sched_ext tasks can be starved by long-running RT tasks, especially since
RT throttling was replaced by deadline servers to boost only SCHED_NORMAL
tasks.
Several users in the community have reported issues with RT stalling
sched_ext tasks. This is fairly common on distributions or environments
where applications like video compositors, audio services, etc. run as RT
tasks by default.
Example trace (showing a per-CPU kthread stalled due to the sway Wayland
compositor running as an RT task):
runnable task stall (kworker/0:0[106377] failed to run for 5.043s)
...
CPU 0 : nr_run=3 flags=0xd cpu_rel=0 ops_qseq=20646200 pnt_seq=45388738
curr=sway[994] class=rt_sched_class
R kworker/0:0[106377] -5043ms
scx_state/flags=3/0x1 dsq_flags=0x0 ops_state/qseq=0/0
sticky/holding_cpu=-1/-1 dsq_id=0x8000000000000002 dsq_vtime=0 slice=20000000
cpus=01
This is often perceived as a bug in the BPF schedulers, but in reality
schedulers can't do much: RT tasks run outside their control and can
potentially consume 100% of the CPU bandwidth.
Fix this by adding a sched_ext deadline server, so that sched_ext tasks are
also boosted and do not suffer starvation.
Two kselftests are also provided to verify the starvation fixes and
bandwidth allocation is correct.
== Highlights in this version ==
- wait for inactive_task_timer() to fire before removing the bandwidth
reservation (Juri/Peter: please check if this new
dl_server_remove_params() implementation makes sense to you)
- removed the explicit dl_server_stop() from dequeue_task_scx() and rely
on the delayed stop behavior (Juri/Peter: ditto)
This patchset is also available in the following git branch:
git://git.kernel.org/pub/scm/linux/kernel/git/arighi/linux.git scx-dl-server
Changes in v10:
- reordered patches to better isolate sched_ext changes vs sched/deadline
changes (Andrea Righi)
- define ext_server only with CONFIG_SCHED_CLASS_EXT=y (Andrea Righi)
- add WARN_ON_ONCE(!cpus) check in dl_server_apply_params() (Andrea Righi)
- wait for inactive_task_timer to fire before removing the bandwidth
reservation (Juri Lelli)
- remove explicit dl_server_stop() in dequeue_task_scx() to reduce timer
reprogramming overhead (Juri Lelli)
- do not restart pick_task() when invoked by the dl_server (Tejun Heo)
- rename rq_dl_server to dl_server (Peter Zijlstra)
- fixed a missing dl_server start in dl_server_on() (Christian Loehle)
- add a comment to the rt_stall selftest to better explain the 4%
threshold (Emil Tsalapatis)
Changes in v9:
- Drop the ->balance() logic as its functionality is now integrated into
->pick_task(), allowing dl_server to call pick_task_scx() directly
- Link to v8: https://lore.kernel.org/all/20250903095008.162049-1-arighi@nvidia.com/
Changes in v8:
- Add tj's patch to de-couple balance and pick_task and avoid changing
sched/core callbacks to propagate @rf
- Simplify dl_se->dl_server check (suggested by PeterZ)
- Small coding style fixes in the kselftests
- Link to v7: https://lore.kernel.org/all/20250809184800.129831-1-joelagnelf@nvidia.com/
Changes in v7:
- Rebased to Linus master
- Link to v6: https://lore.kernel.org/all/20250702232944.3221001-1-joelagnelf@nvidia.com/
Changes in v6:
- Added Acks to few patches
- Fixes to few nits suggested by Tejun
- Link to v5: https://lore.kernel.org/all/20250620203234.3349930-1-joelagnelf@nvidia.com/
Changes in v5:
- Added a kselftest (total_bw) to sched_ext to verify bandwidth values
from debugfs
- Address comment from Andrea about redundant rq clock invalidation
- Link to v4: https://lore.kernel.org/all/20250617200523.1261231-1-joelagnelf@nvidia.com/
Changes in v4:
- Fixed issues with hotplugged CPUs having their DL server bandwidth
altered due to loading SCX
- Fixed other issues
- Rebased on Linus master
- All sched_ext kselftests reliably pass now, also verified that the
total_bw in debugfs (CONFIG_SCHED_DEBUG) is conserved with these patches
- Link to v3: https://lore.kernel.org/all/20250613051734.4023260-1-joelagnelf@nvidia.com/
Changes in v3:
- Removed code duplication in debugfs. Made ext interface separate
- Fixed issue where rq_lock_irqsave was not used in the relinquish patch
- Fixed running bw accounting issue in dl_server_remove_params
- Link to v2: https://lore.kernel.org/all/20250602180110.816225-1-joelagnelf@nvidia.com/
