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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
"A single fix for a ~10 years old problem which causes high resolution
timers to stop after a CPU unplug/plug cycle due to a stale flag in
the per CPU hrtimer base struct.
Paul McKenney was hunting this for about a year, but the heisenbug
nature made it resistant against debug attempts for quite some time"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimer: Reset hrtimer cpu base proper on CPU hotplug
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Thomas Gleixner:
"A single bug fix to prevent a subtle deadlock in the scheduler core
code vs cpu hotplug"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Fix cpu.max vs. cpuhotplug deadlock
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
"Four patches which all address lock inversions and deadlocks in the
perf core code and the Intel debug store"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Fix perf,x86,cpuhp deadlock
perf/core: Fix ctx::mutex deadlock
perf/core: Fix another perf,trace,cpuhp lock inversion
perf/core: Fix lock inversion between perf,trace,cpuhp
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
"Two final locking fixes for 4.15:
- Repair the OWNER_DIED logic in the futex code which got wreckaged
with the recent fix for a subtle race condition.
- Prevent the hard lockup detector from triggering when dumping all
held locks in the system"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/lockdep: Avoid triggering hardlockup from debug_show_all_locks()
futex: Fix OWNER_DEAD fixup
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Pick up urgent bug fix and resolve the conflict.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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The hrtimer interrupt code contains a hang detection and mitigation
mechanism, which prevents that a long delayed hrtimer interrupt causes a
continous retriggering of interrupts which prevent the system from making
progress. If a hang is detected then the timer hardware is programmed with
a certain delay into the future and a flag is set in the hrtimer cpu base
which prevents newly enqueued timers from reprogramming the timer hardware
prior to the chosen delay. The subsequent hrtimer interrupt after the delay
clears the flag and resumes normal operation.
If such a hang happens in the last hrtimer interrupt before a CPU is
unplugged then the hang_detected flag is set and stays that way when the
CPU is plugged in again. At that point the timer hardware is not armed and
it cannot be armed because the hang_detected flag is still active, so
nothing clears that flag. As a consequence the CPU does not receive hrtimer
interrupts and no timers expire on that CPU which results in RCU stalls and
other malfunctions.
Clear the flag along with some other less critical members of the hrtimer
cpu base to ensure starting from a clean state when a CPU is plugged in.
Thanks to Paul, Sebastian and Anna-Maria for their help to get down to the
root cause of that hard to reproduce heisenbug. Once understood it's
trivial and certainly justifies a brown paperbag.
Fixes: 41d2e4949377 ("hrtimer: Tune hrtimer_interrupt hang logic")
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Sewior <bigeasy@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801261447590.2067@nanos
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Commit b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command
for LPM_TRIE map") introduces a bug likes below:
if (!rcu_dereference(trie->root))
return -ENOENT;
if (!key || key->prefixlen > trie->max_prefixlen) {
root = &trie->root;
goto find_leftmost;
}
......
find_leftmost:
for (node = rcu_dereference(*root); node;) {
In the code after label find_leftmost, it is assumed
that *root should not be NULL, but it is not true as
it is possbile trie->root is changed to NULL by an
asynchronous delete operation.
The issue is reported by syzbot and Eric Dumazet with the
below error log:
......
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 8033 Comm: syz-executor3 Not tainted 4.15.0-rc8+ #4
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:trie_get_next_key+0x3c2/0xf10 kernel/bpf/lpm_trie.c:682
......
This patch fixed the issue by use local rcu_dereferenced
pointer instead of *(&trie->root) later on.
Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command or LPM_TRIE map")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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One of the ugly leftovers from the early eBPF days is that div/mod
operations based on registers have a hard-coded src_reg == 0 test
in the interpreter as well as in JIT code generators that would
return from the BPF program with exit code 0. This was basically
adopted from cBPF interpreter for historical reasons.
There are multiple reasons why this is very suboptimal and prone
to bugs. To name one: the return code mapping for such abnormal
program exit of 0 does not always match with a suitable program
type's exit code mapping. For example, '0' in tc means action 'ok'
where the packet gets passed further up the stack, which is just
undesirable for such cases (e.g. when implementing policy) and
also does not match with other program types.
