<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux/kernel/events/core.c, branch v6.0</title>
<subtitle>Mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
</subtitle>
<id>https://git.shady.money/linux/atom?h=v6.0</id>
<link rel='self' href='https://git.shady.money/linux/atom?h=v6.0'/>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/'/>
<updated>2022-09-06T09:33:00Z</updated>
<entry>
<title>perf/core: Fix reentry problem in perf_output_read_group()</title>
<updated>2022-09-06T09:33:00Z</updated>
<author>
<name>Yang Jihong</name>
<email>yangjihong1@huawei.com</email>
</author>
<published>2022-09-02T08:29:18Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=6b959ba22d34ca793ffdb15b5715457c78e38b1a'/>
<id>urn:sha1:6b959ba22d34ca793ffdb15b5715457c78e38b1a</id>
<content type='text'>
perf_output_read_group may respond to IPI request of other cores and invoke
__perf_install_in_context function. As a result, hwc configuration is modified.
causing inconsistency and unexpected consequences.

Interrupts are not disabled when perf_output_read_group reads PMU counter.
In this case, IPI request may be received from other cores.
As a result, PMU configuration is modified and an error occurs when
reading PMU counter:

		     CPU0                                         CPU1
						      __se_sys_perf_event_open
							perf_install_in_context
  perf_output_read_group                                  smp_call_function_single
    for_each_sibling_event(sub, leader) {                   generic_exec_single
      if ((sub != event) &amp;&amp;                                   remote_function
	  (sub-&gt;state == PERF_EVENT_STATE_ACTIVE))                    |
  &lt;enter IPI handler: __perf_install_in_context&gt;   &lt;----RAISE IPI-----+
  __perf_install_in_context
    ctx_resched
      event_sched_out
	armpmu_del
	  ...
	  hwc-&gt;idx = -1; // event-&gt;hwc.idx is set to -1
  ...
  &lt;exit IPI&gt;
	      sub-&gt;pmu-&gt;read(sub);
		armpmu_read
		  armv8pmu_read_counter
		    armv8pmu_read_hw_counter
		      int idx = event-&gt;hw.idx; // idx = -1
		      u64 val = armv8pmu_read_evcntr(idx);
			u32 counter = ARMV8_IDX_TO_COUNTER(idx); // invalid counter = 30
			read_pmevcntrn(counter) // undefined instruction

Signed-off-by: Yang Jihong &lt;yangjihong1@huawei.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20220902082918.179248-1-yangjihong1@huawei.com
</content>
</entry>
<entry>
<title>Merge tag 'perf-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-08-07T00:28:12Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-07T00:28:12Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=592d8362bc2526bbb08cf7d258661691e957b5ea'/>
<id>urn:sha1:592d8362bc2526bbb08cf7d258661691e957b5ea</id>
<content type='text'>
Pull perf fixes from Ingo Molnar:
 "Misc fixes to kprobes and the faddr2line script, plus a cleanup"

* tag 'perf-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Fix ';;' typo
  scripts/faddr2line: Add CONFIG_DEBUG_INFO check
  scripts/faddr2line: Fix vmlinux detection on arm64
  x86/kprobes: Update kcb status flag after singlestepping
  kprobes: Forbid probing on trampoline and BPF code areas
</content>
</entry>
<entry>
<title>perf/core: Fix ';;' typo</title>
<updated>2022-08-04T09:01:30Z</updated>
<author>
<name>Slark Xiao</name>
<email>slark_xiao@163.com</email>
</author>
<published>2022-07-20T09:12:20Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=99643bab36b642be10bf09cd3285c37c9e5b597f'/>
<id>urn:sha1:99643bab36b642be10bf09cd3285c37c9e5b597f</id>
<content type='text'>
Remove double ';;'.

