Commit Graph

34802 Commits

Author SHA1 Message Date
Eric W. Biederman
ab7709b551 exec: Transform exec_update_mutex into a rw_semaphore
[ Upstream commit f7cfd871ae0c5008d94b6f66834e7845caa93c15 ]

Recently syzbot reported[0] that there is a deadlock amongst the users
of exec_update_mutex.  The problematic lock ordering found by lockdep
was:

   perf_event_open  (exec_update_mutex -> ovl_i_mutex)
   chown            (ovl_i_mutex       -> sb_writes)
   sendfile         (sb_writes         -> p->lock)
     by reading from a proc file and writing to overlayfs
   proc_pid_syscall (p->lock           -> exec_update_mutex)

While looking at possible solutions it occured to me that all of the
users and possible users involved only wanted to state of the given
process to remain the same.  They are all readers.  The only writer is
exec.

There is no reason for readers to block on each other.  So fix
this deadlock by transforming exec_update_mutex into a rw_semaphore
named exec_update_lock that only exec takes for writing.

Cc: Jann Horn <jannh@google.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Bernd Edlinger <bernd.edlinger@hotmail.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christopher Yeoh <cyeoh@au1.ibm.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Sargun Dhillon <sargun@sargun.me>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Fixes: eea9673250 ("exec: Add exec_update_mutex to replace cred_guard_mutex")
[0] https://lkml.kernel.org/r/00000000000063640c05ade8e3de@google.com
Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com
Link: https://lkml.kernel.org/r/87ft4mbqen.fsf@x220.int.ebiederm.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-09 13:46:24 +01:00
Eric W. Biederman
933b7cc860 rwsem: Implement down_read_interruptible
[ Upstream commit 31784cff7ee073b34d6eddabb95e3be2880a425c ]

In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_interruptible.  This is needed for perf_event_open to be
converted (with no semantic changes) from working on a mutex to
wroking on a rwsem.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/87k0tybqfy.fsf@x220.int.ebiederm.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-09 13:46:24 +01:00
Eric W. Biederman
27bae39e4f rwsem: Implement down_read_killable_nested
[ Upstream commit 0f9368b5bf6db0c04afc5454b1be79022a681615 ]

In preparation for converting exec_update_mutex to a rwsem so that
multiple readers can execute in parallel and not deadlock, add
down_read_killable_nested.  This is needed so that kcmp_lock
can be converted from working on a mutexes to working on rw_semaphores.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/87o8jabqh3.fsf@x220.int.ebiederm.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-09 13:46:24 +01:00
peterz@infradead.org
2cded5a3cc perf: Break deadlock involving exec_update_mutex
[ Upstream commit 78af4dc949daaa37b3fcd5f348f373085b4e858f ]

Syzbot reported a lock inversion involving perf. The sore point being
perf holding exec_update_mutex() for a very long time, specifically
across a whole bunch of filesystem ops in pmu::event_init() (uprobes)
and anon_inode_getfile().

This then inverts against procfs code trying to take
exec_update_mutex.

Move the permission checks later, such that we need to hold the mutex
over less code.

Reported-by: syzbot+db9cdf3dd1f64252c6ef@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-09 13:46:24 +01:00
Thomas Gleixner
330c1ee7d5 tick/sched: Remove bogus boot "safety" check
[ Upstream commit ba8ea8e7dd6e1662e34e730eadfc52aa6816f9dd ]

can_stop_idle_tick() checks whether the do_timer() duty has been taken over
by a CPU on boot. That's silly because the boot CPU always takes over with
the initial clockevent device.

But even if no CPU would have installed a clockevent and taken over the
duty then the question whether the tick on the current CPU can be stopped
or not is moot. In that case the current CPU would have no clockevent
either, so there would be nothing to keep ticking.

Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20201206212002.725238293@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:56:55 +01:00
Jessica Yu
8b5b2b7683 module: delay kobject uevent until after module init call
[ Upstream commit 38dc717e97153e46375ee21797aa54777e5498f3 ]

Apparently there has been a longstanding race between udev/systemd and
the module loader. Currently, the module loader sends a uevent right
after sysfs initialization, but before the module calls its init
function. However, some udev rules expect that the module has
initialized already upon receiving the uevent.

This race has been triggered recently (see link in references) in some
systemd mount unit files. For instance, the configfs module creates the
/sys/kernel/config mount point in its init function, however the module
loader issues the uevent before this happens. sys-kernel-config.mount
expects to be able to mount /sys/kernel/config upon receipt of the
module loading uevent, but if the configfs module has not called its
init function yet, then this directory will not exist and the mount unit
fails. A similar situation exists for sys-fs-fuse-connections.mount, as
the fuse sysfs mount point is created during the fuse module's init
function. If udev is faster than module initialization then the mount
unit would fail in a similar fashion.

To fix this race, delay the module KOBJ_ADD uevent until after the
module has finished calling its init routine.

References: https://github.com/systemd/systemd/issues/17586
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-By: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:56:54 +01:00
Miroslav Benes
bb2ab902f6 module: set MODULE_STATE_GOING state when a module fails to load
[ Upstream commit 5e8ed280dab9eeabc1ba0b2db5dbe9fe6debb6b5 ]

If a module fails to load due to an error in prepare_coming_module(),
the following error handling in load_module() runs with
MODULE_STATE_COMING in module's state. Fix it by correctly setting
MODULE_STATE_GOING under "bug_cleanup" label.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:56:53 +01:00
Qinglang Miao
bf81221a40 cgroup: Fix memory leak when parsing multiple source parameters
commit 2d18e54dd8662442ef5898c6bdadeaf90b3cebbc upstream.

A memory leak is found in cgroup1_parse_param() when multiple source
parameters overwrite fc->source in the fs_context struct without free.

unreferenced object 0xffff888100d930e0 (size 16):
  comm "mount", pid 520, jiffies 4303326831 (age 152.783s)
  hex dump (first 16 bytes):
    74 65 73 74 6c 65 61 6b 00 00 00 00 00 00 00 00  testleak........
  backtrace:
    [<000000003e5023ec>] kmemdup_nul+0x2d/0xa0
    [<00000000377dbdaa>] vfs_parse_fs_string+0xc0/0x150
    [<00000000cb2b4882>] generic_parse_monolithic+0x15a/0x1d0
    [<000000000f750198>] path_mount+0xee1/0x1820
    [<0000000004756de2>] do_mount+0xea/0x100
    [<0000000094cafb0a>] __x64_sys_mount+0x14b/0x1f0

Fix this bug by permitting a single source parameter and rejecting with
an error all subsequent ones.

