aboutsummaryrefslogtreecommitdiffstats
path: root/kernel
AgeCommit message (Collapse)Author
2020-11-10Merge tag 'v5.8.18' into v5.8/standard/baseBruce Ashfield
This is the 5.8.18 stable release # gpg: Signature made Sun 01 Nov 2020 06:46:02 AM EST # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2020-11-02Merge tag 'v5.8.17' into v5.8/standard/baseBruce Ashfield
This is the 5.8.17 stable release Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>
2020-11-01io_uring: don't rely on weak ->files referencesJens Axboe
commit 0f2122045b946241a9e549c2a76cea54fa58a7ff upstream. Grab actual references to the files_struct. To avoid circular references issues due to this, we add a per-task note that keeps track of what io_uring contexts a task has used. When the tasks execs or exits its assigned files, we cancel requests based on this tracking. With that, we can grab proper references to the files table, and no longer need to rely on stashing away ring_fd and ring_file to check if the ring_fd may have been closed. Cc: stable@vger.kernel.org # v5.5+ Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-29bpf: Limit caller's stack depth 256 for subprogs with tailcallsMaciej Fijalkowski
[ Upstream commit 7f6e4312e15a5c370e84eaa685879b6bdcc717e4 ] Protect against potential stack overflow that might happen when bpf2bpf calls get combined with tailcalls. Limit the caller's stack depth for such case down to 256 so that the worst case scenario would result in 8k stack size (32 which is tailcall limit * 256 = 8k). Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29PM: hibernate: remove the bogus call to get_gendisk() in software_resume()Christoph Hellwig
[ Upstream commit 428805c0c5e76ef643b1fbc893edfb636b3d8aef ] get_gendisk grabs a reference on the disk and file operation, so this code will leak both of them while having absolutely no use for the gendisk itself. This effectively reverts commit 2df83fa4bce421f ("PM / Hibernate: Use get_gendisk to verify partition if resume_file is integer format") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29bpf: Use raw_spin_trylock() for pcpu_freelist_push/pop in NMISong Liu
[ Upstream commit 39d8f0d1026a990604770a658708f5845f7dbec0 ] Recent improvements in LOCKDEP highlighted a potential A-A deadlock with pcpu_freelist in NMI: ./tools/testing/selftests/bpf/test_progs -t stacktrace_build_id_nmi [ 18.984807] ================================ [ 18.984807] WARNING: inconsistent lock state [ 18.984808] 5.9.0-rc6-01771-g1466de1330e1 #2967 Not tainted [ 18.984809] -------------------------------- [ 18.984809] inconsistent {INITIAL USE} -> {IN-NMI} usage. [ 18.984810] test_progs/1990 [HC2[2]:SC0[0]:HE0:SE1] takes: [ 18.984810] ffffe8ffffc219c0 (&head->lock){....}-{2:2}, at: __pcpu_freelist_pop+0xe3/0x180 [ 18.984813] {INITIAL USE} state was registered at: [ 18.984814] lock_acquire+0x175/0x7c0 [ 18.984814] _raw_spin_lock+0x2c/0x40 [ 18.984815] __pcpu_freelist_pop+0xe3/0x180 [ 18.984815] pcpu_freelist_pop+0x31/0x40 [ 18.984816] htab_map_alloc+0xbbf/0xf40 [ 18.984816] __do_sys_bpf+0x5aa/0x3ed0 [ 18.984817] do_syscall_64+0x2d/0x40 [ 18.984818] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 18.984818] irq event stamp: 12 [...] [ 18.984822] other info that might help us debug this: [ 18.984823] Possible unsafe locking scenario: [ 18.984823] [ 18.984824] CPU0 [ 18.984824] ---- [ 18.984824] lock(&head->lock); [ 18.984826] <Interrupt> [ 18.984826] lock(&head->lock); [ 18.984827] [ 18.984828] *** DEADLOCK *** [ 18.984828] [ 18.984829] 2 locks held by test_progs/1990: [...] [ 18.984838] <NMI> [ 18.984838] dump_stack+0x9a/0xd0 [ 18.984839] lock_acquire+0x5c9/0x7c0 [ 18.984839] ? lock_release+0x6f0/0x6f0 [ 18.984840] ? __pcpu_freelist_pop+0xe3/0x180 [ 18.984840] _raw_spin_lock+0x2c/0x40 [ 18.984841] ? __pcpu_freelist_pop+0xe3/0x180 [ 18.984841] __pcpu_freelist_pop+0xe3/0x180 [ 18.984842] pcpu_freelist_pop+0x17/0x40 [ 18.984842] ? lock_release+0x6f0/0x6f0 [ 18.984843] __bpf_get_stackid+0x534/0xaf0 [ 18.984843] bpf_prog_1fd9e30e1438d3c5_oncpu+0x73/0x350 [ 18.984844] bpf_overflow_handler+0x12f/0x3f0 This is because pcpu_freelist_head.lock is accessed in both NMI and non-NMI context. Fix this issue by using raw_spin_trylock() in NMI. Since NMI interrupts non-NMI context, when NMI context tries to lock the raw_spinlock, non-NMI context of the same CPU may already have locked a lock and is blocked from unlocking the lock. For a system with N CPUs, there could be N NMIs at the same time, and they may block N non-NMI raw_spinlocks. This is tricky for pcpu_freelist_push(), where unlike _pop(), failing _push() means leaking memory. This issue is more likely to trigger in non-SMP system. Fix this issue with an extra list, pcpu_freelist.extralist. The extralist is primarily used to take _push() when raw_spin_trylock() failed on all the per CPU lists. It should be empty most of the time. The following table summarizes the behavior of pcpu_freelist in NMI and non-NMI: non-NMI pop(): use _lock(); check per CPU lists first; if all per CPU lists are empty, check extralist; if extralist is empty, return NULL. non-NMI push(): use _lock(); only push to per CPU lists. NMI pop(): use _trylock(); check per CPU lists first; if all per CPU lists are locked or empty, check extralist; if extralist is locked or empty, return NULL. NMI push(): use _trylock(); check per CPU lists first; if all per CPU lists are locked; try push to extralist; if extralist is also locked, keep trying on per CPU lists. Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20201005165838.3735218-1-songliubraving@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29sched/features: Fix !CONFIG_JUMP_LABEL caseJuri Lelli
[ Upstream commit a73f863af4ce9730795eab7097fb2102e6854365 ] Commit: 765cc3a4b224e ("sched/core: Optimize sched_feat() for !CONFIG_SCHED_DEBUG builds") made sched features static for !CONFIG_SCHED_DEBUG configurations, but overlooked the CONFIG_SCHED_DEBUG=y and !CONFIG_JUMP_LABEL cases. For the latter echoing changes to /sys/kernel/debug/sched_features has the nasty effect of effectively changing what sched_features reports, but without actually changing the scheduler behaviour (since different translation units get different sysctl_sched_features). Fix CONFIG_SCHED_DEBUG=y and !CONFIG_JUMP_LABEL configurations by properly restructuring ifdefs. Fixes: 765cc3a4b224e ("sched/core: Optimize sched_feat() for !CONFIG_SCHED_DEBUG builds") Co-developed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Signed-off-by: Juri Lelli <juri.lelli@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Patrick Bellasi <patrick.bellasi@matbug.net> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lore.kernel.org/r/20201013053114.160628-1-juri.lelli@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29module: statically initialize init section freeing dataDaniel Jordan
[ Upstream commit fdf09ab887829cd1b671e45d9549f8ec1ffda0fa ] Corentin hit the following workqueue warning when running with CRYPTO_MANAGER_EXTRA_TESTS: WARNING: CPU: 2 PID: 147 at kernel/workqueue.c:1473 __queue_work+0x3b8/0x3d0 Modules linked in: ghash_generic CPU: 2 PID: 147 Comm: modprobe Not tainted 5.6.0-rc1-next-20200214-00068-g166c9264f0b1-dirty #545 Hardware name: Pine H64 model A (DT) pc : __queue_work+0x3b8/0x3d0 Call trace: __queue_work+0x3b8/0x3d0 queue_work_on+0x6c/0x90 do_init_module+0x188/0x1f0 load_module+0x1d00/0x22b0 I wasn't able to reproduce on x86 or rpi 3b+. This is WARN_ON(!list_empty(&work->entry)) from __queue_work(), and it happens because the init_free_wq work item isn't initialized in time for a crypto test that requests the gcm module. Some crypto tests were recently moved earlier in boot as explained in commit c4741b230597 ("crypto: run initcalls for generic implementations earlier"), which went into mainline less than two weeks before the Fixes commit. Avoid the warning by statically initializing init_free_wq and the corresponding llist. Link: https://lore.kernel.org/lkml/20200217204803.GA13479@Red/ Fixes: 1a7b7d922081 ("modules: Use vmalloc special flag") Reported-by: Corentin Labbe <clabbe.montjoie@gmail.com> Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com> Tested-on: sun50i-h6-pine-h64 Tested-on: imx8mn-ddr4-evk Tested-on: sun50i-a64-bananapi-m64 Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Jessica Yu <jeyu@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29kdb: Fix pager search for multi-line stringsDaniel Thompson