While trying to work out an exception handling scheme, I also
noticed that programs crafted like the following will currently
pass the verifier:
0: (bf) r6 = r1
1: (85) call pc+8
caller:
R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1
callee:
frame1: R1=ctx(id=0,off=0,imm=0) R10=fp0,call_1
10: (b4) (u32) r2 = (u32) 0
11: (b4) (u32) r3 = (u32) 1
12: (3c) (u32) r3 /= (u32) r2
13: (61) r0 = *(u32 *)(r1 +76)
14: (95) exit
returning from callee:
frame1: R0_w=pkt(id=0,off=0,r=0,imm=0)
R1=ctx(id=0,off=0,imm=0) R2_w=inv0
R3_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
R10=fp0,call_1
to caller at 2:
R0_w=pkt(id=0,off=0,r=0,imm=0) R6=ctx(id=0,off=0,imm=0)
R10=fp0,call_-1
from 14 to 2: R0=pkt(id=0,off=0,r=0,imm=0)
R6=ctx(id=0,off=0,imm=0) R10=fp0,call_-1
2: (bf) r1 = r6
3: (61) r1 = *(u32 *)(r1 +80)
4: (bf) r2 = r0
5: (07) r2 += 8
6: (2d) if r2 > r1 goto pc+1
R0=pkt(id=0,off=0,r=8,imm=0) R1=pkt_end(id=0,off=0,imm=0)
R2=pkt(id=0,off=8,r=8,imm=0) R6=ctx(id=0,off=0,imm=0)
R10=fp0,call_-1
7: (71) r0 = *(u8 *)(r0 +0)
8: (b7) r0 = 1
9: (95) exit
from 6 to 8: safe
processed 16 insns (limit 131072), stack depth 0+0
Basically what happens is that in the subprog we make use of a
div/mod by 0 exception and in the 'normal' subprog's exit path
we just return skb->data back to the main prog. This has the
implication that the verifier thinks we always get a pkt pointer
in R0 while we still have the implicit 'return 0' from the div
as an alternative unconditional return path earlier. Thus, R0
then contains 0, meaning back in the parent prog we get the
address range of [0x0, skb->data_end] as read and writeable.
Similar can be crafted with other pointer register types.
Since i) BPF_ABS/IND is not allowed in programs that contain
BPF to BPF calls (and generally it's also disadvised to use in
native eBPF context), ii) unknown opcodes don't return zero
anymore, iii) we don't return an exception code in dead branches,
the only last missing case affected and to fix is the div/mod
handling.
What we would really need is some infrastructure to propagate
exceptions all the way to the original prog unwinding the
current stack and returning that code to the caller of the
BPF program. In user space such exception handling for similar
runtimes is typically implemented with setjmp(3) and longjmp(3)
as one possibility which is not available in the kernel,
though (kgdb used to implement it in kernel long time ago). I
implemented a PoC exception handling mechanism into the BPF
interpreter with porting setjmp()/longjmp() into x86_64 and
adding a new internal BPF_ABRT opcode that can use a program
specific exception code for all exception cases we have (e.g.
div/mod by 0, unknown opcodes, etc). While this seems to work
in the constrained BPF environment (meaning, here, we don't
need to deal with state e.g. from memory allocations that we
would need to undo before going into exception state), it still
has various drawbacks: i) we would need to implement the
setjmp()/longjmp() for every arch supported in the kernel and
for x86_64, arm64, sparc64 JITs currently supporting calls,
ii) it has unconditional additional cost on main program
entry to store CPU register state in initial setjmp() call,
and we would need some way to pass the jmp_buf down into
___bpf_prog_run() for main prog and all subprogs, but also
storing on stack is not really nice (other option would be
per-cpu storage for this, but it also has the drawback that
we need to disable preemption for every BPF program types).
All in all this approach would add a lot of complexity.
Another poor-man's solution would be to have some sort of
additional shared register or scratch buffer to hold state
for exceptions, and test that after every call return to
chain returns and pass R0 all the way down to BPF prog caller.
