| Age | Commit message (Collapse) | Author |
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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>
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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>
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git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy into usb-linus
Vinod writes:
phy: Second round of fixes for 5.9
*) Fix of leak in TI phy driver
* tag 'phy-fixes-2-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy:
phy: ti: am654: Fix a leak in serdes_am654_probe()
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The PR_SPEC_DISABLE_NOEXEC option to the PR_SPEC_STORE_BYPASS prctl()
allows the SSB mitigation to be enabled only until the next execve(),
at which point the state will revert back to PR_SPEC_ENABLE and the
mitigation will be disabled.
Add support for PR_SPEC_DISABLE_NOEXEC on arm64.
Reported-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
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The kbuild robot reports that we're relying on an implicit inclusion to
get a definition of task_stack_page() in the Spectre-v4 mitigation code,
which is not always in place for some configurations:
| arch/arm64/kernel/proton-pack.c:329:2: error: implicit declaration of function 'task_stack_page' [-Werror,-Wimplicit-function-declaration]
| task_pt_regs(task)->pstate |= val;
| ^
| arch/arm64/include/asm/processor.h:268:36: note: expanded from macro 'task_pt_regs'
| ((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
| ^
| arch/arm64/kernel/proton-pack.c:329:2: note: did you mean 'task_spread_page'?
Add the missing include to fix the build error.
Fixes: a44acf477220 ("arm64: Move SSBD prctl() handler alongside other spectre mitigation code")
Reported-by: Anthony Steinhauser <asteinhauser@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202009260013.Ul7AD29w%lkp@intel.com
Signed-off-by: Will Deacon <will@kernel.org>
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Patching the EL2 exception vectors is integral to the Spectre-v2
workaround, where it can be necessary to execute CPU-specific sequences
to nobble the branch predictor before running the hypervisor text proper.
Remove the dependency on CONFIG_RANDOMIZE_BASE and allow the EL2 vectors
to be patched even when KASLR is not enabled.
Fixes: 7a132017e7a5 ("KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE")
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/202009221053.Jv1XsQUZ%lkp@intel.com
Signed-off-by: Will Deacon <will@kernel.org>
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Out with the old ghost, in with the new...
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
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Convert the KVM WA2 code to using the Spectre infrastructure,
making the code much more readable. It also allows us to
take SSBS into account for the mitigation.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
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kvm_arm_have_ssbd() is now completely unused, get rid of it.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
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Owing to the fact that the host kernel is always mitigated, we can
drastically simplify the WA2 handling by keeping the mitigation
state ON when entering the guest. This means the guest is either
unaffected or not mitigated.
This results in a nice simplification of the mitigation space,
and the removal of a lot of code that was never really used anyway.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
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Rewrite the Spectre-v4 mitigation handling code to follow the same
approach as that taken by Spectre-v2.
For now, report to KVM that the system is vulnerable (by forcing
'ssbd_state' to ARM64_SSBD_UNKNOWN), as this will be cleared up in
subsequent steps.
Signed-off-by: Will Deacon <will@kernel.org>
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As part of the spectre consolidation effort to shift all of the ghosts
into their own proton pack, move all of the horrible SSBD prctl() code
out of its own 'ssbd.c' file.
Signed-off-by: Will Deacon <will@kernel.org>
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In a similar manner to the renaming of ARM64_HARDEN_BRANCH_PREDICTOR
to ARM64_SPECTRE_V2, rename ARM64_SSBD to ARM64_SPECTRE_V4. This isn't
_entirely_ accurate, as we also need to take into account the interaction
with SSBS, but that will be taken care of in subsequent patches.
Signed-off-by: Will Deacon <will@kernel.org>
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If all CPUs discovered during boot have SSBS, then spectre-v4 will be
considered to be "mitigated". However, we still allow late CPUs without
SSBS to be onlined, albeit with a "SANITY CHECK" warning. This is
problematic for userspace because it means that the system can quietly
transition to "Vulnerable" at runtime.
Avoid this by treating SSBS as a non-strict system feature: if all of
the CPUs discovered during boot have SSBS, then late arriving secondaries
better have it as well.
Signed-off-by: Will Deacon <will@kernel.org>
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The is_ttbrX_addr() functions have somehow ended up in the middle of
the start_thread() functions, so move them out of the way to keep the
code readable.
