┌────────────┐ ┌───────────────────────────────────┐ ┌────────────────┐
│ │ │ │ │ │
│ │ │ PCI Endpoint │ │ PCI Host │
│ │ │ │ │ │
│ │◄──┤ 1.platform_msi_domain_alloc_irqs()│ │ │
│ │ │ │ │ │
│ MSI ├──►│ 2.write_msi_msg() ├──►├─BAR<n> │
│ Controller │ │ update doorbell register address│ │ │
│ │ │ for BAR │ │ │
│ │ │ │ │ 3. Write BAR<n>│
│ │◄──┼───────────────────────────────────┼───┤ │
│ │ │ │ │ │
│ ├──►│ 4.Irq Handle │ │ │
│ │ │ │ │ │
│ │ │ │ │ │
└────────────┘ └───────────────────────────────────┘ └────────────────┘
This patches based on old https://lore.kernel.org/imx/20221124055036.1630573-1-Frank.Li@nxp.com/
Original patch only target to vntb driver. But actually it is common
method.
This patches add new API to pci-epf-core, so any EP driver can use it.
Previous v2 discussion here.
https://lore.kernel.org/imx/20230911220920.1817033-1-Frank.Li@nxp.com/
Changes in v15:
- rebase to v6.14-rc1
- fix build issue find by kernel test robot
- Link to v14: https://lore.kernel.org/r/20250207-ep-msi-v14-0-9671b136f2b8@nxp.com
Changes in v14:
Marc Zyngier raised concerns about adding DOMAIN_BUS_DEVICE_PCI_EP_MSI. As
a result, the approach has been reverted to the v9 method. However, there
are several improvements:
MSI now supports msi-map in addition to msi-parent.
- The struct device: id is used as the endpoint function (EPF) device
identity to map to the stream ID (sideband information).
- The EPC device tree source (DTS) utilizes msi-map to provide such
information.
- The EPF device's of_node is set to the EPC controller’s node. This
approach is commonly used for multi-function device (MFD) platform child
devices, allowing them to inherit properties from the MFD device’s DTS,
such as reset-cells and gpio-cells. This method is well-suited for the
current case, as the EPF is inherently created/binded to the EPC and
should inherit the EPC’s DTS node properties.
Additionally:
Since the basic IMX95 LUT support has already been merged into the
mainline, a DTS and driver increment patch is added to complete the
solution. The patch is rebased onto the latest linux-next tree and
aligned with the new pcitest framework.
- Link to v13: https://lore.kernel.org/r/20241218-ep-msi-v13-0-646e2192dc24@nxp.com
Changes in v13:
- Change to use DOMAIN_BUS_PCI_DEVICE_EP_MSI
- Change request id as func | vfunc << 3
- Remove IRQ_DOMAIN_MSI_IMMUTABLE
Thomas Gleixner:
I hope capture all your points in review comments. If missed, let me know.
- Link to v12: https://lore.kernel.org/r/20241211-ep-msi-v12-0-33d4532fa520@nxp.com
Changes in v12:
- Change to use IRQ_DOMAIN_MSI_IMMUTABLE and add help function
irq_domain_msi_is_immuatble().
- split PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check to 3 patches
- Link to v11: https://lore.kernel.org/r/20241209-ep-msi-v11-0-7434fa8397bd@nxp.com
Changes in v11:
- Change to use MSI_FLAG_MSG_IMMUTABLE
- Link to v10: https://lore.kernel.org/r/20241204-ep-msi-v10-0-87c378dbcd6d@nxp.com
Changes in v10:
Thomas Gleixner:
There are big change in pci-ep-msi.c. I am sure if go on the
corrent path. The key improvement is remove only 1 function devices's
limitation.
I use new patch for imutable check, which relative additional
feature compared to base enablement patch.
- Remove patch Add msi_remove_device_irq_domain() in platform_device_msi_free_irqs_all()
- Add new patch irqchip/gic-v3-its: Avoid overwriting msi_prepare callback if provided by msi_domain_info
- Remove only support 1 endpoint function limiation.
- Create one MSI domain for each endpoint function devices.
- Use "msi-map" in pci ep controler node, instead of of msi-parent. first
argument is
(func_no << 8 | vfunc_no)
- Link to v9: https://lore.kernel.org/r/20241203-ep-msi-v9-0-a60dbc3f15dd@nxp.com
Changes in v9
- Add patch platform-msi: Add msi_remove_device_irq_domain() in platform_device_msi_free_irqs_all()
- Remove patch PCI: endpoint: Add pci_epc_get_fn() API for customizable filtering
- Remove API pci_epf_align_inbound_addr_lo_hi
- Move doorbell_alloc in to doorbell_enable function.