Fixes: 8d2451f499 ("cgroup1: switch to option-by-option parsing")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Reviewed-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-06 14:56:51 +01:00
Steven Rostedt (VMware)
2bbb320656 Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS"
commit adab66b71abfe206a020f11e561f4df41f0b2aba upstream.

It was believed that metag was the only architecture that required the ring
buffer to keep 8 byte words aligned on 8 byte architectures, and with its
removal, it was assumed that the ring buffer code did not need to handle
this case. It appears that sparc64 also requires this.

The following was reported on a sparc64 boot up:

   kernel: futex hash table entries: 65536 (order: 9, 4194304 bytes, linear)
   kernel: Running postponed tracer tests:
   kernel: Testing tracer function:
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: Kernel unaligned access at TPC[552a24] trace_function+0x44/0x140
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: Kernel unaligned access at TPC[552a24] trace_function+0x44/0x140
   kernel: Kernel unaligned access at TPC[552a20] trace_function+0x40/0x140
   kernel: PASSED

Need to put back the 64BIT aligned code for the ring buffer.

Link: https://lore.kernel.org/r/CADxRZqzXQRYgKc=y-KV=S_yHL+Y8Ay2mh5ezeZUnpRvg+syWKw@mail.gmail.com

Cc: stable@vger.kernel.org
Fixes: 86b3de60a0 ("ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS")
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:29 +01:00
Masami Hiramatsu
f2d7cffc20 tracing: Disable ftrace selftests when any tracer is running
commit 60efe21e5976d3d4170a8190ca76a271d6419754 upstream.

Disable ftrace selftests when any tracer (kernel command line options
like ftrace=, trace_events=, kprobe_events=, and boot-time tracing)
starts running because selftest can disturb it.

Currently ftrace= and trace_events= are checked, but kprobe_events
has a different flag, and boot-time tracing didn't checked. This unifies
the disabled flag and all of those boot-time tracing features sets
the flag.

This also fixes warnings on kprobe-event selftest
(CONFIG_FTRACE_STARTUP_TEST=y and CONFIG_KPROBE_EVENTS=y) with boot-time
tracing (ftrace.event.kprobes.EVENT.probes) like below;

[   59.803496] trace_kprobe: Testing kprobe tracing:
[   59.804258] ------------[ cut here ]------------
[   59.805682] WARNING: CPU: 3 PID: 1 at kernel/trace/trace_kprobe.c:1987 kprobe_trace_self_tests_ib
[   59.806944] Modules linked in:
[   59.807335] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc7+ #172
[   59.808029] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/204
[   59.808999] RIP: 0010:kprobe_trace_self_tests_init+0x5f/0x42b
[   59.809696] Code: e8 03 00 00 48 c7 c7 30 8e 07 82 e8 6d 3c 46 ff 48 c7 c6 00 b2 1a 81 48 c7 c7 7
[   59.812439] RSP: 0018:ffffc90000013e78 EFLAGS: 00010282
[   59.813038] RAX: 00000000ffffffef RBX: 0000000000000000 RCX: 0000000000049443
[   59.813780] RDX: 0000000000049403 RSI: 0000000000049403 RDI: 000000000002deb0
[   59.814589] RBP: ffffc90000013e90 R08: 0000000000000001 R09: 0000000000000001
[   59.815349] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffef
[   59.816138] R13: ffff888004613d80 R14: ffffffff82696940 R15: ffff888004429138
[   59.816877] FS:  0000000000000000(0000) GS:ffff88807dcc0000(0000) knlGS:0000000000000000
[   59.817772] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   59.818395] CR2: 0000000001a8dd38 CR3: 0000000002222000 CR4: 00000000000006a0
[   59.819144] Call Trace:
[   59.819469]  ? init_kprobe_trace+0x6b/0x6b
[   59.819948]  do_one_initcall+0x5f/0x300
[   59.820392]  ? rcu_read_lock_sched_held+0x4f/0x80
[   59.820916]  kernel_init_freeable+0x22a/0x271
[   59.821416]  ? rest_init+0x241/0x241
[   59.821841]  kernel_init+0xe/0x10f
[   59.822251]  ret_from_fork+0x22/0x30
[   59.822683] irq event stamp: 16403349
[   59.823121] hardirqs last  enabled at (16403359): [<ffffffff810db81e>] console_unlock+0x48e/0x580
[   59.824074] hardirqs last disabled at (16403368): [<ffffffff810db786>] console_unlock+0x3f6/0x580
[   59.825036] softirqs last  enabled at (16403200): [<ffffffff81c0033a>] __do_softirq+0x33a/0x484
[   59.825982] softirqs last disabled at (16403087): [<ffffffff81a00f02>] asm_call_irq_on_stack+0x10
[   59.827034] ---[ end trace 200c544775cdfeb3 ]---
[   59.827635] trace_kprobe: error on probing function entry.

Link: https://lkml.kernel.org/r/160741764955.3448999.3347769358299456915.stgit@devnote2

Fixes: 4d655281eb ("tracing/boot Add kprobe event support")
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>
2020-12-30 11:54:28 +01:00
Amir Goldstein
c9be99c861 fsnotify: generalize handle_inode_event()
commit 950cc0d2bef078e1f6459900ca4d4b2a2e0e3c37 upstream.

The handle_inode_event() interface was added as (quoting comment):
"a simple variant of handle_event() for groups that only have inode
marks and don't have ignore mask".

In other words, all backends except fanotify.  The inotify backend
also falls under this category, but because it required extra arguments
it was left out of the initial pass of backends conversion to the
simple interface.

This results in code duplication between the generic helper
fsnotify_handle_event() and the inotify_handle_event() callback
which also happen to be buggy code.

Generalize the handle_inode_event() arguments and add the check for
FS_EXCL_UNLINK flag to the generic helper, so inotify backend could
be converted to use the simple interface.

Link: https://lore.kernel.org/r/20201202120713.702387-2-amir73il@gmail.com
CC: stable@vger.kernel.org
Fixes: b9a1b97725 ("fsnotify: create method handle_inode_event() in fsnotify_operations")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:18 +01:00
Daniel Jordan
771b663fa5 cpuset: fix race between hotplug work and later CPU offline
commit 406100f3da08066c00105165db8520bbc7694a36 upstream.

