Currently, bpf_map_get_info_by_fd calculates and caches the hash of the
map regardless of the map's frozen state.
This leads to a TOCTOU bug where userspace can call
BPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map
contents before freezing.
Therefore, a trusted loader can be tricked into verifying the stale hash
while loading the modified contents.
Fix this by returning -EPERM if the map is not frozen when the hash is
requested. This ensures the hash is only generated for the final,
immutable state of the map.
Fixes: ea2e6467ac ("bpf: Return hashes of maps in BPF_OBJ_GET_INFO_BY_FD")
Reported-by: Toshi Piazza <toshi.piazza@microsoft.com>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260205070755.695776-1-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Practical BPF signatures are significantly smaller than
KMALLOC_MAX_CACHE_SIZE
Allowing larger sizes opens the door for abuse by passing excessive
size values and forcing the kernel into expensive allocation paths (via
kmalloc_large or vmalloc).
Fixes: 3492715683 ("bpf: Implement signature verification for BPF programs")
Reported-by: Chris Mason <clm@meta.com>
Signed-off-by: KP Singh <kpsingh@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260205063807.690823-1-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit fixes a security issue where BPF_PROG_DETACH on tcx or
netkit devices could be executed by any user when no program fd was
provided, bypassing permission checks. The fix adds a capability
check for CAP_NET_ADMIN or CAP_SYS_ADMIN in this case.
Fixes: e420bed025 ("bpf: Add fd-based tcx multi-prog infra with link support")
Signed-off-by: Guillaume Gonnet <ggonnet.linux@gmail.com>
Link: https://lore.kernel.org/r/20260127160200.10395-1-ggonnet.linux@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
After commit 37cce22dbd ("bpf: verifier: Refactor helper access type tracking"),
the verifier started relying on the access type flags in helper
function prototypes to perform memory access optimizations.
Currently, several helper functions utilizing ARG_PTR_TO_MEM lack the
corresponding MEM_RDONLY or MEM_WRITE flags. This omission causes the
verifier to incorrectly assume that the buffer contents are unchanged
across the helper call. Consequently, the verifier may optimize away
subsequent reads based on this wrong assumption, leading to correctness
issues.
For bpf_get_stack_proto_raw_tp, the original MEM_RDONLY was incorrect
since the helper writes to the buffer. Change it to ARG_PTR_TO_UNINIT_MEM
which correctly indicates write access to potentially uninitialized memory.
Similar issues were recently addressed for specific helpers in commit
ac44dcc788 ("bpf: Fix verifier assumptions of bpf_d_path's output buffer")
and commit 2eb7648558 ("bpf: Specify access type of bpf_sysctl_get_name args").
Fix these prototypes by adding the correct memory access flags.
Fixes: 37cce22dbd ("bpf: verifier: Refactor helper access type tracking")
Co-developed-by: Shuran Liu <electronlsr@gmail.com>
Signed-off-by: Shuran Liu <electronlsr@gmail.com>
Co-developed-by: Peili Gao <gplhust955@gmail.com>
Signed-off-by: Peili Gao <gplhust955@gmail.com>
Co-developed-by: Haoran Ni <haoran.ni.cs@gmail.com>
Signed-off-by: Haoran Ni <haoran.ni.cs@gmail.com>
Signed-off-by: Zesen Liu <ftyghome@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260120-helper_proto-v3-1-27b0180b4e77@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce BPF_F_ALL_CPUS flag support for percpu_cgroup_storage maps to
allow updating values for all CPUs with a single value for update_elem
API.
Introduce BPF_F_CPU flag support for percpu_cgroup_storage maps to
allow:
* update value for specified CPU for update_elem API.
* lookup value for specified CPU for lookup_elem API.
The BPF_F_CPU flag is passed via map_flags along with embedded cpu info.
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260107022022.12843-6-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce BPF_F_ALL_CPUS flag support for percpu_hash and lru_percpu_hash
maps to allow updating values for all CPUs with a single value for both
update_elem and update_batch APIs.
Introduce BPF_F_CPU flag support for percpu_hash and lru_percpu_hash
maps to allow:
* update value for specified CPU for both update_elem and update_batch
APIs.
* lookup value for specified CPU for both lookup_elem and lookup_batch
APIs.
The BPF_F_CPU flag is passed via:
* map_flags along with embedded cpu info.
* elem_flags along with embedded cpu info.
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260107022022.12843-4-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce support for the BPF_F_ALL_CPUS flag in percpu_array maps to
allow updating values for all CPUs with a single value for both
update_elem and update_batch APIs.
Introduce support for the BPF_F_CPU flag in percpu_array maps to allow:
* update value for specified CPU for both update_elem and update_batch
APIs.
* lookup value for specified CPU for both lookup_elem and lookup_batch
APIs.
The BPF_F_CPU flag is passed via:
* map_flags of lookup_elem and update_elem APIs along with embedded cpu
info.
* elem_flags of lookup_batch and update_batch APIs along with embedded
cpu info.
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Link: https://lore.kernel.org/r/20260107022022.12843-3-leon.hwang@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When arena allocations were converted from bpf_map_alloc_pages() to
kmalloc_nolock() to support non-sleepable contexts, memcg accounting was
inadvertently lost. This commit restores proper memory accounting for
all arena-related allocations.
All arena related allocations are accounted into memcg of the process
that created bpf_arena.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20260102200230.25168-3-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce bpf_map_memcg_enter() and bpf_map_memcg_exit() helpers to
reduce code duplication in memcg context management.
bpf_map_memcg_enter() gets the memcg from the map, sets it as active,
and returns both the previous and the now active memcg.
bpf_map_memcg_exit() restores the previous active memcg and releases the
reference obtained during enter.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Link: https://lore.kernel.org/r/20260102200230.25168-2-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a new BPF command BPF_PROG_ASSOC_STRUCT_OPS to allow associating
a BPF program with a struct_ops map. This command takes a file
descriptor of a struct_ops map and a BPF program and set
prog->aux->st_ops_assoc to the kdata of the struct_ops map.
The command does not accept a struct_ops program nor a non-struct_ops
map. Programs of a struct_ops map is automatically associated with the
map during map update. If a program is shared between two struct_ops
maps, prog->aux->st_ops_assoc will be poisoned to indicate that the
associated struct_ops is ambiguous. The pointer, once poisoned, cannot
be reset since we have lost track of associated struct_ops. For other
program types, the associated struct_ops map, once set, cannot be
changed later. This restriction may be lifted in the future if there is
a use case.
A kernel helper bpf_prog_get_assoc_struct_ops() can be used to retrieve
the associated struct_ops pointer. The returned pointer, if not NULL, is
guaranteed to be valid and point to a fully updated struct_ops struct.
