On x86 we cannot do fetch_or() with a single instruction and thus end up
using a cmpxchg loop, this reduces determinism. Replace the fetch_or()
with a composite operation: tas-pending + load.
Using two instructions of course opens a window we previously did not
have. Consider the scenario:
CPU0 CPU1 CPU2
1) lock
trylock -> (0,0,1)
2) lock
trylock /* fail */
3) unlock -> (0,0,0)
4) lock
trylock -> (0,0,1)
5) tas-pending -> (0,1,1)
load-val <- (0,1,0) from 3
6) clear-pending-set-locked -> (0,0,1)
FAIL: _2_ owners
where 5) is our new composite operation. When we consider each part of
the qspinlock state as a separate variable (as we can when
_Q_PENDING_BITS == 8) then the above is entirely possible, because
tas-pending will only RmW the pending byte, so the later load is able
to observe prior tail and lock state (but not earlier than its own
trylock, which operates on the whole word, due to coherence).
To avoid this we need 2 things:
- the load must come after the tas-pending (obviously, otherwise it
can trivially observe prior state).
- the tas-pending must be a full word RmW instruction, it cannot be an XCHGB for
example, such that we cannot observe other state prior to setting
pending.
On x86 we can realize this by using "LOCK BTS m32, r32" for
tas-pending followed by a regular load.
Note that observing later state is not a problem:
- if we fail to observe a later unlock, we'll simply spin-wait for
that store to become visible.
- if we observe a later xchg_tail(), there is no difference from that
xchg_tail() having taken place before the tas-pending.
Suggested-by: Will Deacon <will.deacon@arm.com>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: andrea.parri@amarulasolutions.com
Cc: longman@redhat.com
Fixes: 59fb586b4a07 ("locking/qspinlock: Remove unbounded cmpxchg() loop from locking slowpath")
Link: https://lkml.kernel.org/r/20181003130957.183726335@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While working my way through the code again; I felt the comments could
use help.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrea.parri@amarulasolutions.com
Cc: longman@redhat.com
Link: https://lkml.kernel.org/r/20181003130257.156322446@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Flip the branch condition after atomic_fetch_or_acquire(_Q_PENDING_VAL)
such that we loose the indent. This also result in a more natural code
flow IMO.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrea.parri@amarulasolutions.com
Cc: longman@redhat.com
Link: https://lkml.kernel.org/r/20181003130257.156322446@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The comment and the code around the update_min_vruntime() call in
dequeue_entity() are not in agreement.
From commit:
b60205c7c558 ("sched/fair: Fix min_vruntime tracking")
I think that we want to update min_vruntime when a task is sleeping/migrating.
So, the check is inverted there - fix it.
Signed-off-by: Song Muchun <smuchun@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: b60205c7c558 ("sched/fair: Fix min_vruntime tracking")
Link: http://lkml.kernel.org/r/20181014112612.2614-1-smuchun@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Remove the duplicated 'lock_class_ops' percpu array that is not used
anywhere.
Signed-off-by: Waiman Long <longman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Fixes: 8ca2b56cd7da ("locking/lockdep: Make class->ops a percpu counter and move it under CONFIG_DEBUG_LOCKDEP=y")
Link: http://lkml.kernel.org/r/1539380547-16726-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-10-16
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Convert BPF sockmap and kTLS to both use a new sk_msg API and enable
sk_msg BPF integration for the latter, from Daniel and John.
2) Enable BPF syscall side to indicate for maps that they do not support
a map lookup operation as opposed to just missing key, from Prashant.
3) Add bpftool map create command which after map creation pins the
map into bpf fs for further processing, from Jakub.
4) Add bpftool support for attaching programs to maps allowing sock_map
and sock_hash to be used from bpftool, from John.
5) Improve syscall BPF map update/delete path for map-in-map types to
wait a RCU grace period for pending references to complete, from Daniel.
6) Couple of follow-up fixes for the BPF socket lookup to get it
enabled also when IPv6 is compiled as a module, from Joe.
7) Fix a generic-XDP bug to handle the case when the Ethernet header
was mangled and thus update skb's protocol and data, from Jesper.
