<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel, branch v5.12-rc7</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'locking-urgent-2021-04-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2021-04-11T18:47:03+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-04-11T18:47:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=add6b92660b3dca65465d3bd7710b4b1338f34f0'/>
<id>add6b92660b3dca65465d3bd7710b4b1338f34f0</id>
<content type='text'>
Pull locking fixlets from Ingo Molnar:
 "Two minor fixes: one for a Clang warning, the other improves an
  ambiguous/confusing kernel log message"

* tag 'locking-urgent-2021-04-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Address clang -Wformat warning printing for %hd
  lockdep: Add a missing initialization hint to the "INFO: Trying to register non-static key" message
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull locking fixlets from Ingo Molnar:
 "Two minor fixes: one for a Clang warning, the other improves an
  ambiguous/confusing kernel log message"

* tag 'locking-urgent-2021-04-11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Address clang -Wformat warning printing for %hd
  lockdep: Add a missing initialization hint to the "INFO: Trying to register non-static key" message
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2021-04-10T00:06:32+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-04-10T00:06:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=adb2c4174fb2294bfed3b161174e8d79743f0167'/>
<id>adb2c4174fb2294bfed3b161174e8d79743f0167</id>
<content type='text'>
Merge misc fixes from Andrew Morton:
 "14 patches.

  Subsystems affected by this patch series: mm (kasan, gup, pagecache,
  and kfence), MAINTAINERS, mailmap, nds32, gcov, ocfs2, ia64, and lib"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;:
  lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS
  kfence, x86: fix preemptible warning on KPTI-enabled systems
  lib/test_kasan_module.c: suppress unused var warning
  kasan: fix conflict with page poisoning
  fs: direct-io: fix missing sdio-&gt;boundary
  ia64: fix user_stack_pointer() for ptrace()
  ocfs2: fix deadlock between setattr and dio_end_io_write
  gcov: re-fix clang-11+ support
  nds32: flush_dcache_page: use page_mapping_file to avoid races with swapoff
  mm/gup: check page posion status for coredump.
  .mailmap: fix old email addresses
  mailmap: update email address for Jordan Crouse
  treewide: change my e-mail address, fix my name
  MAINTAINERS: update CZ.NIC's Turris information
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge misc fixes from Andrew Morton:
 "14 patches.

  Subsystems affected by this patch series: mm (kasan, gup, pagecache,
  and kfence), MAINTAINERS, mailmap, nds32, gcov, ocfs2, ia64, and lib"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;:
  lib: fix kconfig dependency on ARCH_WANT_FRAME_POINTERS
  kfence, x86: fix preemptible warning on KPTI-enabled systems
  lib/test_kasan_module.c: suppress unused var warning
  kasan: fix conflict with page poisoning
  fs: direct-io: fix missing sdio-&gt;boundary
  ia64: fix user_stack_pointer() for ptrace()
  ocfs2: fix deadlock between setattr and dio_end_io_write
  gcov: re-fix clang-11+ support
  nds32: flush_dcache_page: use page_mapping_file to avoid races with swapoff
  mm/gup: check page posion status for coredump.
  .mailmap: fix old email addresses
  mailmap: update email address for Jordan Crouse
  treewide: change my e-mail address, fix my name
  MAINTAINERS: update CZ.NIC's Turris information
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'net-5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2021-04-09T22:26:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-04-09T22:26:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4e04e7513b0fa2fe8966a1c83fb473f1667e2810'/>
<id>4e04e7513b0fa2fe8966a1c83fb473f1667e2810</id>
<content type='text'>
Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.12-rc7, including fixes from can, ipsec,
  mac80211, wireless, and bpf trees.

  No scary regressions here or in the works, but small fixes for 5.12
  changes keep coming.