One of our machines keeled over trying to rebuild the scheduler domains.
Mainline produces the same splat:

  BUG: unable to handle page fault for address: 0000607f820054db
  CPU: 2 PID: 149 Comm: kworker/1:1 Not tainted 5.10.0-rc1-master+ #6
  Workqueue: events cpuset_hotplug_workfn
  RIP: build_sched_domains
  Call Trace:
   partition_sched_domains_locked
   rebuild_sched_domains_locked
   cpuset_hotplug_workfn

It happens with cgroup2 and exclusive cpusets only.  This reproducer
triggers it on an 8-cpu vm and works most effectively with no
preexisting child cgroups:

  cd $UNIFIED_ROOT
  mkdir cg1
  echo 4-7 > cg1/cpuset.cpus
  echo root > cg1/cpuset.cpus.partition

  # with smt/control reading 'on',
  echo off > /sys/devices/system/cpu/smt/control

RIP maps to

  sd->shared = *per_cpu_ptr(sdd->sds, sd_id);

from sd_init().  sd_id is calculated earlier in the same function:

  cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
  sd_id = cpumask_first(sched_domain_span(sd));

tl->mask(cpu), which reads cpu_sibling_map on x86, returns an empty mask
and so cpumask_first() returns >= nr_cpu_ids, which leads to the bogus
value from per_cpu_ptr() above.

The problem is a race between cpuset_hotplug_workfn() and a later
offline of CPU N.  cpuset_hotplug_workfn() updates the effective masks
when N is still online, the offline clears N from cpu_sibling_map, and
then the worker uses the stale effective masks that still have N to
generate the scheduling domains, leading the worker to read
N's empty cpu_sibling_map in sd_init().

rebuild_sched_domains_locked() prevented the race during the cgroup2
cpuset series up until the Fixes commit changed its check.  Make the
check more robust so that it can detect an offline CPU in any exclusive
cpuset's effective mask, not just the top one.

Fixes: 0ccea8feb9 ("cpuset: Make generate_sched_domains() work with partition")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20201112171711.639541-1-daniel.m.jordan@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:54:11 +01:00
Jason Gunthorpe
537946556c mm/gup: prevent gup_fast from racing with COW during fork
[ Upstream commit 57efa1fe5957694fa541c9062de0a127f0b9acb0 ]

Since commit 70e806e4e6 ("mm: Do early cow for pinned pages during
fork() for ptes") pages under a FOLL_PIN will not be write protected
during COW for fork.  This means that pages returned from
pin_user_pages(FOLL_WRITE) should not become write protected while the pin
is active.

However, there is a small race where get_user_pages_fast(FOLL_PIN) can
establish a FOLL_PIN at the same time copy_present_page() is write
protecting it:

        CPU 0                             CPU 1
   get_user_pages_fast()
    internal_get_user_pages_fast()
                                       copy_page_range()
                                         pte_alloc_map_lock()
                                           copy_present_page()
                                             atomic_read(has_pinned) == 0
					     page_maybe_dma_pinned() == false
     atomic_set(has_pinned, 1);
     gup_pgd_range()
      gup_pte_range()
       pte_t pte = gup_get_pte(ptep)
       pte_access_permitted(pte)
       try_grab_compound_head()
                                             pte = pte_wrprotect(pte)
	                                     set_pte_at();
                                         pte_unmap_unlock()
      // GUP now returns with a write protected page

The first attempt to resolve this by using the write protect caused
problems (and was missing a barrrier), see commit f3c64eda3e ("mm: avoid
early COW write protect games during fork()")

Instead wrap copy_p4d_range() with the write side of a seqcount and check
the read side around gup_pgd_range().  If there is a collision then
get_user_pages_fast() fails and falls back to slow GUP.

Slow GUP is safe against this race because copy_page_range() is only
called while holding the exclusive side of the mmap_lock on the src
mm_struct.

[akpm@linux-foundation.org: coding style fixes]
  Link: https://lore.kernel.org/r/CAHk-=wi=iCnYCARbPGjkVJu9eyYeZ13N64tZYLdOB8CP5Q_PLw@mail.gmail.com

Link: https://lkml.kernel.org/r/2-v4-908497cf359a+4782-gup_fork_jgg@nvidia.com
Fixes: f3c64eda3e ("mm: avoid early COW write protect games during fork()")
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Peter Xu <peterx@redhat.com>
Acked-by: "Ahmed S. Darwish" <a.darwish@linutronix.de>	[seqcount_t parts]
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Leon Romanovsky <leonro@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:54 +01:00
Andrii Nakryiko
4322f9a646 bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address()
[ Upstream commit 12cc126df82c96c89706aa207ad27c56f219047c ]

__module_address() needs to be called with preemption disabled or with
module_mutex taken. preempt_disable() is enough for read-only uses, which is
what this fix does. Also, module_put() does internal check for NULL, so drop
it as well.

Fixes: a38d1107f9 ("bpf: support raw tracepoints in modules")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-2-andrii@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:34 +01:00
Marc Zyngier
f11ebb7651 genirq/irqdomain: Don't try to free an interrupt that has no mapping
[ Upstream commit 4615fbc3788ddc8e7c6d697714ad35a53729aa2c ]

When an interrupt allocation fails for N interrupts, it is pretty
common for the error handling code to free the same number of interrupts,
no matter how many interrupts have actually been allocated.

This may result in the domain freeing code to be unexpectedly called
for interrupts that have no mapping in that domain. Things end pretty
badly.

Instead, add some checks to irq_domain_free_irqs_hierarchy() to make sure
that thiss does not follow the hierarchy if no mapping exists for a given
interrupt.

Fixes: 6a6544e520 ("genirq/irqdomain: Remove auto-recursive hierarchy support")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201129135551.396777-1-maz@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:25 +01:00
Uladzislau Rezki (Sony)
9b81af9c84 rcu/tree: Defer kvfree_rcu() allocation to a clean context
[ Upstream commit 56292e8609e39537297a7468dda4d87b9bd81d6a ]

The current memmory-allocation interface causes the following difficulties
for kvfree_rcu():

a) If built with CONFIG_PROVE_RAW_LOCK_NESTING, the lockdep will
   complain about violation of the nesting rules, as in "BUG: Invalid
   wait context".  This Kconfig option checks for proper raw_spinlock
   vs. spinlock nesting, in particular, it is not legal to acquire a
   spinlock_t while holding a raw_spinlock_t.

   This is a problem because kfree_rcu() uses raw_spinlock_t whereas the
   "page allocator" internally deals with spinlock_t to access to its
   zones. The code also can be broken from higher level of view:
   <snip>
       raw_spin_lock(&some_lock);
       kfree_rcu(some_pointer, some_field_offset);
   <snip>

b) If built with CONFIG_PREEMPT_RT, spinlock_t is converted into
   sleeplock.  This means that invoking the page allocator from atomic
   contexts results in "BUG: scheduling while atomic".

c) Please note that call_rcu() is already invoked from raw atomic context,
   so it is only reasonable to expaect that kfree_rcu() and kvfree_rcu()
   will also be called from atomic raw context.

This commit therefore defers page allocation to a clean context using the
combination of an hrtimer and a workqueue.  The hrtimer stage is required
in order to avoid deadlocks with the scheduler.  This deferred allocation
is required only when kvfree_rcu()'s per-CPU page cache is empty.