Changes in v2:
- Fixed a hang related to using rq_lock instead of rq_lock_irqsave
- Added support to remove BW of DL servers when they are switched to/from EXT
- Link to v1: https://lore.kernel.org/all/20250315022158.2354454-1-joelagnelf@nvidia.com/
Andrea Righi (5):
sched/deadline: Add support to initialize and remove dl_server bandwidth
sched_ext: Add a DL server for sched_ext tasks
sched/deadline: Account ext server bandwidth
sched_ext: Selectively enable ext and fair DL servers
selftests/sched_ext: Add test for sched_ext dl_server
Joel Fernandes (6):
sched/debug: Fix updating of ppos on server write ops
sched/debug: Stop and start server based on if it was active
sched/deadline: Clear the defer params
sched/deadline: Add a server arg to dl_server_update_idle_time()
sched/debug: Add support to change sched_ext server params
selftests/sched_ext: Add test for DL server total_bw consistency
kernel/sched/core.c | 3 +
kernel/sched/deadline.c | 169 +++++++++++---
kernel/sched/debug.c | 171 +++++++++++---
kernel/sched/ext.c | 144 +++++++++++-
kernel/sched/fair.c | 2 +-
kernel/sched/idle.c | 2 +-
kernel/sched/sched.h | 8 +-
kernel/sched/topology.c | 5 +
tools/testing/selftests/sched_ext/Makefile | 2 +
tools/testing/selftests/sched_ext/rt_stall.bpf.c | 23 ++
tools/testing/selftests/sched_ext/rt_stall.c | 222 ++++++++++++++++++
tools/testing/selftests/sched_ext/total_bw.c | 281 +++++++++++++++++++++++
12 files changed, 955 insertions(+), 77 deletions(-)
create mode 100644 tools/testing/selftests/sched_ext/rt_stall.bpf.c
create mode 100644 tools/testing/selftests/sched_ext/rt_stall.c
create mode 100644 tools/testing/selftests/sched_ext/total_bw.c
This is a follow-up series of [1]. It tries to fix a possible UAF in the
fops of cros_ec_chardev after the underlying protocol device has gone by
using revocable.
The 1st patch introduces the revocable which is an implementation of ideas
from the talk [2].
The 2nd and 3rd patches add test cases for revocable in Kunit and selftest.
The 4th patch converts existing protocol devices to resource providers
of cros_ec_device.
The 5th - 7th are PoC patches for showing the use case of "Replace file
operations" below.
---
I came out with 2 possible usages of revocable.
1. Use primitive APIs
Use the primitive APIs of revocable directly.
The file operations make sure the resources are available when using them.
This is what the series original proposed[3][4]. Even though it has the
finest grain for accessing the resources, it makes the user code verbose.
Per feedback from the community, I'm looking for some subsystem level
helpers so that user code can be simlper.
2. Replace file operations
Replace filp->f_op to revocable-aware warppers.
The warppers make sure the resources are available in the file operations.
The user code needs to provide a callback .try_access() to tell the wrappers
where/how to *save* the pointers of resources.
Known drawback:
- The warppers reserve the resources for all file operations even if they
might be unused.
- The user code still needs to be revocable-aware.
- The whole file operation becomes a SRCU read-side critical section. Are
there any functions can't be called in the critical section? If there is,
the file operations may not be awared of that.
See 5th - 7th patches for an example usage.
[1] https://lore.kernel.org/chrome-platform/20250721044456.2736300-6-tzungbi@ke…
[2] https://lpc.events/event/17/contributions/1627/
[3] https://lore.kernel.org/chrome-platform/20250912081718.3827390-5-tzungbi@ke…
[4] https://lore.kernel.org/chrome-platform/20250912081718.3827390-6-tzungbi@ke…
v5:
- Rebase onto next-20251015.
- Add more context about the PoC.
- Support multiple revocable providers in the PoC.
v4: https://lore.kernel.org/chrome-platform/20250923075302.591026-1-tzungbi@ker…
- Rebase onto next-20250922.
- Remove the 5th patch from v3.
- Add fops replacement PoC in 5th - 7th patches.
v3: https://lore.kernel.org/chrome-platform/20250912081718.3827390-1-tzungbi@ke…
- Rebase onto https://lore.kernel.org/chrome-platform/20250828083601.856083-1-tzungbi@ker…
and next-20250912.
- The 4th patch changed accordingly.
v2: https://lore.kernel.org/chrome-platform/20250820081645.847919-1-tzungbi@ker…
- Rename "ref_proxy" -> "revocable".
- Add test cases in Kunit and selftest.