8) Add a missing BTF header length check between header copies from
user space, from Wenwen.
9) Minor fixups in libbpf to use __u32 instead u32 types and include
proper perf_event.h uapi header instead of perf internal one, from Yonghong.
10) Allow to pass user-defined flags through EXTRA_CFLAGS and EXTRA_LDFLAGS
to bpftool's build, from Jiri.
11) BPF kselftest tweaks to add LWTUNNEL to config fragment and to install
with_addr.sh script from flow dissector selftest, from Anders.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In order to prepare sockmap logic to be used in combination with kTLS
we need to detangle it from ULP, and further split it in later commits
into a generic API.
Joint work with John.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf 2018-10-14
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Fix xsk map update and delete operation to not call synchronize_net()
but to piggy back on SOCK_RCU_FREE for sockets instead as we are not
allowed to sleep under RCU, from Björn.
2) Do not change RLIMIT_MEMLOCK in reuseport_bpf selftest if the process
already has unlimited RLIMIT_MEMLOCK, from Eric.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts were easy to resolve using immediate context mostly,
except the cls_u32.c one where I simply too the entire HEAD
chunk.
Signed-off-by: David S. Miller <davem@davemloft.net>
The map-in-map frequently serves as a mechanism for atomic
snapshotting of state that a BPF program might record. The current
implementation is dangerous to use in this way, however, since
userspace has no way of knowing when all programs that might have
retrieved the "old" value of the map may have completed.
This change ensures that map update operations on map-in-map map types
always wait for all references to the old map to drop before returning
to userspace.
Signed-off-by: Daniel Colascione <dancol@google.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Dan's smatch utility found an uninitialized use of offset in a path in
parse_probe_args(). Unless an offset is specifically specified for commands
that allow them, it should default to zero.
Link: http://lkml.kernel.org/r/20181012134246.5doqaobxunlqqs53@mwanda
Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com> (smatch)
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Dmitry writes:
"Input updates for v4.19-rc7
- we added a few scheduling points into various input interfaces to
ensure that large writes will not cause RCU stalls
- fixed configuring PS/2 keyboards as wakeup devices on newer
platforms
- added a new Xbox gamepad ID."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: uinput - add a schedule point in uinput_inject_events()
Input: evdev - add a schedule point in evdev_write()
Input: mousedev - add a schedule point in mousedev_write()
Input: i8042 - enable keyboard wakeups by default when s2idle is used
Input: xpad - add support for Xbox1 PDP Camo series gamepad
The way we calculate logbuf free space percentage overflows signed
integer:
int free;
free = __LOG_BUF_LEN - log_next_idx;
pr_info("early log buf free: %u(%u%%)\n",
free, (free * 100) / __LOG_BUF_LEN);
We support LOG_BUF_LEN of up to 1<<25 bytes. Since setup_log_buf() is
called during early init, logbuf is mostly empty, so
__LOG_BUF_LEN - log_next_idx
is close to 1<<25. Thus when we multiply it by 100, we overflow signed
integer value range: 100 is 2^6 + 2^5 + 2^2.
Example, booting with LOG_BUF_LEN 1<<25 and log_buf_len=2G
boot param:
[ 0.075317] log_buf_len: -2147483648 bytes
[ 0.075319] early log buf free: 33549896(-28%)
Make "free" unsigned integer and use appropriate printk() specifier.
Link: http://lkml.kernel.org/r/20181010113308.9337-1-sergey.senozhatsky@gmail.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
We have a proper 'overflow' check which tells us that we need to
split up existing cont buffer in separate records:
if (cont.len + len > sizeof(cont.buf))
cont_flush();
At the same time we also have one extra flush: "if cont buffer is
80% full then split it up" in cont_add():
if (cont.len > (sizeof(cont.buf) * 80) / 100)
cont_flush();
This looks to be redundant, since the existing "overflow" check
should work just fine, so remove this 80% check and wait for either
a normal cont termination \n, for preliminary flush due to
possible buffer overflow or for preliminary flush due to cont race.