For struct_ops program reused in multiple struct_ops map, the return
will be NULL.
prog->aux->st_ops_assoc is protected by bumping the refcount for
non-struct_ops programs and RCU for struct_ops programs. Since it would
be inefficient to track programs associated with a struct_ops map, every
non-struct_ops program will bump the refcount of the map to make sure
st_ops_assoc stays valid. For a struct_ops program, it is protected by
RCU as map_free will wait for an RCU grace period before disassociating
the program with the map. The helper must be called in BPF program
context or RCU read-side critical section.
struct_ops implementers should note that the struct_ops returned may not
be initialized nor attached yet. The struct_ops implementer will be
responsible for tracking and checking the state of the associated
struct_ops map if the use case expects an initialized or attached
struct_ops.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20251203233748.668365-3-ameryhung@gmail.com
Pull MM updates from Andrew Morton:
"__vmalloc()/kvmalloc() and no-block support" (Uladzislau Rezki)
Rework the vmalloc() code to support non-blocking allocations
(GFP_ATOIC, GFP_NOWAIT)
"ksm: fix exec/fork inheritance" (xu xin)
Fix a rare case where the KSM MMF_VM_MERGE_ANY prctl state is not
inherited across fork/exec
"mm/zswap: misc cleanup of code and documentations" (SeongJae Park)
Some light maintenance work on the zswap code
"mm/page_owner: add debugfs files 'show_handles' and 'show_stacks_handles'" (Mauricio Faria de Oliveira)
Enhance the /sys/kernel/debug/page_owner debug feature by adding
unique identifiers to differentiate the various stack traces so
that userspace monitoring tools can better match stack traces over
time
"mm/page_alloc: pcp->batch cleanups" (Joshua Hahn)
Minor alterations to the page allocator's per-cpu-pages feature
"Improve UFFDIO_MOVE scalability by removing anon_vma lock" (Lokesh Gidra)
Address a scalability issue in userfaultfd's UFFDIO_MOVE operation
"kasan: cleanups for kasan_enabled() checks" (Sabyrzhan Tasbolatov)
"drivers/base/node: fold node register and unregister functions" (Donet Tom)
Clean up the NUMA node handling code a little
"mm: some optimizations for prot numa" (Kefeng Wang)
Cleanups and small optimizations to the NUMA allocation hinting
code
"mm/page_alloc: Batch callers of free_pcppages_bulk" (Joshua Hahn)
Address long lock hold times at boot on large machines. These were
causing (harmless) softlockup warnings
"optimize the logic for handling dirty file folios during reclaim" (Baolin Wang)
Remove some now-unnecessary work from page reclaim
"mm/damon: allow DAMOS auto-tuned for per-memcg per-node memory usage" (SeongJae Park)
Enhance the DAMOS auto-tuning feature
"mm/damon: fixes for address alignment issues in DAMON_LRU_SORT and DAMON_RECLAIM" (Quanmin Yan)
Fix DAMON_LRU_SORT and DAMON_RECLAIM with certain userspace
configuration
"expand mmap_prepare functionality, port more users" (Lorenzo Stoakes)
Enhance the new(ish) file_operations.mmap_prepare() method and port
additional callsites from the old ->mmap() over to ->mmap_prepare()
"Fix stale IOTLB entries for kernel address space" (Lu Baolu)
Fix a bug (and possible security issue on non-x86) in the IOMMU
code. In some situations the IOMMU could be left hanging onto a
stale kernel pagetable entry
"mm/huge_memory: cleanup __split_unmapped_folio()" (Wei Yang)
Clean up and optimize the folio splitting code
"mm, swap: misc cleanup and bugfix" (Kairui Song)
Some cleanups and a minor fix in the swap discard code
"mm/damon: misc documentation fixups" (SeongJae Park)
"mm/damon: support pin-point targets removal" (SeongJae Park)
Permit userspace to remove a specific monitoring target in the
middle of the current targets list
"mm: MISC follow-up patches for linux/pgalloc.h" (Harry Yoo)
A couple of cleanups related to mm header file inclusion
"mm/swapfile.c: select swap devices of default priority round robin" (Baoquan He)
improve the selection of swap devices for NUMA machines
"mm: Convert memory block states (MEM_*) macros to enums" (Israel Batista)
Change the memory block labels from macros to enums so they will
appear in kernel debug info
"ksm: perform a range-walk to jump over holes in break_ksm" (Pedro Demarchi Gomes)
Address an inefficiency when KSM unmerges an address range
"mm/damon/tests: fix memory bugs in kunit tests" (SeongJae Park)
Fix leaks and unhandled malloc() failures in DAMON userspace unit
tests
"some cleanups for pageout()" (Baolin Wang)
Clean up a couple of minor things in the page scanner's
writeback-for-eviction code
"mm/hugetlb: refactor sysfs/sysctl interfaces" (Hui Zhu)
Move hugetlb's sysfs/sysctl handling code into a new file
"introduce VM_MAYBE_GUARD and make it sticky" (Lorenzo Stoakes)
Make the VMA guard regions available in /proc/pid/smaps and
improves the mergeability of guarded VMAs
"mm: perform guard region install/remove under VMA lock" (Lorenzo Stoakes)
Reduce mmap lock contention for callers performing VMA guard region
operations
"vma_start_write_killable" (Matthew Wilcox)
Start work on permitting applications to be killed when they are
waiting on a read_lock on the VMA lock
"mm/damon/tests: add more tests for online parameters commit" (SeongJae Park)
Add additional userspace testing of DAMON's "commit" feature
"mm/damon: misc cleanups" (SeongJae Park)
"make VM_SOFTDIRTY a sticky VMA flag" (Lorenzo Stoakes)
Address the possible loss of a VMA's VM_SOFTDIRTY flag when that
VMA is merged with another
"mm: support device-private THP" (Balbir Singh)
Introduce support for Transparent Huge Page (THP) migration in zone
device-private memory
"Optimize folio split in memory failure" (Zi Yan)
"mm/huge_memory: Define split_type and consolidate split support checks" (Wei Yang)
Some more cleanups in the folio splitting code
"mm: remove is_swap_[pte, pmd]() + non-swap entries, introduce leaf entries" (Lorenzo Stoakes)
Clean up our handling of pagetable leaf entries by introducing the
concept of 'software leaf entries', of type softleaf_t
"reparent the THP split queue" (Muchun Song)
Reparent the THP split queue to its parent memcg. This is in
preparation for addressing the long-standing "dying memcg" problem,
wherein dead memcg's linger for too long, consuming memory
resources
"unify PMD scan results and remove redundant cleanup" (Wei Yang)
A little cleanup in the hugepage collapse code
"zram: introduce writeback bio batching" (Sergey Senozhatsky)
Improve zram writeback efficiency by introducing batched bio
writeback support
"memcg: cleanup the memcg stats interfaces" (Shakeel Butt)
Clean up our handling of the interrupt safety of some memcg stats
"make vmalloc gfp flags usage more apparent" (Vishal Moola)
Clean up vmalloc's handling of incoming GFP flags
"mm: Add soft-dirty and uffd-wp support for RISC-V" (Chunyan Zhang)
Teach soft dirty and userfaultfd write protect tracking to use
RISC-V's Svrsw60t59b extension
"mm: swap: small fixes and comment cleanups" (Youngjun Park)
Fix a small bug and clean up some of the swap code
"initial work on making VMA flags a bitmap" (Lorenzo Stoakes)
Start work on converting the vma struct's flags to a bitmap, so we
stop running out of them, especially on 32-bit
"mm/swapfile: fix and cleanup swap list iterations" (Youngjun Park)
Address a possible bug in the swap discard code and clean things
up a little
[ This merge also reverts commit ebb9aeb980 ("vfio/nvgrace-gpu:
register device memory for poison handling") because it looks
broken to me, I've asked for clarification - Linus ]
* tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
mm: fix vma_start_write_killable() signal handling
mm/swapfile: use plist_for_each_entry in __folio_throttle_swaprate
mm/swapfile: fix list iteration when next node is removed during discard
fs/proc/task_mmu.c: fix make_uffd_wp_huge_pte() huge pte handling
mm/kfence: add reboot notifier to disable KFENCE on shutdown
memcg: remove inc/dec_lruvec_kmem_state helpers
selftests/mm/uffd: initialize char variable to Null
mm: fix DEBUG_RODATA_TEST indentation in Kconfig
mm: introduce VMA flags bitmap type
tools/testing/vma: eliminate dependency on vma->__vm_flags
mm: simplify and rename mm flags function for clarity
mm: declare VMA flags by bit
zram: fix a spelling mistake
mm/page_alloc: optimize lowmem_reserve max lookup using its semantic monotonicity
mm/vmscan: skip increasing kswapd_failures when reclaim was boosted
pagemap: update BUDDY flag documentation
mm: swap: remove scan_swap_map_slots() references from comments
mm: swap: change swap_alloc_slow() to void
mm, swap: remove redundant comment for read_swap_cache_async
mm, swap: use SWP_SOLIDSTATE to determine if swap is rotational
...
