_helper_check_modeset+0x3f3/0xa60 [drm_kms_helper] ? drm_atomic_check_only+0x43/0x780 [drm] drm_atomic_helper_check+0x15/0x90 [drm_kms_helper] nv50_disp_atomic_check+0x83/0x1d0 [nouveau] drm_atomic_check_only+0x54d/0x780 [drm] ? drm_atomic_set_crtc_for_connector+0xec/0x100 [drm] drm_atomic_commit+0x13/0x50 [drm] drm_atomic_helper_set_config+0x81/0x90 [drm_kms_helper] drm_mode_setcrtc+0x194/0x6a0 [drm] ? vprintk_emit+0x16a/0x230 ? drm_ioctl+0x163/0x390 [drm] ? drm_mode_getcrtc+0x180/0x180 [drm] drm_ioctl_kernel+0xaa/0xf0 [drm] drm_ioctl+0x208/0x390 [drm] ? drm_mode_getcrtc+0x180/0x180 [drm] nouveau_drm_ioctl+0x63/0xb0 [nouveau] do_vfs_ioctl+0x405/0x660 ? recalc_sigpending+0x17/0x50 ? _copy_from_user+0x37/0x60 ksys_ioctl+0x5e/0x90 ? exit_to_usermode_loop+0x92/0xe0 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x59/0x190 entry_SYSCALL_64_after_hwframe+0x44/0xa9 WARNING: CPU: 0 PID: 1484 at drivers/gpu/drm/drm_dp_mst_topology.c:3336 drm_dp_atomic_release_vcpi_slots+0x87/0xb0 [drm_kms_helper] ---[ end trace 4c395c0c51b1f88d ]--- [drm:drm_dp_atomic_release_vcpi_slots [drm_kms_helper]] *ERROR* no VCPI for [MST PORT:00000000e288eb7d] found in mst state 000000008e642070 So, fix this by doing what we probably should have done from the start: only call drm_dp_atomic_find_vcpi_slots() when crtc_state->mode_changed is set, so that VCPI allocations remain for as long as the CRTC is enabled. Signed-off-by: Lyude Paul <lyude(a)redhat.com> Fixes: 232c9eec417a ("drm/nouveau: Use atomic VCPI helpers for MST") Cc: Lyude Paul <lyude(a)redhat.com> Cc: Ben Skeggs <bskeggs(a)redhat.com> Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch> Cc: David Airlie <airlied(a)redhat.com> Cc: Jerry Zuo <Jerry.Zuo(a)amd.com> Cc: Harry Wentland <harry.wentland(a)amd.com> Cc: Juston Li <juston.li(a)intel.com> Cc: Karol Herbst <karolherbst(a)gmail.com> Cc: Laurent Pinchart <laurent.pinchart(a)ideasonboard.com> Cc: Ilia Mirkin <imirkin(a)alum.mit.edu> Cc: <stable(a)vger.kernel.org> # v5.1+ --- drivers/gpu/drm/nouveau/dispnv50/disp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c index 8497768f1b41..126703816794 100644 --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c @@ -780,7 +780,7 @@ nv50_msto_atomic_check(struct drm_encoder *encoder, drm_dp_calc_pbn_mode(crtc_state->adjusted_mode.clock, connector->display_info.bpc * 3); - if (drm_atomic_crtc_needs_modeset(crtc_state)) { + if (crtc_state->mode_changed) { slots = drm_dp_atomic_find_vcpi_slots(state, &mstm->mgr, mstc->port, asyh->dp.pbn); -- 2.21.0