This is also problematic in various ways: i) an additional
register doesn't map well into JITs, and some other scratch
space could only be on per-cpu storage, which, again has the
side-effect that this only works when we disable preemption,
or somewhere in the input context which is not available
everywhere either, and ii) this adds significant runtime
overhead by putting conditionals after each and every call,
as well as implementation complexity.
Yet another option is to teach verifier that div/mod can
return an integer, which however is also complex to implement
as verifier would need to walk such fake 'mov r0,<code>; exit;'
sequeuence and there would still be no guarantee for having
propagation of this further down to the BPF caller as proper
exception code. For parent prog, it is also is not distinguishable
from a normal return of a constant scalar value.
The approach taken here is a completely different one with
little complexity and no additional overhead involved in
that we make use of the fact that a div/mod by 0 is undefined
behavior. Instead of bailing out, we adapt the same behavior
as on some major archs like ARMv8 [0] into eBPF as well:
X div 0 results in 0, and X mod 0 results in X. aarch64 and
aarch32 ISA do not generate any traps or otherwise aborts
of program execution for unsigned divides. I verified this
also with a test program compiled by gcc and clang, and the
behavior matches with the spec. Going forward we adapt the
eBPF verifier to emit such rewrites once div/mod by register
was seen. cBPF is not touched and will keep existing 'return 0'
semantics. Given the options, it seems the most suitable from
all of them, also since major archs have similar schemes in
place. Given this is all in the realm of undefined behavior,
we still have the option to adapt if deemed necessary and
this way we would also have the option of more flexibility
from LLVM code generation side (which is then fully visible
to verifier). Thus, this patch i) fixes the panic seen in
above program and ii) doesn't bypass the verifier observations.
[0] ARM Architecture Reference Manual, ARMv8 [ARM DDI 0487B.b]
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0487b.b/DDI0487B_b_armv8_arm.pdf
1) aarch64 instruction set: section C3.4.7 and C6.2.279 (UDIV)
"A division by zero results in a zero being written to
the destination register, without any indication that
the division by zero occurred."
2) aarch32 instruction set: section F1.4.8 and F5.1.263 (UDIV)
"For the SDIV and UDIV instructions, division by zero
always returns a zero result."
Fixes: f4d7e40a5b71 ("bpf: introduce function calls (verification)")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Recent findings by syzcaller fixed in 7891a87efc71 ("bpf: arsh is
not supported in 32 bit alu thus reject it") triggered a warning
in the interpreter due to unknown opcode not being rejected by
the verifier. The 'return 0' for an unknown opcode is really not
optimal, since with BPF to BPF calls, this would go untracked by
the verifier.
Do two things here to improve the situation: i) perform basic insn
sanity check early on in the verification phase and reject every
non-uapi insn right there. The bpf_opcode_in_insntable() table
reuses the same mapping as the jumptable in ___bpf_prog_run() sans
the non-public mappings. And ii) in ___bpf_prog_run() we do need
to BUG in the case where the verifier would ever create an unknown
opcode due to some rewrites.
Note that JITs do not have such issues since they would punt to
interpreter in these situations. Moreover, the BPF_JIT_ALWAYS_ON
would also help to avoid such unknown opcodes in the first place.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Given we recently had c131187db2d3 ("bpf: fix branch pruning
logic") and 95a762e2c8c9 ("bpf: fix incorrect sign extension in
check_alu_op()") in particular where before verifier skipped
verification of the wrongly assumed dead branch, we should not
just replace the dead code parts with nops (mov r0,r0). If there
is a bug such as fixed in 95a762e2c8c9 in future again, where
runtime could execute those insns, then one of the potential
issues with the current setting would be that given the nops
would be at the end of the program, we could execute out of
bounds at some point.
The best in such case would be to just exit the BPF program
altogether and return an exception code. However, given this
would require two instructions, and such a dead code gap could
just be a single insn long, we would need to place 'r0 = X; ret'
snippet at the very end after the user program or at the start
before the program (where we'd skip that region on prog entry),
and then place unconditional ja's into the dead code gap.