Pull networking updates from Jakub Kicinski:
"Core & protocols:
- Replace busylock at the Tx queuing layer with a lockless list.
Resulting in a 300% (4x) improvement on heavy TX workloads, sending
twice the number of packets per second, for half the cpu cycles.
- Allow constantly busy flows to migrate to a more suitable CPU/NIC
queue.
Normally we perform queue re-selection when flow comes out of idle,
but under extreme circumstances the flows may be constantly busy.
Add sysctl to allow periodic rehashing even if it'd risk packet
reordering.
- Optimize the NAPI skb cache, make it larger, use it in more paths.
- Attempt returning Tx skbs to the originating CPU (like we already
did for Rx skbs).
- Various data structure layout and prefetch optimizations from Eric.
- Remove ktime_get() from the recvmsg() fast path, ktime_get() is
sadly quite expensive on recent AMD machines.
- Extend threaded NAPI polling to allow the kthread busy poll for
packets.
- Make MPTCP use Rx backlog processing. This lowers the lock
pressure, improving the Rx performance.
- Support memcg accounting of MPTCP socket memory.
- Allow admin to opt sockets out of global protocol memory accounting
(using a sysctl or BPF-based policy). The global limits are a poor
fit for modern container workloads, where limits are imposed using
cgroups.
- Improve heuristics for when to kick off AF_UNIX garbage collection.
- Allow users to control TCP SACK compression, and default to 33% of
RTT.
- Add tcp_rcvbuf_low_rtt sysctl to let datacenter users avoid
unnecessarily aggressive rcvbuf growth and overshot when the
connection RTT is low.
- Preserve skb metadata space across skb_push / skb_pull operations.
- Support for IPIP encapsulation in the nftables flowtable offload.
- Support appending IP interface information to ICMP messages (RFC
5837).
- Support setting max record size in TLS (RFC 8449).
- Remove taking rtnl_lock from RTM_GETNEIGHTBL and RTM_SETNEIGHTBL.
- Use a dedicated lock (and RCU) in MPLS, instead of rtnl_lock.
- Let users configure the number of write buffers in SMC.
- Add new struct sockaddr_unsized for sockaddr of unknown length,
from Kees.
- Some conversions away from the crypto_ahash API, from Eric Biggers.
- Some preparations for slimming down struct page.
- YAML Netlink protocol spec for WireGuard.
- Add a tool on top of YAML Netlink specs/lib for reporting commonly
computed derived statistics and summarized system state.
Driver API:
- Add CAN XL support to the CAN Netlink interface.
- Add uAPI for reporting PHY Mean Square Error (MSE) diagnostics, as
defined by the OPEN Alliance's "Advanced diagnostic features for
100BASE-T1 automotive Ethernet PHYs" specification.
- Add DPLL phase-adjust-gran pin attribute (and implement it in
zl3073x).
- Refactor xfrm_input lock to reduce contention when NIC offloads
IPsec and performs RSS.
- Add info to devlink params whether the current setting is the
default or a user override. Allow resetting back to default.
- Add standard device stats for PSP crypto offload.
- Leverage DSA frame broadcast to implement simple HSR frame
duplication for a lot of switches without dedicated HSR offload.
- Add uAPI defines for 1.6Tbps link modes.
Device drivers:
- Add Motorcomm YT921x gigabit Ethernet switch support.
- Add MUCSE driver for N500/N210 1GbE NIC series.
- Convert drivers to support dedicated ops for timestamping control,
and away from the direct IOCTL handling. While at it support GET
operations for PHY timestamping.
- Add (and convert most drivers to) a dedicated ethtool callback for
reading the Rx ring count.
- Significant refactoring efforts in the STMMAC driver, which
supports Synopsys turn-key MAC IP integrated into a ton of SoCs.