Link: https://lore.kernel.org/lkml/20200630164543.4mdcf6zb4zfclhln@linutronix.de/
Fixes: 3042f83f19 ("rcu: Support reclaim for head-less object")
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:17 +01:00
Peter Zijlstra
5cacd18c52 rcu,ftrace: Fix ftrace recursion
[ Upstream commit d2098b4440981705e844c50254540ba7b5f82795 ]

Kim reported that perf-ftrace made his box unhappy. It turns out that
commit:

  ff5c4f5cad ("rcu/tree: Mark the idle relevant functions noinstr")

removed one too many notrace qualifiers, probably due to there not being
a helpful comment.

This commit therefore reinstates the notrace and adds a comment to avoid
losing it again.

[ paulmck: Apply Steven Rostedt's feedback on the comment. ]
Fixes: ff5c4f5cad ("rcu/tree: Mark the idle relevant functions noinstr")
Reported-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:17 +01:00
Peter Zijlstra
4540e84bd8 rcu: Allow rcu_irq_enter_check_tick() from NMI
[ Upstream commit 6dbce04d8417ae706596366e16841d77c454ba52 ]

Eugenio managed to tickle #PF from NMI context which resulted in
hitting a WARN in RCU through irqentry_enter() ->
__rcu_irq_enter_check_tick().

However, this situation is perfectly sane and does not warrant an
WARN. The #PF will (necessarily) be atomic and not require messing
with the tick state, so early return is correct.  This commit
therefore removes the WARN.

Fixes: aaf2bc50df ("rcu: Abstract out rcu_irq_enter_check_tick() from rcu_nmi_enter()")
Reported-by: "Eugenio Pérez" <eupm90@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:17 +01:00
Thomas Gleixner
8933a52534 sched: Reenable interrupts in do_sched_yield()
[ Upstream commit 345a957fcc95630bf5535d7668a59ed983eb49a7 ]

do_sched_yield() invokes schedule() with interrupts disabled which is
not allowed. This goes back to the pre git era to commit a6efb709806c
("[PATCH] irqlock patch 2.5.27-H6") in the history tree.

Reenable interrupts and remove the misleading comment which "explains" it.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/87r1pt7y5c.fsf@nanos.tec.linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:52:59 +01:00
Peng Liu
6d4250fe7d sched/deadline: Fix sched_dl_global_validate()
[ Upstream commit a57415f5d1e43c3a5c5d412cd85e2792d7ed9b11 ]

When change sched_rt_{runtime, period}_us, we validate that the new
settings should at least accommodate the currently allocated -dl
bandwidth:

  sched_rt_handler()
    -->	sched_dl_bandwidth_validate()
	{
		new_bw = global_rt_runtime()/global_rt_period();

		for_each_possible_cpu(cpu) {
			dl_b = dl_bw_of(cpu);
			if (new_bw < dl_b->total_bw)    <-------
				ret = -EBUSY;
		}
	}

But under CONFIG_SMP, dl_bw is per root domain , but not per CPU,
dl_b->total_bw is the allocated bandwidth of the whole root domain.
Instead, we should compare dl_b->total_bw against "cpus*new_bw",
where 'cpus' is the number of CPUs of the root domain.

Also, below annotation(in kernel/sched/sched.h) implied implementation
only appeared in SCHED_DEADLINE v2[1], then deadline scheduler kept
evolving till got merged(v9), but the annotation remains unchanged,
meaningless and misleading, update it.

* With respect to SMP, the bandwidth is given on a per-CPU basis,
* meaning that:
*  - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
*  - dl_total_bw array contains, in the i-eth element, the currently
*    allocated bandwidth on the i-eth CPU.

[1]: https://lore.kernel.org/lkml/1267385230.13676.101.camel@Palantir/

Fixes: 332ac17ef5 ("sched/deadline: Add bandwidth management for SCHED_DEADLINE tasks")
Signed-off-by: Peng Liu <iwtbavbm@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lkml.kernel.org/r/db6bbda316048cda7a1bbc9571defde193a8d67e.1602171061.git.iwtbavbm@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:52:59 +01:00
Linus Torvalds
ec6f5e0e5c A set of x86 and membarrier fixes:
- Correct a few problems in the x86 and the generic membarrier
     implementation. Small corrections for assumptions about visibility
     which have turned out not to be true.
 
   - Make the PAT bits for memory encryption correct vs. 4K and 2M/1G page
     table entries as they are at a different location.
 
   - Fix a concurrency issue in the the local bandwidth readout of resource
     control leading to incorrect values
 
   - Fix the ordering of allocating a vector for an interrupt. The order
     missed to respect the provided cpumask when the first attempt of
     allocating node local in the mask fails. It then tries the node instead
     of trying the full provided mask first. This leads to erroneous error
     messages and breaking the (user) supplied affinity request. Reorder it.
 
   - Make the INT3 padding detection in optprobe work correctly.
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Merge tag 'x86-urgent-2020-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 and membarrier fixes:

   - Correct a few problems in the x86 and the generic membarrier
     implementation. Small corrections for assumptions about visibility
     which have turned out not to be true.

   - Make the PAT bits for memory encryption correct vs 4K and 2M/1G
     page table entries as they are at a different location.

   - Fix a concurrency issue in the the local bandwidth readout of
     resource control leading to incorrect values

   - Fix the ordering of allocating a vector for an interrupt. The order
     missed to respect the provided cpumask when the first attempt of
     allocating node local in the mask fails. It then tries the node
     instead of trying the full provided mask first. This leads to
     erroneous error messages and breaking the (user) supplied affinity
     request. Reorder it.

   - Make the INT3 padding detection in optprobe work correctly"

* tag 'x86-urgent-2020-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/kprobes: Fix optprobe to detect INT3 padding correctly
  x86/apic/vector: Fix ordering in vector assignment
  x86/resctrl: Fix incorrect local bandwidth when mba_sc is enabled
  x86/mm/mem_encrypt: Fix definition of PMD_FLAGS_DEC_WP
  membarrier: Execute SYNC_CORE on the calling thread
  membarrier: Explicitly sync remote cores when SYNC_CORE is requested
  membarrier: Add an actual barrier before rseq_preempt()
  x86/membarrier: Get rid of a dubious optimization
2020-12-13 11:31:19 -08:00
Andrii Nakryiko
b7906b70a2 bpf: Fix enum names for bpf_this_cpu_ptr() and bpf_per_cpu_ptr() helpers
Remove bpf_ prefix, which causes these helpers to be reported in verifier
dump as bpf_bpf_this_cpu_ptr() and bpf_bpf_per_cpu_ptr(), respectively. Lets
fix it as long as it is still possible before UAPI freezes on these helpers.