- Link to v8: https://lore.kernel.org/r/20241116-ep-msi-v8-0-6f1f68ffd1bb@nxp.com
Changes in v8:
- update helper function name to pci_epf_align_inbound_addr()
- Link to v7: https://lore.kernel.org/r/20241114-ep-msi-v7-0-d4ac7aafbd2c@nxp.com
Changes in v7:
- Add helper function pci_epf_align_addr();
- Link to v6: https://lore.kernel.org/r/20241112-ep-msi-v6-0-45f9722e3c2a@nxp.com
Changes in v6:
- change doorbell_addr to doorbell_offset
- use round_down()
- add Niklas's test by tag
- rebase to pci/endpoint
- Link to v5: https://lore.kernel.org/r/20241108-ep-msi-v5-0-a14951c0d007@nxp.com
Changes in v5:
- Move request_irq to epf test function driver for more flexiable user case
- Add fixed size bar handler
- Some minor improvememtn to see each patches's changelog.
- Link to v4: https://lore.kernel.org/r/20241031-ep-msi-v4-0-717da2d99b28@nxp.com
Changes in v4:
- Remove patch genirq/msi: Add cleanup guard define for msi_lock_descs()/msi_unlock_descs()
- Use new method to avoid compatible problem.
Add new command DOORBELL_ENABLE and DOORBELL_DISABLE.
pcitest -B send DOORBELL_ENABLE first, EP test function driver try to
remap one of BAR_N (except test register bar) to ITS MSI MMIO space. Old
driver don't support new command, so failure return, not side effect.
After test, DOORBELL_DISABLE command send out to recover original map, so
pcitest bar test can pass as normal.
- Other detail change see each patches's change log
- Link to v3: https://lore.kernel.org/r/20241015-ep-msi-v3-0-cedc89a16c1a@nxp.com
Change from v2 to v3
- Fixed manivannan's comments
- Move common part to pci-ep-msi.c and pci-ep-msi.h
- rebase to 6.12-rc1
- use RevID to distingiush old version
mkdir /sys/kernel/config/pci_ep/functions/pci_epf_test/func1
echo 16 > /sys/kernel/config/pci_ep/functions/pci_epf_test/func1/msi_interrupts
echo 0x080c > /sys/kernel/config/pci_ep/functions/pci_epf_test/func1/deviceid
echo 0x1957 > /sys/kernel/config/pci_ep/functions/pci_epf_test/func1/vendorid
echo 1 > /sys/kernel/config/pci_ep/functions/pci_epf_test/func1/revid
^^^^^^ to enable platform msi support.
ln -s /sys/kernel/config/pci_ep/functions/pci_epf_test/func1 /sys/kernel/config/pci_ep/controllers/4c380000.pcie-ep
- use new device ID, which identify support doorbell to avoid broken
compatility.
Enable doorbell support only for PCI_DEVICE_ID_IMX8_DB, while other devices
keep the same behavior as before.
EP side RC with old driver RC with new driver
PCI_DEVICE_ID_IMX8_DB no probe doorbell enabled
Other device ID doorbell disabled* doorbell disabled*
* Behavior remains unchanged.
Change from v1 to v2
- Add missed patch for endpont/pci-epf-test.c
- Move alloc and free to epc driver from epf.
- Provide general help function for EPC driver to alloc platform msi irq.
- Fixed manivannan's comments.
Signed-off-by: Frank Li <Frank.Li(a)nxp.com>
---
Frank Li (15):
platform-msi: Add msi_remove_device_irq_domain() in platform_device_msi_free_irqs_all()
irqdomain: Add IRQ_DOMAIN_FLAG_MSI_IMMUTABLE and irq_domain_is_msi_immutable()
irqchip/gic-v3-its: Set IRQ_DOMAIN_FLAG_MSI_IMMUTABLE for ITS
irqchip/gic-v3-its: Add support for device tree msi-map and msi-mask
PCI: endpoint: Set ID and of_node for function driver
PCI: endpoint: Add RC-to-EP doorbell support using platform MSI controller
PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check
PCI: endpoint: Add pci_epf_align_inbound_addr() helper for address alignment
PCI: endpoint: pci-epf-test: Add doorbell test support
misc: pci_endpoint_test: Add doorbell test case
selftests: pci_endpoint: Add doorbell test case
pci: imx6: Add helper function imx_pcie_add_lut_by_rid()
pci: imx6: Add LUT setting for MSI/IOMMU in Endpoint mode
arm64: dts: imx95: Add msi-map for pci-ep device
arm64: dts: imx95-19x19-evk: Add PCIe1 endpoint function overlay file
arch/arm64/boot/dts/freescale/Makefile | 3 +
.../dts/freescale/imx95-19x19-evk-pcie1-ep.dtso | 21 ++++
arch/arm64/boot/dts/freescale/imx95.dtsi | 1 +
drivers/base/platform-msi.c | 1 +
drivers/irqchip/irq-gic-v3-its-msi-parent.c | 8 ++
drivers/irqchip/irq-gic-v3-its.c | 2 +-
drivers/misc/pci_endpoint_test.c | 81 +++++++++++++
drivers/pci/controller/dwc/pci-imx6.c | 25 ++--
drivers/pci/endpoint/Makefile | 1 +
drivers/pci/endpoint/functions/pci-epf-test.c | 132 +++++++++++++++++++++
drivers/pci/endpoint/pci-ep-msi.c | 90 ++++++++++++++
drivers/pci/endpoint/pci-epf-core.c | 48 ++++++++
include/linux/irqdomain.h | 7 ++
include/linux/pci-ep-msi.h | 28 +++++
include/linux/pci-epf.h | 21 ++++
include/uapi/linux/pcitest.h | 1 +
.../selftests/pci_endpoint/pci_endpoint_test.c | 25 ++++
17 files changed, 486 insertions(+), 9 deletions(-)
---
base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
change-id: 20241010-ep-msi-8b4cab33b1be
Best regards,
---
Frank Li <Frank.Li(a)nxp.com>
The first fixes setting incorrect skb->truesize.