- Ethernet high-speed NICs:
- Broadcom (bnxt):
- support PPS in/out on all pins
- Intel (100G, ice, idpf):
- ice: implement standard ethtool and timestamping stats
- i40e: support setting the max number of MAC addresses per VF
- iavf: support RSS of GTP tunnels for 5G and LTE deployments
- nVidia/Mellanox (mlx5):
- reduce downtime on interface reconfiguration
- disable being an XDP redirect target by default (same as
other drivers) to avoid wasting resources if feature is
unused
- Meta (fbnic):
- add support for Linux-managed PCS on 25G, 50G, and 100G links
- Wangxun:
- support Rx descriptor merge, and Tx head writeback
- support Rx coalescing offload
- support 25G SPF and 40G QSFP modules
- Ethernet virtual:
- Google (gve):
- allow ethtool to configure rx_buf_len
- implement XDP HW RX Timestamping support for DQ descriptor
format
- Microsoft vNIC (mana):
- support HW link state events
- handle hardware recovery events when probing the device
- Ethernet NICs consumer, and embedded:
- usbnet: add support for Byte Queue Limits (BQL)
- AMD (amd-xgbe):
- add device selftests
- NXP (enetc):
- add i.MX94 support
- Broadcom integrated MACs (bcmgenet, bcmasp):
- bcmasp: add support for PHY-based Wake-on-LAN
- Broadcom switches (b53):
- support port isolation
- support BCM5389/97/98 and BCM63XX ARL formats
- Lantiq/MaxLinear switches:
- support bridge FDB entries on the CPU port
- use regmap for register access
- allow user to enable/disable learning
- support Energy Efficient Ethernet
- support configuring RMII clock delays
- add tagging driver for MaxLinear GSW1xx switches
- Synopsys (stmmac):
- support using the HW clock in free running mode
- add Eswin EIC7700 support
- add Rockchip RK3506 support
- add Altera Agilex5 support
- Cadence (macb):
- cleanup and consolidate descriptor and DMA address handling
- add EyeQ5 support
- TI:
- icssg-prueth: support AF_XDP
- Airoha access points:
- add missing Ethernet stats and link state callback
- add AN7583 support
- support out-of-order Tx completion processing
- Power over Ethernet:
- pd692x0: preserve PSE configuration across reboots
- add support for TPS23881B devices
- Ethernet PHYs:
- Open Alliance OATC14 10BASE-T1S PHY cable diagnostic support
- Support 50G SerDes and 100G interfaces in Linux-managed PHYs
- micrel:
- support for non PTP SKUs of lan8814
- enable in-band auto-negotiation on lan8814
- realtek:
- cable testing support on RTL8224
- interrupt support on RTL8221B
- motorcomm: support for PHY LEDs on YT853
- microchip: support for LAN867X Rev.D0 PHYs w/ SQI and cable diag
- mscc: support for PHY LED control
- CAN drivers:
- m_can: add support for optional reset and system wake up
- remove can_change_mtu() obsoleted by core handling
- mcp251xfd: support GPIO controller functionality
- Bluetooth:
- add initial support for PASTa
- WiFi:
- split ieee80211.h file, it's way too big
- improvements in VHT radiotap reporting, S1G, Channel Switch
Announcement handling, rate tracking in mesh networks
- improve multi-radio monitor mode support, and add a cfg80211
debugfs interface for it
- HT action frame handling on 6 GHz
- initial chanctx work towards NAN
- MU-MIMO sniffer improvements
- WiFi drivers:
- RealTek (rtw89):
- support USB devices RTL8852AU and RTL8852CU
- initial work for RTL8922DE
- improved injection support
- Intel:
- iwlwifi: new sniffer API support
- MediaTek (mt76):
- WED support for >32-bit DMA
- airoha NPU support
- regdomain improvements
- continued WiFi7/MLO work
- Qualcomm/Atheros:
- ath10k: factory test support
- ath11k: TX power insertion support
- ath12k: BSS color change support
- ath12k: statistics improvements
- brcmfmac: Acer A1 840 tablet quirk
- rtl8xxxu: 40 MHz connection fixes/support"
* tag 'net-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1381 commits)
net: page_pool: sanitise allocation order
net: page pool: xa init with destroy on pp init
net/mlx5e: Support XDP target xmit with dummy program
net/mlx5e: Update XDP features in switch channels
selftests/tc-testing: Test CAKE scheduler when enqueue drops packets
net/sched: sch_cake: Fix incorrect qlen reduction in cake_drop
wireguard: netlink: generate netlink code
wireguard: uapi: generate header with ynl-gen
wireguard: uapi: move flag enums
wireguard: uapi: move enum wg_cmd
wireguard: netlink: add YNL specification
selftests: drv-net: Fix tolerance calculation in devlink_rate_tc_bw.py
selftests: drv-net: Fix and clarify TC bandwidth split in devlink_rate_tc_bw.py
selftests: drv-net: Set shell=True for sysfs writes in devlink_rate_tc_bw.py
selftests: drv-net: Use Iperf3Runner in devlink_rate_tc_bw.py
selftests: drv-net: introduce Iperf3Runner for measurement use cases
selftests: drv-net: Add devlink_rate_tc_bw.py to TEST_PROGS
net: ps3_gelic_net: Use napi_alloc_skb() and napi_gro_receive()
Documentation: net: dsa: mention simple HSR offload helpers
Documentation: net: dsa: mention availability of RedBox
...
Pull bpf updates from Alexei Starovoitov:
- Convert selftests/bpf/test_tc_edt and test_tc_tunnel from .sh to
test_progs runner (Alexis Lothoré)
- Convert selftests/bpf/test_xsk to test_progs runner (Bastien
Curutchet)
- Replace bpf memory allocator with kmalloc_nolock() in
bpf_local_storage (Amery Hung), and in bpf streams and range tree
(Puranjay Mohan)
- Introduce support for indirect jumps in BPF verifier and x86 JIT
(Anton Protopopov) and arm64 JIT (Puranjay Mohan)
- Remove runqslower bpf tool (Hoyeon Lee)
- Fix corner cases in the verifier to close several syzbot reports
(Eduard Zingerman, KaFai Wan)
- Several improvements in deadlock detection in rqspinlock (Kumar
Kartikeya Dwivedi)
- Implement "jmp" mode for BPF trampoline and corresponding
DYNAMIC_FTRACE_WITH_JMP. It improves "fexit" program type performance
from 80 M/s to 136 M/s. With Steven's Ack. (Menglong Dong)
- Add ability to test non-linear skbs in BPF_PROG_TEST_RUN (Paul
Chaignon)
- Do not let BPF_PROG_TEST_RUN emit invalid GSO types to stack (Daniel
Borkmann)
- Generalize buildid reader into bpf_dynptr (Mykyta Yatsenko)
- Optimize bpf_map_update_elem() for map-in-map types (Ritesh
Oedayrajsingh Varma)
- Introduce overwrite mode for BPF ring buffer (Xu Kuohai)
* tag 'bpf-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (169 commits)
bpf: optimize bpf_map_update_elem() for map-in-map types
bpf: make kprobe_multi_link_prog_run always_inline
selftests/bpf: do not hardcode target rate in test_tc_edt BPF program
selftests/bpf: remove test_tc_edt.sh
selftests/bpf: integrate test_tc_edt into test_progs
selftests/bpf: rename test_tc_edt.bpf.c section to expose program type
selftests/bpf: Add success stats to rqspinlock stress test
rqspinlock: Precede non-head waiter queueing with AA check
rqspinlock: Disable spinning for trylock fallback
rqspinlock: Use trylock fallback when per-CPU rqnode is busy
rqspinlock: Perform AA checks immediately
rqspinlock: Enclose lock/unlock within lock entry acquisitions
bpf: Remove runqslower tool
selftests/bpf: Remove usage of lsm/file_alloc_security in selftest
bpf: Disable file_alloc_security hook
bpf: check for insn arrays in check_ptr_alignment
bpf: force BPF_F_RDONLY_PROG on insn array creation
bpf: Fix exclusive map memory leak
selftests/bpf: Make CS length configurable for rqspinlock stress test
selftests/bpf: Add lock wait time stats to rqspinlock stress test
...
Updating a BPF_MAP_TYPE_HASH_OF_MAPS or BPF_MAP_TYPE_ARRAY_OF_MAPS via
bpf_map_update_elem() is very expensive.
