The purpose of this patch is to streamline error propagation and in particular
to propagate retrieve_ptr_limit() errors for pointer types that are not defining
a ptr_limit such that register-based alu ops against these types can be rejected.

The main rationale is that a gap has been identified by Piotr in the existing
protection against speculatively out-of-bounds loads, for example, in case of
ctx pointers, unprivileged programs can still perform pointer arithmetic. This
can be abused to execute speculatively out-of-bounds loads without restrictions
and thus extract contents of kernel memory.

Fix this by rejecting unprivileged programs that attempt any pointer arithmetic
on unprotected pointer types. The two affected ones are pointer to ctx as well
as pointer to map. Field access to a modified ctx' pointer is rejected at a
later point in time in the verifier, and 7c696732 ("bpf: Permit map_ptr
arithmetic with opcode add and offset 0") only relevant for root-only use cases.
Risk of unprivileged program breakage is considered very low.

Fixes: 7c696732 ("bpf: Permit map_ptr arithmetic with opcode add and offset 0")
Fixes: b2157399 ("bpf: prevent out-of-bounds speculation")
Signed-off-by: Piotr Krysiuk <piotras@gmail.com>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>

The following sequence of commands:
  register_ftrace_direct(ip, addr1);
  modify_ftrace_direct(ip, addr1, addr2);
  unregister_ftrace_direct(ip, addr2);
will cause the kernel to warn:
[   30.179191] WARNING: CPU: 2 PID: 1961 at kernel/trace/ftrace.c:5223 unregister_ftrace_direct+0x130/0x150
[   30.180556] CPU: 2 PID: 1961 Comm: test_progs    W  O      5.12.0-rc2-00378-g86bc10a0a711-dirty #3246
[   30.182453] RIP: 0010:unregister_ftrace_direct+0x130/0x150

When modify_ftrace_direct() changes the addr from old to new it should update
the addr stored in ftrace_direct_funcs. Otherwise the final
unregister_ftrace_direct() won't find the address and will cause the splat.

Fixes: 0567d680 ("ftrace: Add modify_ftrace_direct()")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/bpf/20210316195815.34714-1-alexei.starovoitov@gmail.com

bpf_fd_inode_storage_lookup_elem() returned NULL when getting a bad FD,
which caused -ENOENT in bpf_map_copy_value. -EBADF error is better than
-ENOENT for a bad FD behaviour.

The patch was partially contributed by CyberArk Software, Inc.

Fixes: 8ea63684 ("bpf: Implement bpf_local_storage for inodes")
Signed-off-by: Tal Lossos <tallossos@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20210307120948.61414-1-tallossos@gmail.com

The syzbot got FD of vmlinux BTF and passed it into map_create which caused
crash in btf_type_id_size() when it tried to access resolved_ids. The vmlinux
BTF doesn't have 'resolved_ids' and 'resolved_sizes' initialized to save
memory. To avoid such issues disallow using vmlinux BTF in prog_load and
map_create commands.

Fixes: 53297220 ("bpf: Assign ID to vmlinux BTF and return extra info for BTF in GET_OBJ_INFO")
Reported-by:  <syzbot+8bab8ed346746e7540e8@syzkaller.appspotmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210307225248.79031-1-alexei.starovoitov@gmail.com

As pointed out by Ilya and explained in the new comment, there's a
discrepancy between x86 and BPF CMPXCHG semantics: BPF always loads
the value from memory into r0, while x86 only does so when r0 and the
value in memory are different. The same issue affects s390.

At first this might sound like pure semantics, but it makes a real
difference when the comparison is 32-bit, since the load will
zero-extend r0/rax.

The fix is to explicitly zero-extend rax after doing such a
CMPXCHG. Since this problem affects multiple archs, this is done in
the verifier by patching in a BPF_ZEXT_REG instruction after every
32-bit cmpxchg. Any archs that don't need such manual zero-extension
can do a look-ahead with insn_is_zext to skip the unnecessary mov.