Link: http://lkml.kernel.org/r/20181002023836.4487-4-sergey.senozhatsky@gmail.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Prior to commit 5c2992ee7fd8a29 ("printk: remove console flushing special
cases for partial buffered lines") we would do console_cont_flush()
for each pr_cont() to print cont fragments, so console_unlock() would
actually print data:
pr_cont();
console_lock();
console_unlock()
console_cont_flush(); // print cont fragment
...
pr_cont();
console_lock();
console_unlock()
console_cont_flush(); // print cont fragment
We don't do console_cont_flush() anymore, so when we do pr_cont()
console_unlock() does nothing (unless we flushed the cont buffer):
pr_cont();
console_lock();
console_unlock(); // noop
...
pr_cont();
console_lock();
console_unlock(); // noop
...
pr_cont();
cont_flush();
console_lock();
console_unlock(); // print data
We also wakeup klogd purposelessly for pr_cont() output - un-flushed
cont buffer is not stored in log_buf; there is nothing to pull.
Thus we can console_lock()/console_unlock()/wake_up_klogd() only when
we know that we log_store()-ed a message and there is something to
print to the consoles/syslog.
Link: http://lkml.kernel.org/r/20181002023836.4487-3-sergey.senozhatsky@gmail.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Since commit 5c2992ee7fd8a29 ("printk: remove console flushing special
cases for partial buffered lines") we don't print cont fragments
to the consoles; cont lines are now proper log_buf entries and
there is no "consecutive continuation flag" anymore: we either
have 'c' entries that mark continuation lines without fragments;
or '-' entries that mark normal logbuf entries. There are no '+'
entries anymore.
However, we still have a small leftover - presence of ext_console
drivers disables kernel cont support and we flush each pr_cont()
and store it as a separate log_buf entry. Previously, it worked
because msg_print_ext_header() had that "an optional external merge
of the records" functionality:
if (msg->flags & LOG_CONT)
cont = (prev_flags & LOG_CONT) ? '+' : 'c';
We don't do this as of now, so keep kernel cont always enabled.
Note from pmladek:
The original purpose was to get full information including
the metadata and dictionary via extended console drivers,
see commit 6fe29354befe4c46e ("printk: implement support
for extended console drivers").
The dictionary probably was the most important part but
it was actually lost:
static void cont_flush(void)
{
[...]
log_store(cont.facility, cont.level, cont.flags, cont.ts_nsec,
NULL, 0, cont.buf, cont.len);
Nobody noticed because the only dictionary user is dev_printk()
and dev_cont() is _not_ defined.
Link: http://lkml.kernel.org/r/20181002023836.4487-2-sergey.senozhatsky@gmail.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
[pmladek@suse.com: Updated commit message]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Tejun writes:
"cgroup fixes for v4.19-rc7
One cgroup2 threaded mode fix for v4.19-rc7. While threaded mode
isn't used widely (yet) and the bug requires somewhat convoluted
sequence of operations, it causes a userland visible malfunction -
EINVAL on a valid attempt to enable threaded mode. This pull request
contains the fix"
* 'for-4.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Fix dom_cgrp propagation when enabling threaded mode
With a very low cpu.cfs_quota_us setting, such as the minimum of 1000,
distribute_cfs_runtime may not empty the throttled_list before it runs
out of runtime to distribute. In that case, due to the change from
c06f04c7048 to put throttled entries at the head of the list, later entries
on the list will starve. Essentially, the same X processes will get pulled
off the list, given CPU time and then, when expired, get put back on the
head of the list where distribute_cfs_runtime will give runtime to the same
set of processes leaving the rest.
Fix the issue by setting a bit in struct cfs_bandwidth when
distribute_cfs_runtime is running, so that the code in throttle_cfs_rq can
decide to put the throttled entry on the tail or the head of the list. The
bit is set/cleared by the callers of distribute_cfs_runtime while they hold
cfs_bandwidth->lock.