In one of our workloads, we're inserting ~1400 maps of type
BPF_MAP_TYPE_ARRAY into a BPF_MAP_TYPE_ARRAY_OF_MAPS. This takes ~21
seconds on a single thread, with an average of ~15ms per call:
Function Name: map_update_elem
Number of calls: 1369
Total time: 21s 182ms 966µs
Maximum: 47ms 937µs
Average: 15ms 473µs
Minimum: 7µs
Profiling shows that nearly all of this time is going to synchronize_rcu(),
via maybe_wait_bpf_programs() in map_update_elem().
The call to synchronize_rcu() is done to ensure that after
bpf_map_update_elem() returns, no BPF programs are still looking at the old
value of the map, per commit 1ae80cf319 ("bpf: wait for running BPF
programs when updating map-in-map").
As discussed on the bpf mailing list, replace synchronize_rcu() with
synchronize_rcu_expedited(). This is 175x faster: it now takes an average
of 88 microseconds per call, for a total of 127 milliseconds in the same
benchmark:
Function Name: map_update_elem
Number of calls: 1439
Total time: 127ms 626µs
Maximum: 445µs
Average: 88µs
Minimum: 10µs
Link: https://lore.kernel.org/bpf/CAH6OuBR=w2kybK6u7aH_35B=Bo1PCukeMZefR=7V4Z2tJNK--Q@mail.gmail.com/
Signed-off-by: Ritesh Oedayrajsingh Varma <ritesh@superluminal.eu>
Link: https://lore.kernel.org/r/20251128000422.20462-1-ritesh@superluminal.eu
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Syzkaller triggers an invalid memory access issue following fault
injection in update_effective_progs. The issue can be described as
follows:
__cgroup_bpf_detach
update_effective_progs
compute_effective_progs
bpf_prog_array_alloc <-- fault inject
purge_effective_progs
/* change to dummy_bpf_prog */
array->items[index] = &dummy_bpf_prog.prog
---softirq start---
__do_softirq
...
__cgroup_bpf_run_filter_skb
__bpf_prog_run_save_cb
bpf_prog_run
stats = this_cpu_ptr(prog->stats)
/* invalid memory access */
flags = u64_stats_update_begin_irqsave(&stats->syncp)
---softirq end---
static_branch_dec(&cgroup_bpf_enabled_key[atype])
The reason is that fault injection caused update_effective_progs to fail
and then changed the original prog into dummy_bpf_prog.prog in
purge_effective_progs. Then a softirq came, and accessing the members of
dummy_bpf_prog.prog in the softirq triggers invalid mem access.
To fix it, skip updating stats when stats is NULL.
Fixes: 492ecee892 ("bpf: enable program stats")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Link: https://lore.kernel.org/r/20251115102343.2200727-1-pulehui@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
mm_get_unmapped_area() is a wrapper around arch_get_unmapped_area() /
arch_get_unmapped_area_topdown(), both of which search current->mm for
some free space. Neither take an mm_struct - they implicitly operate on
current->mm.
But the wrapper takes an mm_struct and uses it to decide whether to search
bottom up or top down. All callers pass in current->mm for this, so
everything is working consistently. But it feels like an accident waiting
to happen; eventually someone will call that function with a different mm,
expecting to find free space in it, but what gets returned is free space
in the current mm.
So let's simplify by removing the parameter and have the wrapper use
current->mm to decide which end to start at. Now everything is consistent
and self-documenting.
Link: https://lkml.kernel.org/r/20251003155306.2147572-1-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Exports three necessary symbols for implementing struct_ops with
tristate subsystem.
To hold or release refcnt of struct_ops refcnt by inline funcs
bpf_try_module_get and bpf_module_put which use bpf_struct_ops_get(put)
conditionally.
And to copy obj name from one to the other with effective checks by
bpf_obj_name_cpy.
Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251107035632.115950-2-alibuda@linux.alibaba.com
On bpf(BPF_PROG_LOAD) syscall user-supplied BPF programs are
translated by the verifier into "xlated" BPF programs. During this
process the original instructions offsets might be adjusted and/or
individual instructions might be replaced by new sets of instructions,
or deleted.
Add a new BPF map type which is aimed to keep track of how, for a
given program, the original instructions were relocated during the
verification. Also, besides keeping track of the original -> xlated
mapping, make x86 JIT to build the xlated -> jitted mapping for every
instruction listed in an instruction array. This is required for every
future application of instruction arrays: static keys, indirect jumps
and indirect calls.
A map of the BPF_MAP_TYPE_INSN_ARRAY type must be created with a u32
keys and value of size 8. The values have different semantics for
userspace and for BPF space. For userspace a value consists of two
u32 values – xlated and jitted offsets. For BPF side the value is
a real pointer to a jitted instruction.
On map creation/initialization, before loading the program, each
element of the map should be initialized to point to an instruction
offset within the program. Before the program load such maps should
be made frozen. After the program verification xlated and jitted
offsets can be read via the bpf(2) syscall.
If a tracked instruction is removed by the verifier, then the xlated
offset is set to (u32)-1 which is considered to be too big for a valid
BPF program offset.
One such a map can, obviously, be used to track one and only one BPF
program. If the verification process was unsuccessful, then the same
map can be re-used to verify the program with a different log level.
However, if the program was loaded fine, then such a map, being
frozen in any case, can't be reused by other programs even after the
program release.
Example. Consider the following original and xlated programs:
Original prog: Xlated prog:
0: r1 = 0x0 0: r1 = 0
1: *(u32 *)(r10 - 0x4) = r1 1: *(u32 *)(r10 -4) = r1
2: r2 = r10 2: r2 = r10
3: r2 += -0x4 3: r2 += -4
4: r1 = 0x0 ll 4: r1 = map[id:88]
6: call 0x1 6: r1 += 272
7: r0 = *(u32 *)(r2 +0)
8: if r0 >= 0x1 goto pc+3
9: r0 <<= 3
10: r0 += r1
11: goto pc+1
12: r0 = 0
7: r6 = r0 13: r6 = r0
8: if r6 == 0x0 goto +0x2 14: if r6 == 0x0 goto pc+4
9: call 0x76 15: r0 = 0xffffffff8d2079c0
17: r0 = *(u64 *)(r0 +0)
10: *(u64 *)(r6 + 0x0) = r0 18: *(u64 *)(r6 +0) = r0
11: r0 = 0x0 19: r0 = 0x0
12: exit 20: exit
An instruction array map, containing, e.g., instructions [0,4,7,12]
will be translated by the verifier to [0,4,13,20]. A map with
index 5 (the middle of 16-byte instruction) or indexes greater than 12
(outside the program boundaries) would be rejected.
The functionality provided by this patch will be extended in consequent
patches to implement BPF Static Keys, indirect jumps, and indirect calls.