Note this still goes on top of Ilya's patch:

https://lore.kernel.org/bpf/20210301154019.129110-1-iii@linux.ibm.com/T/#u

Differences v5->v6[1]:
 - Moved is_cmpxchg_insn and ensured it can be safely re-used. Also renamed it
   and removed 'inline' to match the style of the is_*_function helpers.
 - Fixed up comments in verifier test (thanks for the careful review, Martin!)

Differences v4->v5[1]:
 - Moved the logic entirely into opt_subreg_zext_lo32_rnd_hi32, thanks to Martin
   for suggesting this.

Differences v3->v4[1]:
 - Moved the optimization against pointless zext into the correct place:
   opt_subreg_zext_lo32_rnd_hi32 is called _after_ fixup_bpf_calls.

Differences v2->v3[1]:
 - Moved patching into fixup_bpf_calls (patch incoming to rename this function)
 - Added extra commentary on bpf_jit_needs_zext
 - Added check to avoid adding a pointless zext(r0) if there's already one there.

Difference v1->v2[1]: Now solved centrally in the verifier instead of
  specifically for the x86 JIT. Thanks to Ilya and Daniel for the suggestions!

[1] v5: https://lore.kernel.org/bpf/CA+i-1C3ytZz6FjcPmUg5s4L51pMQDxWcZNvM86w4RHZ_o2khwg@mail.gmail.com/T/#t
    v4: https://lore.kernel.org/bpf/CA+i-1C3ytZz6FjcPmUg5s4L51pMQDxWcZNvM86w4RHZ_o2khwg@mail.gmail.com/T/#t
    v3: https://lore.kernel.org/bpf/08669818-c99d-0d30-e1db-53160c063611@iogearbox.net/T/#t
    v2: https://lore.kernel.org/bpf/08669818-c99d-0d30-e1db-53160c063611@iogearbox.net/T/#t
    v1: https://lore.kernel.org/bpf/d7ebaefb-bfd6-a441-3ff2-2fdfe699b1d2@iogearbox.net/T/#t



Reported-by: Ilya Leoshkevich <iii@linux.ibm.com>
Fixes: 5ffa2550 ("bpf: Add instructions for atomic_[cmp]xchg")
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Provide a generic helper for setting up an io_uring worker. Returns a
task_struct so that the caller can do whatever setup is needed, then call
wake_up_new_task() to kick it into gear.

Add a kernel_clone_args member, io_thread, which tells copy_process() to
mark the task with PF_IO_WORKER.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

insn_has_def32() returns false for 32-bit BPF_FETCH insns. This makes
adjust_insn_aux_data() incorrectly set zext_dst, as can be seen in [1].
This happens because insn_no_def() does not know about the BPF_FETCH
variants of BPF_STX.

Fix in two steps.

First, replace insn_no_def() with insn_def_regno(), which returns the
register an insn defines. Normally insn_no_def() calls are followed by
insn->dst_reg uses; replace those with the insn_def_regno() return
value.

Second, adjust the BPF_STX special case in is_reg64() to deal with
queries made from opt_subreg_zext_lo32_rnd_hi32(), where the state
information is no longer available. Add a comment, since the purpose
of this special case is not clear at first glance.

  [1] https://lore.kernel.org/bpf/20210223150845.1857620-1-jackmanb@google.com/



Fixes: 5ffa2550 ("bpf: Add instructions for atomic_[cmp]xchg")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/bpf/20210301154019.129110-1-iii@linux.ibm.com

If tracing is disabled for some reason (traceoff_on_warning, command line,
etc), the ftrace selftests are guaranteed to fail, as their results are
defined by trace data in the ring buffers. If the ring buffers are turned
off, the tests will fail, due to lack of data.

Because tracing being disabled is for a specific reason (warning, user
decided to, etc), it does not make sense to enable tracing to run the self
tests, as the test output may corrupt the reason for the tracing to be
disabled.