While more complex but possible, there's still another block
in the road that currently prevents from this, namely BPF to
BPF calls. The issue here is that such exception could be
returned from a callee, but the caller would not know that
it's an exception that needs to be propagated further down.
Alternative that has little complexity is to just use a ja-1
code for now which will trap the execution here instead of
silently doing bad things if we ever get there due to bugs.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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There's a risk that a kernel which has full retpoline mitigations becomes
vulnerable when a module gets loaded that hasn't been compiled with the
right compiler or the right option.
To enable detection of that mismatch at module load time, add a module info
string "retpoline" at build time when the module was compiled with
retpoline support. This only covers compiled C source, but assembler source
or prebuilt object files are not checked.
If a retpoline enabled kernel detects a non retpoline protected module at
load time, print a warning and report it in the sysfs vulnerability file.
[ tglx: Massaged changelog ]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: jeyu@kernel.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180125235028.31211-1-andi@firstfloor.org
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Make the code more readable.
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Lockdep noticed the following 3-way lockup scenario:
sys_perf_event_open()
perf_event_alloc()
perf_try_init_event()
#0 ctx = perf_event_ctx_lock_nested(1)
perf_swevent_init()
swevent_hlist_get()
#1 mutex_lock(&pmus_lock)
perf_event_init_cpu()
#1 mutex_lock(&pmus_lock)
#2 mutex_lock(&ctx->mutex)
sys_perf_event_open()
mutex_lock_double()
#2 mutex_lock()
#0 mutex_lock_nested()
And while we need that perf_event_ctx_lock_nested() for HW PMUs such
that they can iterate the sibling list, trying to match it to the
available counters, the software PMUs need do no such thing. Exclude
them.
In particular the swevent triggers the above invertion, while the
tpevent PMU triggers a more elaborate one through their event_mutex.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Lockdep noticed the following 3-way lockup race:
perf_trace_init()
#0 mutex_lock(&event_mutex)
perf_trace_event_init()
perf_trace_event_reg()
tp_event->class->reg() := tracepoint_probe_register
#1 mutex_lock(&tracepoints_mutex)
trace_point_add_func()
#2 static_key_enable()
#2 do_cpu_up()
perf_event_init_cpu()
#3 mutex_lock(&pmus_lock)
#4 mutex_lock(&ctx->mutex)
perf_ioctl()
#4 ctx = perf_event_ctx_lock()
_perf_iotcl()
ftrace_profile_set_filter()
#0 mutex_lock(&event_mutex)
Fudge it for now by noting that the tracepoint state does not depend
on the event <-> context relation. Ugly though :/
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Lockdep gifted us with noticing the following 4-way lockup scenario:
perf_trace_init()
#0 mutex_lock(&event_mutex)
perf_trace_event_init()
perf_trace_event_reg()
tp_event->class->reg() := tracepoint_probe_register
#1 mutex_lock(&tracepoints_mutex)
trace_point_add_func()
#2 static_key_enable()
#2 do_cpu_up()
perf_event_init_cpu()
#3 mutex_lock(&pmus_lock)
#4 mutex_lock(&ctx->mutex)
perf_event_task_disable()
mutex_lock(¤t->perf_event_mutex)
#4 ctx = perf_event_ctx_lock()
#5 perf_event_for_each_child()
do_exit()
task_work_run()
__fput()
perf_release()
perf_event_release_kernel()
#4 mutex_lock(&ctx->mutex)
#5 mutex_lock(&event->child_mutex)
free_event()
_free_event()
event->destroy() := perf_trace_destroy
#0 mutex_lock(&event_mutex);
Fix that by moving the free_event() out from under the locks.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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CONFIG_IRQ_DOMAIN_DEBUG is similar to CONFIG_GENERIC_IRQ_DEBUGFS,
just with less information.
Spring cleanup time.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Yang Shunyong <shunyong.yang@hxt-semitech.com>
Link: https://lkml.kernel.org/r/20180117142647.23622-1-marc.zyngier@arm.com
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Tejun reported the following cpu-hotplug lock (percpu-rwsem) read recursion:
tg_set_cfs_bandwidth()
get_online_cpus()
cpus_read_lock()
cfs_bandwidth_usage_inc()
static_key_slow_inc()
cpus_read_lock()
Reported-by: Tejun Heo <tj@kernel.org>
Tested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180122215328.GP3397@worktop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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debug_show_all_locks() iterates all tasks and print held locks whole
holding tasklist_lock. This can take a while on a slow console device
and may end up triggering NMI hardlockup detector if someone else ends
up waiting for tasklist_lock.