Signed-off-by: Will Deacon <will@kernel.org>
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If the system is not affected by Spectre-v2, then advertise to the KVM
guest that it is not affected, without the need for a safelist in the
guest.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
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The Spectre-v2 mitigation code is pretty unwieldy and hard to maintain.
This is largely due to it being written hastily, without much clue as to
how things would pan out, and also because it ends up mixing policy and
state in such a way that it is very difficult to figure out what's going
on.
Rewrite the Spectre-v2 mitigation so that it clearly separates state from
policy and follows a more structured approach to handling the mitigation.
Signed-off-by: Will Deacon <will@kernel.org>
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The spectre mitigation code is spread over a few different files, which
makes it both hard to follow, but also hard to remove it should we want
to do that in future.
Introduce a new file for housing the spectre mitigations, and populate
it with the spectre-v1 reporting code to start with.
Signed-off-by: Will Deacon <will@kernel.org>
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For better or worse, the world knows about "Spectre" and not about
"Branch predictor hardening". Rename ARM64_HARDEN_BRANCH_PREDICTOR to
ARM64_SPECTRE_V2 as part of moving all of the Spectre mitigations into
their own little corner.
Signed-off-by: Will Deacon <will@kernel.org>
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Use is_hyp_mode_available() to detect whether or not we need to patch
the KVM vectors for branch hardening, which avoids the need to take the
vector pointers as parameters.
Signed-off-by: Will Deacon <will@kernel.org>
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The removal of CONFIG_HARDEN_BRANCH_PREDICTOR means that
CONFIG_KVM_INDIRECT_VECTORS is synonymous with CONFIG_RANDOMIZE_BASE,
so replace it.
Signed-off-by: Will Deacon <will@kernel.org>
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The spectre mitigations are too configurable for their own good, leading
to confusing logic trying to figure out when we should mitigate and when
we shouldn't. Although the plethora of command-line options need to stick
around for backwards compatibility, the default-on CONFIG options that
depend on EXPERT can be dropped, as the mitigations only do anything if
the system is vulnerable, a mitigation is available and the command-line
hasn't disabled it.
Remove CONFIG_HARDEN_BRANCH_PREDICTOR and CONFIG_ARM64_SSBD in favour of
enabling this code unconditionally.
Signed-off-by: Will Deacon <will@kernel.org>
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Commit 606f8e7b27bf ("arm64: capabilities: Use linear array for
detection and verification") changed the way we deal with per-CPU errata
by only calling the .matches() callback until one CPU is found to be
affected. At this point, .matches() stop being called, and .cpu_enable()
will be called on all CPUs.
This breaks the ARCH_WORKAROUND_2 handling, as only a single CPU will be
mitigated.
In order to address this, forcefully call the .matches() callback from a
.cpu_enable() callback, which brings us back to the original behaviour.
Fixes: 606f8e7b27bf ("arm64: capabilities: Use linear array for detection and verification")
Cc: <stable@vger.kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
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The user defined label following "fallthrough" is not considered by GCC
and causes build failure.
kernel-source/include/linux/compiler_attributes.h:208:41: error: attribute
'fallthrough' not preceding a case label or default label [-Werror]
208 define fallthrough _attribute((fallthrough_))
^~~~~~~~~~~~~
Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword")
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/bpf/20200928090023.38117-1-zhe.he@windriver.com
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Blk-mq should call commit_rqs once 'bd.last != true' and no more
request will come(so virtscsi can kick the virtqueue, e.g.). We already
do that in 'blk_mq_dispatch_rq_list/blk_mq_try_issue_list_directly' while
list not empty and 'queued > 0'. However, we can seen the same scene
once the last request in list call queue_rq and return error like
BLK_STS_IOERR which will not requeue the request, and lead that list
empty but need call commit_rqs too(Or the request for virtscsi will stay
timeout until other request kick virtqueue).
We found this problem by do fsstress test with offline/online virtscsi
device repeat quickly.
Fixes: d666ba98f849 ("blk-mq: add mq_ops->commit_rqs()")
Reported-by: zhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: yangerkun <yangerkun@huawei.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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The async buffered reads feature is not working when readahead is
turned off. There are two things to concern:
- when doing retry in io_read, not only the IOCB_WAITQ flag but also
the IOCB_NOWAIT flag is still set, which makes it goes to would_block
phase in generic_file_buffered_read() and then return -EAGAIN. After
that, the io-wq thread work is queued, and later doing the async
reads in the old way.