This is easy to reproduce with a handful of CPU consumers. I use 'crash' on
the live system. In some cases you can simply look at the throttled list and
see the later entries are not changing:
crash> list cfs_rq.throttled_list -H 0xffff90b54f6ade40 -s cfs_rq.runtime_remaining | paste - - | awk '{print $1" "$4}' | pr -t -n3
1 ffff90b56cb2d200 -976050
2 ffff90b56cb2cc00 -484925
3 ffff90b56cb2bc00 -658814
4 ffff90b56cb2ba00 -275365
5 ffff90b166a45600 -135138
6 ffff90b56cb2da00 -282505
7 ffff90b56cb2e000 -148065
8 ffff90b56cb2fa00 -872591
9 ffff90b56cb2c000 -84687
10 ffff90b56cb2f000 -87237
11 ffff90b166a40a00 -164582
crash> list cfs_rq.throttled_list -H 0xffff90b54f6ade40 -s cfs_rq.runtime_remaining | paste - - | awk '{print $1" "$4}' | pr -t -n3
1 ffff90b56cb2d200 -994147
2 ffff90b56cb2cc00 -306051
3 ffff90b56cb2bc00 -961321
4 ffff90b56cb2ba00 -24490
5 ffff90b166a45600 -135138
6 ffff90b56cb2da00 -282505
7 ffff90b56cb2e000 -148065
8 ffff90b56cb2fa00 -872591
9 ffff90b56cb2c000 -84687
10 ffff90b56cb2f000 -87237
11 ffff90b166a40a00 -164582
Sometimes it is easier to see by finding a process getting starved and looking
at the sched_info:
crash> task ffff8eb765994500 sched_info
PID: 7800 TASK: ffff8eb765994500 CPU: 16 COMMAND: "cputest"
sched_info = {
pcount = 8,
run_delay = 697094208,
last_arrival = 240260125039,
last_queued = 240260327513
},
crash> task ffff8eb765994500 sched_info
PID: 7800 TASK: ffff8eb765994500 CPU: 16 COMMAND: "cputest"
sched_info = {
pcount = 8,
run_delay = 697094208,
last_arrival = 240260125039,
last_queued = 240260327513
},
Signed-off-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: c06f04c70489 ("sched: Fix potential near-infinite distribute_cfs_runtime() loop")
Link: http://lkml.kernel.org/r/20181008143639.GA4019@pauld.bos.csb
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The XSKMAP update and delete functions called synchronize_net(), which
can sleep. It is not allowed to sleep during an RCU read section.
Instead we need to make sure that the sock sk_destruct (xsk_destruct)
function is asynchronously called after an RCU grace period. Setting
the SOCK_RCU_FREE flag for XDP sockets takes care of this.
Fixes: fbfc504a24f5 ("bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Allow kprobe-events to record module symbols.
Since data symbols in a non-loaded module doesn't exist, it fails to
define such symbol as an argument of kprobe-event. But if the kprobe
event is defined on that module, we can defer to resolve the symbol
address.
Note that if given symbol is not found, the event is kept unavailable.
User can enable it but the event is not recorded.
Link: http://lkml.kernel.org/r/153547312336.26502.11432902826345374463.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Current kprobe event doesn't checks correctly whether the
given event is on unloaded module or not. It just checks
the event has ":" in the name.
That is not enough because if we define a probe on non-exist
symbol on loaded module, it allows to define that (with
warning message)
To ensure it correctly, this searches the module name on
loaded module list and only if there is not, it allows to
define it. (this event will be available when the target
module is loaded)
Link: http://lkml.kernel.org/r/153547309528.26502.8300278470528281328.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fix probe_mem_read() to return -EFAULT if copy_from_user()
failed. The copy_from_user() returns remaining bytes
when it failed, but probe_mem_read() caller expects it
returns error code like as probe_kernel_read().
Link: http://lkml.kernel.org/r/153547306719.26502.8353484532699160223.stgit@devbox
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add $argN special fetch variable for accessing function
arguments. This allows user to trace the Nth argument easily
at the function entry.
Note that this returns most probably assignment of registers
and stacks. In some case, it may not work well. If you need
to access correct registers or stacks you should use perf-probe.
Link: http://lkml.kernel.org/r/152465888632.26224.3412465701570253696.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add array type support for probe events.
This allows user to get arraied types from memory address.
The array type syntax is
TYPE[N]
Where TYPE is one of types (u8/16/32/64,s8/16/32/64,
x8/16/32/64, symbol, string) and N is a fixed value less
than 64.