[ Upstream commit d081a6e353168f15e63eb9e9334757f20343319f ] Currently using forward search doesn't handle multi-line strings correctly. The search routine replaces line breaks with \0 during the search and, for regular searches ("help | grep Common\n"), there is code after the line has been discarded or printed to replace the break character. However during a pager search ("help\n" followed by "/Common\n") when the string is matched we will immediately return to normal output and the code that should restore the \n becomes unreachable. Fix this by restoring the replaced character when we disable the search mode and update the comment accordingly. Fixes: fb6daa7520f9d ("kdb: Provide forward search at more prompt") Link: https://lore.kernel.org/r/20200909141708.338273-1-daniel.thompson@linaro.org Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29rcutorture: Properly set rcu_fwds for OOM handlingPaul E. McKenney
[ Upstream commit c8fa63714763b7795a3f5fb7ed6d000763e6dccc ] The conversion of rcu_fwds to dynamic allocation failed to actually allocate the required structure. This commit therefore allocates it, frees it, and updates rcu_fwds accordingly. While in the area, it abstracts the cleanup actions into rcu_torture_fwd_prog_cleanup(). Fixes: 5155be9994e5 ("rcutorture: Dynamically allocate rcu_fwds structure") Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29rcu/tree: Force quiescent state on callback overloadNeeraj Upadhyay
[ Upstream commit 9c39245382de4d52a122641952900709d4a9950b ] On callback overload, it is necessary to quickly detect idle CPUs, and rcu_gp_fqs_check_wake() checks for this condition. Unfortunately, the code following the call to this function does not repeat this check, which means that in reality no actual quiescent-state forcing, instead only a couple of quick and pointless wakeups at the beginning of the grace period. This commit therefore adds a check for the RCU_GP_FLAG_OVLD flag in the post-wakeup "if" statement in rcu_gp_fqs_loop(). Fixes: 1fca4d12f4637 ("rcu: Expedite first two FQS scans under callback-overload conditions") Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29tracing: Handle synthetic event array field type checking correctlyTom Zanussi
[ Upstream commit 10819e25799aae564005b6049a45e9808797b3bb ] Since synthetic event array types are derived from the field name, there may be a semicolon at the end of the type which should be stripped off. If there are more characters following that, normal type string checking will result in an invalid type. Without this patch, you can end up with an invalid field type string that gets displayed in both the synthetic event description and the event format: Before: # echo 'myevent char str[16]; int v' >> synthetic_events # cat synthetic_events myevent char[16]; str; int v name: myevent ID: 1936 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:char str[16];; offset:8; size:16; signed:1; field:int v; offset:40; size:4; signed:1; print fmt: "str=%s, v=%d", REC->str, REC->v After: # echo 'myevent char str[16]; int v' >> synthetic_events # cat synthetic_events myevent char[16] str; int v # cat events/synthetic/myevent/format name: myevent ID: 1936 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:char str[16]; offset:8; size:16; signed:1; field:int v; offset:40; size:4; signed:1; print fmt: "str=%s, v=%d", REC->str, REC->v Link: https://lkml.kernel.org/r/6587663b56c2d45ab9d8c8472a2110713cdec97d.1602598160.git.zanussi@kernel.org [ <rostedt@goodmis.org>: wrote parse_synth_field() snippet. ] Fixes: 4b147936fa50 (tracing: Add support for 'synthetic' events) Reported-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessarySuren Baghdasaryan
[ Upstream commit 67197a4f28d28d0b073ab0427b03cb2ee5382578 ] Currently __set_oom_adj loops through all processes in the system to keep oom_score_adj and oom_score_adj_min in sync between processes sharing their mm. This is done for any task with more that one mm_users, which includes processes with multiple threads (sharing mm and signals). However for such processes the loop is unnecessary because their signal structure is shared as well. Android updates oom_score_adj whenever a tasks changes its role (background/foreground/...) or binds to/unbinds from a service, making it more/less important. Such operation can happen frequently. We noticed that updates to oom_score_adj became more expensive and after further investigation found out that the patch mentioned in "Fixes" introduced a regression. Using Pixel 4 with a typical Android workload, write time to oom_score_adj increased from ~3.57us to ~362us. Moreover this regression linearly depends on the number of multi-threaded processes running on the system. Mark the mm with a new MMF_MULTIPROCESS flag bit when task is created with (CLONE_VM && !CLONE_THREAD && !CLONE_VFORK). Change __set_oom_adj to use MMF_MULTIPROCESS instead of mm_users to decide whether oom_score_adj update should be synchronized between multiple processes. To prevent races between clone() and __set_oom_adj(), when oom_score_adj of the process being cloned might be modified from userspace, we use oom_adj_mutex. Its scope is changed to global. The combination of (CLONE_VM && !CLONE_THREAD) is rarely used except for the case of vfork(). To prevent performance regressions of vfork(), we skip taking oom_adj_mutex and setting MMF_MULTIPROCESS when CLONE_VFORK is specified. Clearing the MMF_MULTIPROCESS flag (when the last process sharing the mm exits) is left out of this patch to keep it simple and because it is believed that this threading model is rare. Should there ever be a need for optimizing that case as well, it can be done by hooking into the exit path, likely following the mm_update_next_owner pattern. With the combination of (CLONE_VM && !CLONE_THREAD && !CLONE_VFORK) being quite rare, the regression is gone after the change is applied. [surenb@google.com: v3] Link: https://lkml.kernel.org/r/20200902012558.2335613-1-surenb@google.com Fixes: 44a70adec910 ("mm, oom_adj: make sure processes sharing mm have same view of oom_score_adj") Reported-by: Tim Murray <timmurray@google.com> Suggested-by: Michal Hocko <mhocko@kernel.org> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Eugene Syromiatnikov <esyr@redhat.com> Cc: Christian Kellner <christian@kellner.me> Cc: Adrian Reber <areber@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Gladkov <gladkov.alexey@gmail.com> Cc: Michel Lespinasse <walken@google.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Bernd Edlinger <bernd.edlinger@hotmail.de> Cc: John Johansen <john.johansen@canonical.com> Cc: Yafang Shao <laoar.shao@gmail.com> Link: https://lkml.kernel.org/r/20200824153036.3201505-1-surenb@google.com Debugged-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29tracing: Fix parse_synth_field() error handlingTom Zanussi