When xdp-mb prog returns XDP_PASS, skb is allocated and initialized.
Currently, The truesize is calculated as BNXT_RX_PAGE_SIZE *
sinfo->nr_frags, but sinfo->nr_frags is flushed by napi_build_skb().
So, it stores sinfo before calling napi_build_skb() and then use it
for calculate truesize.
The second fixes kernel panic in the bnxt_queue_mem_alloc().
The bnxt_queue_mem_alloc() accesses rx ring descriptor.
rx ring descriptors are allocated when the interface is up and it's
freed when the interface is down.
So, if bnxt_queue_mem_alloc() is called when the interface is down,
kernel panic occurs.
This patch makes the bnxt_queue_mem_alloc() return -ENETDOWN if rx ring
descriptors are not allocated.
The third patch fixes kernel panic in the bnxt_queue_{start | stop}().
When a queue is restarted bnxt_queue_{start | stop}() are called.
These functions set MRU to 0 to stop packet flow and then to set up the
remaining things.
MRU variable is a member of vnic_info[] the first vnic_info is for
default and the second is for ntuple.
The first vnic_info is always allocated when interface is up, but the
second is allocated only when ntuple is enabled.
(ethtool -K eth0 ntuple <on | off>).
Currently, the bnxt_queue_{start | stop}() access
vnic_info[BNXT_VNIC_NTUPLE] regardless of whether ntuple is enabled or
not.
So kernel panic occurs.
This patch make the bnxt_queue_{start | stop}() use bp->nr_vnics instead
of BNXT_VNIC_NTUPLE.
The fourth patch fixes a warning due to checksum state.
The bnxt_rx_pkt() checks whether skb->ip_summed is not CHECKSUM_NONE
before updating ip_summed. if ip_summed is not CHECKSUM_NONE, it WARNS
about it. However, the bnxt_xdp_build_skb() is called in XDP-MB-PASS
path and it updates ip_summed earlier than bnxt_rx_pkt().
So, in the XDP-MB-PASS path, the bnxt_rx_pkt() always warns about
checksum.
Updating ip_summed at the bnxt_xdp_build_skb() is unnecessary and
duplicate, so it is removed.
The fifth patch fixes a kernel panic in the
bnxt_get_queue_stats{rx | tx}().
The bnxt_get_queue_stats{rx | tx}() callback functions are called when
a queue is resetting.
These internally access rx and tx rings without null check, but rings
are allocated and initialized when the interface is up.
So, these functions are called when the interface is down, it
occurs a kernel panic.
The sixth patch fixes memory leak in queue reset logic.
When a queue is resetting, tpa_info is allocated for the new queue and
tpa_info for an old queue is not used anymore.
So it should be freed, but not.
The seventh patch makes net_devmem_unbind_dmabuf() ignore -ENETDOWN.
When devmem socket is closed, net_devmem_unbind_dmabuf() is called to
unbind/release resources.
If interface is down, the driver returns -ENETDOWN.
The -ENETDOWN return value is not an actual error, because the interface
will release resources when the interface is down.
So, net_devmem_unbind_dmabuf() needs to ignore -ENETDOWN.
The last patch adds XDP testcases to
tools/testing/selftests/drivers/net/ping.py.
v3:
- Copy nr_frags instead of full copy. (1/8)
- Add Review tags from Somnath. (3/8)
- Add new patch for fixing kernel panic in the
bnxt_get_queue_stats{rx | tx}(). (5/8)
- Add new patch for fixing memory leak in queue reset. (6/8)
v2:
- Do not use num_frags in the bnxt_xdp_build_skb(). (1/6)
- Add Review tags from Somnath and Jakub. (2/6)
- Add new patch for fixing checksum warning. (4/6)
- Add new patch for fixing warning in net_devmem_unbind_dmabuf(). (5/6)
- Add new XDP testcases to ping.py (6/6)
Taehee Yoo (8):
eth: bnxt: fix truesize for mb-xdp-pass case
eth: bnxt: return fail if interface is down in bnxt_queue_mem_alloc()
eth: bnxt: do not use BNXT_VNIC_NTUPLE unconditionally in queue
restart logic
eth: bnxt: do not update checksum in bnxt_xdp_build_skb()
eth: bnxt: fix kernel panic in the bnxt_get_queue_stats{rx | tx}
eth: bnxt: fix memory leak in queue reset
net: devmem: do not WARN conditionally after netdev_rx_queue_restart()
selftests: drv-net: add xdp cases for ping.py
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 25 ++-
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 13 +-
drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.h | 3 +-
net/core/devmem.c | 4 +-
tools/testing/selftests/drivers/net/ping.py | 200 ++++++++++++++++--
.../testing/selftests/net/lib/xdp_dummy.bpf.c | 6 +
6 files changed, 220 insertions(+), 31 deletions(-)
--
2.34.1
Hello,
While trying to implement an eBPF gatekeeper program, we ran into an
issue whereas the LSM hooks are missing some relevant data.