The string array type is a bit different from other types. For
other base types, <base-type>[1] is equal to <base-type>
(e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not
equal to string. The string type itself represents "char array",
but string array type represents "char * array". So, for example,
+0(%di):string[1] is equal to +0(+0(%di)):string.
Link: http://lkml.kernel.org/r/152465891533.26224.6150658225601339931.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add "symbol" type to probeevent, which is an alias of u32 or u64
(depends on BITS_PER_LONG). This shows the result value in
symbol+offset style. This type is only available with kprobe
events.
Link: http://lkml.kernel.org/r/152465882860.26224.14779072294412467338.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Unify the fetch_insn bottom process (from stage 2: dereference
indirect data) from kprobe and uprobe events, since those are
mostly same.
Link: http://lkml.kernel.org/r/152465879965.26224.8547240824606804815.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cleanup string fetching routine so that returns the consumed
bytes of dynamic area and store the string information as
data_loc format instead of data_rloc.
This simplifies the fetcharg loop.
Link: http://lkml.kernel.org/r/152465874163.26224.12125143907501289031.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Unify {k,u}probe_fetch_type_table to probe_fetch_type_table
because the main difference of those type tables (fetcharg
methods) are gone. Now we can consolidate it.
Link: http://lkml.kernel.org/r/152465871274.26224.13999436317830479698.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Replace {k,u}probe event argument fetching framework with switch-case based.
Currently that is implemented with structures, macros and chain of
function-pointers, which is more complicated than necessary and may get a
performance penalty by retpoline.
This simplify that with an array of "fetch_insn" (opcode and oprands), and
make process_fetch_insn() just interprets it. No function pointers are used.
Link: http://lkml.kernel.org/r/152465868340.26224.2551120475197839464.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Remove unneeded NOKPROBE_SYMBOL from print functions since
the print functions are only used when printing out the
trace data, and not from kprobe handler.
Link: http://lkml.kernel.org/r/152465865422.26224.10111548170594014954.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cleanup the print-argument function to decouple it into
print-name and print-value, so that it can support more
flexible expression, like array type.
Link: http://lkml.kernel.org/r/152465859635.26224.13452846788717102315.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This patch enables uprobes with reference counter in fd-based uprobe.
Highest 32 bits of perf_event_attr.config is used to stored offset
of the reference count (semaphore).
Format information in /sys/bus/event_source/devices/uprobe/format/ is
updated to reflect this new feature.
Link: http://lkml.kernel.org/r/20181002053636.1896903-1-songliubraving@fb.com
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-and-tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
While fixing an out of bounds array access in known_siginfo_layout
reported by the kernel test robot it became apparent that the same bug
exists in siginfo_layout and affects copy_siginfo_from_user32.
The straight forward fix that makes guards against making this mistake
in the future and should keep the code size small is to just take an
unsigned signal number instead of a signed signal number, as I did to
fix known_siginfo_layout.
Cc: stable@vger.kernel.org
Fixes: cc731525f26a ("signal: Remove kernel interal si_code magic")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The bounds checks in known_siginfo_layout only guards against positive
numbers that are too large, large negative can slip through and
can cause out of bounds accesses.
Ordinarily this is not a concern because early in signal processing
the signal number is filtered with valid_signal which ensures it
is a small positive signal number, but copy_siginfo_from_user
is called before this check is performed.