Touch the NMI watchdog while printing the held locks to avoid
spuriously triggering the hardlockup detector.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Link: http://lkml.kernel.org/r/20180122220055.GB1771050@devbig577.frc2.facebook.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Both Geert and DaveJ reported that the recent futex commit:
c1e2f0eaf015 ("futex: Avoid violating the 10th rule of futex")
introduced a problem with setting OWNER_DEAD. We set the bit on an
uninitialized variable and then entirely optimize it away as a
dead-store.
Move the setting of the bit to where it is more useful.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: c1e2f0eaf015 ("futex: Avoid violating the 10th rule of futex")
Link: http://lkml.kernel.org/r/20180122103947.GD2228@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The ftrace function tracer self tests calls some functions to verify
the get traced. This relies on them not being inlined. Previously
this was ensured by putting them into another file, but with LTO
the compiler can inline across files, which makes the tests fail.
Mark these functions as noinline and noclone.
Link: http://lkml.kernel.org/r/20171221233732.31896-1-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Recently, how the pointers being printed with %p has been changed
by commit ad67b74d2469 ("printk: hash addresses printed with %p").
This is causing a regression while showing offset in the
uprobe_events file. Instead of %p, use %px to display offset.
Before patch:
# perf probe -vv -x /tmp/a.out main
Opening /sys/kernel/debug/tracing//uprobe_events write=1
Writing event: p:probe_a/main /tmp/a.out:0x58c
# cat /sys/kernel/debug/tracing/uprobe_events
p:probe_a/main /tmp/a.out:0x0000000049a0f352
After patch:
# cat /sys/kernel/debug/tracing/uprobe_events
p:probe_a/main /tmp/a.out:0x000000000000058c
Link: http://lkml.kernel.org/r/20180106054246.15375-1-ravi.bangoria@linux.vnet.ibm.com
Cc: stable@vger.kernel.org
Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Always mark the parsed string with a terminated nul '\0' character. This removes
the need for the users to have to append the '\0' before using the parsed string.
Link: http://lkml.kernel.org/r/1516093350-12045-4-git-send-email-changbin.du@intel.com
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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If only spaces were read while parsing the next string, then parser->idx should be
cleared in order to make trace_parser_loaded() return false.
Link: http://lkml.kernel.org/r/1516093350-12045-3-git-send-email-changbin.du@intel.com
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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User space can pass in a C nul character '\0' along with its input. The
function trace_get_user() will try to process it as a normal character,
and that will fail to parse.
open("/sys/kernel/debug/tracing//set_ftrace_pid", O_WRONLY|O_TRUNC) = 3
write(3, " \0", 2) = -1 EINVAL (Invalid argument)
while parse can handle spaces, so below works.
$ echo "" > set_ftrace_pid
$ echo " " > set_ftrace_pid
$ echo -n " " > set_ftrace_pid
Have the parser stop on '\0' and cease any further parsing. Only process
the characters up to the nul '\0' character and do not process it.
Link: http://lkml.kernel.org/r/1516093350-12045-2-git-send-email-changbin.du@intel.com
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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With the addition of ORC unwinder and FRAME POINTER unwinder, the stack
trace skipping requirements have changed.
I went through the tracing stack trace dumps with ORC and with frame
pointers and recalculated the proper values.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The function tracer can create a dynamically allocated trampoline that is
called by the function mcount or fentry hook that is used to call the
function callback that is registered. The problem is that the orc undwinder
will bail if it encounters one of these trampolines. This breaks the stack
trace of function callbacks, which include the stack tracer and setting the
stack trace for individual functions.