Fixes: eaa6bcb71e ("bpf: Introduce bpf_per_cpu_ptr()")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-11 14:19:07 -08:00
Arnd Bergmann
6e7b64b9dd elfcore: fix building with clang
kernel/elfcore.c only contains weak symbols, which triggers a bug with
clang in combination with recordmcount:

  Cannot find symbol for section 2: .text.
  kernel/elfcore.o: failed

Move the empty stubs into linux/elfcore.h as inline functions.  As only
two architectures use these, just use the architecture specific Kconfig
symbols to key off the declaration.

Link: https://lkml.kernel.org/r/20201204165742.3815221-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Barret Rhoden <brho@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-11 14:02:14 -08:00
Linus Torvalds
4d31058b82 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) IPsec compat fixes, from Dmitry Safonov.

 2) Fix memory leak in xfrm_user_policy(). Fix from Yu Kuai.

 3) Fix polling in xsk sockets by using sk_poll_wait() instead of
    datagram_poll() which keys off of sk_wmem_alloc and such which xsk
    sockets do not update. From Xuan Zhuo.

 4) Missing init of rekey_data in cfgh80211, from Sara Sharon.

 5) Fix destroy of timer before init, from Davide Caratti.

 6) Missing CRYPTO_CRC32 selects in ethernet driver Kconfigs, from Arnd
    Bergmann.

 7) Missing error return in rtm_to_fib_config() switch case, from Zhang
    Changzhong.

 8) Fix some src/dest address handling in vrf and add a testcase. From
    Stephen Suryaputra.

 9) Fix multicast handling in Seville switches driven by mscc-ocelot
    driver. From Vladimir Oltean.

10) Fix proto value passed to skb delivery demux in udp, from Xin Long.

11) HW pkt counters not reported correctly in enetc driver, from Claudiu
    Manoil.

12) Fix deadlock in bridge, from Joseph Huang.

13) Missing of_node_pur() in dpaa2 driver, fromn Christophe JAILLET.

14) Fix pid fetching in bpftool when there are a lot of results, from
    Andrii Nakryiko.

15) Fix long timeouts in nft_dynset, from Pablo Neira Ayuso.

16) Various stymmac fixes, from Fugang Duan.

17) Fix null deref in tipc, from Cengiz Can.

18) When mss is biog, coose more resonable rcvq_space in tcp, fromn Eric
    Dumazet.

19) Revert a geneve change that likely isnt necessary, from Jakub
    Kicinski.

20) Avoid premature rx buffer reuse in various Intel driversm from Björn
    Töpel.

21) retain EcT bits during TIS reflection in tcp, from Wei Wang.

22) Fix Tso deferral wrt. cwnd limiting in tcp, from Neal Cardwell.

23) MPLS_OPT_LSE_LABEL attribute is 342 ot 8 bits, from Guillaume Nault

24) Fix propagation of 32-bit signed bounds in bpf verifier and add test
    cases, from Alexei Starovoitov.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (81 commits)
  selftests: fix poll error in udpgro.sh
  selftests/bpf: Fix "dubious pointer arithmetic" test
  selftests/bpf: Fix array access with signed variable test
  selftests/bpf: Add test for signed 32-bit bound check bug
  bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds.
  MAINTAINERS: Add entry for Marvell Prestera Ethernet Switch driver
  net: sched: Fix dump of MPLS_OPT_LSE_LABEL attribute in cls_flower
  net/mlx4_en: Handle TX error CQE
  net/mlx4_en: Avoid scheduling restart task if it is already running
  tcp: fix cwnd-limited bug for TSO deferral where we send nothing
  net: flow_offload: Fix memory leak for indirect flow block
  tcp: Retain ECT bits for tos reflection
  ethtool: fix stack overflow in ethnl_parse_bitset()
  e1000e: fix S0ix flow to allow S0i3.2 subset entry
  ice: avoid premature Rx buffer reuse
  ixgbe: avoid premature Rx buffer reuse
  i40e: avoid premature Rx buffer reuse
  igb: avoid transmit queue timeout in xdp path
  igb: use xdp_do_flush
  igb: skb add metasize for xdp
  ...
2020-12-10 15:30:13 -08:00
David S. Miller
d9838b1d39 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2020-12-10

The following pull-request contains BPF updates for your *net* tree.

We've added 21 non-merge commits during the last 12 day(s) which contain
a total of 21 files changed, 163 insertions(+), 88 deletions(-).

The main changes are:

1) Fix propagation of 32-bit signed bounds from 64-bit bounds, from Alexei.

2) Fix ring_buffer__poll() return value, from Andrii.

3) Fix race in lwt_bpf, from Cong.

4) Fix test_offload, from Toke.

5) Various xsk fixes.

Please consider pulling these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git

Thanks a lot!

Also thanks to reporters, reviewers and testers of commits in this pull-request:

Cong Wang, Hulk Robot, Jakub Kicinski, Jean-Philippe Brucker, John
Fastabend, Magnus Karlsson, Maxim Mikityanskiy, Yonghong Song
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-12-10 14:29:30 -08:00
Alexei Starovoitov
b02709587e bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds.
The 64-bit signed bounds should not affect 32-bit signed bounds unless the
verifier knows that upper 32-bits are either all 1s or all 0s. For example the
register with smin_value==1 doesn't mean that s32_min_value is also equal to 1,
since smax_value could be larger than 32-bit subregister can hold.
The verifier refines the smax/s32_max return value from certain helpers in
do_refine_retval_range(). Teach the verifier to recognize that smin/s32_min
value is also bounded. When both smin and smax bounds fit into 32-bit
subregister the verifier can propagate those bounds.

Fixes: 3f50f132d8 ("bpf: Verifier, do explicit ALU32 bounds tracking")
Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-12-10 13:02:53 -08:00
Andy Lutomirski
e45cdc71d1 membarrier: Execute SYNC_CORE on the calling thread
membarrier()'s MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE is documented as
syncing the core on all sibling threads but not necessarily the calling
thread.  This behavior is fundamentally buggy and cannot be used safely.

Suppose a user program has two threads.  Thread A is on CPU 0 and thread B
is on CPU 1.  Thread A modifies some text and calls
membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE).

Then thread B executes the modified code.  If, at any point after
membarrier() decides which CPUs to target, thread A could be preempted and
replaced by thread B on CPU 0.  This could even happen on exit from the
membarrier() syscall.  If this happens, thread B will end up running on CPU
0 without having synced.

In principle, this could be fixed by arranging for the scheduler to issue
sync_core_before_usermode() whenever switching between two threads in the
same mm if there is any possibility of a concurrent membarrier() call, but
this would have considerable overhead.  Instead, make membarrier() sync the
calling CPU as well.