Signed-off-by: Slark Xiao &lt;slark_xiao@163.com&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20220720091220.14200-1-slark_xiao@163.com
</content>
</entry>
<entry>
<title>Merge tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next</title>
<updated>2022-08-03T23:29:08Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-03T23:29:08Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=f86d1fbbe7858884d6754534a0afbb74fc30bc26'/>
<id>urn:sha1:f86d1fbbe7858884d6754534a0afbb74fc30bc26</id>
<content type='text'>
Pull networking changes from Paolo Abeni:
 "Core:

   - Refactor the forward memory allocation to better cope with memory
     pressure with many open sockets, moving from a per socket cache to
     a per-CPU one

   - Replace rwlocks with RCU for better fairness in ping, raw sockets
     and IP multicast router.

   - Network-side support for IO uring zero-copy send.

   - A few skb drop reason improvements, including codegen the source
     file with string mapping instead of using macro magic.

   - Rename reference tracking helpers to a more consistent netdev_*
     schema.

   - Adapt u64_stats_t type to address load/store tearing issues.

   - Refine debug helper usage to reduce the log noise caused by bots.

  BPF:

   - Improve socket map performance, avoiding skb cloning on read
     operation.

   - Add support for 64 bits enum, to match types exposed by kernel.

   - Introduce support for sleepable uprobes program.

   - Introduce support for enum textual representation in libbpf.

   - New helpers to implement synproxy with eBPF/XDP.

   - Improve loop performances, inlining indirect calls when possible.

   - Removed all the deprecated libbpf APIs.

   - Implement new eBPF-based LSM flavor.

   - Add type match support, which allow accurate queries to the eBPF
     used types.

   - A few TCP congetsion control framework usability improvements.

   - Add new infrastructure to manipulate CT entries via eBPF programs.

   - Allow for livepatch (KLP) and BPF trampolines to attach to the same
     kernel function.

  Protocols:

   - Introduce per network namespace lookup tables for unix sockets,
     increasing scalability and reducing contention.

   - Preparation work for Wi-Fi 7 Multi-Link Operation (MLO) support.

   - Add support to forciby close TIME_WAIT TCP sockets via user-space
     tools.

   - Significant performance improvement for the TLS 1.3 receive path,
     both for zero-copy and not-zero-copy.

   - Support for changing the initial MTPCP subflow priority/backup
     status

   - Introduce virtually contingus buffers for sockets over RDMA, to
     cope better with memory pressure.

   - Extend CAN ethtool support with timestamping capabilities

   - Refactor CAN build infrastructure to allow building only the needed
     features.

  Driver API:

   - Remove devlink mutex to allow parallel commands on multiple links.

   - Add support for pause stats in distributed switch.

   - Implement devlink helpers to query and flash line cards.

   - New helper for phy mode to register conversion.

  New hardware / drivers:

   - Ethernet DSA driver for the rockchip mt7531 on BPI-R2 Pro.

   - Ethernet DSA driver for the Renesas RZ/N1 A5PSW switch.

   - Ethernet DSA driver for the Microchip LAN937x switch.

   - Ethernet PHY driver for the Aquantia AQR113C EPHY.

   - CAN driver for the OBD-II ELM327 interface.

   - CAN driver for RZ/N1 SJA1000 CAN controller.

   - Bluetooth: Infineon CYW55572 Wi-Fi plus Bluetooth combo device.

  Drivers:

   - Intel Ethernet NICs:
      - i40e: add support for vlan pruning
      - i40e: add support for XDP framented packets
      - ice: improved vlan offload support
      - ice: add support for PPPoE offload

   - Mellanox Ethernet (mlx5)
      - refactor packet steering offload for performance and scalability
      - extend support for TC offload
      - refactor devlink code to clean-up the locking schema
      - support stacked vlans for bridge offloads
      - use TLS objects pool to improve connection rate

   - Netronome Ethernet NICs (nfp):
      - extend support for IPv6 fields mangling offload
      - add support for vepa mode in HW bridge
      - better support for virtio data path acceleration (VDPA)
      - enable TSO by default

   - Microsoft vNIC driver (mana)
      - add support for XDP redirect

   - Others Ethernet drivers:
      - bonding: add per-port priority support
      - microchip lan743x: extend phy support
      - Fungible funeth: support UDP segmentation offload and XDP xmit
      - Solarflare EF100: add support for virtual function representors
      - MediaTek SoC: add XDP support