Certain subcommands passed to the bpf() syscall can be invoked from
either the kernel or userspace. Additionally, some fields in the
bpf_attr struct contain pointers, and depending on where the
subcommand was invoked, they could point to either user or kernel
memory. One example of this is the bpf_prog_load subcommand and its
fd_array. This data is made available and used by the verifier but not
made available to the LSM subsystem. This patchset simply exposes that
information to applicable LSM hooks.
Change list:
- v5 -> v6
- fix regression caused by is_kernel renaming
- simplify test logic
- v4 -> v5
- merge v4 selftest breakout patch back into a single patch
- change "is_kernel" to "kernel"
- add selftest using new kernel flag
- v3 -> v4
- split out selftest changes into a separate patch
- v2 -> v3
- reorder params so that the new boolean flag is the last param
- fixup function signatures in bpf selftests
- v1 -> v2
- Pass a boolean flag in lieu of bpfptr_t
Revisions:
- v5
https://lore.kernel.org/bpf/20250307213651.3065714-1-bboscaccy@linux.micros…
- v4
https://lore.kernel.org/bpf/20250304203123.3935371-1-bboscaccy@linux.micros…
- v3
https://lore.kernel.org/bpf/20250303222416.3909228-1-bboscaccy@linux.micros…
- v2
https://lore.kernel.org/bpf/20250228165322.3121535-1-bboscaccy@linux.micros…
- v1
https://lore.kernel.org/bpf/20250226003055.1654837-1-bboscaccy@linux.micros…
Blaise Boscaccy (2):
security: Propagate caller information in bpf hooks
selftests/bpf: Add a kernel flag test for LSM bpf hook
include/linux/lsm_hook_defs.h | 6 +--
include/linux/security.h | 12 +++---
kernel/bpf/syscall.c | 10 ++---
security/security.c | 15 ++++---
security/selinux/hooks.c | 6 +--
.../selftests/bpf/prog_tests/kernel_flag.c | 43 +++++++++++++++++++
.../selftests/bpf/progs/rcu_read_lock.c | 3 +-
.../bpf/progs/test_cgroup1_hierarchy.c | 4 +-
.../selftests/bpf/progs/test_kernel_flag.c | 28 ++++++++++++
.../bpf/progs/test_kfunc_dynptr_param.c | 6 +--
.../selftests/bpf/progs/test_lookup_key.c | 2 +-
.../selftests/bpf/progs/test_ptr_untrusted.c | 2 +-
.../bpf/progs/test_task_under_cgroup.c | 2 +-
.../bpf/progs/test_verify_pkcs7_sig.c | 2 +-
14 files changed, 108 insertions(+), 33 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/kernel_flag.c
create mode 100644 tools/testing/selftests/bpf/progs/test_kernel_flag.c
--
2.48.1
When an after-split folio is large and needs to be dropped due to EOF,
folio_put_refs(folio, folio_nr_pages(folio)) should be used to drop
all page cache refs. Otherwise, the folio will not be freed, causing
memory leak.
This leak would happen on a filesystem with blocksize > page_size and
a truncate is performed, where the blocksize makes folios split to
>0 order ones, causing truncated folios not being freed.
Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages")
Reported-by: Hugh Dickins <hughd(a)google.com>
Closes: https://lore.kernel.org/all/fcbadb7f-dd3e-21df-f9a7-2853b53183c4@google.com/
Cc: stable(a)vger.kernel.org
Signed-off-by: Zi Yan <ziy(a)nvidia.com>
---
mm/huge_memory.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 3d3ebdc002d5..373781b21e5c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3304,7 +3304,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
folio_account_cleaned(tail,
inode_to_wb(folio->mapping->host));
__filemap_remove_folio(tail, NULL);
- folio_put(tail);
+ folio_put_refs(tail, folio_nr_pages(tail));
} else if (!folio_test_anon(folio)) {
__xa_store(&folio->mapping->i_pages, tail->index,
tail, 0);
--
2.47.2
Hi all,
This patchset adds a new buddy allocator like (or non-uniform) large folio
split from a order-n folio to order-m with m < n. It reduces
1. the total number of after-split folios from 2^(n-m) to n-m+1;
2. the amount of memory needed for multi-index xarray split from 2^(n/6-m/6) to
n/6-m/6, assuming XA_CHUNK_SHIFT=6;
3. keep more large folios after a split from all order-m folios to
order-(n-1) to order-m folios.
For example, to split an order-9 to order-0, folio split generates 10
(or 11 for anonymous memory) folios instead of 512, allocates 1 xa_node
instead of 8, and leaves 1 order-8, 1 order-7, ..., 1 order-1 and 2 order-0
folios (or 4 order-0 for anonymous memory) instead of 512 order-0 folios.