  Current release - regressions:

   - virtio: do not pull payload in skb-&gt;head

   - virtio: ensure mac header is set in virtio_net_hdr_to_skb()

   - Revert "net: correct sk_acceptq_is_full()"

   - mptcp: revert "mptcp: provide subflow aware release function"

   - ethernet: lan743x: fix ethernet frame cutoff issue

   - dsa: fix type was not set for devlink port

   - ethtool: remove link_mode param and derive link params from driver

   - sched: htb: fix null pointer dereference on a null new_q

   - wireless: iwlwifi: Fix softirq/hardirq disabling in
     iwl_pcie_enqueue_hcmd()

   - wireless: iwlwifi: fw: fix notification wait locking

   - wireless: brcmfmac: p2p: Fix deadlock introduced by avoiding the
     rtnl dependency

  Current release - new code bugs:

   - napi: fix hangup on napi_disable for threaded napi

   - bpf: take module reference for trampoline in module

   - wireless: mt76: mt7921: fix airtime reporting and related tx hangs

   - wireless: iwlwifi: mvm: rfi: don't lock mvm-&gt;mutex when sending
     config command

  Previous releases - regressions:

   - rfkill: revert back to old userspace API by default

   - nfc: fix infinite loop, refcount &amp; memory leaks in LLCP sockets

   - let skb_orphan_partial wake-up waiters

   - xfrm/compat: Cleanup WARN()s that can be user-triggered

   - vxlan, geneve: do not modify the shared tunnel info when PMTU
     triggers an ICMP reply

   - can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

   - can: uapi: mark union inside struct can_frame packed

   - sched: cls: fix action overwrite reference counting

   - sched: cls: fix err handler in tcf_action_init()

   - ethernet: mlxsw: fix ECN marking in tunnel decapsulation

   - ethernet: nfp: Fix a use after free in nfp_bpf_ctrl_msg_rx

   - ethernet: i40e: fix receiving of single packets in xsk zero-copy
     mode

   - ethernet: cxgb4: avoid collecting SGE_QBASE regs during traffic

  Previous releases - always broken:

   - bpf: Refuse non-O_RDWR flags in BPF_OBJ_GET

   - bpf: Refcount task stack in bpf_get_task_stack

   - bpf, x86: Validate computation of branch displacements

   - ieee802154: fix many similar syzbot-found bugs
       - fix NULL dereferences in netlink attribute handling
       - reject unsupported operations on monitor interfaces
       - fix error handling in llsec_key_alloc()

   - xfrm: make ipv4 pmtu check honor ip header df

   - xfrm: make hash generation lock per network namespace

   - xfrm: esp: delete NETIF_F_SCTP_CRC bit from features for esp
     offload

   - ethtool: fix incorrect datatype in set_eee ops

   - xdp: fix xdp_return_frame() kernel BUG throw for page_pool memory
     model

   - openvswitch: fix send of uninitialized stack memory in ct limit
     reply

  Misc:

   - udp: add get handling for UDP_GRO sockopt"

* tag 'net-5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (182 commits)
  net: fix hangup on napi_disable for threaded napi
  net: hns3: Trivial spell fix in hns3 driver
  lan743x: fix ethernet frame cutoff issue
  net: ipv6: check for validity before dereferencing cfg-&gt;fc_nlinfo.nlh
  net: dsa: lantiq_gswip: Configure all remaining GSWIP_MII_CFG bits
  net: dsa: lantiq_gswip: Don't use PHY auto polling
  net: sched: sch_teql: fix null-pointer dereference
  ipv6: report errors for iftoken via netlink extack
  net: sched: fix err handler in tcf_action_init()
  net: sched: fix action overwrite reference counting
  Revert "net: sched: bump refcount for new action in ACT replace mode"
  ice: fix memory leak of aRFS after resuming from suspend
  i40e: Fix sparse warning: missing error code 'err'
  i40e: Fix sparse error: 'vsi-&gt;netdev' could be null
  i40e: Fix sparse error: uninitialized symbol 'ring'
  i40e: Fix sparse errors in i40e_txrx.c
  i40e: Fix parameters in aq_get_phy_register()
  nl80211: fix beacon head validation
  bpf, x86: Validate computation of branch displacements for x86-32
  bpf, x86: Validate computation of branch displacements for x86-64
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.12-rc7, including fixes from can, ipsec,
  mac80211, wireless, and bpf trees.

  No scary regressions here or in the works, but small fixes for 5.12
  changes keep coming.