Instead, simply skip the self tests and report that they are being skipped
due to tracing being disabled.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kmemleak report:
unreferenced object 0xc5a6f708 (size 8):
  comm "ftracetest", pid 1209, jiffies 4294911500 (age 6.816s)
  hex dump (first 8 bytes):
    00 c1 3d 60 14 83 1f 8a                          ..=`....
  backtrace:
    [<f0aa4ac4>] __kmalloc_track_caller+0x2a6/0x460
    [<7d3d60a6>] kstrndup+0x37/0x70
    [<45a0e739>] argv_split+0x1c/0x120
    [<c17982f8>] __create_synth_event+0x192/0xb00
    [<0708b8a3>] create_synth_event+0xbb/0x150
    [<3d1941e1>] create_dyn_event+0x5c/0xb0
    [<5cf8b9e3>] trace_parse_run_command+0xa7/0x140
    [<04deb2ef>] dyn_event_write+0x10/0x20
    [<8779ac95>] vfs_write+0xa9/0x3c0
    [<ed93722a>] ksys_write+0x89/0xc0
    [<b9ca0507>] __ia32_sys_write+0x15/0x20
    [<7ce02d85>] __do_fast_syscall_32+0x45/0x80
    [<cb0ecb35>] do_fast_syscall_32+0x29/0x60
    [<2467454a>] do_SYSENTER_32+0x15/0x20
    [<9beaa61d>] entry_SYSENTER_32+0xa9/0xfc
unreferenced object 0xc5a6f078 (size 8):
  comm "ftracetest", pid 1209, jiffies 4294911500 (age 6.816s)
  hex dump (first 8 bytes):
    08 f7 a6 c5 00 00 00 00                          ........
  backtrace:
    [<bbac096a>] __kmalloc+0x2b6/0x470
    [<aa2624b4>] argv_split+0x82/0x120
    [<c17982f8>] __create_synth_event+0x192/0xb00
    [<0708b8a3>] create_synth_event+0xbb/0x150
    [<3d1941e1>] create_dyn_event+0x5c/0xb0
    [<5cf8b9e3>] trace_parse_run_command+0xa7/0x140
    [<04deb2ef>] dyn_event_write+0x10/0x20
    [<8779ac95>] vfs_write+0xa9/0x3c0
    [<ed93722a>] ksys_write+0x89/0xc0
    [<b9ca0507>] __ia32_sys_write+0x15/0x20
    [<7ce02d85>] __do_fast_syscall_32+0x45/0x80
    [<cb0ecb35>] do_fast_syscall_32+0x29/0x60
    [<2467454a>] do_SYSENTER_32+0x15/0x20
    [<9beaa61d>] entry_SYSENTER_32+0xa9/0xfc

In __create_synth_event(), while iterating field/type arguments, the
argv_split() will return array of atleast 2 elements even when zero
arguments(argc=0) are passed. for e.g. when there is double delimiter
or string ends with delimiter

To fix call argv_free() even when argc=0.

Link: https://lkml.kernel.org/r/20210304094521.GA1826@cosmos



Signed-off-by: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

When the CONFIG_RING_BUFFER_VALIDATE_TIME_DELTAS is enabled, and the time
stamps are detected as not being valid, it reports information about the
write stamp, but does not show the before_stamp which is still useful
information. Also, it should give a warning once, such that tests detect
this happening.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Part of the logic of the new time stamp code depends on the before_stamp and
the write_stamp to be different if the write_stamp does not match the last
event on the buffer, as it will be used to calculate the delta of the next
event written on the buffer.

The discard logic depends on this, as the next event to come in needs to
inject a full timestamp as it can not rely on the last event timestamp in
the buffer because it is unknown due to events after it being discarded. But
by changing the write_stamp back to the time before it, it forces the next
event to use a full time stamp, instead of relying on it.