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251105090410.1250500-2-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The following kmemleak splat:
[ 8.105530] kmemleak: Trying to color unknown object at 0xff11000100e918c0 as Black
[ 8.106521] Call Trace:
[ 8.106521] <TASK>
[ 8.106521] dump_stack_lvl+0x4b/0x70
[ 8.106521] kvfree_call_rcu+0xcb/0x3b0
[ 8.106521] ? hrtimer_cancel+0x21/0x40
[ 8.106521] bpf_obj_free_fields+0x193/0x200
[ 8.106521] htab_map_update_elem+0x29c/0x410
[ 8.106521] bpf_prog_cfc8cd0f42c04044_overwrite_cb+0x47/0x4b
[ 8.106521] bpf_prog_8c30cd7c4db2e963_overwrite_timer+0x65/0x86
[ 8.106521] bpf_prog_test_run_syscall+0xe1/0x2a0
happens due to the combination of features and fixes, but mainly due to
commit 6d78b4473c ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()")
It's using __GFP_HIGH, which instructs slub/kmemleak internals to skip
kmemleak_alloc_recursive() on allocation, so subsequent kfree_rcu()->
kvfree_call_rcu()->kmemleak_ignore() complains with the above splat.
To fix this imbalance, replace bpf_map_kmalloc_node() with
kmalloc_nolock() and kfree_rcu() with call_rcu() + kfree_nolock() to
make sure that the objects allocated with kmalloc_nolock() are freed
with kfree_nolock() rather than the implicit kfree() that kfree_rcu()
uses internally.
Note, the kmalloc_nolock() happens under bpf_spin_lock_irqsave(), so
it will always fail in PREEMPT_RT. This is not an issue at the moment,
since bpf_timers are disabled in PREEMPT_RT. In the future
bpf_spin_lock will be replaced with state machine similar to
bpf_task_work.
Fixes: 6d78b4473c ("bpf: Tell memcg to use allow_spinning=false path in bpf_timer_init()")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/bpf/20251015000700.28988-1-alexei.starovoitov@gmail.com
Pull slab updates from Vlastimil Babka:
- A new layer for caching objects for allocation and free via percpu
arrays called sheaves.
The aim is to combine the good parts of SLAB (lower-overhead and
simpler percpu caching, compared to SLUB) without the past issues
with arrays for freeing remote NUMA node objects and their flushing.
It also allows more efficient kfree_rcu(), and cheaper object
preallocations for cases where the exact number of objects is
unknown, but an upper bound is.
Currently VMAs and maple nodes are using this new caching, with a
plan to enable it for all caches and remove the complex SLUB fastpath
based on cpu (partial) slabs and this_cpu_cmpxchg_double().
(Vlastimil Babka, with Liam Howlett and Pedro Falcato for the maple
tree changes)
- Re-entrant kmalloc_nolock(), which allows opportunistic allocations
from NMI and tracing/kprobe contexts.
Building on prior page allocator and memcg changes, it will result in
removing BPF-specific caches on top of slab (Alexei Starovoitov)
- Various fixes and cleanups. (Kuan-Wei Chiu, Matthew Wilcox, Suren
Baghdasaryan, Ye Liu)
* tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (40 commits)
slab: Introduce kmalloc_nolock() and kfree_nolock().
slab: Reuse first bit for OBJEXTS_ALLOC_FAIL
slab: Make slub local_(try)lock more precise for LOCKDEP
mm: Introduce alloc_frozen_pages_nolock()
mm: Allow GFP_ACCOUNT to be used in alloc_pages_nolock().
locking/local_lock: Introduce local_lock_is_locked().
maple_tree: Convert forking to use the sheaf interface
maple_tree: Add single node allocation support to maple state
maple_tree: Prefilled sheaf conversion and testing
tools/testing: Add support for prefilled slab sheafs
maple_tree: Replace mt_free_one() with kfree()
maple_tree: Use kfree_rcu in ma_free_rcu
testing/radix-tree/maple: Hack around kfree_rcu not existing
tools/testing: include maple-shim.c in maple.c
maple_tree: use percpu sheaves for maple_node_cache
mm, vma: use percpu sheaves for vm_area_struct cache
tools/testing: Add support for changes to slab for sheaves
slab: allow NUMA restricted allocations to use percpu sheaves
tools/testing/vma: Implement vm_refcnt reset
slab: skip percpu sheaves for remote object freeing
...
Change alloc_pages_nolock() to default to __GFP_COMP when allocating
pages, since upcoming reentrant alloc_slab_page() needs __GFP_COMP.
Also allow __GFP_ACCOUNT flag to be specified,
since most of BPF infra needs __GFP_ACCOUNT except BPF streams.
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
The stacktrace map can be easily full, which will lead to failure in
obtaining the stack. In addition to increasing the size of the map,
another solution is to delete the stack_id after looking it up from
the user, so extend the existing bpf_map_lookup_and_delete_elem()
functionality to stacktrace map types.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250925175030.1615837-1-chen.dylane@linux.dev
This patch adds necessary plumbing in verifier, syscall and maps to
support handling new kfunc bpf_task_work_schedule and kernel structure
bpf_task_work. The idea is similar to how we already handle bpf_wq and
bpf_timer.
verifier changes validate calls to bpf_task_work_schedule to make sure
it is safe and expected invariants hold.
btf part is required to detect bpf_task_work structure inside map value
and store its offset, which will be used in the next patch to calculate
key and value addresses.
arraymap and hashtab changes are needed to handle freeing of the
bpf_task_work: run code needed to deinitialize it, for example cancel
task_work callback if possible.
The use of bpf_task_work and proper implementation for kfuncs are
introduced in the next patch.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20250923112404.668720-6-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This patch extends the BPF_PROG_LOAD command by adding three new fields
to `union bpf_attr` in the user-space API:
- signature: A pointer to the signature blob.
- signature_size: The size of the signature blob.
- keyring_id: The serial number of a loaded kernel keyring (e.g.,
the user or session keyring) containing the trusted public keys.
When a BPF program is loaded with a signature, the kernel:
1. Retrieves the trusted keyring using the provided `keyring_id`.
2. Verifies the supplied signature against the BPF program's
instruction buffer.
3. If the signature is valid and was generated by a key in the trusted
keyring, the program load proceeds.
4. If no signature is provided, the load proceeds as before, allowing
for backward compatibility. LSMs can chose to restrict unsigned
programs and implement a security policy.
5. If signature verification fails for any reason,
the program is not loaded.
Tested-by: syzbot@syzkaller.appspotmail.com
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250921160120.9711-2-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently only array maps are supported, but the implementation can be
extended for other maps and objects. The hash is memoized only for
exclusive and frozen maps as their content is stable until the exclusive
program modifies the map.
This is required for BPF signing, enabling a trusted loader program to
verify a map's integrity. The loader retrieves
the map's runtime hash from the kernel and compares it against an
expected hash computed at build time.
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-7-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Exclusive maps allow maps to only be accessed by program with a
program with a matching hash which is specified in the excl_prog_hash
attr.
For the signing use-case, this allows the trusted loader program
to load the map and verify the integrity
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-3-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
system_unbound_wq should be the default workqueue so as not to enforce
locality constraints for random work whenever it's not required.