- even if we remove IOCB_NOWAIT when doing retry, the feature is still
not running properly, since in generic_file_buffered_read() it goes to
lock_page_killable() after calling mapping->a_ops->readpage() to do
IO, and thus causing process to sleep.
Fixes: 1a0a7853b901 ("mm: support async buffered reads in generic_file_buffered_read()")
Fixes: 3b2a4439e0ae ("io_uring: get rid of kiocb_wait_page_queue_init()")
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Currently, on arm64, we abort on any failure from efi_get_random_bytes()
other than EFI_NOT_FOUND when it comes to setting the physical seed for
KASLR, but ignore such failures when obtaining the seed for virtual
KASLR or for early seeding of the kernel's entropy pool via the config
table. This is inconsistent, and may lead to unexpected boot failures.
So let's permit any failure for the physical seed, and simply report
the error code if it does not equal EFI_NOT_FOUND.
Cc: <stable@vger.kernel.org> # v5.8+
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux into fixes
gpio: fixes for v5.9-rc7
- fix uninitialized variable in gpio-pca953x
- enable all 160 lines and fix interrupt configuration in gpio-aspeed-gpio
- fix ast2600 bank properties in gpio-aspeed
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Qian Cai reported a BFS_EQUEUEFULL warning [1] after read recursive
deadlock detection merged into tip tree recently. Unlike the previous
lockep graph searching, which iterate every lock class (every node in
the graph) exactly once, the graph searching for read recurisve deadlock
detection needs to iterate every lock dependency (every edge in the
graph) once, as a result, the maximum memory cost of the circular queue
changes from O(V), where V is the number of lock classes (nodes or
vertices) in the graph, to O(E), where E is the number of lock
dependencies (edges), because every lock class or dependency gets
enqueued once in the BFS. Therefore we hit the BFS_EQUEUEFULL case.
However, actually we don't need to enqueue all dependencies for the BFS,
because every time we enqueue a dependency, we almostly enqueue all
other dependencies in the same dependency list ("almostly" is because
we currently check before enqueue, so if a dependency doesn't pass the
check stage we won't enqueue it, however, we can always do in reverse
ordering), based on this, we can only enqueue the first dependency from
a dependency list and every time we want to fetch a new dependency to
work, we can either:
1) fetch the dependency next to the current dependency in the
dependency list
or
2) if the dependency in 1) doesn't exist, fetch the dependency from
the queue.
With this approach, the "max bfs queue depth" for a x86_64_defconfig +
lockdep and selftest config kernel can get descreased from:
max bfs queue depth: 201
to (after apply this patch)
max bfs queue depth: 61
While I'm at it, clean up the code logic a little (e.g. directly return
other than set a "ret" value and goto the "exit" label).
[1]: https://lore.kernel.org/lkml/17343f6f7f2438fc376125384133c5ba70c2a681.camel@redhat.com/
Reported-by: Qian Cai <cai@redhat.com>
Reported-by: syzbot+62ebe501c1ce9a91f68c@syzkaller.appspotmail.com
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200917080210.108095-1-boqun.feng@gmail.com
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Like all genl families ethtool_genl_family needs to not
be a straight up constant, because it's modified/initialized
by genl_register_family(). After init, however, it's only
passed to genlmsg_put() & co. therefore we can mark it
as __ro_after_init.
Since genl_family structure contains function pointers
mark this as a fix.
Fixes: 2b4a8990b7df ("ethtool: introduce ethtool netlink interface")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Validation flags are missing kdoc, add it.
Fixes: ef6243acb478 ("genetlink: optionally validate strictly/dumps")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Adds the driver_info and usb ids of the AX88179 based MCT U3-A9003 USB
3.0 ethernet adapter.
Signed-off-by: Wilken Gottwalt <wilken.gottwalt@mailbox.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Adds the missing .stop entry in the Belkin driver_info structure.
Fixes: e20bd60bf62a ("net: usb: asix88179_178a: Add support for the Belkin B2B128")
Signed-off-by: Wilken Gottwalt <wilken.gottwalt@mailbox.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Touchpad on this laptop is not detected properly during boot, as PNP
enumerates (wrongly) AUX port as disabled on this machine.
Fix that by adding this board (with admittedly quite funny DMI
identifiers) to nopnp quirk list.