The issue came when a full time stamp was used for the event, and
rb_time_delta() returns zero in that case. The update to the write_stamp
(which subtracts delta) made it not change. Then when the event is removed
from the buffer, because the before_stamp and write_stamp still match, the
next event written would calculate its delta from the write_stamp, but that
would be wrong as the write_stamp is of the time of the event that was
discarded.

In the case that the delta change being made to write_stamp is zero, set the
before_stamp to zero as well, and this will force the next event to inject a
full timestamp and not use the current write_stamp.

Cc: stable@vger.kernel.org
Fixes: a389d86f ("ring-buffer: Have nested events still record running time stamp")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

It's "cond_resched()" not "cond_sched()".

Link: https://lkml.kernel.org/r/1863065.aFVDpXsuPd@devpool47



Signed-off-by: Rolf Eike Beer <eb@emlix.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

A declaration of function "int trace_empty(struct trace_iterator *iter)"
shows up twice in the header file kernel/trace/trace.h

Link: https://lkml.kernel.org/r/20210304092348.208033-1-y.karadz@gmail.com



Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Currently breakpoints in kernel .init.text section are not handled
correctly while allowing to remove them even after corresponding pages
have been freed.

Fix it via killing .init.text section breakpoints just prior to initmem
pages being freed.

Doug: "HW breakpoints aren't handled by this patch but it's probably
not such a big deal".

Link: https://lkml.kernel.org/r/20210224081652.587785-1-sumit.garg@linaro.org


Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Suggested-by: Doug Anderson <dianders@chromium.org>
Acked-by: Doug Anderson <dianders@chromium.org>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Drop repeated words in kernel/events/.
{if, the, that, with, time}

Drop repeated words in kernel/locking/.
{it, no, the}

Drop repeated words in kernel/sched/.
{in, not}

Link: https://lkml.kernel.org/r/20210127023412.26292-1-rdunlap@infradead.org


Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Will Deacon <will@kernel.org>	[kernel/locking/]
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Combine kmalloc and vmalloc into a single call.  Use struct_size macro
instead of direct size calculation.

Link: https://lkml.kernel.org/r/ba9ba5beea9a44b7196c41a0d9528abd5f20dd2e.1611620846.git.hubert.jasudowicz@gmail.com


Signed-off-by: Hubert Jasudowicz <hubert.jasudowicz@gmail.com>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Micah Morton <mortonm@chromium.org>
Cc: Michael Kelley <mikelley@microsoft.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Thomas Cedeno <thomascedeno@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Apart from subsystem specific .proc_handler handler, all ctl_tables with
extra1 and extra2 members set should use proc_dointvec_minmax instead of
proc_dointvec, or the limit set in extra* never work and potentially echo
underflow values(negative numbers) is likely make system unstable.

Especially vfs_cache_pressure and zone_reclaim_mode, -1 is apparently not
a valid value, but we can set to them.  And then kernel may crash.

# echo -1 > /proc/sys/vm/vfs_cache_pressure

Link: https://lkml.kernel.org/r/20201223105535.2875-1-linf@wangsu.com


Signed-off-by: Lin Feng <linf@wangsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "Add error_report_end tracepoint to KFENCE and KASAN", v3.

This patchset adds a tracepoint, error_repor_end, that is to be used by
KFENCE, KASAN, and potentially other bug detection tools, when they print
an error report.  One of the possible use cases is userspace collection of
kernel error reports: interested parties can subscribe to the tracing
event via tracefs, and get notified when an error report occurs.

This patch (of 3):

Introduce error_report_end tracepoint.  It can be used in debugging tools
like KASAN, KFENCE, etc.  to provide extensions to the error reporting
mechanisms (e.g.  allow tests hook into error reporting, ease error report
collection from production kernels).  Another benefit would be making use
of ftrace for debugging or benchmarking the tools themselves.

Should we need it, the tracepoint name leaves us with the possibility to
introduce a complementary error_report_start tracepoint in the future.