   - Mellanox Ethernet/IB switch (mlxsw):
      - dropped support for unreleased H/W (XM router).
      - improved stats accuracy
      - unified bridge model coversion improving scalability (parts 1-6)
      - support for PTP in Spectrum-2 asics

   - Broadcom PHYs
      - add PTP support for BCM54210E
      - add support for the BCM53128 internal PHY

   - Marvell Ethernet switches (prestera):
      - implement support for multicast forwarding offload

   - Embedded Ethernet switches:
      - refactor OcteonTx MAC filter for better scalability
      - improve TC H/W offload for the Felix driver
      - refactor the Microchip ksz8 and ksz9477 drivers to share the
        probe code (parts 1, 2), add support for phylink mac
        configuration

   - Other WiFi:
      - Microchip wilc1000: diable WEP support and enable WPA3
      - Atheros ath10k: encapsulation offload support

  Old code removal:

   - Neterion vxge ethernet driver: this is untouched since more than 10 years"

* tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1890 commits)
  doc: sfp-phylink: Fix a broken reference
  wireguard: selftests: support UML
  wireguard: allowedips: don't corrupt stack when detecting overflow
  wireguard: selftests: update config fragments
  wireguard: ratelimiter: use hrtimer in selftest
  net/mlx5e: xsk: Discard unaligned XSK frames on striding RQ
  net: usb: ax88179_178a: Bind only to vendor-specific interface
  selftests: net: fix IOAM test skip return code
  net: usb: make USB_RTL8153_ECM non user configurable
  net: marvell: prestera: remove reduntant code
  octeontx2-pf: Reduce minimum mtu size to 60
  net: devlink: Fix missing mutex_unlock() call
  net/tls: Remove redundant workqueue flush before destroy
  net: txgbe: Fix an error handling path in txgbe_probe()
  net: dsa: Fix spelling mistakes and cleanup code
  Documentation: devlink: add add devlink-selftests to the table of contents
  dccp: put dccp_qpolicy_full() and dccp_qpolicy_push() in the same lock
  net: ionic: fix error check for vlan flags in ionic_set_nic_features()
  net: ice: fix error NETIF_F_HW_VLAN_CTAG_FILTER check in ice_vsi_sync_fltr()
  nfp: flower: add support for tunnel offload without key ID
  ...
</content>
</entry>
<entry>
<title>Merge tag 'perf-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2022-08-01T19:24:30Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2022-08-01T19:24:30Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=63e6053add5a6cec4dbfa3dec12e0d4439daac4a'/>
<id>urn:sha1:63e6053add5a6cec4dbfa3dec12e0d4439daac4a</id>
<content type='text'>
Pull perf events updates from Ingo Molnar:

 - Fix Intel Alder Lake PEBS memory access latency &amp; data source
   profiling info bugs.

 - Use Intel large-PEBS hardware feature in more circumstances, to
   reduce PMI overhead &amp; reduce sampling data.

 - Extend the lost-sample profiling output with the PERF_FORMAT_LOST ABI
   variant, which tells tooling the exact number of samples lost.

 - Add new IBS register bits definitions.

 - AMD uncore events: Add PerfMonV2 DF (Data Fabric) enhancements.

* tag 'perf-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/ibs: Add new IBS register bits into header
  perf/x86/intel: Fix PEBS data source encoding for ADL
  perf/x86/intel: Fix PEBS memory access info encoding for ADL
  perf/core: Add a new read format to get a number of lost samples
  perf/x86/amd/uncore: Add PerfMonV2 RDPMC assignments
  perf/x86/amd/uncore: Add PerfMonV2 DF event format
  perf/x86/amd/uncore: Detect available DF counters
  perf/x86/amd/uncore: Use attr_update for format attributes
  perf/x86/amd/uncore: Use dynamic events array
  x86/events/intel/ds: Enable large PEBS for PERF_SAMPLE_WEIGHT_TYPE
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2022-07-21T20:03:39Z</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-07-21T20:03:39Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=6e0e846ee2ab01bc44254e6a0a6a6a0db1cba16d'/>
<id>urn:sha1:6e0e846ee2ab01bc44254e6a0a6a6a0db1cba16d</id>
<content type='text'>
No conflicts.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()</title>
<updated>2022-07-13T09:29:12Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2022-07-05T13:07:26Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=68e3c69803dada336893640110cb87221bb01dcf'/>
<id>urn:sha1:68e3c69803dada336893640110cb87221bb01dcf</id>
<content type='text'>
Yang Jihing reported a race between perf_event_set_output() and
perf_mmap_close():