Reported-by: Andrés Barrantes Silman <andresbs2000@protonmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Link: https://lore.kernel.org/r/nycvar.YFH.7.76.2009252337340.3336@cbobk.fhfr.pm
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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Add Synaptics IDs in trackpoint_start_protocol() to mark them as valid.
Signed-off-by: Vincent Huang <vincent.huang@tw.synaptics.com>
Fixes: 6c77545af100 ("Input: trackpoint - add new trackpoint variant IDs")
Reviewed-by: Harry Cutts <hcutts@chromium.org>
Tested-by: Harry Cutts <hcutts@chromium.org>
Link: https://lore.kernel.org/r/20200924053013.1056953-1-vincent.huang@tw.synaptics.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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The rcu read locks are needed to avoid potential race condition while
dereferencing radix tree from multiple threads. The issue was identified
by syzbot. Below is the crash report:
=============================
WARNING: suspicious RCU usage
5.7.0-syzkaller #0 Not tainted
-----------------------------
include/linux/radix-tree.h:176 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
2 locks held by kworker/u4:1/21:
#0: ffff88821b097938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline]
#0: ffff88821b097938 ((wq_completion)qrtr_ns_handler){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241
#1: ffffc90000dd7d80 ((work_completion)(&qrtr_ns.work)){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243
stack backtrace:
CPU: 0 PID: 21 Comm: kworker/u4:1 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: qrtr_ns_handler qrtr_ns_worker
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1e9/0x30e lib/dump_stack.c:118
radix_tree_deref_slot include/linux/radix-tree.h:176 [inline]
ctrl_cmd_new_lookup net/qrtr/ns.c:558 [inline]
qrtr_ns_worker+0x2aff/0x4500 net/qrtr/ns.c:674
process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268
worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414
kthread+0x353/0x380 kernel/kthread.c:268
Fixes: 0c2204a4ad71 ("net: qrtr: Migrate nameservice to kernel from userspace")
Reported-and-tested-by: syzbot+0f84f6eed90503da72fc@syzkaller.appspotmail.com
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We offer both PTRACE_PEEKMTETAGS and PTRACE_POKEMTETAGS requests via
ptrace().
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
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Taehee Yoo says:
====================
net: core: fix a lockdep splat in the dev_addr_list.
This patchset is to avoid lockdep splat.
When a stacked interface graph is changed, netif_addr_lock() is called
recursively and it internally calls spin_lock_nested().
The parameter of spin_lock_nested() is 'dev->lower_level',
this is called subclass.
The problem of 'dev->lower_level' is that while 'dev->lower_level' is
being used as a subclass of spin_lock_nested(), its value can be changed.
So, spin_lock_nested() would be called recursively with the same
subclass value, the lockdep understands a deadlock.
In order to avoid this, a new variable is needed and it is going to be
used as a parameter of spin_lock_nested().
The first and second patch is a preparation patch for the third patch.
In the third patch, the problem will be fixed.
The first patch is to add __netdev_upper_dev_unlink().
An existed netdev_upper_dev_unlink() is renamed to
__netdev_upper_dev_unlink(). and netdev_upper_dev_unlink()
is added as an wrapper of this function.
The second patch is to add the netdev_nested_priv structure.
netdev_walk_all_{ upper | lower }_dev() pass both private functions
and "data" pointer to handle their own things.
At this point, the data pointer type is void *.
In order to make it easier to expand common variables and functions,
this new netdev_nested_priv structure is added.
The third patch is to add a new variable 'nested_level'
into the net_device structure.
This variable will be used as a parameter of spin_lock_nested() of
dev->addr_list_lock.
Due to this variable, it can avoid lockdep splat.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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|
This patch is to add a new variable 'nested_level' into the net_device
structure.
This variable will be used as a parameter of spin_lock_nested() of
dev->addr_list_lock.
netif_addr_lock() can be called recursively so spin_lock_nested() is
used instead of spin_lock() and dev->lower_level is used as a parameter
of spin_lock_nested().
But, dev->lower_level value can be updated while it is being used.
So, lockdep would warn a possible deadlock scenario.
When a stacked interface is deleted, netif_{uc | mc}_sync() is
called recursively.
So, spin_lock_nested() is called recursively too.
At this moment, the dev->lower_level variable is used as a parameter of it.
dev->lower_level value is updated when interfaces are being unlinked/linked
immediately.