  Current release - regressions:

   - virtio: do not pull payload in skb-&gt;head

   - virtio: ensure mac header is set in virtio_net_hdr_to_skb()

   - Revert "net: correct sk_acceptq_is_full()"

   - mptcp: revert "mptcp: provide subflow aware release function"

   - ethernet: lan743x: fix ethernet frame cutoff issue

   - dsa: fix type was not set for devlink port

   - ethtool: remove link_mode param and derive link params from driver

   - sched: htb: fix null pointer dereference on a null new_q

   - wireless: iwlwifi: Fix softirq/hardirq disabling in
     iwl_pcie_enqueue_hcmd()

   - wireless: iwlwifi: fw: fix notification wait locking

   - wireless: brcmfmac: p2p: Fix deadlock introduced by avoiding the
     rtnl dependency

  Current release - new code bugs:

   - napi: fix hangup on napi_disable for threaded napi

   - bpf: take module reference for trampoline in module

   - wireless: mt76: mt7921: fix airtime reporting and related tx hangs

   - wireless: iwlwifi: mvm: rfi: don't lock mvm-&gt;mutex when sending
     config command

  Previous releases - regressions:

   - rfkill: revert back to old userspace API by default

   - nfc: fix infinite loop, refcount &amp; memory leaks in LLCP sockets

   - let skb_orphan_partial wake-up waiters

   - xfrm/compat: Cleanup WARN()s that can be user-triggered

   - vxlan, geneve: do not modify the shared tunnel info when PMTU
     triggers an ICMP reply

   - can: fix msg_namelen values depending on CAN_REQUIRED_SIZE

   - can: uapi: mark union inside struct can_frame packed

   - sched: cls: fix action overwrite reference counting

   - sched: cls: fix err handler in tcf_action_init()

   - ethernet: mlxsw: fix ECN marking in tunnel decapsulation

   - ethernet: nfp: Fix a use after free in nfp_bpf_ctrl_msg_rx

   - ethernet: i40e: fix receiving of single packets in xsk zero-copy
     mode

   - ethernet: cxgb4: avoid collecting SGE_QBASE regs during traffic

  Previous releases - always broken:

   - bpf: Refuse non-O_RDWR flags in BPF_OBJ_GET

   - bpf: Refcount task stack in bpf_get_task_stack

   - bpf, x86: Validate computation of branch displacements

   - ieee802154: fix many similar syzbot-found bugs
       - fix NULL dereferences in netlink attribute handling
       - reject unsupported operations on monitor interfaces
       - fix error handling in llsec_key_alloc()

   - xfrm: make ipv4 pmtu check honor ip header df

   - xfrm: make hash generation lock per network namespace

   - xfrm: esp: delete NETIF_F_SCTP_CRC bit from features for esp
     offload

   - ethtool: fix incorrect datatype in set_eee ops

   - xdp: fix xdp_return_frame() kernel BUG throw for page_pool memory
     model

   - openvswitch: fix send of uninitialized stack memory in ct limit
     reply

  Misc:

   - udp: add get handling for UDP_GRO sockopt"

* tag 'net-5.12-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (182 commits)
  net: fix hangup on napi_disable for threaded napi
  net: hns3: Trivial spell fix in hns3 driver
  lan743x: fix ethernet frame cutoff issue
  net: ipv6: check for validity before dereferencing cfg-&gt;fc_nlinfo.nlh
  net: dsa: lantiq_gswip: Configure all remaining GSWIP_MII_CFG bits
  net: dsa: lantiq_gswip: Don't use PHY auto polling
  net: sched: sch_teql: fix null-pointer dereference
  ipv6: report errors for iftoken via netlink extack
  net: sched: fix err handler in tcf_action_init()
  net: sched: fix action overwrite reference counting
  Revert "net: sched: bump refcount for new action in ACT replace mode"
  ice: fix memory leak of aRFS after resuming from suspend
  i40e: Fix sparse warning: missing error code 'err'
  i40e: Fix sparse error: 'vsi-&gt;netdev' could be null
  i40e: Fix sparse error: uninitialized symbol 'ring'
  i40e: Fix sparse errors in i40e_txrx.c
  i40e: Fix parameters in aq_get_phy_register()
  nl80211: fix beacon head validation
  bpf, x86: Validate computation of branch displacements for x86-32
  bpf, x86: Validate computation of branch displacements for x86-64
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>gcov: re-fix clang-11+ support</title>
<updated>2021-04-09T21:54:23+00:00</updated>
<author>
<name>Nick Desaulniers</name>
<email>ndesaulniers@google.com</email>
</author>
<published>2021-04-09T20:27:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9562fd132985ea9185388a112e50f2a51557827d'/>
<id>9562fd132985ea9185388a112e50f2a51557827d</id>
<content type='text'>
LLVM changed the expected function signature for llvm_gcda_emit_function()
in the clang-11 release.  Users of clang-11 or newer may have noticed
their kernels producing invalid coverage information:

  $ llvm-cov gcov -a -c -u -f -b &lt;input&gt;.gcda -- gcno=&lt;input&gt;.gcno
  1 &lt;func&gt;: checksum mismatch, \
    (&lt;lineno chksum A&gt;, &lt;cfg chksum B&gt;) != (&lt;lineno chksum A&gt;, &lt;cfg chksum C&gt;)
  2 Invalid .gcda File!
  ...

Fix up the function signatures so calling this function interprets its
parameters correctly and computes the correct cfg checksum.  In
particular, in clang-11, the additional checksum is no longer optional.

Link: https://reviews.llvm.org/rG25544ce2df0daa4304c07e64b9c8b0f7df60c11d
Link: https://lkml.kernel.org/r/20210408184631.1156669-1-ndesaulniers@google.com
Reported-by: Prasad Sodagudi &lt;psodagud@quicinc.com&gt;
Tested-by: Prasad Sodagudi &lt;psodagud@quicinc.com&gt;
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Reviewed-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[5.4+]

Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
LLVM changed the expected function signature for llvm_gcda_emit_function()
in the clang-11 release.  Users of clang-11 or newer may have noticed
their kernels producing invalid coverage information:

  $ llvm-cov gcov -a -c -u -f -b &lt;input&gt;.gcda -- gcno=&lt;input&gt;.gcno
  1 &lt;func&gt;: checksum mismatch, \
    (&lt;lineno chksum A&gt;, &lt;cfg chksum B&gt;) != (&lt;lineno chksum A&gt;, &lt;cfg chksum C&gt;)
  2 Invalid .gcda File!
  ...

Fix up the function signatures so calling this function interprets its
parameters correctly and computes the correct cfg checksum.  In
particular, in clang-11, the additional checksum is no longer optional.

Link: https://reviews.llvm.org/rG25544ce2df0daa4304c07e64b9c8b0f7df60c11d
Link: https://lkml.kernel.org/r/20210408184631.1156669-1-ndesaulniers@google.com
Reported-by: Prasad Sodagudi &lt;psodagud@quicinc.com&gt;
Tested-by: Prasad Sodagudi &lt;psodagud@quicinc.com&gt;
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Reviewed-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: &lt;stable@vger.kernel.org&gt;	[5.4+]

Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>workqueue/watchdog: Make unbound workqueues aware of touch_softlockup_watchdog()</title>
<updated>2021-04-04T17:26:49+00:00</updated>
<author>
<name>Wang Qing</name>
<email>wangqing@vivo.com</email>
</author>
<published>2021-03-24T11:40:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=89e28ce60cb65971c73359c66d076aa20a395cd5'/>
<id>89e28ce60cb65971c73359c66d076aa20a395cd5</id>
<content type='text'>
84;0;0c84;0;0c
There are two workqueue-specific watchdog timestamps:

    + @wq_watchdog_touched_cpu (per-CPU) updated by
      touch_softlockup_watchdog()

    + @wq_watchdog_touched (global) updated by
      touch_all_softlockup_watchdogs()

watchdog_timer_fn() checks only the global @wq_watchdog_touched for
unbound workqueues. As a result, unbound workqueues are not aware
of touch_softlockup_watchdog(). The watchdog might report a stall
even when the unbound workqueues are blocked by a known slow code.

Solution:
touch_softlockup_watchdog() must touch also the global @wq_watchdog_touched
timestamp.

The global timestamp can no longer be used for bound workqueues because
it is now updated from all CPUs. Instead, bound workqueues have to check
only @wq_watchdog_touched_cpu and these timestamps have to be updated for
all CPUs in touch_all_softlockup_watchdogs().