[ Upstream commit 8fbeb52a598c7ab5aa603d6bb083b8a8d16d607a ] synth_field_size() returns either a positive size or an error (zero or a negative value). However, the existing code assumes the only error value is 0. It doesn't handle negative error codes, as it assigns directly to field->size (a size_t; unsigned), thereby interpreting the error code as a valid size instead. Do the test before assignment to field->size. [ axelrasmussen@google.com: changelog addition, first paragraph above ] Link: https://lkml.kernel.org/r/9b6946d9776b2eeb43227678158196de1c3c6e1d.1601848695.git.zanussi@kernel.org Fixes: 4b147936fa50 (tracing: Add support for 'synthetic' events) Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Axel Rasmussen <axelrasmussen@google.com> Signed-off-by: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29bpf: disallow attaching modify_return tracing functions to other BPF programsToke Høiland-Jørgensen
[ Upstream commit 1af9270e908cd50a4f5d815c9b6f794c7d57ed07 ] From the checks and commit messages for modify_return, it seems it was never the intention that it should be possible to attach a tracing program with expected_attach_type == BPF_MODIFY_RETURN to another BPF program. However, check_attach_modify_return() will only look at the function name, so if the target function starts with "security_", the attach will be allowed even for bpf2bpf attachment. Fix this oversight by also blocking the modification if a target program is supplied. Fixes: 18644cec714a ("bpf: Fix use-after-free in fmod_ret check") Fixes: 6ba43b761c41 ("bpf: Attachment verification for BPF_MODIFY_RETURN") Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29perf/core: Fix race in the perf_mmap_close() functionJiri Olsa
[ Upstream commit f91072ed1b7283b13ca57fcfbece5a3b92726143 ] There's a possible race in perf_mmap_close() when checking ring buffer's mmap_count refcount value. The problem is that the mmap_count check is not atomic because we call atomic_dec() and atomic_read() separately. perf_mmap_close: ... atomic_dec(&rb->mmap_count); ... if (atomic_read(&rb->mmap_count)) goto out_put; <ring buffer detach> free_uid out_put: ring_buffer_put(rb); /* could be last */ The race can happen when we have two (or more) events sharing same ring buffer and they go through atomic_dec() and then they both see 0 as refcount value later in atomic_read(). Then both will go on and execute code which is meant to be run just once. The code that detaches ring buffer is probably fine to be executed more than once, but the problem is in calling free_uid(), which will later on demonstrate in related crashes and refcount warnings, like: refcount_t: addition on 0; use-after-free. ... RIP: 0010:refcount_warn_saturate+0x6d/0xf ... Call Trace: prepare_creds+0x190/0x1e0 copy_creds+0x35/0x172 copy_process+0x471/0x1a80 _do_fork+0x83/0x3a0 __do_sys_wait4+0x83/0x90 __do_sys_clone+0x85/0xa0 do_syscall_64+0x5b/0x1e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Using atomic decrease and check instead of separated calls. Tested-by: Michael Petlan <mpetlan@redhat.com> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Wade Mealing <wmealing@redhat.com> Fixes: 9bb5d40cd93c ("perf: Fix mmap() accounting hole"); Link: https://lore.kernel.org/r/20200916115311.GE2301783@krava Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29sched/fair: Use dst group while checking imbalance for NUMA balancerBarry Song
[ Upstream commit 233e7aca4c8a2c764f556bba9644c36154017e7f ] Barry Song noted the following Something is wrong. In find_busiest_group(), we are checking if src has higher load, however, in task_numa_find_cpu(), we are checking if dst will have higher load after balancing. It seems it is not sensible to check src. It maybe cause wrong imbalance value, for example, if dst_running = env->dst_stats.nr_running + 1 results in 3 or above, and src_running = env->src_stats.nr_running - 1 results in 1; The current code is thinking imbalance as 0 since src_running is smaller than 2. This is inconsistent with load balancer. Basically, in find_busiest_group(), the NUMA imbalance is ignored if moving a task "from an almost idle domain" to a "domain with spare capacity". This patch forbids movement "from a misplaced domain" to "an almost idle domain" as that is closer to what the CPU load balancer expects. This patch is not a universal win. The old behaviour was intended to allow a task from an almost idle NUMA node to migrate to its preferred node if the destination had capacity but there are corner cases. For example, a NAS compute load could be parallelised to use 1/3rd of available CPUs but not all those potential tasks are active at all times allowing this logic to trigger. An obvious example is specjbb 2005 running various numbers of warehouses on a 2 socket box with 80 cpus. specjbb 5.9.0-rc4 5.9.0-rc4 vanilla dstbalance-v1r1 Hmean tput-1 46425.00 ( 0.00%) 43394.00 * -6.53%* Hmean tput-2 98416.00 ( 0.00%) 96031.00 * -2.42%* Hmean tput-3 150184.00 ( 0.00%) 148783.00 * -0.93%* Hmean tput-4 200683.00 ( 0.00%) 197906.00 * -1.38%* Hmean tput-5 236305.00 ( 0.00%) 245549.00 * 3.91%* Hmean tput-6 281559.00 ( 0.00%) 285692.00 * 1.47%* Hmean tput-7 338558.00 ( 0.00%) 334467.00 * -1.21%* Hmean tput-8 340745.00 ( 0.00%) 372501.00 * 9.32%* Hmean tput-9 424343.00 ( 0.00%) 413006.00 * -2.67%* Hmean tput-10 421854.00 ( 0.00%) 434261.00 * 2.94%* Hmean tput-11 493256.00 ( 0.00%) 485330.00 * -1.61%* Hmean tput-12 549573.00 ( 0.00%) 529959.00 * -3.57%* Hmean tput-13 593183.00 ( 0.00%) 555010.00 * -6.44%* Hmean tput-14 588252.00 ( 0.00%) 599166.00 * 1.86%* Hmean tput-15 623065.00 ( 0.00%) 642713.00 * 3.15%* Hmean tput-16 703924.00 ( 0.00%) 660758.00 * -6.13%* Hmean tput-17 666023.00 ( 0.00%) 697675.00 * 4.75%* Hmean tput-18 761502.00 ( 0.00%) 758360.00 * -0.41%* Hmean tput-19 796088.00 ( 0.00%) 798368.00 * 0.29%* Hmean tput-20 733564.00 ( 0.00%) 823086.00 * 12.20%* Hmean tput-21 840980.00 ( 0.00%) 856711.00 * 1.87%* Hmean tput-22 804285.00 ( 0.00%) 872238.00 * 8.45%* Hmean tput-23 795208.00 ( 0.00%) 889374.00 * 11.84%* Hmean tput-24 848619.00 ( 0.00%) 966783.00 * 13.92%* Hmean tput-25 750848.00 ( 0.00%) 903790.00 * 20.37%* Hmean tput-26 780523.00 ( 0.00%) 962254.00 * 23.28%* Hmean tput-27 1042245.00 ( 0.00%) 991544.00 * -4.86%* Hmean tput-28 1090580.00 ( 0.00%) 1035926.00 * -5.01%* Hmean tput-29 999483.00 ( 0.00%) 1082948.00 * 8.35%* Hmean tput-30 1098663.00 ( 0.00%) 1113427.00 * 1.34%* Hmean tput-31 1125671.00 ( 0.00%) 1134175.00 * 0.76%* Hmean tput-32 968167.00 ( 0.00%) 1250286.00 * 29.14%* Hmean tput-33 1077676.00 ( 0.00%) 1060893.00 * -1.56%* Hmean tput-34 1090538.00 ( 0.00%) 1090933.00 * 0.04%* Hmean tput-35 967058.00 ( 0.00%) 1107421.00 * 14.51%* Hmean tput-36 1051745.00 ( 0.00%) 1210663.00 * 15.11%* Hmean tput-37 1019465.00 ( 0.00%) 1351446.00 * 32.56%* Hmean tput-38 1083102.00 ( 0.00%) 1064541.00 * -1.71%* Hmean tput-39 1232990.00 ( 0.00%) 1303623.00 * 5.73%* Hmean tput-40 1175542.00 ( 0.00%) 1340943.00 * 14.07%* Hmean tput-41 1127826.00 ( 0.00%) 1339492.00 * 18.77%* Hmean tput-42 1198313.00 ( 0.00%) 1411023.00 * 17.75%* Hmean tput-43 1163733.00 ( 0.00%) 1228253.00 * 5.54%* Hmean tput-44 1305562.00 ( 0.00%) 1357886.00 * 4.01%* Hmean tput-45 1326752.00 ( 0.00%) 1406061.00 * 5.98%* Hmean tput-46 1339424.00 ( 0.00%) 1418451.00 * 5.90%* Hmean tput-47 1415057.00 ( 0.00%) 1381570.00 * -2.37%* Hmean tput-48 1392003.00 ( 0.00%) 1421167.00 * 2.10%* Hmean tput-49 1408374.00 ( 0.00%) 1418659.00 * 0.73%* Hmean tput-50 1359822.00 ( 0.00%) 1391070.00 * 2.30%* Hmean tput-51 1414246.00 ( 0.00%) 1392679.00 * -1.52%* Hmean tput-52 1432352.00 ( 0.00%) 1354020.00 * -5.47%* Hmean tput-53 1387563.00 ( 0.00%) 1409563.00 * 1.59%* Hmean tput-54 1406420.00 ( 0.00%) 1388711.00 * -1.26%* Hmean tput-55 1438804.00 ( 0.00%) 1387472.00 * -3.57%* Hmean tput-56 1399465.00 ( 0.00%) 1400296.00 * 0.06%* Hmean tput-57 1428132.00 ( 0.00%) 1396399.00 * -2.22%* Hmean tput-58 1432385.00 ( 0.00%) 1386253.00 * -3.22%* Hmean tput-59 1421612.00 ( 0.00%) 1371416.00 * -3.53%* Hmean tput-60 1429423.00 ( 0.00%) 1389412.00 * -2.80%* Hmean tput-61 1396230.00 ( 0.00%) 1351122.00 * -3.23%* Hmean tput-62 1418396.00 ( 0.00%) 1383098.00 * -2.49%* Hmean tput-63 1409918.00 ( 0.00%) 1374662.00 * -2.50%* Hmean tput-64 1410236.00 ( 0.00%) 1376216.00 * -2.41%* Hmean tput-65 1396405.00 ( 0.00%) 1364418.00 * -2.29%* Hmean tput-66 1395975.00 ( 0.00%) 1357326.00 * -2.77%* Hmean tput-67 1392986.00 ( 0.00%) 1349642.00 * -3.11%* Hmean tput-68 1386541.00 ( 0.00%) 1343261.00 * -3.12%* Hmean tput-69 1374407.00 ( 0.00%) 1342588.00 * -2.32%* Hmean tput-70 1377513.00 ( 0.00%) 1334654.00 * -3.11%* Hmean tput-71 1369319.00 ( 0.00%) 1334952.00 * -2.51%* Hmean tput-72 1354635.00 ( 0.00%) 1329005.00 * -1.89%* Hmean tput-73 1350933.00 ( 0.00%) 1318942.00 * -2.37%* Hmean tput-74 1351714.00 ( 0.00%) 1316347.00 * -2.62%* Hmean tput-75 1352198.00 ( 0.00%) 1309974.00 * -3.12%* Hmean tput-76 1349490.00 ( 0.00%) 1286064.00 * -4.70%* Hmean tput-77 1336131.00 ( 0.00%) 1303684.00 * -2.43%* Hmean tput-78 1308896.00 ( 0.00%) 1271024.00 * -2.89%* Hmean tput-79 1326703.00 ( 0.00%) 1290862.00 * -2.70%* Hmean tput-80 1336199.00 ( 0.00%) 1291629.00 * -3.34%* The performance at the mid-point is better but not universally better. The patch is a mixed bag depending on the workload, machine and overall levels of utilisation. Sometimes it's better (sometimes much better), other times it is worse (sometimes much worse). Given that there isn't a universally good decision in this section and more people seem to prefer the patch then it may be best to keep the LB decisions consistent and revisit imbalance handling when the load balancer code changes settle down. Jirka Hladky added the following observation. Our results are mostly in line with what you see. We observe big gains (20-50%) when the system is loaded to 1/3 of the maximum capacity and mixed results at the full load - some workloads benefit from the patch at the full load, others not, but performance changes at the full load are mostly within the noise of results (+/-5%). Overall, we think this patch is helpful. [mgorman@techsingularity.net: Rewrote changelog] Fixes: fb86f5b211 ("sched/numa: Use similar logic to the load balancer for moving between domains with spare capacity") Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200921221849.GI3179@techsingularity.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29sched/fair: Fix wrong cpu selecting from isolated domainXunlei Pang
[ Upstream commit df3cb4ea1fb63ff326488efd671ba3c39034255e ] We've met problems that occasionally tasks with full cpumask (e.g. by putting it into a cpuset or setting to full affinity) were migrated to our isolated cpus in production environment. After some analysis, we found that it is due to the current select_idle_smt() not considering the sched_domain mask. Steps to reproduce on my 31-CPU hyperthreads machine: 1. with boot parameter: "isolcpus=domain,2-31" (thread lists: 0,16 and 1,17) 2. cgcreate -g cpu:test; cgexec -g cpu:test "test_threads" 3. some threads will be migrated to the isolated cpu16~17. Fix it by checking the valid domain mask in select_idle_smt(). Fixes: 10e2f1acd010 ("sched/core: Rewrite and improve select_idle_siblings()) Reported-by: Wetp Zhang <wetp.zy@linux.alibaba.com> Signed-off-by: Xunlei Pang <xlpang@linux.alibaba.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Jiang Biao <benbjiang@tencent.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lkml.kernel.org/r/1600930127-76857-1-git-send-email-xlpang@linux.alibaba.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-29sched/fair: Fix wrong negative conversion in find_energy_efficient_cpu()Lukasz Luba
[ Upstream commit da0777d35f47892f359c3f73ea155870bb595700 ] In find_energy_efficient_cpu() 'cpu_cap' could be less that 'util'. It might be because of RT, DL (so higher sched class than CFS), irq or thermal pressure signal, which reduce the capacity value. In such situation the result of 'cpu_cap - util' might be negative but stored in the unsigned long. Then it might be compared with other unsigned long when uclamp_rq_util_with() reduced the 'util' such that is passes the fits_capacity() check. Prevent this situation and make the arithmetic more safe. Fixes: 1d42509e475cd ("sched/fair: Make EAS wakeup placement consider uclamp restrictions") Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Link: https://lkml.kernel.org/r/20200810083004.26420-1-lukasz.luba@arm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-16Merge tag 'v5.8.15' into v5.8/standard/baseBruce Ashfield
This is the 5.8.15 stable release # gpg: Signature made Wed 14 Oct 2020 05:56:21 AM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2020-10-16Merge tag 'v5.8.14' into v5.8/standard/baseBruce Ashfield
This is the 5.8.14 stable release # gpg: Signature made Wed 07 Oct 2020 02:03:43 AM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2020-10-14perf: Fix task_function_call() error handlingKajol Jain
[ Upstream commit 6d6b8b9f4fceab7266ca03d194f60ec72bd4b654 ] The error handling introduced by commit: 2ed6edd33a21 ("perf: Add cond_resched() to task_function_call()") looses any return value from smp_call_function_single() that is not {0, -EINVAL}. This is a problem because it will return -EXNIO when the target CPU is offline. Worse, in that case it'll turn into an infinite loop. Fixes: 2ed6edd33a21 ("perf: Add cond_resched() to task_function_call()") Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Barret Rhoden <brho@google.com> Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: https://lkml.kernel.org/r/20200827064732.20860-1-kjain@linux.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-14bpf: Fix sysfs export of empty BTF sectionTony Ambardar
commit e23bb04b0c938588eae41b7f4712b722290ed2b8 upstream. If BTF data is missing or removed from the ELF section it is still exported via sysfs as a zero-length file: root@OpenWrt:/# ls -l /sys/kernel/btf/vmlinux -r--r--r-- 1 root root 0 Jul 18 02:59 /sys/kernel/btf/vmlinux Moreover, reads from this file succeed and leak kernel data: root@OpenWrt:/# hexdump -C /sys/kernel/btf/vmlinux|head -10 000000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 000cc0 00 00 00 00 00 00 00 00 00 00 00 00 80 83 b0 80 |................| 000cd0 00 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| 000ce0 00 00 00 00 00 00 00 00 00 00 00 00 57 ac 6e 9d |............W.n.| 000cf0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 002650 00 00 00 00 00 00 00 10 00 00 00 01 00 00 00 01 |................| 002660 80 82 9a c4 80 85 97 80 81 a9 51 68 00 00 00 02 |..........Qh....| 002670 80 25 44 dc 80 85 97 80 81 a9 50 24 81 ab c4 60 |.%D.......P$...`| This situation was first observed with kernel 5.4.x, cross-compiled for a MIPS target system. Fix by adding a sanity-check for export of zero-length data sections. Fixes: 341dfcf8d78e ("btf: expose BTF info through sysfs") Signed-off-by: Tony Ambardar <Tony.Ambardar@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/b38db205a66238f70823039a8c531535864eaac5.1600417359.git.Tony.Ambardar@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-14usermodehelper: reset umask to default before executing user processLinus Torvalds
commit 4013c1496c49615d90d36b9d513eee8e369778e9 upstream. Kernel threads intentionally do CLONE_FS in order to follow any changes that 'init' does to set up the root directory (or cwd). It is admittedly a bit odd, but it avoids the situation where 'init' does some extensive setup to initialize the system environment, and then we execute a usermode helper program, and it uses the original FS setup from boot time that may be very limited and incomplete. [ Both Al Viro and Eric Biederman point out that 'pivot_root()' will follow the root regardless, since it fixes up other users of root (see chroot_fs_refs() for details), but overmounting root and doing a chroot() would not. ] However, Vegard Nossum noticed that the CLONE_FS not only means that we follow the root and current working directories, it also means we share umask with whatever init changed it to. That wasn't intentional. Just reset umask to the original default (0022) before actually starting the usermode helper program. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-14bpf: Fix scalar32_min_max_or bounds trackingDaniel Borkmann