[ 73.031126] BUG: unable to handle kernel paging request at ffffffff6281bcb6
[ 73.032038] PGD 3014067 P4D 3014067 PUD 0
[ 73.032565] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[ 73.033287] CPU: 0 PID: 732 Comm: trinity-c3 Tainted: G W T 4.19.0-rc1-00077-g4ce5f9c #1
[ 73.034423] RIP: 0010:copy_siginfo_from_user+0x4d/0xd0
[ 73.034908] Code: 00 8b 53 08 81 fa 80 00 00 00 0f 84 90 00 00 00 85 d2 7e 2d 48 63 0b 83 f9 1f 7f 1c 8d 71 ff bf d8 04 01 50 48 0f a3 f7 73 0e <0f> b6 8c 09 20 bb 81 82 39 ca 7f 15 eb 68 31 c0 83 fa 06 7f 0c eb
[ 73.036665] RSP: 0018:ffff88001b8f7e20 EFLAGS: 00010297
[ 73.037160] RAX: 0000000000000000 RBX: ffff88001b8f7e90 RCX: fffffffff00000cb
[ 73.037865] RDX: 0000000000000001 RSI: 00000000f00000ca RDI: 00000000500104d8
[ 73.038546] RBP: ffff88001b8f7e80 R08: 0000000000000000 R09: 0000000000000000
[ 73.039201] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000008
[ 73.039874] R13: 00000000000002dc R14: 0000000000000000 R15: 0000000000000000
[ 73.040613] FS: 000000000104a880(0000) GS:ffff88001f000000(0000) knlGS:0000000000000000
[ 73.041649] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 73.042405] CR2: ffffffff6281bcb6 CR3: 000000001cb52003 CR4: 00000000001606b0
[ 73.043351] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 73.044286] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
[ 73.045221] Call Trace:
[ 73.045556] __x64_sys_rt_tgsigqueueinfo+0x34/0xa0
[ 73.046199] do_syscall_64+0x1a4/0x390
[ 73.046708] ? vtime_user_enter+0x61/0x80
[ 73.047242] ? __context_tracking_enter+0x4e/0x60
[ 73.047714] ? __context_tracking_enter+0x4e/0x60
[ 73.048278] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Therefore fix known_siginfo_layout to take an unsigned signal number
instead of a signed signal number. All valid signal numbers are small
positive numbers so they will not be affected, but invalid negative
signal numbers will now become large positive signal numbers and will
not be used as indices into the sig_sicodes array.
Making the signal number unsigned makes it difficult for similar mistakes to
happen in the future.
Fixes: 4ce5f9c9e754 ("signal: Use a smaller struct siginfo in the kernel")
Inspired-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The error value returned by map_lookup_elem doesn't differentiate
whether lookup was failed because of invalid key or lookup is not
supported.
Lets add handling for -EOPNOTSUPP return value of map_lookup_elem()
method of map, with expectation from map's implementation that it
should return -EOPNOTSUPP if lookup is not supported.
The errno for bpf syscall for BPF_MAP_LOOKUP_ELEM command will be set
to EOPNOTSUPP if map lookup is not supported.
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In btf_parse_hdr(), the length of the btf data header is firstly copied
from the user space to 'hdr_len' and checked to see whether it is larger
than 'btf_data_size'. If yes, an error code EINVAL is returned. Otherwise,
the whole header is copied again from the user space to 'btf->hdr'.
However, after the second copy, there is no check between
'btf->hdr->hdr_len' and 'hdr_len' to confirm that the two copies get the
same value. Given that the btf data is in the user space, a malicious user
can race to change the data between the two copies. By doing so, the user
can provide malicious data to the kernel and cause undefined behavior.
This patch adds a necessary check after the second copy, to make sure
'btf->hdr->hdr_len' has the same value as 'hdr_len'. Otherwise, an error
code EINVAL will be returned.
Signed-off-by: Wenwen Wang <wang6495@umn.edu>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- Drop BUG_ON()s and do normal error handling instead, in
find_next_iomem_res().
- Align function arguments on opening braces.
- Get rid of local var sibling_only in find_next_iomem_res().
- Shorten unnecessarily long first_level_children_only arg name.
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Brijesh Singh <brijesh.singh@amd.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Lianbo Jiang <lijiang@redhat.com>
CC: Takashi Iwai <tiwai@suse.de>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Tom Lendacky <thomas.lendacky@amd.com>
CC: Vivek Goyal <vgoyal@redhat.com>
CC: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
CC: bhe@redhat.com
CC: dan.j.williams@intel.com
CC: dyoung@redhat.com
CC: kexec@lists.infradead.org
CC: mingo@redhat.com
Link: <new submission>
Previously find_next_iomem_res() used "*res" as both an input parameter for
the range to search and the type of resource to search for, and an output
parameter for the resource we found, which makes the interface confusing.