Since these dynamic trampolines are basically copies of the static ftrace
trampolines defined in ftrace_*.S, we do not need to create new orc entries
for the dynamic trampolines. Finding the return address on the stack will be
identical as the functions that were copied to create the dynamic
trampolines. When encountering a ftrace dynamic trampoline, we can just use
the orc entry of the ftrace static function that was copied for that
trampoline.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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en_rx_am.c was deleted in 'net-next' but had a bug fixed in it in
'net'.
The esp{4,6}_offload.c conflicts were overlapping changes.
The 'out' label is removed so we just return ERR_PTR(-EINVAL)
directly.
Signed-off-by: David S. Miller <davem@davemloft.net>
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In commit b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map"),
the implemented MAP_GET_NEXT_KEY callback function is guarded with rcu read lock.
In the function body, "kmalloc(size, GFP_USER | __GFP_NOWARN)" is used which may
sleep and violate rcu read lock region requirements. This patch fixed the issue
by using GFP_ATOMIC instead to avoid blocking kmalloc. Tested with
CONFIG_DEBUG_ATOMIC_SLEEP=y as suggested by Eric Dumazet.
Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map")
Signed-off-by: Yonghong Song <yhs@fb.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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There are so many places that build struct siginfo by hand that at
least one of them is bound to get it wrong. A handful of cases in the
kernel arguably did just that when using the errno field of siginfo to
pass no errno values to userspace. The usage is limited to a single
si_code so at least does not mess up anything else.
Encapsulate this questionable pattern in a helper function so
that the userspace ABI is preserved.
Update all of the places that use this pattern to use the new helper
function.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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The helpers added are:
send_sig_mceerr
force_sig_mceerr
force_sig_bnderr
force_sig_pkuerr
Filling out siginfo properly can ge tricky. Especially for these
specialized cases where the temptation is to share code with other
cases which use a different subset of siginfo fields. Unfortunately
that code sharing frequently results in bugs with the wrong siginfo
fields filled in, and makes it harder to verify that the siginfo
structure was properly initialized.
Provide these helpers instead that get all of the details right, and
guarantee that siginfo is properly initialized.
send_sig_mceerr and force_sig_mceer are a little special as two si
codes BUS_MCEERR_AO and BUS_MCEER_AR both use the same extended
signinfo layout.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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The vast majority of signals sent from architecture specific code are
simple faults. Encapsulate this reality with two helper functions so
that the nit-picky implementation of preparing a siginfo does not need
to be repeated many times on each architecture.
As only some architectures support the trapno field, make the trapno
arguement only present on those architectures.
Similary as ia64 has three fields: imm, flags, and isr that
are specific to it. Have those arguments always present on ia64
and no where else.
This ensures the architecture specific code always remembers which
fields it needs to pass into the siginfo structure.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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The function clear_siginfo is just a nice wrapper around memset so
this results in no functional change. This change makes mistakes
a little more difficult and it makes it clearer what is going on.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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The siginfo structure has all manners of holes with the result that a
structure initializer is not guaranteed to initialize all of the bits.
As we have to copy the structure to userspace don't even try to use
a structure initializer. Instead use clear_siginfo followed by initializing
selected fields. This gives a guarantee that uninitialized kernel memory
is not copied to userspace.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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We copy in null terminated strings "on" and "off", no
need to zero out devkmsg_log_str in control_devkmsg().
Link: http://lkml.kernel.org/r/20180119043901.1728-1-sergey.senozhatsky@gmail.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Thomas Gleixner:
"A single fix for the new matrix allocator to prevent vector exhaustion
by certain network drivers which allocate gazillions of unused vectors
which cannot be put into reservation mode due to MSI and the lack of
MSI entry masking.
The fix/workaround is to spread the vectors across CPUs by searching
the supplied target CPU mask for the CPU with the smallest number of
allocated vectors"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irq/matrix: Spread interrupts on allocation
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Alexei Starovoitov says:
====================
pull-request: bpf-next 2018-01-19
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) bpf array map HW offload, from Jakub.
2) support for bpf_get_next_key() for LPM map, from Yonghong.
3) test_verifier now runs loaded programs, from Alexei.
4) xdp cpumap monitoring, from Jesper.