v1: https://lore.kernel.org/chrome-platform/20250814091020.1302888-1-tzungbi@ke…
Tzung-Bi Shih (7):
revocable: Revocable resource management
revocable: Add Kunit test cases
selftests: revocable: Add kselftest cases
platform/chrome: Protect cros_ec_device lifecycle with revocable
revocable: Add fops replacement
char: misc: Leverage revocable fops replacement
platform/chrome: cros_ec_chardev: Secure cros_ec_device via revocable
.../driver-api/driver-model/index.rst | 1 +
.../driver-api/driver-model/revocable.rst | 87 +++++++
MAINTAINERS | 9 +
drivers/base/Kconfig | 8 +
drivers/base/Makefile | 5 +-
drivers/base/revocable.c | 233 ++++++++++++++++++
drivers/base/revocable_test.c | 110 +++++++++
drivers/char/misc.c | 8 +
drivers/platform/chrome/cros_ec.c | 5 +
drivers/platform/chrome/cros_ec_chardev.c | 22 +-
fs/Makefile | 2 +-
fs/fs_revocable.c | 154 ++++++++++++
include/linux/fs.h | 2 +
include/linux/fs_revocable.h | 21 ++
include/linux/miscdevice.h | 4 +
include/linux/platform_data/cros_ec_proto.h | 4 +
include/linux/revocable.h | 53 ++++
tools/testing/selftests/Makefile | 1 +
.../selftests/drivers/base/revocable/Makefile | 7 +
.../drivers/base/revocable/revocable_test.c | 116 +++++++++
.../drivers/base/revocable/test-revocable.sh | 39 +++
.../base/revocable/test_modules/Makefile | 10 +
.../revocable/test_modules/revocable_test.c | 188 ++++++++++++++
23 files changed, 1086 insertions(+), 3 deletions(-)
create mode 100644 Documentation/driver-api/driver-model/revocable.rst
create mode 100644 drivers/base/revocable.c
create mode 100644 drivers/base/revocable_test.c
create mode 100644 fs/fs_revocable.c
create mode 100644 include/linux/fs_revocable.h
create mode 100644 include/linux/revocable.h
create mode 100644 tools/testing/selftests/drivers/base/revocable/Makefile
create mode 100644 tools/testing/selftests/drivers/base/revocable/revocable_test.c
create mode 100755 tools/testing/selftests/drivers/base/revocable/test-revocable.sh
create mode 100644 tools/testing/selftests/drivers/base/revocable/test_modules/Makefile
create mode 100644 tools/testing/selftests/drivers/base/revocable/test_modules/revocable_test.c
--
2.51.0.788.g6d19910ace-goog
This series adds namespace support to vhost-vsock and loopback. It does
not add namespaces to any of the other guest transports (virtio-vsock,
hyperv, or vmci).
The current revision supports two modes: local and global. Local
mode is complete isolation of namespaces, while global mode is complete
sharing between namespaces of CIDs (the original behavior).
The mode is set using /proc/sys/net/vsock/ns_mode.
Modes are per-netns and write-once. This allows a system to configure
namespaces independently (some may share CIDs, others are completely
isolated). This also supports future possible mixed use cases, where
there may be namespaces in global mode spinning up VMs while there are
mixed mode namespaces that provide services to the VMs, but are not
allowed to allocate from the global CID pool (this mode not implemented
in this series).
If a socket or VM is created when a namespace is global but the
namespace changes to local, the socket or VM will continue working
normally. That is, the socket or VM assumes the mode behavior of the
namespace at the time the socket/VM was created. The original mode is
captured in vsock_create() and so occurs at the time of socket(2) and
accept(2) for sockets and open(2) on /dev/vhost-vsock for VMs. This
prevents a socket/VM connection from suddenly breaking due to a
namespace mode change. Any new sockets/VMs created after the mode change
will adopt the new mode's behavior.
Additionally, added tests for the new namespace features:
tools/testing/selftests/vsock/vmtest.sh
1..30
ok 1 vm_server_host_client
ok 2 vm_client_host_server
ok 3 vm_loopback
ok 4 ns_host_vsock_ns_mode_ok
ok 5 ns_host_vsock_ns_mode_write_once_ok
ok 6 ns_global_same_cid_fails
ok 7 ns_local_same_cid_ok
ok 8 ns_global_local_same_cid_ok
ok 9 ns_local_global_same_cid_ok
ok 10 ns_diff_global_host_connect_to_global_vm_ok
ok 11 ns_diff_global_host_connect_to_local_vm_fails
ok 12 ns_diff_global_vm_connect_to_global_host_ok
ok 13 ns_diff_global_vm_connect_to_local_host_fails
ok 14 ns_diff_local_host_connect_to_local_vm_fails
ok 15 ns_diff_local_vm_connect_to_local_host_fails
ok 16 ns_diff_global_to_local_loopback_local_fails
ok 17 ns_diff_local_to_global_loopback_fails
ok 18 ns_diff_local_to_local_loopback_fails
ok 19 ns_diff_global_to_global_loopback_ok
ok 20 ns_same_local_loopback_ok
ok 21 ns_same_local_host_connect_to_local_vm_ok
ok 22 ns_same_local_vm_connect_to_local_host_ok
ok 23 ns_mode_change_connection_continue_vm_ok
ok 24 ns_mode_change_connection_continue_host_ok
ok 25 ns_mode_change_connection_continue_both_ok
ok 26 ns_delete_vm_ok
ok 27 ns_delete_host_ok
ok 28 ns_delete_both_ok
ok 29 ns_loopback_global_global_late_module_load_ok
ok 30 ns_loopback_local_local_late_module_load_fails
SUMMARY: PASS=30 SKIP=0 FAIL=0
Dependent on series:
https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements…
Thanks again for everyone's help and reviews!