Beware:
The change might cause the opposite problem. An unbound workqueue
might get blocked on CPU A because of a real softlockup. The workqueue
watchdog would miss it when the timestamp got touched on CPU B.

It is acceptable because softlockups are detected by softlockup
watchdog. The workqueue watchdog is there to detect stalls where
a work never finishes, for example, because of dependencies of works
queued into the same workqueue.

V3:
- Modify the commit message clearly according to Petr's suggestion.

Signed-off-by: Wang Qing &lt;wangqing@vivo.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
84;0;0c84;0;0c
There are two workqueue-specific watchdog timestamps:

    + @wq_watchdog_touched_cpu (per-CPU) updated by
      touch_softlockup_watchdog()

    + @wq_watchdog_touched (global) updated by
      touch_all_softlockup_watchdogs()

watchdog_timer_fn() checks only the global @wq_watchdog_touched for
unbound workqueues. As a result, unbound workqueues are not aware
of touch_softlockup_watchdog(). The watchdog might report a stall
even when the unbound workqueues are blocked by a known slow code.

Solution:
touch_softlockup_watchdog() must touch also the global @wq_watchdog_touched
timestamp.

The global timestamp can no longer be used for bound workqueues because
it is now updated from all CPUs. Instead, bound workqueues have to check
only @wq_watchdog_touched_cpu and these timestamps have to be updated for
all CPUs in touch_all_softlockup_watchdogs().

Beware:
The change might cause the opposite problem. An unbound workqueue
might get blocked on CPU A because of a real softlockup. The workqueue
watchdog would miss it when the timestamp got touched on CPU B.

It is acceptable because softlockups are detected by softlockup
watchdog. The workqueue watchdog is there to detect stalls where
a work never finishes, for example, because of dependencies of works
queued into the same workqueue.

V3:
- Modify the commit message clearly according to Petr's suggestion.

Signed-off-by: Wang Qing &lt;wangqing@vivo.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>workqueue: Move the position of debug_work_activate() in __queue_work()</title>
<updated>2021-04-04T17:26:46+00:00</updated>
<author>
<name>Zqiang</name>
<email>qiang.zhang@windriver.com</email>
</author>
<published>2021-02-18T03:16:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0687c66b5f666b5ad433f4e94251590d9bc9d10e'/>
<id>0687c66b5f666b5ad433f4e94251590d9bc9d10e</id>
<content type='text'>
The debug_work_activate() is called on the premise that
the work can be inserted, because if wq be in WQ_DRAINING
status, insert work may be failed.

Fixes: e41e704bc4f4 ("workqueue: improve destroy_workqueue() debuggability")
Signed-off-by: Zqiang &lt;qiang.zhang@windriver.com&gt;
Reviewed-by: Lai Jiangshan &lt;jiangshanlai@gmail.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The debug_work_activate() is called on the premise that
the work can be inserted, because if wq be in WQ_DRAINING
status, insert work may be failed.

Fixes: e41e704bc4f4 ("workqueue: improve destroy_workqueue() debuggability")
Signed-off-by: Zqiang &lt;qiang.zhang@windriver.com&gt;
Reviewed-by: Lai Jiangshan &lt;jiangshanlai@gmail.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'trace-v5.12-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace</title>
<updated>2021-04-02T15:39:00+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-04-02T15:39:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=05de45383bd134fcb2b7d70d35ebb0bb50b5e4aa'/>
<id>05de45383bd134fcb2b7d70d35ebb0bb50b5e4aa</id>
<content type='text'>
Pull tracing fix from Steven Rostedt:
 "Fix stack trace entry size to stop showing garbage

  The macro that creates both the structure and the format displayed to
  user space for the stack trace event was changed a while ago to fix
  the parsing by user space tooling. But this change also modified the
  structure used to store the stack trace event. It changed the caller
  array field from [0] to [8].

  Even though the size in the ring buffer is dynamic and can be
  something other than 8 (user space knows how to handle this), the 8
  extra words was not accounted for when reserving the event on the ring
  buffer, and added 8 more entries, due to the calculation of
  "sizeof(*entry) + nr_entries * sizeof(long)", as the sizeof(*entry)
  now contains 8 entries.