Adding system_dfl_wq to encourage its use when unbound work should be used.
queue_work() / queue_delayed_work() / mod_delayed_work() will now use the
new unbound wq: whether the user still use the old wq a warn will be
printed along with a wq redirect to the new one.
The old system_unbound_wq will be kept for a few release cycles.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Link: https://lore.kernel.org/r/20250905085309.94596-3-marco.crivellari@suse.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Given this is only relevant for BPF tail call maps, it is adding up space
and penalizing other map types. We also need to extend this with further
objects to track / compare to. Therefore, lets move this out into a separate
structure and dynamically allocate it only for BPF tail call maps.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20250730234733.530041-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The 'commit 35f96de041 ("bpf: Introduce BPF token object")' added
BPF token as a new kind of BPF kernel object. And BPF_OBJ_GET_INFO_BY_FD
already used to get BPF object info, so we can also get token info with
this cmd.
One usage scenario, when program runs failed with token, because of
the permission failure, we can report what BPF token is allowing with
this API for debugging.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Link: https://lore.kernel.org/r/20250716134654.1162635-1-chen.dylane@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for a stream API to the kernel and expose related kfuncs to
BPF programs. Two streams are exposed, BPF_STDOUT and BPF_STDERR. These
can be used for printing messages that can be consumed from user space,
thus it's similar in spirit to existing trace_pipe interface.
The kernel will use the BPF_STDERR stream to notify the program of any
errors encountered at runtime. BPF programs themselves may use both
streams for writing debug messages. BPF library-like code may use
BPF_STDERR to print warnings or errors on misuse at runtime.
The implementation of a stream is as follows. Everytime a message is
emitted from the kernel (directly, or through a BPF program), a record
is allocated by bump allocating from per-cpu region backed by a page
obtained using alloc_pages_nolock(). This ensures that we can allocate
memory from any context. The eventual plan is to discard this scheme in
favor of Alexei's kmalloc_nolock() [0].
This record is then locklessly inserted into a list (llist_add()) so
that the printing side doesn't require holding any locks, and works in
any context. Each stream has a maximum capacity of 4MB of text, and each
printed message is accounted against this limit.
Messages from a program are emitted using the bpf_stream_vprintk kfunc,
which takes a stream_id argument in addition to working otherwise
similar to bpf_trace_vprintk.
The bprintf buffer helpers are extracted out to be reused for printing
the string into them before copying it into the stream, so that we can
(with the defined max limit) format a string and know its true length
before performing allocations of the stream element.
For consuming elements from a stream, we expose a bpf(2) syscall command
named BPF_PROG_STREAM_READ_BY_FD, which allows reading data from the
stream of a given prog_fd into a user space buffer. The main logic is
implemented in bpf_stream_read(). The log messages are queued in
bpf_stream::log by the bpf_stream_vprintk kfunc, and then pulled and
ordered correctly in the stream backlog.
For this purpose, we hold a lock around bpf_stream_backlog_peek(), as
llist_del_first() (if we maintained a second lockless list for the
backlog) wouldn't be safe from multiple threads anyway. Then, if we
fail to find something in the backlog log, we splice out everything from
the lockless log, and place it in the backlog log, and then return the
head of the backlog. Once the full length of the element is consumed, we
will pop it and free it.
The lockless list bpf_stream::log is a LIFO stack. Elements obtained
using a llist_del_all() operation are in LIFO order, thus would break
the chronological ordering if printed directly. Hence, this batch of
messages is first reversed. Then, it is stashed into a separate list in
the stream, i.e. the backlog_log. The head of this list is the actual
message that should always be returned to the caller. All of this is
done in bpf_stream_backlog_fill().
From the kernel side, the writing into the stream will be a bit more
involved than the typical printk. First, the kernel typically may print
a collection of messages into the stream, and parallel writers into the
stream may suffer from interleaving of messages. To ensure each group of
messages is visible atomically, we can lift the advantage of using a
lockless list for pushing in messages.
To enable this, we add a bpf_stream_stage() macro, and require kernel
users to use bpf_stream_printk statements for the passed expression to
write into the stream. Underneath the macro, we have a message staging
API, where a bpf_stream_stage object on the stack accumulates the
messages being printed into a local llist_head, and then a commit
operation splices the whole batch into the stream's lockless log list.
This is especially pertinent for rqspinlock deadlock messages printed to
program streams. After this change, we see each deadlock invocation as a
non-interleaving contiguous message without any confusion on the
reader's part, improving their user experience in debugging the fault.
While programs cannot benefit from this staged stream writing API, they
could just as well hold an rqspinlock around their print statements to
serialize messages, hence this is kept kernel-internal for now.
Overall, this infrastructure provides NMI-safe any context printing of
messages to two dedicated streams.
Later patches will add support for printing splats in case of BPF arena
page faults, rqspinlock deadlocks, and cond_break timeouts, and
integration of this facility into bpftool for dumping messages to user
space.
[0]: https://lore.kernel.org/bpf/20250501032718.65476-1-alexei.starovoitov@gmail.com
Reviewed-by: Eduard Zingerman <eddyz87@gmail.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20250703204818.925464-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Alexei suggested, 'link_type' can be more precise and differentiate
for human in fdinfo. In fact BPF_LINK_TYPE_KPROBE_MULTI includes
kretprobe_multi type, the same as BPF_LINK_TYPE_UPROBE_MULTI, so we
can show it more concretely.
link_type: kprobe_multi
link_id: 1
prog_tag: d2b307e915f0dd37
...
link_type: kretprobe_multi
link_id: 2
prog_tag: ab9ea0545870781d
...
link_type: uprobe_multi
link_id: 9
prog_tag: e729f789e34a8eca
...
link_type: uretprobe_multi
link_id: 10
prog_tag: 7db356c03e61a4d4
Co-developed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Link: https://lore.kernel.org/r/20250702153958.639852-1-chen.dylane@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Current cgroup prog ordering is appending at attachment time. This is not
ideal. In some cases, users want specific ordering at a particular cgroup
level. To address this, the existing mprog API seems an ideal solution with
supporting BPF_F_BEFORE and BPF_F_AFTER flags.
But there are a few obstacles to directly use kernel mprog interface.
Currently cgroup bpf progs already support prog attach/detach/replace
and link-based attach/detach/replace. For example, in struct
bpf_prog_array_item, the cgroup_storage field needs to be together
with bpf prog. But the mprog API struct bpf_mprog_fp only has bpf_prog
as the member, which makes it difficult to use kernel mprog interface.
In another case, the current cgroup prog detach tries to use the
same flag as in attach. This is different from mprog kernel interface
which uses flags passed from user space.
So to avoid modifying existing behavior, I made the following changes to
support mprog API for cgroup progs:
- The support is for prog list at cgroup level. Cross-level prog list
(a.k.a. effective prog list) is not supported.
- Previously, BPF_F_PREORDER is supported only for prog attach, now
BPF_F_PREORDER is also supported by link-based attach.