Signed-off-by: Bobby Eshleman <bobbyeshleman(a)gmail.com>
To: Stefano Garzarella <sgarzare(a)redhat.com>
To: Shuah Khan <shuah(a)kernel.org>
To: David S. Miller <davem(a)davemloft.net>
To: Eric Dumazet <edumazet(a)google.com>
To: Jakub Kicinski <kuba(a)kernel.org>
To: Paolo Abeni <pabeni(a)redhat.com>
To: Simon Horman <horms(a)kernel.org>
To: Stefan Hajnoczi <stefanha(a)redhat.com>
To: Michael S. Tsirkin <mst(a)redhat.com>
To: Jason Wang <jasowang(a)redhat.com>
To: Xuan Zhuo <xuanzhuo(a)linux.alibaba.com>
To: Eugenio Pérez <eperezma(a)redhat.com>
To: K. Y. Srinivasan <kys(a)microsoft.com>
To: Haiyang Zhang <haiyangz(a)microsoft.com>
To: Wei Liu <wei.liu(a)kernel.org>
To: Dexuan Cui <decui(a)microsoft.com>
To: Bryan Tan <bryan-bt.tan(a)broadcom.com>
To: Vishnu Dasa <vishnu.dasa(a)broadcom.com>
To: Broadcom internal kernel review list <bcm-kernel-feedback-list(a)broadcom.com>
Cc: virtualization(a)lists.linux.dev
Cc: netdev(a)vger.kernel.org
Cc: linux-kselftest(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
Cc: kvm(a)vger.kernel.org
Cc: linux-hyperv(a)vger.kernel.org
Cc: berrange(a)redhat.com
Changes in v8:
- Break generic cleanup/refactoring patches into standalone series,
remove those from this series
- Link to dependency: https://lore.kernel.org/all/20251022-vsock-selftests-fixes-and-improvements…
- Link to v7: https://lore.kernel.org/r/20251021-vsock-vmtest-v7-0-0661b7b6f081@meta.com
Changes in v7:
- fix hv_sock build
- break out vmtest patches into distinct, more well-scoped patches
- change `orig_net_mode` to `net_mode`
- many fixes and style changes in per-patch change sets (see individual
patches for specific changes)
- optimize `virtio_vsock_skb_cb` layout
- update commit messages with more useful descriptions
- vsock_loopback: use orig_net_mode instead of current net mode
- add tests for edge cases (ns deletion, mode changing, loopback module
load ordering)
- Link to v6: https://lore.kernel.org/r/20250916-vsock-vmtest-v6-0-064d2eb0c89d@meta.com
Changes in v6:
- define behavior when mode changes to local while socket/VM is alive
- af_vsock: clarify description of CID behavior
- af_vsock: use stronger langauge around CID rules (dont use "may")
- af_vsock: improve naming of buf/buffer
- af_vsock: improve string length checking on proc writes
- vsock_loopback: add space in struct to clarify lock protection
- vsock_loopback: do proper cleanup/unregister on vsock_loopback_exit()
- vsock_loopback: use virtio_vsock_skb_net() instead of sock_net()
- vsock_loopback: set loopback to NULL after kfree()
- vsock_loopback: use pernet_operations and remove callback mechanism
- vsock_loopback: add macros for "global" and "local"
- vsock_loopback: fix length checking
- vmtest.sh: check for namespace support in vmtest.sh
- Link to v5: https://lore.kernel.org/r/20250827-vsock-vmtest-v5-0-0ba580bede5b@meta.com
Changes in v5:
- /proc/net/vsock_ns_mode -> /proc/sys/net/vsock/ns_mode
- vsock_global_net -> vsock_global_dummy_net
- fix netns lookup in vhost_vsock to respect pid namespaces
- add callbacks for vsock_loopback to avoid circular dependency
- vmtest.sh loads vsock_loopback module
- remove vsock_net_mode_can_set()
- change vsock_net_write_mode() to return true/false based on success
- make vsock_net_mode enum instead of u8
- Link to v4: https://lore.kernel.org/r/20250805-vsock-vmtest-v4-0-059ec51ab111@meta.com
Changes in v4:
- removed RFC tag
- implemented loopback support
- renamed new tests to better reflect behavior
- completed suite of tests with permutations of ns modes and vsock_test
as guest/host
- simplified socat bridging with unix socket instead of tcp + veth
- only use vsock_test for success case, socat for failure case (context
in commit message)
- lots of cleanup
Changes in v3:
- add notion of "modes"
- add procfs /proc/net/vsock_ns_mode
- local and global modes only
- no /dev/vhost-vsock-netns
- vmtest.sh already merged, so new patch just adds new tests for NS
- Link to v2:
https://lore.kernel.org/kvm/20250312-vsock-netns-v2-0-84bffa1aa97a@gmail.com
Changes in v2:
- only support vhost-vsock namespaces
- all g2h namespaces retain old behavior, only common API changes
impacted by vhost-vsock changes
- add /dev/vhost-vsock-netns for "opt-in"
- leave /dev/vhost-vsock to old behavior
- removed netns module param
- Link to v1:
https://lore.kernel.org/r/20200116172428.311437-1-sgarzare@redhat.com
Changes in v1:
- added 'netns' module param to vsock.ko to enable the
network namespace support (disabled by default)