  The size of the caller field needs to be subtracted from the size of
  the entry to create the correct allocation size"

* tag 'trace-v5.12-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix stack trace event size
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull tracing fix from Steven Rostedt:
 "Fix stack trace entry size to stop showing garbage

  The macro that creates both the structure and the format displayed to
  user space for the stack trace event was changed a while ago to fix
  the parsing by user space tooling. But this change also modified the
  structure used to store the stack trace event. It changed the caller
  array field from [0] to [8].

  Even though the size in the ring buffer is dynamic and can be
  something other than 8 (user space knows how to handle this), the 8
  extra words was not accounted for when reserving the event on the ring
  buffer, and added 8 more entries, due to the calculation of
  "sizeof(*entry) + nr_entries * sizeof(long)", as the sizeof(*entry)
  now contains 8 entries.

  The size of the caller field needs to be subtracted from the size of
  the entry to create the correct allocation size"

* tag 'trace-v5.12-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix stack trace event size
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: program: Refuse non-O_RDWR flags in BPF_OBJ_GET</title>
<updated>2021-04-01T21:33:48+00:00</updated>
<author>
<name>Lorenz Bauer</name>
<email>lmb@cloudflare.com</email>
</author>
<published>2021-03-26T16:05:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d37300ed182131f1757895a62e556332857417e5'/>
<id>d37300ed182131f1757895a62e556332857417e5</id>
<content type='text'>
As for bpf_link, refuse creating a non-O_RDWR fd. Since program fds
currently don't allow modifications this is a precaution, not a
straight up bug fix.

Signed-off-by: Lorenz Bauer &lt;lmb@cloudflare.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20210326160501.46234-2-lmb@cloudflare.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As for bpf_link, refuse creating a non-O_RDWR fd. Since program fds
currently don't allow modifications this is a precaution, not a
straight up bug fix.

Signed-off-by: Lorenz Bauer &lt;lmb@cloudflare.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20210326160501.46234-2-lmb@cloudflare.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: link: Refuse non-O_RDWR flags in BPF_OBJ_GET</title>
<updated>2021-04-01T21:33:14+00:00</updated>
<author>
<name>Lorenz Bauer</name>
<email>lmb@cloudflare.com</email>
</author>
<published>2021-03-26T16:05:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=25fc94b2f02d832fa8e29419699dcc20b0b05c6a'/>
<id>25fc94b2f02d832fa8e29419699dcc20b0b05c6a</id>
<content type='text'>
Invoking BPF_OBJ_GET on a pinned bpf_link checks the path access
permissions based on file_flags, but the returned fd ignores flags.
This means that any user can acquire a "read-write" fd for a pinned
link with mode 0664 by invoking BPF_OBJ_GET with BPF_F_RDONLY in
file_flags. The fd can be used to invoke BPF_LINK_DETACH, etc.

Fix this by refusing non-O_RDWR flags in BPF_OBJ_GET. This works
because OBJ_GET by default returns a read write mapping and libbpf
doesn't expose a way to override this behaviour for programs
and links.

Fixes: 70ed506c3bbc ("bpf: Introduce pinnable bpf_link abstraction")
Signed-off-by: Lorenz Bauer &lt;lmb@cloudflare.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20210326160501.46234-1-lmb@cloudflare.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Invoking BPF_OBJ_GET on a pinned bpf_link checks the path access
permissions based on file_flags, but the returned fd ignores flags.
This means that any user can acquire a "read-write" fd for a pinned
link with mode 0664 by invoking BPF_OBJ_GET with BPF_F_RDONLY in
file_flags. The fd can be used to invoke BPF_LINK_DETACH, etc.

Fix this by refusing non-O_RDWR flags in BPF_OBJ_GET. This works
because OBJ_GET by default returns a read write mapping and libbpf
doesn't expose a way to override this behaviour for programs
and links.