Thus, After unlinking, dev->lower_level shouldn't be a parameter of
spin_lock_nested().
A (macvlan)
|
B (vlan)
|
C (bridge)
|
D (macvlan)
|
E (vlan)
|
F (bridge)
A->lower_level : 6
B->lower_level : 5
C->lower_level : 4
D->lower_level : 3
E->lower_level : 2
F->lower_level : 1
When an interface 'A' is removed, it releases resources.
At this moment, netif_addr_lock() would be called.
Then, netdev_upper_dev_unlink() is called recursively.
Then dev->lower_level is updated.
There is no problem.
But, when the bridge module is removed, 'C' and 'F' interfaces
are removed at once.
If 'F' is removed first, a lower_level value is like below.
A->lower_level : 5
B->lower_level : 4
C->lower_level : 3
D->lower_level : 2
E->lower_level : 1
F->lower_level : 1
Then, 'C' is removed. at this moment, netif_addr_lock() is called
recursively.
The ordering is like this.
C(3)->D(2)->E(1)->F(1)
At this moment, the lower_level value of 'E' and 'F' are the same.
So, lockdep warns a possible deadlock scenario.
In order to avoid this problem, a new variable 'nested_level' is added.
This value is the same as dev->lower_level - 1.
But this value is updated in rtnl_unlock().
So, this variable can be used as a parameter of spin_lock_nested() safely
in the rtnl context.
Test commands:
ip link add br0 type bridge vlan_filtering 1
ip link add vlan1 link br0 type vlan id 10
ip link add macvlan2 link vlan1 type macvlan
ip link add br3 type bridge vlan_filtering 1
ip link set macvlan2 master br3
ip link add vlan4 link br3 type vlan id 10
ip link add macvlan5 link vlan4 type macvlan
ip link add br6 type bridge vlan_filtering 1
ip link set macvlan5 master br6
ip link add vlan7 link br6 type vlan id 10
ip link add macvlan8 link vlan7 type macvlan
ip link set br0 up
ip link set vlan1 up
ip link set macvlan2 up
ip link set br3 up
ip link set vlan4 up
ip link set macvlan5 up
ip link set br6 up
ip link set vlan7 up
ip link set macvlan8 up
modprobe -rv bridge
Splat looks like:
[ 36.057436][ T744] WARNING: possible recursive locking detected
[ 36.058848][ T744] 5.9.0-rc6+ #728 Not tainted
[ 36.059959][ T744] --------------------------------------------
[ 36.061391][ T744] ip/744 is trying to acquire lock:
[ 36.062590][ T744] ffff8c4767509280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: dev_set_rx_mode+0x19/0x30
[ 36.064922][ T744]
[ 36.064922][ T744] but task is already holding lock:
[ 36.066626][ T744] ffff8c4767769280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: dev_uc_add+0x1e/0x60
[ 36.068851][ T744]
[ 36.068851][ T744] other info that might help us debug this:
[ 36.070731][ T744] Possible unsafe locking scenario:
[ 36.070731][ T744]
[ 36.072497][ T744] CPU0
[ 36.073238][ T744] ----
[ 36.074007][ T744] lock(&vlan_netdev_addr_lock_key);
[ 36.075290][ T744] lock(&vlan_netdev_addr_lock_key);
[ 36.076590][ T744]
[ 36.076590][ T744] *** DEADLOCK ***
[ 36.076590][ T744]
[ 36.078515][ T744] May be due to missing lock nesting notation
[ 36.078515][ T744]
[ 36.080491][ T744] 3 locks held by ip/744:
[ 36.081471][ T744] #0: ffffffff98571df0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x236/0x490
[ 36.083614][ T744] #1: ffff8c4767769280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: dev_uc_add+0x1e/0x60
[ 36.085942][ T744] #2: ffff8c476c8da280 (&bridge_netdev_addr_lock_key/4){+...}-{2:2}, at: dev_uc_sync+0x39/0x80
[ 36.088400][ T744]
[ 36.088400][ T744] stack backtrace:
[ 36.089772][ T744] CPU: 6 PID: 744 Comm: ip Not tainted 5.9.0-rc6+ #728
[ 36.091364][ T744] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 36.093630][ T744] Call Trace:
[ 36.094416][ T744] dump_stack+0x77/0x9b
[ 36.095385][ T744] __lock_acquire+0xbc3/0x1f40
[ 36.096522][ T744] lock_acquire+0xb4/0x3b0
[ 36.097540][ T744] ? dev_set_rx_mode+0x19/0x30
[ 36.098657][ T744] ? rtmsg_ifinfo+0x1f/0x30
[ 36.099711][ T744] ? __dev_notify_flags+0xa5/0xf0
[ 36.100874][ T744] ? rtnl_is_locked+0x11/0x20
[ 36.101967][ T744] ? __dev_set_promiscuity+0x7b/0x1a0
[ 36.103230][ T744] _raw_spin_lock_bh+0x38/0x70
[ 36.104348][ T744] ? dev_set_rx_mode+0x19/0x30
[ 36.105461][ T744] dev_set_rx_mode+0x19/0x30
[ 36.106532][ T744] dev_set_promiscuity+0x36/0x50
[ 36.107692][ T744] __dev_set_promiscuity+0x123/0x1a0
[ 36.108929][ T744] dev_set_promiscuity+0x1e/0x50
[ 36.110093][ T744] br_port_set_promisc+0x1f/0x40 [bridge]
[ 36.111415][ T744] br_manage_promisc+0x8b/0xe0 [bridge]
[ 36.112728][ T744] __dev_set_promiscuity+0x123/0x1a0
[ 36.113967][ T744] ? __hw_addr_sync_one+0x23/0x50
[ 36.115135][ T744] __dev_set_rx_mode+0x68/0x90
[ 36.116249][ T744] dev_uc_sync+0x70/0x80
[ 36.117244][ T744] dev_uc_add+0x50/0x60
[ 36.118223][ T744] macvlan_open+0x18e/0x1f0 [macvlan]
[ 36.119470][ T744] __dev_open+0xd6/0x170
[ 36.120470][ T744] __dev_change_flags+0x181/0x1d0
[ 36.121644][ T744] dev_change_flags+0x23/0x60
[ 36.122741][ T744] do_setlink+0x30a/0x11e0
[ 36.123778][ T744] ? __lock_acquire+0x92c/0x1f40
[ 36.124929][ T744] ? __nla_validate_parse.part.6+0x45/0x8e0
[ 36.126309][ T744] ? __lock_acquire+0x92c/0x1f40
[ 36.127457][ T744] __rtnl_newlink+0x546/0x8e0
[ 36.128560][ T744] ? lock_acquire+0xb4/0x3b0
[ 36.129623][ T744] ? deactivate_slab.isra.85+0x6a1/0x850
[ 36.130946][ T744] ? __lock_acquire+0x92c/0x1f40
[ 36.132102][ T744] ? lock_acquire+0xb4/0x3b0
[ 36.133176][ T744] ? is_bpf_text_address+0x5/0xe0
[ 36.134364][ T744] ? rtnl_newlink+0x2e/0x70
[ 36.135445][ T744] ? rcu_read_lock_sched_held+0x32/0x60
[ 36.136771][ T744] ? kmem_cache_alloc_trace+0x2d8/0x380
[ 36.138070][ T744] ? rtnl_newlink+0x2e/0x70
[ 36.139164][ T744] rtnl_newlink+0x47/0x70
[ ... ]
Fixes: 845e0ebb4408 ("net: change addr_list_lock back to static key")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
infrastructure
Functions related to nested interface infrastructure such as
netdev_walk_all_{ upper | lower }_dev() pass both private functions
and "data" pointer to handle their own things.
At this point, the data pointer type is void *.
In order to make it easier to expand common variables and functions,
this new netdev_nested_priv structure is added.
In the following patch, a new member variable will be added into this
struct to fix the lockdep issue.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
The netdev_upper_dev_unlink() has to work differently according to flags.
This idea is the same with __netdev_upper_dev_link().
In the following patches, new flags will be added.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The SMMUv3 driver would like to read the MMFR0 PARANGE field in order to
share CPU page tables with devices. Allow the driver to be built as
module by exporting the read_sanitized_ftr_reg() cpufeature symbol.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20200918101852.582559-7-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
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To enable address space sharing with the IOMMU, introduce
arm64_mm_context_get() and arm64_mm_context_put(), that pin down a
context and ensure that it will keep its ASID after a rollover. Export
the symbols to let the modular SMMUv3 driver use them.