commit 5b9fbeb75b6a98955f628e205ac26689bcb1383e upstream. Simon reported an issue with the current scalar32_min_max_or() implementation. That is, compared to the other 32 bit subreg tracking functions, the code in scalar32_min_max_or() stands out that it's using the 64 bit registers instead of 32 bit ones. This leads to bounds tracking issues, for example: [...] 8: R0=map_value(id=0,off=0,ks=4,vs=48,imm=0) R10=fp0 fp-8=mmmmmmmm 8: (79) r1 = *(u64 *)(r0 +0) R0=map_value(id=0,off=0,ks=4,vs=48,imm=0) R10=fp0 fp-8=mmmmmmmm 9: R0=map_value(id=0,off=0,ks=4,vs=48,imm=0) R1_w=inv(id=0) R10=fp0 fp-8=mmmmmmmm 9: (b7) r0 = 1 10: R0_w=inv1 R1_w=inv(id=0) R10=fp0 fp-8=mmmmmmmm 10: (18) r2 = 0x600000002 12: R0_w=inv1 R1_w=inv(id=0) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 12: (ad) if r1 < r2 goto pc+1 R0_w=inv1 R1_w=inv(id=0,umin_value=25769803778) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 13: R0_w=inv1 R1_w=inv(id=0,umin_value=25769803778) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 13: (95) exit 14: R0_w=inv1 R1_w=inv(id=0,umax_value=25769803777,var_off=(0x0; 0x7ffffffff)) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 14: (25) if r1 > 0x0 goto pc+1 R0_w=inv1 R1_w=inv(id=0,umax_value=0,var_off=(0x0; 0x7fffffff),u32_max_value=2147483647) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 15: R0_w=inv1 R1_w=inv(id=0,umax_value=0,var_off=(0x0; 0x7fffffff),u32_max_value=2147483647) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 15: (95) exit 16: R0_w=inv1 R1_w=inv(id=0,umin_value=1,umax_value=25769803777,var_off=(0x0; 0x77fffffff),u32_max_value=2147483647) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 16: (47) r1 |= 0 17: R0_w=inv1 R1_w=inv(id=0,umin_value=1,umax_value=32212254719,var_off=(0x1; 0x700000000),s32_max_value=1,u32_max_value=1) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm [...] The bound tests on the map value force the upper unsigned bound to be 25769803777 in 64 bit (0b11000000000000000000000000000000001) and then lower one to be 1. By using OR they are truncated and thus result in the range [1,1] for the 32 bit reg tracker. This is incorrect given the only thing we know is that the value must be positive and thus 2147483647 (0b1111111111111111111111111111111) at max for the subregs. Fix it by using the {u,s}32_{min,max}_value vars instead. This also makes sense, for example, for the case where we update dst_reg->s32_{min,max}_value in the else branch we need to use the newly computed dst_reg->u32_{min,max}_value as we know that these are positive. Previously, in the else branch the 64 bit values of umin_value=1 and umax_value=32212254719 were used and latter got truncated to be 1 as upper bound there. After the fix the subreg range is now correct: [...] 8: R0=map_value(id=0,off=0,ks=4,vs=48,imm=0) R10=fp0 fp-8=mmmmmmmm 8: (79) r1 = *(u64 *)(r0 +0) R0=map_value(id=0,off=0,ks=4,vs=48,imm=0) R10=fp0 fp-8=mmmmmmmm 9: R0=map_value(id=0,off=0,ks=4,vs=48,imm=0) R1_w=inv(id=0) R10=fp0 fp-8=mmmmmmmm 9: (b7) r0 = 1 10: R0_w=inv1 R1_w=inv(id=0) R10=fp0 fp-8=mmmmmmmm 10: (18) r2 = 0x600000002 12: R0_w=inv1 R1_w=inv(id=0) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 12: (ad) if r1 < r2 goto pc+1 R0_w=inv1 R1_w=inv(id=0,umin_value=25769803778) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 13: R0_w=inv1 R1_w=inv(id=0,umin_value=25769803778) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 13: (95) exit 14: R0_w=inv1 R1_w=inv(id=0,umax_value=25769803777,var_off=(0x0; 0x7ffffffff)) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 14: (25) if r1 > 0x0 goto pc+1 R0_w=inv1 R1_w=inv(id=0,umax_value=0,var_off=(0x0; 0x7fffffff),u32_max_value=2147483647) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 15: R0_w=inv1 R1_w=inv(id=0,umax_value=0,var_off=(0x0; 0x7fffffff),u32_max_value=2147483647) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 15: (95) exit 16: R0_w=inv1 R1_w=inv(id=0,umin_value=1,umax_value=25769803777,var_off=(0x0; 0x77fffffff),u32_max_value=2147483647) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm 16: (47) r1 |= 0 17: R0_w=inv1 R1_w=inv(id=0,umin_value=1,umax_value=32212254719,var_off=(0x0; 0x77fffffff),u32_max_value=2147483647) R2_w=inv25769803778 R10=fp0 fp-8=mmmmmmmm [...] Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: Simon Scannell <scannell.smn@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-07tracing: Make the space reserved for the pid widerSebastian Andrzej Siewior
[ Upstream commit 795d6379a47bcbb88bd95a69920e4acc52849f88 ] For 64bit CONFIG_BASE_SMALL=0 systems PID_MAX_LIMIT is set by default to 4194304. During boot the kernel sets a new value based on number of CPUs but no lower than 32768. It is 1024 per CPU so with 128 CPUs the default becomes 131072 which needs six digits. This value can be increased during run time but must not exceed the initial upper limit. Systemd sometime after v241 sets it to the upper limit during boot. The result is that when the pid exceeds five digits, the trace output is a little hard to read because it is no longer properly padded (same like on big iron with 98+ CPUs). Increase the pid padding to seven digits. Link: https://lkml.kernel.org/r/20200904082331.dcdkrr3bkn3e4qlg@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-07tracing: Fix trace_find_next_entry() accounting of temp buffer sizeSteven Rostedt (VMware)
commit 851e6f61cd076954f9d521e0d79b173ad3a2453b upstream. The temp buffer size variable for trace_find_next_entry() was incorrectly being updated when the size did not change. The temp buffer size should only be updated when it is reallocated. This is mostly an issue when used with ftrace_dump(). That's because ftrace_dump() can not allocate a new buffer, and instead uses a temporary buffer with a fix size. But the variable that keeps track of that size is incorrectly updated with each call, and it could fall into the path that would try to reallocate the buffer and produce a warning. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1601 at kernel/trace/trace.c:3548 trace_find_next_entry+0xd0/0xe0 Modules linked in [..] CPU: 1 PID: 1601 Comm: bash Not tainted 5.9.0-rc5-test+ #521 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:trace_find_next_entry+0xd0/0xe0 Code: 40 21 00 00 4c 89 e1 31 d2 4c 89 ee 48 89 df e8 c6 9e ff ff 89 ab 54 21 00 00 5b 5d 41 5c 41 5d c3 48 63 d5 eb bf 31 c0 eb f0 <0f> 0b 48 63 d5 eb b4 66 0f 1f 84 00 00 00 00 00 53 48 8d 8f 60 21 RSP: 0018:ffff95a4f2e8bd70 EFLAGS: 00010046 RAX: ffffffff96679fc0 RBX: ffffffff97910de0 RCX: ffffffff96679fc0 RDX: ffff95a4f2e8bd98 RSI: ffff95a4ee321098 RDI: ffffffff97913000 RBP: 0000000000000018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000046 R12: ffff95a4f2e8bd98 R13: 0000000000000000 R14: ffff95a4ee321098 R15: 00000000009aa301 FS: 00007f8565484740(0000) GS:ffff95a55aa40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055876bd43d90 CR3: 00000000b76e6003 CR4: 00000000001706e0 Call Trace: trace_print_lat_context+0x58/0x2d0 ? cpumask_next+0x16/0x20 print_trace_line+0x1a4/0x4f0 ftrace_dump.cold+0xad/0x12c __handle_sysrq.cold+0x51/0x126 write_sysrq_trigger+0x3f/0x4a proc_reg_write+0x53/0x80 vfs_write+0xca/0x210 ksys_write+0x70/0xf0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f8565579487 Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24 RSP: 002b:00007ffd40707948 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f8565579487 RDX: 0000000000000002 RSI: 000055876bd74de0 RDI: 0000000000000001 RBP: 000055876bd74de0 R08: 000000000000000a R09: 0000000000000001 R10: 000055876bdec280 R11: 0000000000000246 R12: 0000000000000002 R13: 00007f856564a500 R14: 0000000000000002 R15: 00007f856564a700 irq event stamp: 109958 ---[ end trace 7aab5b7e51484b00 ]--- Not only fix the updating of the temp buffer, but also do not free the temp buffer before a new buffer is allocated (there's no reason to not continue to use the current temp buffer if an allocation fails). Cc: stable@vger.kernel.org Fixes: 8e99cf91b99bb ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic") Reported-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-07ftrace: Move RCU is watching check after recursion checkSteven Rostedt (VMware)