Instead of duplicating existing split_huge_page*() code, __folio_split()
is introduced as the shared backend code for both
split_huge_page_to_list_to_order() and folio_split(). __folio_split()
can support both uniform split and buddy allocator like (or non-uniform) split.
All existing split_huge_page*() users can be gradually converted to use
folio_split() if possible. In this patchset, I converted
truncate_inode_partial_folio() to use folio_split().
xfstests quick group passed for both tmpfs and xfs.
It is on top of mm-everything-2025-02-26-03-56 with V8 reverted. It is ready to
be merged.
Changelog
===
From V8[11]:
1. Removed gfp parameter from xas_try_split() and GFP_NOWAIT is used all
the time. (per Baolin Wang)
2. Used __xas_init_node_for_split() instead of
__xas_alloc_node_for_split() and moved node allocation out. It fixed
a bug when xa_node is pre-allocated by xas_nomem() before
xas_try_split() is called without being initialized for split.
From V7[9]:
1. Fixed a wrong function name in lib/test_xarray.c.
2. Made __split_folio_to_order() never fail, since the old order check
is already done in __folio_split(). (per David Hildenbrand)
3. Fixed an issue reported by syzbot[10] by not dropping the original
folio during truncate.
4. Fixed a WARNING when READ_ONLY_THP_FOR_FS is enabled. (Thank David
Hildenbrand for reporting the issue)
5. Used two separate struct page* parameters, split_at and lock_at, to
specify at which subpage the non-uniform split happens and which subpage
to keep locked after the split, respectively. It improves code
readability.
From V6[8]:
1. Added an xarray function xas_try_split() to support iterative folio split,
removing the need of using xas_split_alloc() and xas_split(). The
function guarantees that at most one xa_node is allocated for each
call.
2. Added concrete numbers of after-split folios and xa_node savings to
cover letter, commit log. (per Andrew)
From V5[7]:
1. Split shmem to any lower order patches are in mm tree, so dropped
from this series.
2. Rename split_folio_at() to try_folio_split() to clarify that
non-uniform split will not be used if it is not supported.
From V4[6]:
1. Enabled shmem support in both uniform and buddy allocator like split
and added selftests for it.
2. Added functions to check if uniform split and buddy allocator like
split are supported for the given folio and order.
3. Made truncate fall back to uniform split if buddy allocator split is
not supported (CONFIG_READ_ONLY_THP_FOR_FS and FS without large folio).
4. Added the missing folio_clear_has_hwpoisoned() to
__split_unmapped_folio().
From V3[5]:
1. Used xas_split_alloc(GFP_NOWAIT) instead of xas_nomem(), since extra
operations inside xas_split_alloc() are needed for correctness.
2. Enabled folio_split() for shmem and no issue was found with xfstests
quick test group.
3. Split both ends of a truncate range in truncate_inode_partial_folio()
to avoid wasting memory in shmem truncate (per David Hildenbrand).
4. Removed page_in_folio_offset() since page_folio() does the same
thing.
5. Finished truncate related tests from xfstests quick test group on XFS and
tmpfs without issues.
6. Disabled buddy allocator like split on CONFIG_READ_ONLY_THP_FOR_FS
and FS without large folio. This check was missed in the prior
versions.
From V2[3]:
1. Incorporated all the feedback from Kirill[4].
2. Used GFP_NOWAIT for xas_nomem().
3. Tested the code path when xas_nomem() fails.
4. Added selftests for folio_split().
5. Fixed no THP config build error.
From V1[2]:
1. Split the original patch 1 into multiple ones for easy review (per
Kirill).
2. Added xas_destroy() to avoid memory leak.
3. Fixed nr_dropped not used error (per kernel test robot).
4. Added proper error handling when xas_nomem() fails to allocate memory
for xas_split() during buddy allocator like split.
From RFC[1]:
1. Merged backend code of split_huge_page_to_list_to_order() and
folio_split(). The same code is used for both uniform split and buddy
allocator like split.
2. Use xas_nomem() instead of xas_split_alloc() for folio_split().
3. folio_split() now leaves the first after-split folio unlocked,
instead of the one containing the given page, since
the caller of truncate_inode_partial_folio() locks and unlocks the
first folio.
4. Extended split_huge_page debugfs to use folio_split().
5. Added truncate_inode_partial_folio() as first user of folio_split().
Design
===
folio_split() splits a large folio in the same way as buddy allocator
splits a large free page for allocation. The purpose is to minimize the
number of folios after the split. For example, if user wants to free the
3rd subpage in a order-9 folio, folio_split() will split the order-9 folio
as:
O-0, O-0, O-0, O-0, O-2, O-3, O-4, O-5, O-6, O-7, O-8 if it is anon
O-1, O-0, O-0, O-2, O-3, O-4, O-5, O-6, O-7, O-9 if it is pagecache
Since anon folio does not support order-1 yet.