- added 'vsock_net_eq()' to check the "net" assigned to a socket
only when 'netns' support is enabled
- Link to RFC: https://patchwork.ozlabs.org/cover/1202235/
---
Bobby Eshleman (14):
vsock: a per-net vsock NS mode state
vsock/virtio: pack struct virtio_vsock_skb_cb
vsock: add netns to vsock skb cb
vsock: add netns to vsock core
vsock/loopback: add netns support
vsock/virtio: add netns to virtio transport common
vhost/vsock: add netns support
selftests/vsock: add namespace helpers to vmtest.sh
selftests/vsock: prepare vm management helpers for namespaces
selftests/vsock: add tests for proc sys vsock ns_mode
selftests/vsock: add namespace tests for CID collisions
selftests/vsock: add tests for host <-> vm connectivity with namespaces
selftests/vsock: add tests for namespace deletion and mode changes
selftests/vsock: add tests for module loading order
MAINTAINERS | 1 +
drivers/vhost/vsock.c | 48 +-
include/linux/virtio_vsock.h | 47 +-
include/net/af_vsock.h | 70 ++-
include/net/net_namespace.h | 4 +
include/net/netns/vsock.h | 22 +
net/vmw_vsock/af_vsock.c | 264 +++++++-
net/vmw_vsock/virtio_transport.c | 7 +-
net/vmw_vsock/virtio_transport_common.c | 21 +-
net/vmw_vsock/vsock_loopback.c | 89 ++-
tools/testing/selftests/vsock/vmtest.sh | 1044 ++++++++++++++++++++++++++++++-
11 files changed, 1532 insertions(+), 85 deletions(-)
---
base-commit: 962ac5ca99a5c3e7469215bf47572440402dfd59
change-id: 20250325-vsock-vmtest-b3a21d2102c2
prerequisite-message-id: <20251022-vsock-selftests-fixes-and-improvements-v1-0-edeb179d6463(a)meta.com>
prerequisite-patch-id: a2eecc3851f2509ed40009a7cab6990c6d7cfff5
prerequisite-patch-id: 501db2100636b9c8fcb3b64b8b1df797ccbede85
prerequisite-patch-id: ba1a2f07398a035bc48ef72edda41888614be449
prerequisite-patch-id: fd5cc5445aca9355ce678e6d2bfa89fab8a57e61
prerequisite-patch-id: 795ab4432ffb0843e22b580374782e7e0d99b909
prerequisite-patch-id: 1499d263dc933e75366c09e045d2125ca39f7ddd
prerequisite-patch-id: f92d99bb1d35d99b063f818a19dcda999152d74c
prerequisite-patch-id: e3296f38cdba6d903e061cff2bbb3e7615e8e671
prerequisite-patch-id: bc4662b4710d302d4893f58708820fc2a0624325
prerequisite-patch-id: f8991f2e98c2661a706183fde6b35e2b8d9aedcf
prerequisite-patch-id: 44bf9ed69353586d284e5ee63d6fffa30439a698
prerequisite-patch-id: d50621bc630eeaf608bbaf260370c8dabf6326df
Best regards,
--
Bobby Eshleman <bobbyeshleman(a)meta.com>
From: Steven Rostedt <rostedt(a)goodmis.org>
Commit 64cf7d058a00 ("tracing: Have trace_marker use per-cpu data to read
user space") made an update that fixed both trace_marker and
trace_marker_raw. But the small difference made to trace_marker_raw had a
blatant bug in it that any basic testing would have uncovered.
Unfortunately, the self tests have tests for trace_marker but nothing for
trace_marker_raw which allowed the bug to get upstream.
Add basic selftests to test trace_marker_raw so that this doesn't happen
again.
Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org>
---
.../ftrace/test.d/00basic/trace_marker_raw.tc | 107 ++++++++++++++++++
1 file changed, 107 insertions(+)
create mode 100644 tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc
diff --git a/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc
new file mode 100644
index 000000000000..7daf7292209e
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/00basic/trace_marker_raw.tc
@@ -0,0 +1,107 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Basic tests on writing to trace_marker_raw
+# requires: trace_marker_raw
+# flags: instance
+
+is_little_endian() {
+ if lscpu | grep -q 'Little Endian'; then
+ echo 1;
+ else
+ echo 0;
+ fi
+}
+
+little=`is_little_endian`
+
+make_str() {
+ id=$1
+ cnt=$2
+
+ if [ $little -eq 1 ]; then
+ val=`printf "\\%03o\\%03o\\%03o\\%03o" \
+ $(($id & 0xff)) \
+ $((($id >> 8) & 0xff)) \
+ $((($id >> 16) & 0xff)) \
+ $((($id >> 24) & 0xff))`
+ else
+ val=`printf "\\%03o\\%03o\\%03o\\%03o" \
+ $((($id >> 24) & 0xff)) \
+ $((($id >> 16) & 0xff)) \
+ $((($id >> 8) & 0xff)) \
+ $(($id & 0xff))`
+ fi
+
+ data=`printf -- 'X%.0s' $(seq $cnt)`
+
+ printf "${val}${data}"
+}
+
+write_buffer() {
+ id=$1
+ size=$2
+
+ # write the string into the raw marker
+ make_str $id $size > trace_marker_raw
+}
+
+
+test_multiple_writes() {
+
+ # Write a bunch of data where the id is the count of
+ # data to write
+ for i in `seq 1 10` `seq 101 110` `seq 1001 1010`; do
+ write_buffer $i $i
+ done
+
+ # add a little buffer
+ echo stop > trace_marker
+