commit b40341fad6cc2daa195f8090fd3348f18fff640a upstream. The first thing that the ftrace function callback helper functions should do is to check for recursion. Peter Zijlstra found that when "rcu_is_watching()" had its notrace removed, it caused perf function tracing to crash. This is because the call of rcu_is_watching() is tested before function recursion is checked and and if it is traced, it will cause an infinite recursion loop. rcu_is_watching() should still stay notrace, but to prevent this should never had crashed in the first place. The recursion prevention must be the first thing done in callback functions. Link: https://lore.kernel.org/r/20200929112541.GM2628@hirez.programming.kicks-ass.net Cc: stable@vger.kernel.org Cc: Paul McKenney <paulmck@kernel.org> Fixes: c68c0fa293417 ("ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags too") Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reported-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-06Merge tag 'v5.8.13' into v5.8/standard/baseBruce Ashfield
This is the 5.8.13 stable release # gpg: Signature made Thu 01 Oct 2020 11:39:08 AM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2020-10-01kprobes: tracing/kprobes: Fix to kill kprobes on initmem after bootMasami Hiramatsu
commit 82d083ab60c3693201c6f5c7a5f23a6ed422098d upstream. Since kprobe_event= cmdline option allows user to put kprobes on the functions in initmem, kprobe has to make such probes gone after boot. Currently the probes on the init functions in modules will be handled by module callback, but the kernel init text isn't handled. Without this, kprobes may access non-exist text area to disable or remove it. Link: https://lkml.kernel.org/r/159972810544.428528.1839307531600646955.stgit@devnote2 Fixes: 970988e19eb0 ("tracing/kprobe: Add kprobe_event= boot parameter") Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()Masami Hiramatsu
commit 3031313eb3d549b7ad6f9fbcc52ba04412e3eb9e upstream. Commit 0cb2f1372baa ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler") fixed one bug but not completely fixed yet. If we run a kprobe_module.tc of ftracetest, kernel showed a warning as below. # ./ftracetest test.d/kprobe/kprobe_module.tc === Ftrace unit tests === [1] Kprobe dynamic event - probing module ... [ 22.400215] ------------[ cut here ]------------ [ 22.400962] Failed to disarm kprobe-ftrace at trace_printk_irq_work+0x0/0x7e [trace_printk] (-2) [ 22.402139] WARNING: CPU: 7 PID: 200 at kernel/kprobes.c:1091 __disarm_kprobe_ftrace.isra.0+0x7e/0xa0 [ 22.403358] Modules linked in: trace_printk(-) [ 22.404028] CPU: 7 PID: 200 Comm: rmmod Not tainted 5.9.0-rc2+ #66 [ 22.404870] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014 [ 22.406139] RIP: 0010:__disarm_kprobe_ftrace.isra.0+0x7e/0xa0 [ 22.406947] Code: 30 8b 03 eb c9 80 3d e5 09 1f 01 00 75 dc 49 8b 34 24 89 c2 48 c7 c7 a0 c2 05 82 89 45 e4 c6 05 cc 09 1f 01 01 e8 a9 c7 f0 ff <0f> 0b 8b 45 e4 eb b9 89 c6 48 c7 c7 70 c2 05 82 89 45 e4 e8 91 c7 [ 22.409544] RSP: 0018:ffffc90000237df0 EFLAGS: 00010286 [ 22.410385] RAX: 0000000000000000 RBX: ffffffff83066024 RCX: 0000000000000000 [ 22.411434] RDX: 0000000000000001 RSI: ffffffff810de8d3 RDI: ffffffff810de8d3 [ 22.412687] RBP: ffffc90000237e10 R08: 0000000000000001 R09: 0000000000000001 [ 22.413762] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88807c478640 [ 22.414852] R13: ffffffff8235ebc0 R14: ffffffffa00060c0 R15: 0000000000000000 [ 22.415941] FS: 00000000019d48c0(0000) GS:ffff88807d7c0000(0000) knlGS:0000000000000000 [ 22.417264] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 22.418176] CR2: 00000000005bb7e3 CR3: 0000000078f7a000 CR4: 00000000000006a0 [ 22.419309] Call Trace: [ 22.419990] kill_kprobe+0x94/0x160 [ 22.420652] kprobes_module_callback+0x64/0x230 [ 22.421470] notifier_call_chain+0x4f/0x70 [ 22.422184] blocking_notifier_call_chain+0x49/0x70 [ 22.422979] __x64_sys_delete_module+0x1ac/0x240 [ 22.423733] do_syscall_64+0x38/0x50 [ 22.424366] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 22.425176] RIP: 0033:0x4bb81d [ 22.425741] Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e0 ff ff ff f7 d8 64 89 01 48 [ 22.428726] RSP: 002b:00007ffc70fef008 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0 [ 22.430169] RAX: ffffffffffffffda RBX: 00000000019d48a0 RCX: 00000000004bb81d [ 22.431375] RDX: 0000000000000000 RSI: 0000000000000880 RDI: 00007ffc70fef028 [ 22.432543] RBP: 0000000000000880 R08: 00000000ffffffff R09: 00007ffc70fef320 [ 22.433692] R10: 0000000000656300 R11: 0000000000000246 R12: 00007ffc70fef028 [ 22.434635] R13: 0000000000000000 R14: 0000000000000002 R15: 0000000000000000 [ 22.435682] irq event stamp: 1169 [ 22.436240] hardirqs last enabled at (1179): [<ffffffff810df542>] console_unlock+0x422/0x580 [ 22.437466] hardirqs last disabled at (1188): [<ffffffff810df19b>] console_unlock+0x7b/0x580 [ 22.438608] softirqs last enabled at (866): [<ffffffff81c0038e>] __do_softirq+0x38e/0x490 [ 22.439637] softirqs last disabled at (859): [<ffffffff81a00f42>] asm_call_on_stack+0x12/0x20 [ 22.440690] ---[ end trace 1e7ce7e1e4567276 ]--- [ 22.472832] trace_kprobe: This probe might be able to register after target module is loaded. Continue. This is because the kill_kprobe() calls disarm_kprobe_ftrace() even if the given probe is not enabled. In that case, ftrace_set_filter_ip() fails because the given probe point is not registered to ftrace. Fix to check the given (going) probe is enabled before invoking disarm_kprobe_ftrace(). Link: https://lkml.kernel.org/r/159888672694.1411785.5987998076694782591.stgit@devnote2 Fixes: 0cb2f1372baa ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler") Cc: Ingo Molnar <mingo@kernel.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Chengming Zhou <zhouchengming@bytedance.com> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01tracing: fix double freeTom Rix
commit 46bbe5c671e06f070428b9be142cc4ee5cedebac upstream. clang static analyzer reports this problem trace_events_hist.c:3824:3: warning: Attempt to free released memory kfree(hist_data->attrs->var_defs.name[i]); In parse_var_defs() if there is a problem allocating var_defs.expr, the earlier var_defs.name is freed. This free is duplicated by free_var_defs() which frees the rest of the list. Because free_var_defs() has to run anyway, remove the second free fom parse_var_defs(). Link: https://lkml.kernel.org/r/20200907135845.15804-1-trix@redhat.com Cc: stable@vger.kernel.org Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers") Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Tom Rix <trix@redhat.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01bpf: Fix a rcu warning for bpffs map pretty-printYonghong Song