The split process is similar to existing approach:
1. Unmap all page mappings (split PMD mappings if exist);
2. Split meta data like memcg, page owner, page alloc tag;
3. Copy meta data in struct folio to sub pages, but instead of spliting
the whole folio into multiple smaller ones with the same order in a
shot, this approach splits the folio iteratively. Taking the example
above, this approach first splits the original order-9 into two order-8,
then splits left part of order-8 to two order-7 and so on;
4. Post-process split folios, like write mapping->i_pages for pagecache,
adjust folio refcounts, add split folios to corresponding list;
5. Remap split folios
6. Unlock split folios.
__split_unmapped_folio() and __split_folio_to_order() replace
__split_huge_page() and __split_huge_page_tail() respectively.
__split_unmapped_folio() uses different approaches to perform
uniform split and buddy allocator like split:
1. uniform split: one single call to __split_folio_to_order() is used to
uniformly split the given folio. All resulting folios are put back to
the list after split. The folio containing the given page is left to
caller to unlock and others are unlocked.
2. buddy allocator like (or non-uniform) split: (old_order - new_order) calls
to __split_folio_to_order() are used to split the given folio at order N to
order N-1. After each call, the target folio is changed to the one
containing the page, which is given as a folio_split() parameter.
After each call, folios not containing the page are put back to the list.
The folio containing the page is put back to the list when its order
is new_order. All folios are unlocked except the first folio, which
is left to caller to unlock.
Patch Overview
===
1. Patch 1 added a new xarray function xas_try_split() to perform
iterative xarray split.
2. Patch 2 added __split_unmapped_folio() and __split_folio_to_order() to
prepare for moving to new backend split code.
3. Patch 3 moved common code in split_huge_page_to_list_to_order() to
__folio_split().
4. Patch 4 added new folio_split() and made
split_huge_page_to_list_to_order() share the new
__split_unmapped_folio() with folio_split().
5. Patch 5 removed no longer used __split_huge_page() and
__split_huge_page_tail().
6. Patch 6 added a new in_folio_offset to split_huge_page debugfs for
folio_split() test.
7. Patch 7 used try_folio_split() for truncate operation.
8. Patch 8 added folio_split() tests.
Any comments and/or suggestions are welcome. Thanks.
[1] https://lore.kernel.org/linux-mm/20241008223748.555845-1-ziy@nvidia.com/
[2] https://lore.kernel.org/linux-mm/20241028180932.1319265-1-ziy@nvidia.com/
[3] https://lore.kernel.org/linux-mm/20241101150357.1752726-1-ziy@nvidia.com/
[4] https://lore.kernel.org/linux-mm/e6ppwz5t4p4kvir6eqzoto4y5fmdjdxdyvxvtw43nc…
[5] https://lore.kernel.org/linux-mm/20241205001839.2582020-1-ziy@nvidia.com/
[6] https://lore.kernel.org/linux-mm/20250106165513.104899-1-ziy@nvidia.com/
[7] https://lore.kernel.org/linux-mm/20250116211042.741543-1-ziy@nvidia.com/
[8] https://lore.kernel.org/linux-mm/20250205031417.1771278-1-ziy@nvidia.com/
[9] https://lore.kernel.org/linux-mm/20250211155034.268962-1-ziy@nvidia.com/
[10] https://lore.kernel.org/all/67af65cb.050a0220.21dd3.004a.GAE@google.com/
[11] https://lore.kernel.org/linux-mm/20250218235012.1542225-1-ziy@nvidia.com/
Zi Yan (8):
xarray: add xas_try_split() to split a multi-index entry
mm/huge_memory: add two new (not yet used) functions for folio_split()
mm/huge_memory: move folio split common code to __folio_split()
mm/huge_memory: add buddy allocator like (non-uniform) folio_split()
mm/huge_memory: remove the old, unused __split_huge_page()
mm/huge_memory: add folio_split() to debugfs testing interface
mm/truncate: use buddy allocator like folio split for truncate
operation
selftests/mm: add tests for folio_split(), buddy allocator like split
Documentation/core-api/xarray.rst | 14 +-
include/linux/huge_mm.h | 36 +
include/linux/xarray.h | 6 +
lib/test_xarray.c | 52 ++
lib/xarray.c | 131 ++-
mm/huge_memory.c | 755 ++++++++++++------
mm/truncate.c | 31 +-
tools/testing/radix-tree/Makefile | 1 +
.../selftests/mm/split_huge_page_test.c | 34 +-
9 files changed, 783 insertions(+), 277 deletions(-)
--
2.47.2
1. Issue
Syzkaller reported this issue [1].