- For attach, BPF_F_BEFORE/BPF_F_AFTER/BPF_F_ID/BPF_F_LINK is supported
similar to kernel mprog but with different implementation.
- For detach and replace, use the existing implementation.
- For attach, detach and replace, the revision for a particular prog
list, associated with a particular attach type, will be updated
by increasing count by 1.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250606163141.2428937-1-yonghong.song@linux.dev
Pull MM updates from Andrew Morton:
- "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
creating a pte which addresses the first page in a folio and reduces
the amount of plumbing which architecture must implement to provide
this.
- "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
largely unrelated folio infrastructure changes which clean things up
and better prepare us for future work.
- "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
Price adds early-init code to prevent x86 from leaving physical
memory unused when physical address regions are not aligned to memory
block size.
- "mm/compaction: allow more aggressive proactive compaction" from
Michal Clapinski provides some tuning of the (sadly, hard-coded (more
sadly, not auto-tuned)) thresholds for our invokation of proactive
compaction. In a simple test case, the reduction of a guest VM's
memory consumption was dramatic.
- "Minor cleanups and improvements to swap freeing code" from Kemeng
Shi provides some code cleaups and a small efficiency improvement to
this part of our swap handling code.
- "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
adds the ability for a ptracer to modify syscalls arguments. At this
time we can alter only "system call information that are used by
strace system call tampering, namely, syscall number, syscall
arguments, and syscall return value.
This series should have been incorporated into mm.git's "non-MM"
branch, but I goofed.
- "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
against /proc/pid/pagemap. This permits CRIU to more efficiently get
at the info about guard regions.
- "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
implements that fix. No runtime effect is expected because
validate_page_before_insert() happens to fix up this error.
- "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
Hildenbrand basically brings uprobe text poking into the current
decade. Remove a bunch of hand-rolled implementation in favor of
using more current facilities.
- "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
Khandual provides enhancements and generalizations to the pte dumping
code. This might be needed when 128-bit Page Table Descriptors are
enabled for ARM.
- "Always call constructor for kernel page tables" from Kevin Brodsky
ensures that the ctor/dtor is always called for kernel pgtables, as
it already is for user pgtables.
This permits the addition of more functionality such as "insert hooks
to protect page tables". This change does result in various
architectures performing unnecesary work, but this is fixed up where
it is anticipated to occur.
- "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
Ryhl adds plumbing to permit Rust access to core MM structures.
- "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
Stoakes takes advantage of some VMA merging opportunities which we've
been missing for 15 years.
- "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
SeongJae Park optimizes process_madvise()'s TLB flushing.
Instead of flushing each address range in the provided iovec, we
batch the flushing across all the iovec entries. The syscall's cost
was approximately halved with a microbenchmark which was designed to
load this particular operation.
- "Track node vacancy to reduce worst case allocation counts" from
Sidhartha Kumar makes the maple tree smarter about its node
preallocation.
stress-ng mmap performance increased by single-digit percentages and
the amount of unnecessarily preallocated memory was dramaticelly
reduced.
- "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
a few unnecessary things which Baoquan noted when reading the code.
- ""Enhance sysfs handling for memory hotplug in weighted interleave"
from Rakie Kim "enhances the weighted interleave policy in the memory
management subsystem by improving sysfs handling, fixing memory
leaks, and introducing dynamic sysfs updates for memory hotplug
support". Fixes things on error paths which we are unlikely to hit.
- "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
from SeongJae Park introduces new DAMOS quota goal metrics which
eliminate the manual tuning which is required when utilizing DAMON
for memory tiering.
- "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
provides cleanups and small efficiency improvements which Baoquan
found via code inspection.
- "vmscan: enforce mems_effective during demotion" from Gregory Price
changes reclaim to respect cpuset.mems_effective during demotion when
possible. because presently, reclaim explicitly ignores
cpuset.mems_effective when demoting, which may cause the cpuset
settings to violated.
This is useful for isolating workloads on a multi-tenant system from
certain classes of memory more consistently.
- "Clean up split_huge_pmd_locked() and remove unnecessary folio
pointers" from Gavin Guo provides minor cleanups and efficiency gains
in in the huge page splitting and migrating code.
- "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
for `struct mem_cgroup', yielding improved memory utilization.
- "add max arg to swappiness in memory.reclaim and lru_gen" from
Zhongkun He adds a new "max" argument to the "swappiness=" argument
for memory.reclaim MGLRU's lru_gen.
This directs proactive reclaim to reclaim from only anon folios
rather than file-backed folios.
- "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
first step on the path to permitting the kernel to maintain existing
VMs while replacing the host kernel via file-based kexec. At this
time only memblock's reserve_mem is preserved.
- "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
and uses a smarter way of looping over a pfn range. By skipping
ranges of invalid pfns.
- "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
when a task is pinned a single NUMA mode.
Dramatic performance benefits were seen in some real world cases.
- "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
Garg addresses a warning which occurs during memory compaction when
using JFS.
- "move all VMA allocation, freeing and duplication logic to mm" from
Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
appropriate mm/vma.c.
- "mm, swap: clean up swap cache mapping helper" from Kairui Song
provides code consolidation and cleanups related to the folio_index()
function.
- "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.
- "memcg: Fix test_memcg_min/low test failures" from Waiman Long
addresses some bogus failures which are being reported by the
test_memcontrol selftest.
- "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
Stoakes commences the deprecation of file_operations.mmap() in favor
of the new file_operations.mmap_prepare().
The latter is more restrictive and prevents drivers from messing with
things in ways which, amongst other problems, may defeat VMA merging.
- "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
the per-cpu memcg charge cache from the objcg's one.
This is a step along the way to making memcg and objcg charging
NMI-safe, which is a BPF requirement.
- "mm/damon: minor fixups and improvements for code, tests, and
documents" from SeongJae Park is yet another batch of miscellaneous
DAMON changes. Fix and improve minor problems in code, tests and
documents.
- "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
stats to be irq safe. Another step along the way to making memcg
charging and stats updates NMI-safe, a BPF requirement.
- "Let unmap_hugepage_range() and several related functions take folio
instead of page" from Fan Ni provides folio conversions in the
hugetlb code.
* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
mm: pcp: increase pcp->free_count threshold to trigger free_high
mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
mm/hugetlb: pass folio instead of page to unmap_ref_private()
memcg: objcg stock trylock without irq disabling
memcg: no stock lock for cpu hot-unplug
memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
memcg: make count_memcg_events re-entrant safe against irqs
memcg: make mod_memcg_state re-entrant safe against irqs
memcg: move preempt disable to callers of memcg_rstat_updated
memcg: memcg_rstat_updated re-entrant safe against irqs
mm: khugepaged: decouple SHMEM and file folios' collapse
selftests/eventfd: correct test name and improve messages
alloc_tag: check mem_profiling_support in alloc_tag_init
Docs/damon: update titles and brief introductions to explain DAMOS
selftests/damon/_damon_sysfs: read tried regions directories in order
mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
...