Fixes: 70ed506c3bbc ("bpf: Introduce pinnable bpf_link abstraction")
Signed-off-by: Lorenz Bauer &lt;lmb@cloudflare.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Link: https://lore.kernel.org/bpf/20210326160501.46234-1-lmb@cloudflare.com
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Refcount task stack in bpf_get_task_stack</title>
<updated>2021-04-01T20:58:07+00:00</updated>
<author>
<name>Dave Marchevsky</name>
<email>davemarchevsky@fb.com</email>
</author>
<published>2021-04-01T00:07:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=06ab134ce8ecfa5a69e850f88f81c8a4c3fa91df'/>
<id>06ab134ce8ecfa5a69e850f88f81c8a4c3fa91df</id>
<content type='text'>
On x86 the struct pt_regs * grabbed by task_pt_regs() points to an
offset of task-&gt;stack. The pt_regs are later dereferenced in
__bpf_get_stack (e.g. by user_mode() check). This can cause a fault if
the task in question exits while bpf_get_task_stack is executing, as
warned by task_stack_page's comment:

* When accessing the stack of a non-current task that might exit, use
* try_get_task_stack() instead.  task_stack_page will return a pointer
* that could get freed out from under you.

Taking the comment's advice and using try_get_task_stack() and
put_task_stack() to hold task-&gt;stack refcount, or bail early if it's
already 0. Incrementing stack_refcount will ensure the task's stack
sticks around while we're using its data.

I noticed this bug while testing a bpf task iter similar to
bpf_iter_task_stack in selftests, except mine grabbed user stack, and
getting intermittent crashes, which resulted in dumps like:

  BUG: unable to handle page fault for address: 0000000000003fe0
  \#PF: supervisor read access in kernel mode
  \#PF: error_code(0x0000) - not-present page
  RIP: 0010:__bpf_get_stack+0xd0/0x230
  &lt;snip...&gt;
  Call Trace:
  bpf_prog_0a2be35c092cb190_get_task_stacks+0x5d/0x3ec
  bpf_iter_run_prog+0x24/0x81
  __task_seq_show+0x58/0x80
  bpf_seq_read+0xf7/0x3d0
  vfs_read+0x91/0x140
  ksys_read+0x59/0xd0
  do_syscall_64+0x48/0x120
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: fa28dcb82a38 ("bpf: Introduce helper bpf_get_task_stack()")
Signed-off-by: Dave Marchevsky &lt;davemarchevsky@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/bpf/20210401000747.3648767-1-davemarchevsky@fb.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On x86 the struct pt_regs * grabbed by task_pt_regs() points to an
offset of task-&gt;stack. The pt_regs are later dereferenced in
__bpf_get_stack (e.g. by user_mode() check). This can cause a fault if
the task in question exits while bpf_get_task_stack is executing, as
warned by task_stack_page's comment:

* When accessing the stack of a non-current task that might exit, use
* try_get_task_stack() instead.  task_stack_page will return a pointer
* that could get freed out from under you.

Taking the comment's advice and using try_get_task_stack() and
put_task_stack() to hold task-&gt;stack refcount, or bail early if it's
already 0. Incrementing stack_refcount will ensure the task's stack
sticks around while we're using its data.

I noticed this bug while testing a bpf task iter similar to
bpf_iter_task_stack in selftests, except mine grabbed user stack, and
getting intermittent crashes, which resulted in dumps like:

  BUG: unable to handle page fault for address: 0000000000003fe0
  \#PF: supervisor read access in kernel mode
  \#PF: error_code(0x0000) - not-present page
  RIP: 0010:__bpf_get_stack+0xd0/0x230
  &lt;snip...&gt;
  Call Trace:
  bpf_prog_0a2be35c092cb190_get_task_stacks+0x5d/0x3ec
  bpf_iter_run_prog+0x24/0x81
  __task_seq_show+0x58/0x80
  bpf_seq_read+0xf7/0x3d0
  vfs_read+0x91/0x140
  ksys_read+0x59/0xd0
  do_syscall_64+0x48/0x120
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: fa28dcb82a38 ("bpf: Introduce helper bpf_get_task_stack()")
Signed-off-by: Dave Marchevsky &lt;davemarchevsky@fb.com&gt;
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Acked-by: Song Liu &lt;songliubraving@fb.com&gt;
Link: https://lore.kernel.org/bpf/20210401000747.3648767-1-davemarchevsky@fb.com
</pre>
</div>
</content>
</entry>
</feed>