As an optimization, this avoids an extra smp_mb() in the default
barrier-only mode and an extra rseq preempt on the caller.

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/250ded637696d490c69bef1877148db86066881c.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Andy Lutomirski
758c9373d8 membarrier: Explicitly sync remote cores when SYNC_CORE is requested
membarrier() does not explicitly sync_core() remote CPUs; instead, it
relies on the assumption that an IPI will result in a core sync.  On x86,
this may be true in practice, but it's not architecturally reliable.  In
particular, the SDM and APM do not appear to guarantee that interrupt
delivery is serializing.  While IRET does serialize, IPI return can
schedule, thereby switching to another task in the same mm that was
sleeping in a syscall.  The new task could then SYSRET back to usermode
without ever executing IRET.

Make this more robust by explicitly calling sync_core_before_usermode()
on remote cores.  (This also helps people who search the kernel tree for
instances of sync_core() and sync_core_before_usermode() -- one might be
surprised that the core membarrier code doesn't currently show up in a
such a search.)

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/776b448d5f7bd6b12690707f5ed67bcda7f1d427.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Andy Lutomirski
2ecedd7569 membarrier: Add an actual barrier before rseq_preempt()
It seems that most RSEQ membarrier users will expect any stores done before
the membarrier() syscall to be visible to the target task(s).  While this
is extremely likely to be true in practice, nothing actually guarantees it
by a strict reading of the x86 manuals.  Rather than providing this
guarantee by accident and potentially causing a problem down the road, just
add an explicit barrier.

Fixes: 70216e18e5 ("membarrier: Provide core serializing command, *_SYNC_CORE")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/d3e7197e034fa4852afcf370ca49c30496e58e40.1607058304.git.luto@kernel.org
2020-12-09 09:37:43 +01:00
Linus Torvalds
cd796ed334 Fix userstacktrace option for instances
While writing an application that requires user stack trace option
 to work in instances, I found that the instance option has a bug
 that makes it a nop. The check for performing the user stack trace
 in an instance, checks the top level options (not the instance options)
 to determine if a user stack trace should be performed or not.
 
 This is not only incorrect, but also confusing for users. It confused
 me for a bit!
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Merge tag 'trace-v5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Fix userstacktrace option for instances

  While writing an application that requires user stack trace option to
  work in instances, I found that the instance option has a bug that
  makes it a nop. The check for performing the user stack trace in an
  instance, checks the top level options (not the instance options) to
  determine if a user stack trace should be performed or not.

  This is not only incorrect, but also confusing for users. It confused
  me for a bit!"

* tag 'trace-v5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix userstacktrace option for instances
2020-12-07 11:20:26 -08:00
Linus Torvalds
592d9a0835 A set of updates for the interrupt subsystem:
- Make multiqueue devices which use the managed interrupt affinity
     infrastructure work on PowerPC/Pseries. PowerPC does not use the
     generic infrastructure for setting up PCI/MSI interrupts and the
     multiqueue changes failed to update the legacy PCI/MSI infrastructure.
     Make this work by passing the affinity setup information down to the
     mapping and allocation functions.
 
   - Move Jason Cooper from MAINTAINERS to CREDITS as his mail is bouncing
     and he's not reachable. We hope all is well with him and say thanks
     for his work over the years.
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Merge tag 'irq-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull irq fixes from Thomas Gleixner:
 "A set of updates for the interrupt subsystem:

   - Make multiqueue devices which use the managed interrupt affinity
     infrastructure work on PowerPC/Pseries. PowerPC does not use the
     generic infrastructure for setting up PCI/MSI interrupts and the
     multiqueue changes failed to update the legacy PCI/MSI
     infrastructure. Make this work by passing the affinity setup
     information down to the mapping and allocation functions.

   - Move Jason Cooper from MAINTAINERS to CREDITS as his mail is
     bouncing and he's not reachable. We hope all is well with him and
     say thanks for his work over the years"

* tag 'irq-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  powerpc/pseries: Pass MSI affinity to irq_create_mapping()
  genirq/irqdomain: Add an irq_create_mapping_affinity() function
  MAINTAINERS: Move Jason Cooper to CREDITS
2020-12-06 11:15:55 -08:00
Linus Torvalds
32f741b02f powerpc fixes for 5.10 #5
Three commits fixing possible missed TLB invalidations for multi-threaded
 processes when CPUs are hotplugged in and out.
 
 A fix for a host crash triggerable by host userspace (qemu) in KVM on Power9.
 
 A fix for a host crash in machine check handling when running HPT guests on a
 HPT host.
 
 One commit fixing potential missed TLB invalidations when using the hash MMU on
 Power9 or later.
 
 A regression fix for machines with CPUs on node 0 but no memory.
 
 Thanks to:
   Aneesh Kumar K.V, Cédric Le Goater, Greg Kurz, Milan Mohanty, Milton Miller,
   Nicholas Piggin, Paul Mackerras, Srikar Dronamraju.
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Merge tag 'powerpc-5.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.10:

   - Three commits fixing possible missed TLB invalidations for
     multi-threaded processes when CPUs are hotplugged in and out.

   - A fix for a host crash triggerable by host userspace (qemu) in KVM
     on Power9.

   - A fix for a host crash in machine check handling when running HPT
     guests on a HPT host.

   - One commit fixing potential missed TLB invalidations when using the
     hash MMU on Power9 or later.

   - A regression fix for machines with CPUs on node 0 but no memory.

  Thanks to Aneesh Kumar K.V, Cédric Le Goater, Greg Kurz, Milan
  Mohanty, Milton Miller, Nicholas Piggin, Paul Mackerras, and Srikar
  Dronamraju"

* tag 'powerpc-5.10-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s/powernv: Fix memory corruption when saving SLB entries on MCE
  KVM: PPC: Book3S HV: XIVE: Fix vCPU id sanity check
  powerpc/numa: Fix a regression on memoryless node 0
  powerpc/64s: Trim offlined CPUs from mm_cpumasks
  kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
  powerpc/64s/pseries: Fix hash tlbiel_all_isa300 for guest kernels
  powerpc/64s: Fix hash ISA v3.0 TLBIEL instruction generation
2020-12-05 11:16:21 -08:00
Steven Rostedt (VMware)
bcee527895 tracing: Fix userstacktrace option for instances
When the instances were able to use their own options, the userstacktrace
option was left hardcoded for the top level. This made the instance
userstacktrace option bascially into a nop, and will confuse users that set
it, but nothing happens (I was confused when it happened to me!)