+ # Check to make sure the number of entries is the id (rounded up by 4)
+ awk '/.*: # [0-9a-f]* / {
+ print;
+ cnt = -1;
+ for (i = 0; i < NF; i++) {
+ # The counter is after the "#" marker
+ if ( $i == "#" ) {
+ i++;
+ cnt = strtonum("0x" $i);
+ num = NF - (i + 1);
+ # The number of items is always rounded up by 4
+ cnt2 = int((cnt + 3) / 4) * 4;
+ if (cnt2 != num) {
+ exit 1;
+ }
+ break;
+ }
+ }
+ }
+ // { if (NR > 30) { exit 0; } } ' trace_pipe;
+}
+
+
+get_buffer_data_size() {
+ sed -ne 's/^.*data.*size:\([0-9][0-9]*\).*/\1/p' events/header_page
+}
+
+test_buffer() {
+
+ # The id must be four bytes, test that 3 bytes fails a write
+ if echo -n abc > ./trace_marker_raw ; then
+ echo "Too small of write expected to fail but did not"
+ exit_fail
+ fi
+
+ size=`get_buffer_data_size`
+ echo size = $size
+
+ # Now add a little more than what it can handle
+
+ if write_buffer 0xdeadbeef $size ; then
+ echo "Too big of write expected to fail but did not"
+ exit_fail
+ fi
+}
+
+test_buffer
+test_multiple_writes
--
2.51.0
From: Chia-Yu Chang <chia-yu.chang(a)nokia-bell-labs.com>
Hello,
Plesae find the v5 AccECN case handling patch series, which covers
several excpetional case handling of Accurate ECN spec (RFC9768),
adds new identifiers to be used by CC modules, adds ecn_delta into
rate_sample, and keeps the ACE counter for computation, etc.
This patch series is part of the full AccECN patch series, which is available at
https://github.com/L4STeam/linux-net-next/commits/upstream_l4steam/
Best regards,
Chia-Yu
---
v5:
- Move previous #11 in v4 in latter patch after discussion with RFC author.
- Add #3 to update the comments for SKB_GSO_TCP_ECN and SKB_GSO_TCP_ACCECN. (Parav Pandit <parav(a)nvidia.com>)
- Add gro self-test for TCP CWR flag in #4. (Eric Dumazet <edumazet(a)google.com>)
- Add fixes: tag into #7 (Paolo Abeni <pabeni(a)redhat.com>)
- Update commit message of #8 and if condition check (Paolo Abeni <pabeni(a)redhat.com>)
- Add empty line between variable declarations and code in #13 (Paolo Abeni <pabeni(a)redhat.com>)
v4:
- Add previous #13 in v2 back after dicussion with the RFC author.
- Add TCP_ACCECN_OPTION_PERSIST to tcp_ecn_option sysctl to ignore AccECN fallback policy on sending AccECN option.
v3:
- Add additional min() check if pkts_acked_ewma is not initialized in #1. (Paolo Abeni <pabeni(a)redhat.com>)
- Change TCP_CONG_WANTS_ECT_1 into individual flag add helper function INET_ECN_xmit_wants_ect_1() in #3. (Paolo Abeni <pabeni(a)redhat.com>)
- Add empty line between variable declarations and code in #4. (Paolo Abeni <pabeni(a)redhat.com>)
- Update commit message to fix old AccECN commits in #5. (Paolo Abeni <pabeni(a)redhat.com>)
- Remove unnecessary brackets in #10. (Paolo Abeni <pabeni(a)redhat.com>)
- Move patch #3 in v2 to a later Prague patch serise and remove patch #13 in v2. (Paolo Abeni <pabeni(a)redhat.com>)
---
Chia-Yu Chang (12):
net: update commnets for SKB_GSO_TCP_ECN and SKB_GSO_TCP_ACCECN
selftests/net: gro: add self-test for TCP CWR flag
tcp: L4S ECT(1) identifier and NEEDS_ACCECN for CC modules
tcp: disable RFC3168 fallback identifier for CC modules
tcp: accecn: handle unexpected AccECN negotiation feedback
tcp: accecn: retransmit downgraded SYN in AccECN negotiation
tcp: move increment of num_retrans
tcp: accecn: retransmit SYN/ACK without AccECN option or non-AccECN
SYN/ACK
tcp: accecn: unset ECT if receive or send ACE=0 in AccECN negotiaion
tcp: accecn: fallback outgoing half link to non-AccECN
tcp: accecn: detect loss ACK w/ AccECN option and add
TCP_ACCECN_OPTION_PERSIST
tcp: accecn: enable AccECN
Ilpo Järvinen (2):
tcp: try to avoid safer when ACKs are thinned
gro: flushing when CWR is set negatively affects AccECN
Documentation/networking/ip-sysctl.rst | 4 +-
.../networking/net_cachelines/tcp_sock.rst | 1 +
include/linux/skbuff.h | 13 ++-
include/linux/tcp.h | 4 +-
include/net/inet_ecn.h | 20 +++-
include/net/tcp.h | 32 ++++++-
include/net/tcp_ecn.h | 92 ++++++++++++++-----
net/ipv4/sysctl_net_ipv4.c | 4 +-
net/ipv4/tcp.c | 2 +
net/ipv4/tcp_cong.c | 10 +-
net/ipv4/tcp_input.c | 37 +++++++-
net/ipv4/tcp_minisocks.c | 40 +++++---
net/ipv4/tcp_offload.c | 3 +-
net/ipv4/tcp_output.c | 42 ++++++---
tools/testing/selftests/net/gro.c | 80 +++++++++++-----
15 files changed, 294 insertions(+), 90 deletions(-)
--
2.34.1
The generic vDSO provides a lot common functionality shared between
different architectures. SPARC is the last architecture not using it,
preventing some necessary code cleanup.