Link: https://lkml.kernel.org/r/20210121131915.1331302-1-glider@google.com
Link: https://lkml.kernel.org/r/20210121131915.1331302-2-glider@google.com


Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Marco Elver <elver@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The size of the buffer being bounced is not checked if it happens
to be larger than the size of the mapped buffer. Because the size
can be controlled by a device, as it's the case with virtio devices,
this can lead to memory corruption.

This patch saves the remaining buffer memory for each slab and uses
that information for validation in the sync/unmap paths before
swiotlb_bounce is called.

Validating this argument is important under the threat models of
AMD SEV-SNP and Intel TDX, where the HV is considered untrusted.

Signed-off-by: Martin Radev <martin.b.radev@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Respect the min_align_mask in struct device_dma_parameters in swiotlb.

There are two parts to it:
 1) for the lower bits of the alignment inside the io tlb slot, just
    extent the size of the allocation and leave the start of the slot
     empty
 2) for the high bits ensure we find a slot that matches the high bits
    of the alignment to avoid wasting too much memory

Based on an earlier patch from Jianxiong Gao <jxgao@google.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jianxiong Gao <jxgao@google.com>
Tested-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Add missing ":" after rwbs function parameter documentation that fixes
following warning :-

./kernel/trace/blktrace.c:1877: warning: Function parameter or member 'rwbs' not described in 'blk_fill_rwbs'

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 1f83bb4b ("blktrace: add blk_fill_rwbs documentation comment")
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Now it is possible for global function to have a pointer argument that
points to something different than struct. Drop the irrelevant log
message and keep the logic same.

Fixes: e5069b9c ("bpf: Support pointers in global func args")
Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210223090416.333943-1-me@ubique.spb.ru

This change adds build support for using objtool to generate
__mcount_loc sections.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

These debugfs dentries do not need to be saved for anything as the whole
directory and everything in it is properly cleaned up when the parent
directory is removed.  So remove them from struct blk_trace and don't
save them when created as it's not necessary.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

swiotlb_tbl_map_single currently nevers sets a tlb_addr that is not
aligned to the tlb bucket size.  But we're going to add such a case
soon, for which this adjustment would be bogus.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jianxiong Gao <jxgao@google.com>
Tested-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Split out a bunch of a self-contained helpers to make the function easier
to follow.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jianxiong Gao <jxgao@google.com>
Tested-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Similar to bpf_prog_realloc(), bpf_prog_clone_create() also copies
the percpu pointers, but the clone still shares them with the original
prog, so we have to clear these two percpu pointers in
bpf_prog_clone_free(). Otherwise we would get a double free:

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: 0000 [#1] SMP PTI
 CPU: 13 PID: 8140 Comm: kworker/13:247 Kdump: loaded Tainted: G                W    OE
  5.11.0-rc4.bm.1-amd64+ #1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
 test_bpf: #1 TXA
 Workqueue: events bpf_prog_free_deferred
 RIP: 0010:percpu_ref_get_many.constprop.97+0x42/0xf0
 Code: [...]
 RSP: 0018:ffffa6bce1f9bda0 EFLAGS: 00010002
 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000021dfc7b
 RDX: ffffffffae2eeb90 RSI: 867f92637e338da5 RDI: 0000000000000046
 RBP: ffffa6bce1f9bda8 R08: 0000000000000000 R09: 0000000000000001
 R10: 0000000000000046 R11: 0000000000000000 R12: 0000000000000280
 R13: 0000000000000000 R14: 0000000000000000 R15: ffff9b5f3ffdedc0
 FS:    0000000000000000(0000) GS:ffff9b5f2fb40000(0000) knlGS:0000000000000000
 CS:    0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 000000027c36c002 CR4: 00000000003706e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
    refill_obj_stock+0x5e/0xd0
    free_percpu+0xee/0x550
    __bpf_prog_free+0x4d/0x60
    process_one_work+0x26a/0x590
    worker_thread+0x3c/0x390
    ? process_one_work+0x590/0x590
    kthread+0x130/0x150
    ? kthread_park+0x80/0x80
    ret_from_fork+0x1f/0x30

This bug is 100% reproducible with test_kmod.sh.