Pinning is necessary because a device constantly needs a valid ASID,
unlike tasks that only require one when running. Without pinning, we would
need to notify the IOMMU when we're about to use a new ASID for a task,
and it would get complicated when a new task is assigned a shared ASID.
Consider the following scenario with no ASID pinned:
1. Task t1 is running on CPUx with shared ASID (gen=1, asid=1)
2. Task t2 is scheduled on CPUx, gets ASID (1, 2)
3. Task tn is scheduled on CPUy, a rollover occurs, tn gets ASID (2, 1)
We would now have to immediately generate a new ASID for t1, notify
the IOMMU, and finally enable task tn. We are holding the lock during
all that time, since we can't afford having another CPU trigger a
rollover. The IOMMU issues invalidation commands that can take tens of
milliseconds.
It gets needlessly complicated. All we wanted to do was schedule task tn,
that has no business with the IOMMU. By letting the IOMMU pin tasks when
needed, we avoid stalling the slow path, and let the pinning fail when
we're out of shareable ASIDs.
After a rollover, the allocator expects at least one ASID to be available
in addition to the reserved ones (one per CPU). So (NR_ASIDS - NR_CPUS -
1) is the maximum number of ASIDs that can be shared with the IOMMU.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200918101852.582559-5-jean-philippe@linaro.org
Signed-off-by: Will Deacon <will@kernel.org>
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_sdei_event_unregister() is called by sdei_event_unregister() and
sdei_device_freeze(). _sdei_event_unregister() covers the shared
and private events, but sdei_device_freeze() only covers the shared
events. So the logic to cover the private events isn't needed by
sdei_device_freeze().
sdei_event_unregister sdei_device_freeze
_sdei_event_unregister sdei_unregister_shared
_sdei_event_unregister
This removes _sdei_event_unregister(). Its logic is moved to its
callers accordingly. This shouldn't cause any logical changes.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200922130423.10173-14-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
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The function _sdei_event_register() is called by sdei_event_register()
and sdei_device_thaw() as the following functional call chain shows.
_sdei_event_register() covers the shared and private events, but
sdei_device_thaw() only covers the shared events. So the logic to
cover the private events in _sdei_event_register() isn't needed by
sdei_device_thaw().
Similarly, sdei_reregister_event_llocked() covers the shared and
private events in the regard of reenablement. The logic to cover
the private events isn't needed by sdei_device_thaw() either.
sdei_event_register sdei_device_thaw
_sdei_event_register sdei_reregister_shared
sdei_reregister_event_llocked
_sdei_event_register
This removes _sdei_event_register() and sdei_reregister_event_llocked().
Their logic is moved to sdei_event_register() and sdei_reregister_shared().
This shouldn't cause any logical changes.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200922130423.10173-13-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
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During the CPU hotplug, the private events are registered, enabled
or unregistered on the specific CPU. It repeats the same steps:
initializing cross call argument, make function call on local CPU,
check the returned error.
This introduces sdei_do_local_call() to cover the first steps. The
other benefit is to make CROSSCALL_INIT and struct sdei_crosscall_args
are only visible to sdei_do_{cross, local}_call().
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200922130423.10173-12-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
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This applies cleanup on the cross call functions, no functional
changes are introduced:
* Wrap the code block of CROSSCALL_INIT inside "do { } while (0)"
as linux kernel usually does. Otherwise, scripts/checkpatch.pl
reports warning regarding this.
* Use smp_call_func_t for @fn argument in sdei_do_cross_call()
as the function is called on target CPU(s).
* Remove unnecessary space before @event in sdei_do_cross_call()
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200922130423.10173-11-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
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This removes the unnecessary while loop in sdei_event_unregister()
because of the following two reasons. This shouldn't cause any
functional changes.
* The while loop is executed for once, meaning it's not needed
in theory.
* With the while loop removed, the nested statements can be
avoid to make the code a bit cleaner.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200922130423.10173-10-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
|
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This removes the unnecessary while loop in sdei_event_register()
because of the following two reasons. This shouldn't cause any
functional changes.
* The while loop is executed for once, meaning it's not needed
in theory.
* With the while loop removed, the nested statements can be
avoid to make the code a bit cleaner.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200922130423.10173-9-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
|
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This removes the redundant error message in sdei_probe() because
the case can be identified from the errno in next error message.
Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20200922130423.10173-8-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>
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