Make use of the generic infrastructure.
Follow-up to and replacement for Arnd's SPARC vDSO removal patches:
https://lore.kernel.org/lkml/20250707144726.4008707-1-arnd@kernel.org/
SPARC64 can not map .bss into userspace, so the vDSO datapages are
switched over to be allocated dynamically. This requires changes to the
s390 and random subsystem vDSO initialization as preparation.
The random subsystem changes in turn require some cleanup of the vDSO
headers to not end up as ugly #ifdef mess.
Tested on a Niagara T4 and QEMU.
This has a semantic conflict with my series "vdso: Reject absolute
relocations during build" [0]. The last patch of this series expects all
users of the generic vDSO library to use the vdsocheck tool.
This is not the case (yet) for SPARC64. I do have the patches for the
integration, the specifics will depend on which series is applied first.
Based on v6.18-rc1.
[0] https://lore.kernel.org/lkml/20250812-vdso-absolute-reloc-v4-0-61a8b615e5ec…
Signed-off-by: Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>
---
Changes in v4:
- Rebase on v6.18-rc1.
- Keep inclusion of asm/clocksource.h from linux/clocksource.h
- Reword description of "s390/time: Set up vDSO datapage later"
- Link to v3: https://lore.kernel.org/r/20250917-vdso-sparc64-generic-2-v3-0-3679b1bc8ee8…
Changes in v3:
- Allocate vDSO data pages dynamically (and lots of preparations for that)
- Drop clock_getres()
- Fix 32bit clock_gettime() syscall fallback
- Link to v2: https://lore.kernel.org/r/20250815-vdso-sparc64-generic-2-v2-0-b5ff80672347…
Changes in v2:
- Rebase on v6.17-rc1
- Drop RFC state
- Fix typo in commit message
- Drop duplicate 'select GENERIC_TIME_VSYSCALL'
- Merge "sparc64: time: Remove architecture-specific clocksource data" into the
main conversion patch. It violated the check in __clocksource_register_scale()
- Link to v1: https://lore.kernel.org/r/20250724-vdso-sparc64-generic-2-v1-0-e376a3bd24d1…
---
Arnd Bergmann (1):
clocksource: remove ARCH_CLOCKSOURCE_DATA
Thomas Weißschuh (34):
selftests: vDSO: vdso_test_correctness: Handle different tv_usec types
arm64: vDSO: getrandom: Explicitly include asm/alternative.h
arm64: vDSO: gettimeofday: Explicitly include vdso/clocksource.h
arm64: vDSO: compat_gettimeofday: Add explicit includes
ARM: vdso: gettimeofday: Add explicit includes
powerpc/vdso/gettimeofday: Explicitly include vdso/time32.h
powerpc/vdso: Explicitly include asm/cputable.h and asm/feature-fixups.h
LoongArch: vDSO: Explicitly include asm/vdso/vdso.h
MIPS: vdso: Add include guard to asm/vdso/vdso.h
MIPS: vdso: Explicitly include asm/vdso/vdso.h
random: vDSO: Add explicit includes
vdso/gettimeofday: Add explicit includes
vdso/helpers: Explicitly include vdso/processor.h
vdso/datapage: Remove inclusion of gettimeofday.h
vdso/datapage: Trim down unnecessary includes
random: vDSO: trim vDSO includes
random: vDSO: remove ifdeffery
random: vDSO: split out datapage update into helper functions
random: vDSO: only access vDSO datapage after random_init()
s390/time: Set up vDSO datapage later
vdso/datastore: Reduce scope of some variables in vvar_fault()
vdso/datastore: Drop inclusion of linux/mmap_lock.h
vdso/datastore: Map pages through struct page
vdso/datastore: Allocate data pages dynamically
sparc64: vdso: Link with -z noexecstack
sparc64: vdso: Remove obsolete "fake section table" reservation
sparc64: vdso: Replace code patching with runtime conditional
sparc64: vdso: Move hardware counter read into header
sparc64: vdso: Move syscall fallbacks into header
sparc64: vdso: Introduce vdso/processor.h
sparc64: vdso: Switch to the generic vDSO library
sparc64: vdso2c: Drop sym_vvar_start handling
sparc64: vdso2c: Remove symbol handling
sparc64: vdso: Implement clock_gettime64()
arch/arm/include/asm/vdso/gettimeofday.h | 2 +
arch/arm64/include/asm/vdso/compat_gettimeofday.h | 3 +
arch/arm64/include/asm/vdso/gettimeofday.h | 2 +
arch/arm64/kernel/vdso/vgetrandom.c | 2 +
arch/loongarch/kernel/process.c | 1 +
arch/loongarch/kernel/vdso.c | 1 +
arch/mips/include/asm/vdso/vdso.h | 5 +
arch/mips/kernel/vdso.c | 1 +
arch/powerpc/include/asm/vdso/gettimeofday.h | 1 +
arch/powerpc/include/asm/vdso/processor.h | 3 +
arch/s390/kernel/time.c | 4 +-