	CPU1					CPU2

	perf_mmap_close(e2)
	  if (atomic_dec_and_test(&amp;e2-&gt;rb-&gt;mmap_count)) // 1 - &gt; 0
	    detach_rest = true

						ioctl(e1, IOC_SET_OUTPUT, e2)
						  perf_event_set_output(e1, e2)

	  ...
	  list_for_each_entry_rcu(e, &amp;e2-&gt;rb-&gt;event_list, rb_entry)
	    ring_buffer_attach(e, NULL);
	    // e1 isn't yet added and
	    // therefore not detached

						    ring_buffer_attach(e1, e2-&gt;rb)
						      list_add_rcu(&amp;e1-&gt;rb_entry,
								   &amp;e2-&gt;rb-&gt;event_list)

After this; e1 is attached to an unmapped rb and a subsequent
perf_mmap() will loop forever more:

	again:
		mutex_lock(&amp;e-&gt;mmap_mutex);
		if (event-&gt;rb) {
			...
			if (!atomic_inc_not_zero(&amp;e-&gt;rb-&gt;mmap_count)) {
				...
				mutex_unlock(&amp;e-&gt;mmap_mutex);
				goto again;
			}
		}

The loop in perf_mmap_close() holds e2-&gt;mmap_mutex, while the attach
in perf_event_set_output() holds e1-&gt;mmap_mutex. As such there is no
serialization to avoid this race.

Change perf_event_set_output() to take both e1-&gt;mmap_mutex and
e2-&gt;mmap_mutex to alleviate that problem. Additionally, have the loop
in perf_mmap() detach the rb directly, this avoids having to wait for
the concurrent perf_mmap_close() to get around to doing it to make
progress.

Fixes: 9bb5d40cd93c ("perf: Fix mmap() accounting hole")
Reported-by: Yang Jihong &lt;yangjihong1@huawei.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Tested-by: Yang Jihong &lt;yangjihong1@huawei.com&gt;
Link: https://lkml.kernel.org/r/YsQ3jm2GR38SW7uD@worktop.programming.kicks-ass.net
</content>
</entry>
<entry>
<title>perf/core: Add a new read format to get a number of lost samples</title>
<updated>2022-06-28T07:08:31Z</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2022-06-16T18:06:23Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=119a784c81270eb88e573174ed2209225d646656'/>
<id>urn:sha1:119a784c81270eb88e573174ed2209225d646656</id>
<content type='text'>
Sometimes we want to know an accurate number of samples even if it's
lost.  Currenlty PERF_RECORD_LOST is generated for a ring-buffer which
might be shared with other events.  So it's hard to know per-event
lost count.

Add event-&gt;lost_samples field and PERF_FORMAT_LOST to retrieve it from
userspace.

Original-patch-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lkml.kernel.org/r/20220616180623.1358843-1-namhyung@kernel.org
</content>
</entry>
<entry>
<title>Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2022-06-18T02:35:19Z</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-06-18T02:35:17Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=9fb424c4c29df0d7f39b686d4037cbc7e06ed7b5'/>
<id>urn:sha1:9fb424c4c29df0d7f39b686d4037cbc7e06ed7b5</id>
<content type='text'>
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-06-17

We've added 72 non-merge commits during the last 15 day(s) which contain
a total of 92 files changed, 4582 insertions(+), 834 deletions(-).

The main changes are:

1) Add 64 bit enum value support to BTF, from Yonghong Song.