[ Upstream commit ce880cb825fcc22d4e39046a6c3a3a7f6603883d ] Running selftest ./btf_btf -p the kernel had the following warning: [ 51.528185] WARNING: CPU: 3 PID: 1756 at kernel/bpf/hashtab.c:717 htab_map_get_next_key+0x2eb/0x300 [ 51.529217] Modules linked in: [ 51.529583] CPU: 3 PID: 1756 Comm: test_btf Not tainted 5.9.0-rc1+ #878 [ 51.530346] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-1.el7.centos 04/01/2014 [ 51.531410] RIP: 0010:htab_map_get_next_key+0x2eb/0x300 ... [ 51.542826] Call Trace: [ 51.543119] map_seq_next+0x53/0x80 [ 51.543528] seq_read+0x263/0x400 [ 51.543932] vfs_read+0xad/0x1c0 [ 51.544311] ksys_read+0x5f/0xe0 [ 51.544689] do_syscall_64+0x33/0x40 [ 51.545116] entry_SYSCALL_64_after_hwframe+0x44/0xa9 The related source code in kernel/bpf/hashtab.c: 709 static int htab_map_get_next_key(struct bpf_map *map, void *key, void *next_key) 710 { 711 struct bpf_htab *htab = container_of(map, struct bpf_htab, map); 712 struct hlist_nulls_head *head; 713 struct htab_elem *l, *next_l; 714 u32 hash, key_size; 715 int i = 0; 716 717 WARN_ON_ONCE(!rcu_read_lock_held()); In kernel/bpf/inode.c, bpffs map pretty print calls map->ops->map_get_next_key() without holding a rcu_read_lock(), hence causing the above warning. To fix the issue, just surrounding map->ops->map_get_next_key() with rcu read lock. Fixes: a26ca7c982cb ("bpf: btf: Add pretty print support to the basic arraymap") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Cc: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200916004401.146277-1-yhs@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01lockdep: fix order in trace_hardirqs_off_caller()Sven Schnelle
[ Upstream commit 73ac74c7d489756d2313219a108809921dbfaea1 ] Switch order so that locking state is consistent even if the IRQ tracer calls into lockdep again. Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-23Merge tag 'v5.8.11' into v5.8/standard/baseBruce Ashfield
This is the 5.8.11 stable release # gpg: Signature made Wed 23 Sep 2020 07:00:26 AM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2020-09-23Merge tag 'v5.8.10' into v5.8/standard/baseBruce Ashfield
This is the 5.8.10 stable release # gpg: Signature made Thu 17 Sep 2020 07:56:19 AM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2020-09-23kprobes: fix kill kprobe which has been marked as goneMuchun Song
commit b0399092ccebd9feef68d4ceb8d6219a8c0caa05 upstream. If a kprobe is marked as gone, we should not kill it again. Otherwise, we can disarm the kprobe more than once. In that case, the statistics of kprobe_ftrace_enabled can unbalance which can lead to that kprobe do not work. Fixes: e8386a0cb22f ("kprobes: support probing module __exit function") Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Song Liu <songliubraving@fb.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200822030055.32383-1-songmuchun@bytedance.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-23locking/percpu-rwsem: Use this_cpu_{inc,dec}() for read_countHou Tao
[ Upstream commit e6b1a44eccfcab5e5e280be376f65478c3b2c7a2 ] The __this_cpu*() accessors are (in general) IRQ-unsafe which, given that percpu-rwsem is a blocking primitive, should be just fine. However, file_end_write() is used from IRQ context and will cause load-store issues on architectures where the per-cpu accessors are not natively irq-safe. Fix it by using the IRQ-safe this_cpu_*() for operations on read_count. This will generate more expensive code on a number of platforms, which might cause a performance regression for some of the other percpu-rwsem users. If any such is reported, we can consider alternative solutions. Fixes: 70fe2f48152e ("aio: fix freeze protection of aio writes") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Link: https://lkml.kernel.org/r/20200915140750.137881-1-houtao1@huawei.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-23locking/lockdep: Fix "USED" <- "IN-NMI" inversionspeterz@infradead.org
[ Upstream commit 23870f1227680d2aacff6f79c3ab2222bd04e86e ] During the LPC RCU BoF Paul asked how come the "USED" <- "IN-NMI" detector doesn't trip over rcu_read_lock()'s lockdep annotation. Looking into this I found a very embarrasing typo in verify_lock_unused(): - if (!(class->usage_mask & LOCK_USED)) + if (!(class->usage_mask & LOCKF_USED)) fixing that will indeed cause rcu_read_lock() to insta-splat :/ The above typo means that instead of testing for: 0x100 (1 << LOCK_USED), we test for 8 (LOCK_USED), which corresponds to (1 << LOCK_ENABLED_HARDIRQ). So instead of testing for _any_ used lock, it will only match any lock used with interrupts enabled. The rcu_read_lock() annotation uses .check=0, which means it will not set any of the interrupt bits and will thus never match. In order to properly fix the situation and allow rcu_read_lock() to correctly work, split LOCK_USED into LOCK_USED and LOCK_USED_READ and by having .read users set USED_READ and test USED, pure read-recursive locks are permitted. Fixes: f6f48e180404 ("lockdep: Teach lockdep about "USED" <- "IN-NMI" inversions") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20200902160323.GK1362448@hirez.programming.kicks-ass.net Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17gcov: add support for GCC 10.1Peter Oberparleiter
[ Upstream commit 40249c6962075c040fd071339acae524f18bfac9 ] Using gcov to collect coverage data for kernels compiled with GCC 10.1 causes random malfunctions and kernel crashes. This is the result of a changed GCOV_COUNTERS value in GCC 10.1 that causes a mismatch between the layout of the gcov_info structure created by GCC profiling code and the related structure used by the kernel. Fix this by updating the in-kernel GCOV_COUNTERS value. Also re-enable config GCOV_KERNEL for use with GCC 10. Reported-by: Colin Ian King <colin.king@canonical.com> Reported-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com> Tested-by: Leon Romanovsky <leonro@nvidia.com> Tested-and-Acked-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17gcov: Disable gcov build with GCC 10Leon Romanovsky
[ Upstream commit cfc905f158eaa099d6258031614d11869e7ef71c ] GCOV built with GCC 10 doesn't initialize n_function variable. This produces different kernel panics as was seen by Colin in Ubuntu and me in FC 32. As a workaround, let's disable GCOV build for broken GCC 10 version. Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1891288 Link: https://lore.kernel.org/lkml/20200827133932.3338519-1-leon@kernel.org Link: https://lore.kernel.org/lkml/CAHk-=whbijeSdSvx-Xcr0DPMj0BiwhJ+uiNnDSVZcr_h_kg7UA@mail.gmail.com/ Cc: Colin Ian King <colin.king@canonical.com> Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17seccomp: don't leak memory when filter install racesTycho Andersen
[ Upstream commit a566a9012acd7c9a4be7e30dc7acb7a811ec2260 ] In seccomp_set_mode_filter() with TSYNC | NEW_LISTENER, we first initialize the listener fd, then check to see if we can actually use it later in seccomp_may_assign_mode(), which can fail if anyone else in our thread group has installed a filter and caused some divergence. If we can't, we partially clean up the newly allocated file: we put the fd, put the file, but don't actually clean up the *memory* that was allocated at filter->notif. Let's clean that up too. To accomplish this, let's hoist the actual "detach a notifier from a filter" code to its own helper out of seccomp_notify_release(), so that in case anyone adds stuff to init_listener(), they only have to add the cleanup code in one spot. This does a bit of extra locking and such on the failure path when the filter is not attached, but it's a slow failure path anyway. Fixes: 51891498f2da ("seccomp: allow TSYNC and USER_NOTIF together") Reported-by: syzbot+3ad9614a12f80994c32e@syzkaller.appspotmail.com Signed-off-by: Tycho Andersen <tycho@tycho.pizza> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20200902014017.934315-1-tycho@tycho.pizza Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-17padata: fix possible padata_works_lock deadlockDaniel Jordan