5) variety of tests, cleanups and small x64 JIT optimization, from Daniel.
6) user space can now retrieve HW JITed program, from Jiong.
Note there is a minor conflict between Russell's arm32 JIT fixes
and removal of bpf_jit_enable variable by Daniel which should
be resolved by keeping Russell's comment and removing that variable.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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The BPF verifier conflict was some minor contextual issue.
The TUN conflict was less trivial. Cong Wang fixed a memory leak of
tfile->tx_array in 'net'. This is an skb_array. But meanwhile in
net-next tun changed tfile->tx_arry into tfile->tx_ring which is a
ptr_ring.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Given the limit could potentially get further adjustments in the
future, add it to the log so it becomes obvious what the current
limit is w/o having to check the source first. This may also be
helpful for debugging complexity related issues on kernels that
backport from upstream.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Having a pure_initcall() callback just to permanently enable BPF
JITs under CONFIG_BPF_JIT_ALWAYS_ON is unnecessary and could leave
a small race window in future where JIT is still disabled on boot.
Since we know about the setting at compilation time anyway, just
initialize it properly there. Also consolidate all the individual
bpf_jit_enable variables into a single one and move them under one
location. Moreover, don't allow for setting unspecified garbage
values on them.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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I've seen two patch proposals now for helper additions that used
ARG_PTR_TO_MEM or similar in reg_X but no corresponding ARG_CONST_SIZE
in reg_X+1. Verifier won't complain in such case, but it will omit
verifying the memory passed to the helper thus ending up badly.
Detect such buggy helper function signature and bail out during
verification rather than finding them through review.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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If devm_memremap_pages() detects a collision while adding entries
to the radix-tree, we call pgmap_radix_release(). Unfortunately,
the function removes *all* entries for the range -- including the
entries that caused the collision in the first place.
Modify pgmap_radix_release() to take an additional argument to
indicate where to stop, so that only newly added entries are removed
from the tree.
Cc: <stable@vger.kernel.org>
Fixes: 9476df7d80df ("mm: introduce find_dev_pagemap()")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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The functions devm_memremap_pages() and devm_memremap_pages_release() use
different ways to calculate the section-aligned amount of memory. The
latter function may use an incorrect size if the memory region is small
but straddles a section border.
Use the same code for both.
Cc: <stable@vger.kernel.org>
Fixes: 5f29a77cd957 ("mm: fix mixed zone detection in devm_memremap_pages")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Current LPM_TRIE map type does not implement MAP_GET_NEXT_KEY
command. This command is handy when users want to enumerate
keys. Otherwise, a different map which supports key
enumeration may be required to store the keys. If the
map data is sparse and all map data are to be deleted without
closing file descriptor, using MAP_GET_NEXT_KEY to find
all keys is much faster than enumerating all key space.
This patch implements MAP_GET_NEXT_KEY command for LPM_TRIE map.
If user provided key pointer is NULL or the key does not have
an exact match in the trie, the first key will be returned.
Otherwise, the next key will be returned.
In this implemenation, key enumeration follows a postorder
traversal of internal trie. More specific keys
will be returned first than less specific ones, given
a sequence of MAP_GET_NEXT_KEY syscalls.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Two more small fixes
- The conversion of enums into their actual numbers to display in the
event format file had an off-by-one bug, that could cause an enum
not to be converted, and break user space parsing tools.
- A fix to a previous fix to bring back the context recursion checks.
The interrupt case checks for NMI, IRQ and softirq, but the softirq
returned the same number regardless if it was set or not, although
the logic would force it to be set if it were hit"
* tag 'trace-v4.15-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix converting enum's from the map in trace_event_eval_update()
ring-buffer: Fix duplicate results in mapping context to bits in recursive lock
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
"cgroup.threads should be delegatable (ie. a container should be able
to write to it from inside) but was missing the flag.
The change is very low risk"
* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: make cgroup.threads delegatable
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fixlet from Tejun Heo:
"One patch to add touch_nmi_watchdog() while dumping workqueue debug
messages to avoid triggering the lockup detector spuriously.
The change is very low risk"
* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: avoid hard lockups in show_workqueue_state()
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