2. Reproduce
We can reproduce this issue by using the test_sockmap_with_close_on_write()
test I provided in selftest, also you need to apply the following patch to
ensure 100% reproducibility (sleep after checking sock):
'''
static void sk_psock_verdict_data_ready(struct sock *sk)
{
.......
if (unlikely(!sock))
return;
+ if (!strcmp("test_progs", current->comm)) {
+ printk("sleep 2s to wait socket freed\n");
+ mdelay(2000);
+ printk("sleep end\n");
+ }
ops = READ_ONCE(sock->ops);
if (!ops || !ops->read_skb)
return;
}
'''
Then running './test_progs -v sockmap_basic', and if the kernel has KASAN
enabled [2], you will see the following warning:
'''
BUG: KASAN: slab-use-after-free in sk_psock_verdict_data_ready+0x29b/0x2d0
Read of size 8 at addr ffff88813a777020 by task test_progs/47055
Tainted: [O]=OOT_MODULE
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
print_address_description.constprop.0+0x30/0x420
? sk_psock_verdict_data_ready+0x29b/0x2d0
print_report+0xb7/0x270
? sk_psock_verdict_data_ready+0x29b/0x2d0
? kasan_addr_to_slab+0xd/0xa0
? sk_psock_verdict_data_ready+0x29b/0x2d0
kasan_report+0xca/0x100
? sk_psock_verdict_data_ready+0x29b/0x2d0
sk_psock_verdict_data_ready+0x29b/0x2d0
unix_stream_sendmsg+0x4a6/0xa40
? __pfx_unix_stream_sendmsg+0x10/0x10
? fdget+0x2c1/0x3a0
__sys_sendto+0x39c/0x410
'''
3. Reason
'''
CPU0 CPU1
unix_stream_sendmsg(sk):
other = unix_peer(sk)
other->sk_data_ready(other):
socket *sock = sk->sk_socket
if (unlikely(!sock))
return;
close(other):
...
other->close()
free(socket)
READ_ONCE(sock->ops)
^
use 'sock' after free
'''
For TCP, UDP, or other protocols, we have already performed
rcu_read_lock() when the network stack receives packets in ip_input.c:
'''
ip_local_deliver_finish():
rcu_read_lock()
ip_protocol_deliver_rcu()
xxx_rcv
rcu_read_unlock()
'''
However, for Unix sockets, sk_data_ready is called directly from the
process context without rcu_read_lock() protection.
4. Solution
Based on the fact that the 'struct socket' is released using call_rcu(),
We add rcu_read_{un}lock() at the entrance and exit of our sk_data_ready.
It will not increase performance overhead, at least for TCP and UDP, they
are already in a relatively large critical section.
Of course, we can also add a custom callback for Unix sockets and call
rcu_read_lock() before calling _verdict_data_ready like this:
'''
if (sk_is_unix(sk))
sk->sk_data_ready = sk_psock_verdict_data_ready_rcu;
else
sk->sk_data_ready = sk_psock_verdict_data_ready;
sk_psock_verdict_data_ready_rcu():
rcu_read_lock()
sk_psock_verdict_data_ready()
rcu_read_unlock()
'''
However, this will cause too many branches, and it's not suitable to
distinguish network protocols in skmsg.c.
[1] https://syzkaller.appspot.com/bug?extid=dd90a702f518e0eac072
[2] https://syzkaller.appspot.com/text?tag=KernelConfig&x=1362a5aee630ff34
---
v1 -> v2:
1. Add Fixes tag.
2. Extend selftest of edge case for TCP/UDP sockets.
3. Add Reviewed-by and Acked-by tag.
https://lore.kernel.org/bpf/20250226132242.52663-1-jiayuan.chen@linux.dev/T…
Jiayuan Chen (3):
bpf, sockmap: avoid using sk_socket after free
selftests/bpf: Add socketpair to create_pair to support unix socket
selftests/bpf: Add edge case tests for sockmap
net/core/skmsg.c | 18 ++++--
.../selftests/bpf/prog_tests/socket_helpers.h | 13 +++-
.../selftests/bpf/prog_tests/sockmap_basic.c | 59 +++++++++++++++++++
3 files changed, 84 insertions(+), 6 deletions(-)
--
2.47.1
This series expands the XDP TX metadata framework to allow user
applications to pass per packet 64-bit launch time directly to the kernel
driver, requesting launch time hardware offload support. The XDP TX
metadata framework will not perform any clock conversion or packet
reordering.
Please note that the role of Tx metadata is just to pass the launch time,
not to enable the offload feature. Users will need to enable the launch
time hardware offload feature of the device by using the respective
command, such as the tc-etf command.
Although some devices use the tc-etf command to enable their launch time
hardware offload feature, xsk packets will not go through the etf qdisc.
Therefore, in my opinion, the launch time should always be based on the PTP
Hardware Clock (PHC). Thus, i did not include a clock ID to indicate the
clock source.
To simplify the test steps, I modified the xdp_hw_metadata bpf self-test
tool in such a way that it will set the launch time based on the offset
provided by the user and the value of the Receive Hardware Timestamp, which
is against the PHC. This will eliminate the need to discipline System Clock
with the PHC and then use clock_gettime() to get the time.
Please note that AF_XDP lacks a feedback mechanism to inform the
application if the requested launch time is invalid. So, users are expected
to familiar with the horizon of the launch time of the device they use and
not request a launch time that is beyond the horizon. Otherwise, the driver
might interpret the launch time incorrectly and react wrongly. For stmmac
and igc, where modulo computation is used, a launch time larger than the
horizon will cause the device to transmit the packet earlier that the
requested launch time.