[ Upstream commit 1b0df11fde0f14a269a181b3b7f5122415bc5ed7 ] syzbot reports, WARNING: inconsistent lock state 5.9.0-rc2-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. syz-executor.0/26715 takes: (padata_works_lock){+.?.}-{2:2}, at: padata_do_parallel kernel/padata.c:220 {IN-SOFTIRQ-W} state was registered at: spin_lock include/linux/spinlock.h:354 [inline] padata_do_parallel kernel/padata.c:220 ... __do_softirq kernel/softirq.c:298 ... sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt arch/x86/include/asm/idtentry.h:581 Possible unsafe locking scenario: CPU0 ---- lock(padata_works_lock); <Interrupt> lock(padata_works_lock); padata_do_parallel() takes padata_works_lock with softirqs enabled, so a deadlock is possible if, on the same CPU, the lock is acquired in process context and then softirq handling done in an interrupt leads to the same path. Fix by leaving softirqs disabled while do_parallel holds padata_works_lock. Reported-by: syzbot+f4b9f49e38e25eb4ef52@syzkaller.appspotmail.com Fixes: 4611ce2246889 ("padata: allocate work structures for parallel jobs from a pool") Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-09Merge tag 'v5.8.8' into v5.8/standard/baseBruce Ashfield
This is the 5.8.8 stable release # gpg: Signature made Wed 09 Sep 2020 01:15:04 PM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2020-09-09Merge tag 'v5.8.6' into v5.8/standard/baseBruce Ashfield
This is the 5.8.6 stable release # gpg: Signature made Thu 03 Sep 2020 05:30:12 AM EDT # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2020-09-09bpf: Fix a buffer out-of-bound access when filling raw_tp link_infoYonghong Song
[ Upstream commit b474959d5afda6e341a02c85f9595d85d39189ae ] Commit f2e10bff16a0 ("bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link") added link query for raw_tp. One of fields in link_info is to fill a user buffer with tp_name. The Scurrent checking only declares "ulen && !ubuf" as invalid. So "!ulen && ubuf" will be valid. Later on, we do "copy_to_user(ubuf, tp_name, ulen - 1)" which may overwrite user memory incorrectly. This patch fixed the problem by disallowing "!ulen && ubuf" case as well. Fixes: f2e10bff16a0 ("bpf: Add support for BPF_OBJ_GET_INFO_BY_FD for bpf_link") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200821191054.714731-1-yhs@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03dma-pool: Fix an uninitialized variable bug in atomic_pool_expand()Dan Carpenter
commit 892fc9f6835ecf075efac20789b012c5c9997fcc upstream. The "page" pointer can be used with out being initialized. Fixes: d7e673ec2c8e ("dma-pool: Only allocate from CMA when in same memory zone") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03genirq/matrix: Deal with the sillyness of for_each_cpu() on UPThomas Gleixner
commit 784a0830377d0761834e385975bc46861fea9fa0 upstream. Most of the CPU mask operations behave the same way, but for_each_cpu() and it's variants ignore the cpumask argument and claim that CPU0 is always in the mask. This is historical, inconsistent and annoying behaviour. The matrix allocator uses for_each_cpu() and can be called on UP with an empty cpumask. The calling code does not expect that this succeeds but until commit e027fffff799 ("x86/irq: Unbreak interrupt affinity setting") this went unnoticed. That commit added a WARN_ON() to catch cases which move an interrupt from one vector to another on the same CPU. The warning triggers on UP. Add a check for the cpumask being empty to prevent this. Fixes: 2f75d9e1c905 ("genirq: Implement bitmap matrix allocator") Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-03bpf: Avoid visit same object multiple timesYonghong Song
[ Upstream commit e60572b8d4c39572be6857d1ec91fdf979f8775f ] Currently when traversing all tasks, the next tid is always increased by one. This may result in visiting the same task multiple times in a pid namespace. This patch fixed the issue by seting the next tid as pid_nr_ns(pid, ns) + 1, similar to funciton next_tgid(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: https://lore.kernel.org/bpf/20200818222310.2181500-1-yhs@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-03bpf: Fix a rcu_sched stall issue with bpf task/task_file iteratorYonghong Song
[ Upstream commit e679654a704e5bd676ea6446fa7b764cbabf168a ] In our production system, we observed rcu stalls when 'bpftool prog` is running. rcu: INFO: rcu_sched self-detected stall on CPU rcu: \x097-....: (20999 ticks this GP) idle=302/1/0x4000000000000000 softirq=1508852/1508852 fqs=4913 \x09(t=21031 jiffies g=2534773 q=179750) NMI backtrace for cpu 7 CPU: 7 PID: 184195 Comm: bpftool Kdump: loaded Tainted: G W 5.8.0-00004-g68bfc7f8c1b4 #6 Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A17 05/03/2019 Call Trace: <IRQ> dump_stack+0x57/0x70 nmi_cpu_backtrace.cold+0x14/0x53 ? lapic_can_unplug_cpu.cold+0x39/0x39 nmi_trigger_cpumask_backtrace+0xb7/0xc7 rcu_dump_cpu_stacks+0xa2/0xd0 rcu_sched_clock_irq.cold+0x1ff/0x3d9 ? tick_nohz_handler+0x100/0x100 update_process_times+0x5b/0x90 tick_sched_timer+0x5e/0xf0 __hrtimer_run_queues+0x12a/0x2a0 hrtimer_interrupt+0x10e/0x280 __sysvec_apic_timer_interrupt+0x51/0xe0 asm_call_on_stack+0xf/0x20 </IRQ> sysvec_apic_timer_interrupt+0x6f/0x80 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:task_file_seq_get_next+0x71/0x220 Code: 00 00 8b 53 1c 49 8b 7d 00 89 d6 48 8b 47 20 44 8b 18 41 39 d3 76 75 48 8b 4f 20 8b 01 39 d0 76 61 41 89 d1 49 39 c1 48 19 c0 <48> 8b 49 08 21 d0 48 8d 04 c1 4c 8b 08 4d 85 c9 74 46 49 8b 41 38 RSP: 0018:ffffc90006223e10 EFLAGS: 00000297 RAX: ffffffffffffffff RBX: ffff888f0d172388 RCX: ffff888c8c07c1c0 RDX: 00000000000f017b RSI: 00000000000f017b RDI: ffff888c254702c0 RBP: ffffc90006223e68 R08: ffff888be2a1c140 R09: 00000000000f017b R10: 0000000000000002 R11: 0000000000100000 R12: ffff888f23c24118 R13: ffffc90006223e60 R14: ffffffff828509a0 R15: 00000000ffffffff task_file_seq_next+0x52/0xa0 bpf_seq_read+0xb9/0x320 vfs_read+0x9d/0x180 ksys_read+0x5f/0xe0 do_syscall_64+0x38/0x60 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f8815f4f76e Code: c0 e9 f6 fe ff ff 55 48 8d 3d 76 70 0a 00 48 89 e5 e8 36 06 02 00 66 0f 1f 44 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 52 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 RSP: 002b:00007fff8f9df578 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000170b9c0 RCX: 00007f8815f4f76e RDX: 0000000000001000 RSI: 00007fff8f9df5b0 RDI: 0000000000000007 RBP: 00007fff8f9e05f0 R08: 0000000000000049 R09: 0000000000000010 R10: 00007f881601fa40 R11: 0000000000000246 R12: 00007fff8f9e05a8 R13: 00007fff8f9e05a8 R14: 0000000001917f90 R15: 000000000000e22e Note that `bpftool prog` actually calls a task_file bpf iterator program to establish an association between prog/map/link/btf anon files and processes. In the case where the above rcu stall occured, we had a process having 1587 tasks and each task having roughly 81305 files. This implied 129 million bpf prog invocations. Unfortunwtely none of these files are prog/map/link/btf files so bpf iterator/prog needs to traverse all these files and not able to return to user space since there are no seq_file buffer overflow. This patch fixed the issue in bpf_seq_read() to limit the number of visited objects. If the maximum number of visited objects is reached, no more objects will be visited in the current syscall. If there is nothing written in the seq_file buffer, -EAGAIN will return to the user so user can try again. The maximum number of visited objects is set at 1 million. In our Intel Xeon D-2191 2.3GHZ 18-core server, bpf_seq_read() visiting 1 million files takes around 0.18 seconds. We did not use cond_resched() since for some iterators, e.g., netlink iterator, where rcu read_lock critical section spans between consecutive seq_ops->next(), which makes impossible to do cond_resched() in the key while loop of function bpf_seq_read(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/bpf/20200818222309.2181348-1-yhs@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org>