2) Implement support for sleepable BPF uprobe programs, from Delyan Kratunov.

3) Add new BPF helpers to issue and check TCP SYN cookies without binding to a
   socket especially useful in synproxy scenarios, from Maxim Mikityanskiy.

4) Fix libbpf's internal USDT address translation logic for shared libraries as
   well as uprobe's symbol file offset calculation, from Andrii Nakryiko.

5) Extend libbpf to provide an API for textual representation of the various
   map/prog/attach/link types and use it in bpftool, from Daniel Müller.

6) Provide BTF line info for RV64 and RV32 JITs, and fix a put_user bug in the
   core seen in 32 bit when storing BPF function addresses, from Pu Lehui.

7) Fix libbpf's BTF pointer size guessing by adding a list of various aliases
   for 'long' types, from Douglas Raillard.

8) Fix bpftool to readd setting rlimit since probing for memcg-based accounting
   has been unreliable and caused a regression on COS, from Quentin Monnet.

9) Fix UAF in BPF cgroup's effective program computation triggered upon BPF link
   detachment, from Tadeusz Struk.

10) Fix bpftool build bootstrapping during cross compilation which was pointing
    to the wrong AR process, from Shahab Vahedi.

11) Fix logic bug in libbpf's is_pow_of_2 implementation, from Yuze Chi.

12) BPF hash map optimization to avoid grabbing spinlocks of all CPUs when there
    is no free element. Also add a benchmark as reproducer, from Feng Zhou.

13) Fix bpftool's codegen to bail out when there's no BTF, from Michael Mullin.

14) Various minor cleanup and improvements all over the place.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (72 commits)
  bpf: Fix bpf_skc_lookup comment wrt. return type
  bpf: Fix non-static bpf_func_proto struct definitions
  selftests/bpf: Don't force lld on non-x86 architectures
  selftests/bpf: Add selftests for raw syncookie helpers in TC mode
  bpf: Allow the new syncookie helpers to work with SKBs
  selftests/bpf: Add selftests for raw syncookie helpers
  bpf: Add helpers to issue and check SYN cookies in XDP
  bpf: Allow helpers to accept pointers with a fixed size
  bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie
  selftests/bpf: add tests for sleepable (uk)probes
  libbpf: add support for sleepable uprobe programs
  bpf: allow sleepable uprobe programs to attach
  bpf: implement sleepable uprobes by chaining gps
  bpf: move bpf_prog to bpf.h
  libbpf: Fix internal USDT address translation logic for shared libraries
  samples/bpf: Check detach prog exist or not in xdp_fwd
  selftests/bpf: Avoid skipping certain subtests
  selftests/bpf: Fix test_varlen verification failure with latest llvm
  bpftool: Do not check return value from libbpf_set_strict_mode()
  Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK"
  ...
====================

Link: https://lore.kernel.org/r/20220617220836.7373-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>bpf: allow sleepable uprobe programs to attach</title>
<updated>2022-06-17T02:27:29Z</updated>
<author>
<name>Delyan Kratunov</name>
<email>delyank@fb.com</email>
</author>
<published>2022-06-14T23:10:43Z</published>
<link rel='alternate' type='text/html' href='https://git.shady.money/linux/commit/?id=64ad7556c75ea102eec2f5bcd60fe2d66ce70308'/>
<id>urn:sha1:64ad7556c75ea102eec2f5bcd60fe2d66ce70308</id>
<content type='text'>
uprobe and kprobe programs have the same program type, KPROBE, which is
currently not allowed to load sleepable programs.

To avoid adding a new UPROBE type, instead allow sleepable KPROBE
programs to load and defer the is-it-actually-a-uprobe-program check
to attachment time, where there's already validation of the
corresponding perf_event.

A corollary of this patch is that you can now load a sleepable kprobe
program but cannot attach it.

Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Signed-off-by: Delyan Kratunov &lt;delyank@fb.com&gt;
Link: https://lore.kernel.org/r/fcd44a7cd204f372f6bb03ef794e829adeaef299.1655248076.git.delyank@fb.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
</entry>
</feed>