Cc: stable@vger.kernel.org
Fixes: 16270145ce ("tracing: Add trace options for core options to instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-12-04 16:36:16 -05:00
Linus Torvalds
ef6900acc8 Tracing fixes for 5.10-rc6
- Use correct timestamp variable for ring buffer write stamp update
  - Fix up before stamp and write stamp when crossing ring buffer sub
    buffers
  - Keep a zero delta in ring buffer in slow path if cmpxchg fails
  - Fix trace_printk static buffer for archs that care
  - Fix ftrace record accounting for ftrace ops with trampolines
  - Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
  - Remove WARN_ON in hwlat tracer that triggers on something that is OK
  - Make "my_tramp" trampoline in ftrace direct sample code global
  - Fixes in the bootconfig tool for better alignment management
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Merge tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Use correct timestamp variable for ring buffer write stamp update

 - Fix up before stamp and write stamp when crossing ring buffer sub
   buffers

 - Keep a zero delta in ring buffer in slow path if cmpxchg fails

 - Fix trace_printk static buffer for archs that care

 - Fix ftrace record accounting for ftrace ops with trampolines

 - Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency

 - Remove WARN_ON in hwlat tracer that triggers on something that is OK

 - Make "my_tramp" trampoline in ftrace direct sample code global

 - Fixes in the bootconfig tool for better alignment management

* tag 'trace-v5.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Always check to put back before stamp when crossing pages
  ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
  ftrace: Fix updating FTRACE_FL_TRAMP
  tracing: Fix alignment of static buffer
  tracing: Remove WARN_ON in start_thread()
  samples/ftrace: Mark my_tramp[12]? global
  ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()
  ring-buffer: Update write stamp with the correct ts
  docs: bootconfig: Update file format on initrd image
  tools/bootconfig: Align the bootconfig applied initrd image size to 4
  tools/bootconfig: Fix to check the write failure correctly
  tools/bootconfig: Fix errno reference after printf()
2020-12-01 15:30:18 -08:00
Steven Rostedt (VMware)
68e10d5ff5 ring-buffer: Always check to put back before stamp when crossing pages
The current ring buffer logic checks to see if the updating of the event
buffer was interrupted, and if it is, it will try to fix up the before stamp
with the write stamp to make them equal again. This logic is flawed, because
if it is not interrupted, the two are guaranteed to be different, as the
current event just updated the before stamp before allocation. This
guarantees that the next event (this one or another interrupting one) will
think it interrupted the time updates of a previous event and inject an
absolute time stamp to compensate.

The correct logic is to always update the timestamps when traversing to a
new sub buffer.

Cc: stable@vger.kernel.org
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 23:21:51 -05:00
Naveen N. Rao
49a962c075 ftrace: Fix DYNAMIC_FTRACE_WITH_DIRECT_CALLS dependency
DYNAMIC_FTRACE_WITH_DIRECT_CALLS should depend on
DYNAMIC_FTRACE_WITH_REGS since we need ftrace_regs_caller().

Link: https://lkml.kernel.org/r/fc4b257ea8689a36f086d2389a9ed989496ca63a.1606412433.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: 763e34e74b ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:08 -05:00
Naveen N. Rao
4c75b0ff4e ftrace: Fix updating FTRACE_FL_TRAMP
On powerpc, kprobe-direct.tc triggered FTRACE_WARN_ON() in
ftrace_get_addr_new() followed by the below message:
  Bad trampoline accounting at: 000000004222522f (wake_up_process+0xc/0x20) (f0000001)

The set of steps leading to this involved:
- modprobe ftrace-direct-too
- enable_probe
- modprobe ftrace-direct
- rmmod ftrace-direct <-- trigger

The problem turned out to be that we were not updating flags in the
ftrace record properly. From the above message about the trampoline
accounting being bad, it can be seen that the ftrace record still has
FTRACE_FL_TRAMP set though ftrace-direct module is going away. This
happens because we are checking if any ftrace_ops has the
FTRACE_FL_TRAMP flag set _before_ updating the filter hash.

The fix for this is to look for any _other_ ftrace_ops that also needs
FTRACE_FL_TRAMP.

Link: https://lkml.kernel.org/r/56c113aa9c3e10c19144a36d9684c7882bf09af5.1606412433.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: a124692b69 ("ftrace: Enable trampoline when rec count returns back to one")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Minchan Kim
8fa655a3a0 tracing: Fix alignment of static buffer
With 5.9 kernel on ARM64, I found ftrace_dump output was broken but
it had no problem with normal output "cat /sys/kernel/debug/tracing/trace".

With investigation, it seems coping the data into temporal buffer seems to
break the align binary printf expects if the static buffer is not aligned
with 4-byte. IIUC, get_arg in bstr_printf expects that args has already
right align to be decoded and seq_buf_bprintf says ``the arguments are saved
in a 32bit word array that is defined by the format string constraints``.
So if we don't keep the align under copy to temporal buffer, the output
will be broken by shifting some bytes.

This patch fixes it.

Link: https://lkml.kernel.org/r/20201125225654.1618966-1-minchan@kernel.org

Cc: <stable@vger.kernel.org>
Fixes: 8e99cf91b9 ("tracing: Do not allocate buffer in trace_find_next_entry() in atomic")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Vasily Averin
310e3a4b5a tracing: Remove WARN_ON in start_thread()
This patch reverts commit 978defee11 ("tracing: Do a WARN_ON()
 if start_thread() in hwlat is called when thread exists")

.start hook can be legally called several times if according
tracer is stopped

screen window 1
[root@localhost ~]# echo 1 > /sys/kernel/tracing/events/kmem/kfree/enable
[root@localhost ~]# echo 1 > /sys/kernel/tracing/options/pause-on-trace
[root@localhost ~]# less -F /sys/kernel/tracing/trace

screen window 2
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo hwlat >  /sys/kernel/debug/tracing/current_tracer
[root@localhost ~]# echo 1 > /sys/kernel/debug/tracing/tracing_on
[root@localhost ~]# cat /sys/kernel/debug/tracing/tracing_on
0
[root@localhost ~]# echo 2 > /sys/kernel/debug/tracing/tracing_on

triggers warning in dmesg:
WARNING: CPU: 3 PID: 1403 at kernel/trace/trace_hwlat.c:371 hwlat_tracer_start+0xc9/0xd0

Link: https://lkml.kernel.org/r/bd4d3e70-400d-9c82-7b73-a2d695e86b58@virtuozzo.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 978defee11 ("tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 21:43:07 -05:00
Andrea Righi
8785f51a17 ring-buffer: Set the right timestamp in the slow path of __rb_reserve_next()
In the slow path of __rb_reserve_next() a nested event(s) can happen
between evaluating the timestamp delta of the current event and updating
write_stamp via local_cmpxchg(); in this case the delta is not valid
anymore and it should be set to 0 (same timestamp as the interrupting
event), since the event that we are currently processing is not the last
event in the buffer.