Although there is no feedback mechanism for the launch time request
for now, user still can check whether the requested launch time is
working or not, by requesting the Transmit Completion Hardware Timestamp.
v12:
- Fix the comment in include/uapi/linux/if_xdp.h to allign with what is
generated by ./tools/net/ynl/ynl-regen.sh to avoid dirty tree error in
the netdev/ynl checks.
v11: https://lore.kernel.org/netdev/20250216074302.956937-1-yoong.siang.song@int…
- regenerate netdev_xsk_flags based on latest netdev.yaml (Jakub)
v10: https://lore.kernel.org/netdev/20250207021943.814768-1-yoong.siang.song@int…
- use net_err_ratelimited(), instead of net_ratelimit() (Maciej)
- accumulate the amount of used descs in local variable and update the
igc_metadata_request::used_desc once (Maciej)
- Ensure reverse christmas tree rule (Maciej)
V9: https://lore.kernel.org/netdev/20250206060408.808325-1-yoong.siang.song@int…
- Remove the igc_desc_unused() checking (Maciej)
- Ensure that skb allocation and DMA mapping work before proceeding to
fill in igc_tx_buffer info, context desc, and data desc (Maciej)
- Rate limit the error messages (Maciej)
- Update the comment to indicate that the 2 descriptors needed by the
empty frame are already taken into consideration (Maciej)
- Handle the case where the insertion of an empty frame fails and
explain the reason behind (Maciej)
- put self SOB tag as last tag (Maciej)
V8: https://lore.kernel.org/netdev/20250205024116.798862-1-yoong.siang.song@int…
- check the number of used descriptor in xsk_tx_metadata_request()
by using used_desc of struct igc_metadata_request, and then decreases
the budget with it (Maciej)
- submit another bug fix patch to set the buffer type for empty frame (Maciej):
https://lore.kernel.org/netdev/20250205023603.798819-1-yoong.siang.song@int…
V7: https://lore.kernel.org/netdev/20250204004907.789330-1-yoong.siang.song@int…
- split the refactoring code of igc empty packet insertion into a separate
commit (Faizal)
- add explanation on why the value "4" is used as igc transmit budget
(Faizal)
- perform a stress test by sending 1000 packets with 10ms interval and
launch time set to 500us in the future (Faizal & Yong Liang)
V6: https://lore.kernel.org/netdev/20250116155350.555374-1-yoong.siang.song@int…
- fix selftest build errors by using asprintf() and realloc(), instead of
managing the buffer sizes manually (Daniel, Stanislav)
V5: https://lore.kernel.org/netdev/20250114152718.120588-1-yoong.siang.song@int…
- change netdev feature name from tx-launch-time to tx-launch-time-fifo
to explicitly state the FIFO behaviour (Stanislav)
- improve the looping of xdp_hw_metadata app to wait for packet tx
completion to be more readable by using clock_gettime() (Stanislav)
- add launch time setup steps into xdp_hw_metadata app (Stanislav)
V4: https://lore.kernel.org/netdev/20250106135506.9687-1-yoong.siang.song@intel…
- added XDP launch time support to the igc driver (Jesper & Florian)
- added per-driver launch time limitation on xsk-tx-metadata.rst (Jesper)
- added explanation on FIFO behavior on xsk-tx-metadata.rst (Jakub)
- added step to enable launch time in the commit message (Jesper & Willem)
- explicitly documented the type of launch_time and which clock source
it is against (Willem)
V3: https://lore.kernel.org/netdev/20231203165129.1740512-1-yoong.siang.song@in…
- renamed to use launch time (Jesper & Willem)
- changed the default launch time in xdp_hw_metadata apps from 1s to 0.1s
because some NICs do not support such a large future time.
V2: https://lore.kernel.org/netdev/20231201062421.1074768-1-yoong.siang.song@in…
- renamed to use Earliest TxTime First (Willem)
- renamed to use txtime (Willem)
V1: https://lore.kernel.org/netdev/20231130162028.852006-1-yoong.siang.song@int…
Song Yoong Siang (5):
xsk: Add launch time hardware offload support to XDP Tx metadata
selftests/bpf: Add launch time request to xdp_hw_metadata
net: stmmac: Add launch time support to XDP ZC
igc: Refactor empty frame insertion for launch time support
igc: Add launch time support to XDP ZC
Documentation/netlink/specs/netdev.yaml | 4 +
Documentation/networking/xsk-tx-metadata.rst | 62 +++++++
drivers/net/ethernet/intel/igc/igc.h | 1 +
drivers/net/ethernet/intel/igc/igc_main.c | 143 +++++++++++----
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 2 +
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 13 ++
include/net/xdp_sock.h | 10 ++
include/net/xdp_sock_drv.h | 1 +
include/uapi/linux/if_xdp.h | 10 ++
include/uapi/linux/netdev.h | 3 +
net/core/netdev-genl.c | 2 +
net/xdp/xsk.c | 3 +
tools/include/uapi/linux/if_xdp.h | 10 ++
tools/include/uapi/linux/netdev.h | 3 +
tools/testing/selftests/bpf/xdp_hw_metadata.c | 168 +++++++++++++++++-
15 files changed, 396 insertions(+), 39 deletions(-)
--
2.34.1