5 years, 3 months

2
1
0 0

[PATCH 3/3] drm/i915: Flush extra hard after writing relocations through the GTT

by Chris Wilson

Recently discovered in commit bdae33b8b82b ("drm/i915: Use maximum write flush for pwrite_gtt") was that we needed to our full write barrier before changing the GGTT PTE to ensure that our indirect writes through the GTT landed before the PTE changed (and the writes end up in a different page). That also applies to our GGTT relocation path. Signed-off-by: Chris Wilson <chris(a)chris-wilson.co.uk> Cc: stable(a)vger.kernel.org --- drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c index 8a2047c4e7c3..01901dad33f7 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c @@ -1019,11 +1019,12 @@ static void reloc_cache_reset(struct reloc_cache *cache) kunmap_atomic(vaddr); i915_gem_object_finish_access((struct drm_i915_gem_object *)cache->node.mm); } else { - wmb(); + struct i915_ggtt *ggtt = cache_to_ggtt(cache); + + intel_gt_flush_ggtt_writes(ggtt->vm.gt); io_mapping_unmap_atomic((void __iomem *)vaddr); - if (cache->node.allocated) { - struct i915_ggtt *ggtt = cache_to_ggtt(cache); + if (cache->node.allocated) { ggtt->vm.clear_range(&ggtt->vm, cache->node.start, cache->node.size); @@ -1078,6 +1079,7 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj, void *vaddr; if (cache->vaddr) { + intel_gt_flush_ggtt_writes(ggtt->vm.gt); io_mapping_unmap_atomic((void __force __iomem *) unmask_page(cache->vaddr)); } else { struct i915_vma *vma; @@ -1119,7 +1121,6 @@ static void *reloc_iomap(struct drm_i915_gem_object *obj, offset = cache->node.start; if (cache->node.allocated) { - wmb(); ggtt->vm.insert_page(&ggtt->vm, i915_gem_object_get_dma_address(obj, page), offset, I915_CACHE_NONE, 0); -- 2.22.0

5 years, 3 months

2
3
0 0

[PATCH] tipc: compat: allow tipc commands without arguments

by Taras Kondratiuk

Commit 2753ca5d9009 ("tipc: fix uninit-value in tipc_nl_compat_doit") broke older tipc tools that use compat interface (e.g. tipc-config from tipcutils package): % tipc-config -p operation not supported The commit started to reject TIPC netlink compat messages that do not have attributes. It is too restrictive because some of such messages are valid (they don't need any arguments): % grep 'tx none' include/uapi/linux/tipc_config.h #define TIPC_CMD_NOOP 0x0000 /* tx none, rx none */ #define TIPC_CMD_GET_MEDIA_NAMES 0x0002 /* tx none, rx media_name(s) */ #define TIPC_CMD_GET_BEARER_NAMES 0x0003 /* tx none, rx bearer_name(s) */ #define TIPC_CMD_SHOW_PORTS 0x0006 /* tx none, rx ultra_string */ #define TIPC_CMD_GET_REMOTE_MNG 0x4003 /* tx none, rx unsigned */ #define TIPC_CMD_GET_MAX_PORTS 0x4004 /* tx none, rx unsigned */ #define TIPC_CMD_GET_NETID 0x400B /* tx none, rx unsigned */ #define TIPC_CMD_NOT_NET_ADMIN 0xC001 /* tx none, rx none */ This patch relaxes the original fix and rejects messages without arguments only if such arguments are expected by a command (reg_type is non zero). Fixes: 2753ca5d9009 ("tipc: fix uninit-value in tipc_nl_compat_doit") Cc: stable(a)vger.kernel.org Signed-off-by: Taras Kondratiuk <takondra(a)cisco.com> --- The patch is based on v5.3-rc2. net/tipc/netlink_compat.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index d86030ef1232..e135d4e11231 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -55,6 +55,7 @@ struct tipc_nl_compat_msg { int rep_type; int rep_size; int req_type; + int req_size; struct net *net; struct sk_buff *rep; struct tlv_desc *req; @@ -257,7 +258,8 @@ static int tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd, int err; struct sk_buff *arg; - if (msg->req_type && !TLV_CHECK_TYPE(msg->req, msg->req_type)) + if (msg->req_type && (!msg->req_size || + !TLV_CHECK_TYPE(msg->req, msg->req_type))) return -EINVAL; msg->rep = tipc_tlv_alloc(msg->rep_size); @@ -354,7 +356,8 @@ static int tipc_nl_compat_doit(struct tipc_nl_compat_cmd_doit *cmd, { int err; - if (msg->req_type && !TLV_CHECK_TYPE(msg->req, msg->req_type)) + if (msg->req_type && (!msg->req_size || + !TLV_CHECK_TYPE(msg->req, msg->req_type))) return -EINVAL; err = __tipc_nl_compat_doit(cmd, msg); @@ -1278,8 +1281,8 @@ static int tipc_nl_compat_recv(struct sk_buff *skb, struct genl_info *info) goto send; } - len = nlmsg_attrlen(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN); - if (!len || !TLV_OK(msg.req, len)) { + msg.req_size = nlmsg_attrlen(req_nlh, GENL_HDRLEN + TIPC_GENL_HDRLEN); + if (msg.req_size && !TLV_OK(msg.req, msg.req_size)) { msg.rep = tipc_get_err_tlv(TIPC_CFG_NOT_SUPPORTED); err = -EOPNOTSUPP; goto send; -- 2.19.1

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Linux-stable-mirror August 2019