Link: https://lkml.kernel.org/r/X8IVJcp1gRE+FJCJ@xps-13-7390

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lwn.net/Articles/831207
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 15:22:05 -05:00
Steven Rostedt (VMware)
55ea4cf403 ring-buffer: Update write stamp with the correct ts
The write stamp, used to calculate deltas between events, was updated with
the stale "ts" value in the "info" structure, and not with the updated "ts"
variable. This caused the deltas between events to be inaccurate, and when
crossing into a new sub buffer, had time go backwards.

Link: https://lkml.kernel.org/r/20201124223917.795844-1-elavila@google.com

Cc: stable@vger.kernel.org
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Reported-by: "J. Avila" <elavila@google.com>
Tested-by: Daniel Mentz <danielmentz@google.com>
Tested-by: Will McVicker <willmcvicker@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-11-30 15:21:31 -05:00
Laurent Vivier
bb4c6910c8 genirq/irqdomain: Add an irq_create_mapping_affinity() function
There is currently no way to convey the affinity of an interrupt
via irq_create_mapping(), which creates issues for devices that
expect that affinity to be managed by the kernel.

In order to sort this out, rename irq_create_mapping() to
irq_create_mapping_affinity() with an additional affinity parameter that
can be passed down to irq_domain_alloc_descs().

irq_create_mapping() is re-implemented as a wrapper around
irq_create_mapping_affinity().

No functional change.

Fixes: e75eafb9b0 ("genirq/msi: Switch to new irq spreading infrastructure")
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kurz <groug@kaod.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201126082852.1178497-2-lvivier@redhat.com
2020-11-30 12:21:31 +01:00
Linus Torvalds
f91a3aa6bc Yet two more places which invoke tracing from RCU disabled regions in the
idle path. Similar to the entry path the low level idle functions have to
 be non-instrumentable.
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Merge tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "Two more places which invoke tracing from RCU disabled regions in the
  idle path.

  Similar to the entry path the low level idle functions have to be
  non-instrumentable"

* tag 'locking-urgent-2020-11-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  intel_idle: Fix intel_idle() vs tracing
  sched/idle: Fix arch_cpu_idle() vs tracing
2020-11-29 11:19:26 -08:00
Linus Torvalds
43d6ecd97c Urgent printk fix for 5.10
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Merge tag 'printk-for-5.10-rc6-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fixes from Petr Mladek:

 - do not lose trailing newline in pr_cont() calls

 - two trivial fixes for a dead store and a config description

* tag 'printk-for-5.10-rc6-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: finalize records with trailing newlines
  printk: remove unneeded dead-store assignment
  init/Kconfig: Fix CPU number in LOG_CPU_MAX_BUF_SHIFT description
2020-11-27 10:38:36 -08:00
Petr Mladek
739e7116b1 Merge branch 'for-5.10-pr_cont-fixup' into for-linus 2020-11-27 13:41:23 +01:00
John Ogness
4ad9921af4 printk: finalize records with trailing newlines
Any record with a trailing newline (LOG_NEWLINE flag) cannot
be continued because the newline has been stripped and will
not be visible if the message is appended. This was already
handled correctly when committing in log_output() but was
not handled correctly when committing in log_store().

Fixes: f5f022e53b ("printk: reimplement log_cont using record extension")
Link: https://lore.kernel.org/r/20201126114836.14750-1-john.ogness@linutronix.de
Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2020-11-27 11:58:54 +01:00
Nicholas Piggin
8ff00399b1 kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling
powerpc/64s keeps a counter in the mm which counts bits set in
mm_cpumask as well as other things. This means it can't use generic code
to clear bits out of the mask and doesn't adjust the arch specific
counter.

Add an arch override that allows powerpc/64s to use
clear_tasks_mm_cpumask().

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126102530.691335-4-npiggin@gmail.com
2020-11-27 00:10:39 +11:00
Peter Zijlstra
58c644ba51 sched/idle: Fix arch_cpu_idle() vs tracing
We call arch_cpu_idle() with RCU disabled, but then use
local_irq_{en,dis}able(), which invokes tracing, which relies on RCU.

Switch all arch_cpu_idle() implementations to use
raw_local_irq_{en,dis}able() and carefully manage the
lockdep,rcu,tracing state like we do in entry.

(XXX: we really should change arch_cpu_idle() to not return with
interrupts enabled)

Reported-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20201120114925.594122626@infradead.org
2020-11-24 16:47:35 +01:00
Linus Torvalds
f4b936f5d6 A couple of scheduler fixes:
- Make the conditional update of the overutilized state work correctly by
    caching the relevant flags state before overwriting them and checking
    them afterwards.
 
  - Fix a data race in the wakeup path which caused loadavg on ARM64
    platforms to become a random number generator.
 
  - Fix the ordering of the iowaiter accounting operations so it can't be
    decremented before it is incremented.
 
  - Fix a bug in the deadline scheduler vs. priority inheritance when a
    non-deadline task A has inherited the parameters of a deadline task B
    and then blocks on a non-deadline task C.
 
    The second inheritance step used the static deadline parameters of task
    A, which are usually 0, instead of further propagating task B's
    parameters. The zero initialized parameters trigger a bug in the
    deadline scheduler.
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Merge tag 'sched-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "A couple of scheduler fixes:

   - Make the conditional update of the overutilized state work
     correctly by caching the relevant flags state before overwriting
     them and checking them afterwards.

   - Fix a data race in the wakeup path which caused loadavg on ARM64
     platforms to become a random number generator.

   - Fix the ordering of the iowaiter accounting operations so it can't
     be decremented before it is incremented.

   - Fix a bug in the deadline scheduler vs. priority inheritance when a
     non-deadline task A has inherited the parameters of a deadline task
     B and then blocks on a non-deadline task C.

     The second inheritance step used the static deadline parameters of
     task A, which are usually 0, instead of further propagating task
     B's parameters. The zero initialized parameters trigger a bug in
     the deadline scheduler"

* tag 'sched-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix priority inheritance with multiple scheduling classes
  sched: Fix rq->nr_iowait ordering
  sched: Fix data-race in wakeup
  sched/fair: Fix overutilized update in enqueue_task_fair()
2020-11-22 13:26:07 -08:00
Linus Torvalds
855cf1ee47 A single fix for lockdep which makes the recursion protection cover graph
lock/unlock.
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Merge tag 'locking-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fix from Thomas Gleixner:
 "A single fix for lockdep which makes the recursion protection cover
  graph lock/unlock"

* tag 'locking-urgent-2020-11-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Put graph lock/unlock under lock_recursion protection
2020-11-22 13:19:53 -08:00