The current callers use find_next_iomem_res() incorrectly because they
allocate a single struct resource and use it for repeated calls to
find_next_iomem_res(). When find_next_iomem_res() returns a resource, it
overwrites the start, end, flags, and desc members of the struct. If we
call find_next_iomem_res() again, we must update or restore these fields.
The previous code restored res.start and res.end, but not res.flags or
res.desc.
Since the callers did not restore res.flags, if they searched for flags
IORESOURCE_MEM | IORESOURCE_BUSY and found a resource with flags
IORESOURCE_MEM | IORESOURCE_BUSY | IORESOURCE_SYSRAM, the next search would
incorrectly skip resources unless they were also marked as
IORESOURCE_SYSRAM.
Fix this by restructuring the interface so it takes explicit "start, end,
flags" parameters and uses "*res" only as an output parameter.
Based on a patch by Lianbo Jiang <lijiang@redhat.com>.
[ bp: While at it:
- make comments kernel-doc style.
-
Originally-by: http://lore.kernel.org/lkml/20180921073211.20097-2-lijiang@redhat.com
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Brijesh Singh <brijesh.singh@amd.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Lianbo Jiang <lijiang@redhat.com>
CC: Takashi Iwai <tiwai@suse.de>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Tom Lendacky <thomas.lendacky@amd.com>
CC: Vivek Goyal <vgoyal@redhat.com>
CC: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
CC: bhe@redhat.com
CC: dan.j.williams@intel.com
CC: dyoung@redhat.com
CC: kexec@lists.infradead.org
CC: mingo@redhat.com
CC: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/153805812916.1157.177580438135143788.stgit@bhelgaas-glaptop.roam.corp.google.com
find_next_iomem_res() finds an iomem resource that covers part of a range
described by "start, end". All callers expect that range to be inclusive,
i.e., both start and end are included, but find_next_iomem_res() doesn't
handle the end address correctly.
If it finds an iomem resource that contains exactly the end address, it
skips it, e.g., if "start, end" is [0x0-0x10000] and there happens to be an
iomem resource [mem 0x10000-0x10000] (the single byte at 0x10000), we skip
it:
find_next_iomem_res(...)
{
start = 0x0;
end = 0x10000;
for (p = next_resource(...)) {
# p->start = 0x10000;
# p->end = 0x10000;
# we *should* return this resource, but this condition is false:
if ((p->end >= start) && (p->start < end))
break;
Adjust find_next_iomem_res() so it allows a resource that includes the
single byte at the end of the range. This is a corner case that we
probably don't see in practice.
Fixes: 58c1b5b07907 ("[PATCH] memory hotadd fixes: find_next_system_ram catch range fix")
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Brijesh Singh <brijesh.singh@amd.com>
CC: Dan Williams <dan.j.williams@intel.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Lianbo Jiang <lijiang@redhat.com>
CC: Takashi Iwai <tiwai@suse.de>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Tom Lendacky <thomas.lendacky@amd.com>
CC: Vivek Goyal <vgoyal@redhat.com>
CC: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
CC: bhe@redhat.com
CC: dan.j.williams@intel.com
CC: dyoung@redhat.com
CC: kexec@lists.infradead.org
CC: mingo@redhat.com
CC: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/153805812254.1157.16736368485811773752.stgit@bhelgaas-glaptop.roam.corp.google.com
Respect the DMA_ATTR_NO_WARN flags for allocations in dma-direct.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
The current printk() is ready to handle log buffer size up to 2G.
Give an explicit error for users who want to use larger log buffer.
Also fix printk formatting to show the 2G as a positive number.
Link: http://lkml.kernel.org/r/20181008135916.gg4kkmoki5bgtco5@pathway.suse.cz
Cc: rostedt@goodmis.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
[pmladek: Fixed to the really safe limit 2GB.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
lockdep_assert_held() is better suited for checking locking requirements,
since it won't get confused when the lock is held by some other task. This
is also a step towards possibly removing spin_is_locked().
Signed-off-by: Lance Roy <ldr709@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Link: https://lkml.kernel.org/r/20181003053902.6910-12-ldr709@gmail.com