Fixes: 700d4796 ("bpf: Optimize program stats")
Fixes: ca06f55b ("bpf: Add per-program recursion prevention mechanism")
Reported-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210218001647.71631-1-xiyou.wangcong@gmail.com

The WARN_ON() argument is a condition, not an error message.  So this
code will print a stack trace but will not print the warning message.
Fix that and also change it to only WARN_ONCE().

Fixes: 4ddb7416 ("bpf: Extract nullable reg type conversion into a helper function")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/YCzJlV3hnF%2Ft1Pk4@mwanda

blk_fill_rwbs() is an expoted function, add kernel style documentation
comment.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The last parameter for the function blk_fill_rwbs() was added in
5782138e47 ("tracing/events: convert block trace points to
TRACE_EVENT()") in order to signal read request and use of that parameter
was replaced with using switch case REQ_OP_READ with
1b9a9ab7 ("blktrace: use op accessors"), but the parameter was never
removed.

Remove the unused parameter and adjust the respective call sites.

Fixes: 1b9a9ab7 ("blktrace: use op accessors")
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The kernel test robot reports the following compiler warning:

  | arch/arm64/kernel/machine_kexec.c:62:5: warning: no previous prototype for
  | function 'machine_kexec_post_load' [-Wmissing-prototypes]
  |    int machine_kexec_post_load(struct kimage *kimage)

Fix it by moving the declaration of machine_kexec_post_load() from
kexec_internal.h to the public header instead.

Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/linux-arm-kernel/202102030727.gqTokACH-lkp@intel.com


Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Link: https://lore.kernel.org/r/20210219195142.13571-1-pasha.tatashin@soleen.com


Fixes: 4c3c3123 ("arm64: kexec: move relocation function setup")
Signed-off-by: Will Deacon <will@kernel.org>

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Remove a layer of pointless indentation, replace a hard to follow
ternary expression with a plain if/else.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jianxiong Gao <jxgao@google.com>
Tested-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Factor out a helper to find the number of slots for a given size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jianxiong Gao <jxgao@google.com>
Tested-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Replace the very genericly named OFFSET macro with a little inline
helper that hardcodes the alignment to the only value ever passed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jianxiong Gao <jxgao@google.com>
Tested-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Add a new IO_TLB_SIZE define instead open coding it using
IO_TLB_SHIFT all over.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jianxiong Gao <jxgao@google.com>
Tested-by: Jianxiong Gao <jxgao@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Commit 36dadef2 ("kprobes: Init kprobes in early_initcall")
moved the kprobe setup in early_initcall(), which includes kprobe
jump optimization.
The kprobes jump optimizer involves synchronize_rcu_tasks() which
depends on the ksoftirqd and rcu_spawn_tasks_*(). However, since
those are setup in core_initcall(), kprobes jump optimizer can not
run at the early_initcall().

To avoid this issue, make the kprobe optimization disabled in the
early_initcall() and enables it in subsys_initcall().

Note that non-optimized kprobes is still available after
early_initcall(). Only jump optimization is delayed.

Link: https://lkml.kernel.org/r/161365856280.719838.12423085451287256713.stgit@devnote2



Fixes: 36dadef2 ("kprobes: Init kprobes in early_initcall")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: RCU <rcu@vger.kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Theodore Y . Ts'o" <tytso@mit.edu>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: stable@vger.kernel.org
Reported-by: Paul E. McKenney <paulmck@kernel.org>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reported-by: Uladzislau Rezki <urezki@gmail.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Currently, update_lock is also used in sugov_update_single_freq().

The comment is not helpful anymore.

Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Since sg_policy is a member of struct sugov_cpu.

Also remove the local variable in sugov_update_single_common() to
make the code more clean.

Signed-off-by: Yue Hu <huyue2@yulong.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Minor subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>