arch/sparc/Kconfig | 3 +-
arch/sparc/include/asm/clocksource.h | 9 -
arch/sparc/include/asm/processor.h | 3 +
arch/sparc/include/asm/processor_32.h | 2 -
arch/sparc/include/asm/processor_64.h | 25 --
arch/sparc/include/asm/vdso.h | 2 -
arch/sparc/include/asm/vdso/clocksource.h | 10 +
arch/sparc/include/asm/vdso/gettimeofday.h | 184 ++++++++++
arch/sparc/include/asm/vdso/processor.h | 41 +++
arch/sparc/include/asm/vdso/vsyscall.h | 10 +
arch/sparc/include/asm/vvar.h | 75 ----
arch/sparc/kernel/Makefile | 1 -
arch/sparc/kernel/time_64.c | 6 +-
arch/sparc/kernel/vdso.c | 69 ----
arch/sparc/vdso/Makefile | 8 +-
arch/sparc/vdso/vclock_gettime.c | 380 ++-------------------
arch/sparc/vdso/vdso-layout.lds.S | 26 +-
arch/sparc/vdso/vdso.lds.S | 2 -
arch/sparc/vdso/vdso2c.c | 24 --
arch/sparc/vdso/vdso2c.h | 45 +--
arch/sparc/vdso/vdso32/vdso32.lds.S | 4 +-
arch/sparc/vdso/vma.c | 274 +--------------
drivers/char/random.c | 71 ++--
include/linux/clocksource.h | 6 +-
include/linux/vdso_datastore.h | 6 +
include/vdso/datapage.h | 23 +-
include/vdso/helpers.h | 1 +
init/main.c | 2 +
kernel/time/Kconfig | 4 -
lib/vdso/datastore.c | 73 ++--
lib/vdso/getrandom.c | 3 +
lib/vdso/gettimeofday.c | 17 +
.../testing/selftests/vDSO/vdso_test_correctness.c | 8 +-
44 files changed, 448 insertions(+), 994 deletions(-)
---
base-commit: 28b1ac5ccd8d4900a8f53f0e6e84d517a7ccc71f
change-id: 20250722-vdso-sparc64-generic-2-25f2e058e92c
Best regards,
--
Thomas Weißschuh <thomas.weissschuh(a)linutronix.de>
Currently, guard regions are not visible to users except through
/proc/$pid/pagemap, with no explicit visibility at the VMA level.
This makes the feature less useful, as it isn't entirely apparent which
VMAs may have these entries present, especially when performing actions
which walk through memory regions such as those performed by CRIU.
This series addresses this issue by introducing the VM_MAYBE_GUARD flag
which fulfils this role, updating the smaps logic to display an entry for
these.
The semantics of this flag are that a guard region MAY be present if set
(we cannot be sure, as we can't efficiently track whether an
MADV_GUARD_REMOVE finally removes all the guard regions in a VMA) - but if
not set the VMA definitely does NOT have any guard regions present.
It's problematic to establish this flag without further action, because
that means that VMAs with guard regions in them become non-mergeable with
adjacent VMAs for no especially good reason.
To work around this, this series also introduces the concept of 'sticky'
VMA flags - that is flags which:
a. if set in one VMA and not in another still permit those VMAs to be
merged (if otherwise compatible).
b. When they are merged, the resultant VMA must have the flag set.
The VMA logic is updated to propagate these flags correctly.
Additionally, VM_MAYBE_GUARD being an explicit VMA flag allows us to solve
an issue with file-backed guard regions - previously these established an
anon_vma object for file-backed mappings solely to have vma_needs_copy()
correctly propagate guard region mappings to child processes.
We introduce a new flag alias VM_COPY_ON_FORK (which currently only
specifies VM_MAYBE_GUARD) and update vma_needs_copy() to check explicitly
for this flag and to copy page tables if it is present, which resolves this
issue.
Finally we introduce extensive VMA userland tests to assert that the sticky
VMA logic behaves correctly as well as guard region self tests to assert
that smaps visibility is correctly implemented.
Lorenzo Stoakes (3):
mm: introduce VM_MAYBE_GUARD and make visible for guard regions
mm: implement sticky, copy on fork VMA flags
selftests/mm/guard-regions: add smaps visibility test
Documentation/filesystems/proc.rst | 1 +
fs/proc/task_mmu.c | 1 +
include/linux/mm.h | 33 ++++++
include/trace/events/mmflags.h | 1 +
mm/madvise.c | 22 ++--
mm/memory.c | 3 +
mm/vma.c | 22 ++--
tools/testing/selftests/mm/guard-regions.c | 120 +++++++++++++++++++++
tools/testing/selftests/mm/vm_util.c | 5 +
tools/testing/selftests/mm/vm_util.h | 1 +
tools/testing/vma/vma.c | 89 +++++++++++++--
tools/testing/vma/vma_internal.h | 33 ++++++
12 files changed, 303 insertions(+), 28 deletions(-)
--
2.51.0