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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /mm/shuffle.c | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'mm/shuffle.c')
-rw-r--r-- | mm/shuffle.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/mm/shuffle.c b/mm/shuffle.c new file mode 100644 index 000000000..fb1393b8b --- /dev/null +++ b/mm/shuffle.c @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright(c) 2018 Intel Corporation. All rights reserved. + +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/mmzone.h> +#include <linux/random.h> +#include <linux/moduleparam.h> +#include "internal.h" +#include "shuffle.h" + +DEFINE_STATIC_KEY_FALSE(page_alloc_shuffle_key); + +static bool shuffle_param; + +static __meminit int shuffle_param_set(const char *val, + const struct kernel_param *kp) +{ + if (param_set_bool(val, kp)) + return -EINVAL; + if (*(bool *)kp->arg) + static_branch_enable(&page_alloc_shuffle_key); + return 0; +} + +static const struct kernel_param_ops shuffle_param_ops = { + .set = shuffle_param_set, + .get = param_get_bool, +}; +module_param_cb(shuffle, &shuffle_param_ops, &shuffle_param, 0400); + +/* + * For two pages to be swapped in the shuffle, they must be free (on a + * 'free_area' lru), have the same order, and have the same migratetype. + */ +static struct page * __meminit shuffle_valid_page(struct zone *zone, + unsigned long pfn, int order) +{ + struct page *page = pfn_to_online_page(pfn); + + /* + * Given we're dealing with randomly selected pfns in a zone we + * need to ask questions like... + */ + + /* ... is the page managed by the buddy? */ + if (!page) + return NULL; + + /* ... is the page assigned to the same zone? */ + if (page_zone(page) != zone) + return NULL; + + /* ...is the page free and currently on a free_area list? */ + if (!PageBuddy(page)) + return NULL; + + /* + * ...is the page on the same list as the page we will + * shuffle it with? + */ + if (buddy_order(page) != order) + return NULL; + + return page; +} + +/* + * Fisher-Yates shuffle the freelist which prescribes iterating through an + * array, pfns in this case, and randomly swapping each entry with another in + * the span, end_pfn - start_pfn. + * + * To keep the implementation simple it does not attempt to correct for sources + * of bias in the distribution, like modulo bias or pseudo-random number + * generator bias. I.e. the expectation is that this shuffling raises the bar + * for attacks that exploit the predictability of page allocations, but need not + * be a perfect shuffle. + */ +#define SHUFFLE_RETRY 10 +void __meminit __shuffle_zone(struct zone *z) +{ + unsigned long i, flags; + unsigned long start_pfn = z->zone_start_pfn; + unsigned long end_pfn = zone_end_pfn(z); + const int order = SHUFFLE_ORDER; + const int order_pages = 1 << order; + + spin_lock_irqsave(&z->lock, flags); + start_pfn = ALIGN(start_pfn, order_pages); + for (i = start_pfn; i < end_pfn; i += order_pages) { + unsigned long j; + int migratetype, retry; + struct page *page_i, *page_j; + + /* + * We expect page_i, in the sub-range of a zone being added + * (@start_pfn to @end_pfn), to more likely be valid compared to + * page_j randomly selected in the span @zone_start_pfn to + * @spanned_pages. + */ + page_i = shuffle_valid_page(z, i, order); + if (!page_i) + continue; + + for (retry = 0; retry < SHUFFLE_RETRY; retry++) { + /* + * Pick a random order aligned page in the zone span as + * a swap target. If the selected pfn is a hole, retry + * up to SHUFFLE_RETRY attempts find a random valid pfn + * in the zone. + */ + j = z->zone_start_pfn + + ALIGN_DOWN(get_random_long() % z->spanned_pages, + order_pages); + page_j = shuffle_valid_page(z, j, order); + if (page_j && page_j != page_i) + break; + } + if (retry >= SHUFFLE_RETRY) { + pr_debug("%s: failed to swap %#lx\n", __func__, i); + continue; + } + + /* + * Each migratetype corresponds to its own list, make sure the + * types match otherwise we're moving pages to lists where they + * do not belong. + */ + migratetype = get_pageblock_migratetype(page_i); + if (get_pageblock_migratetype(page_j) != migratetype) { + pr_debug("%s: migratetype mismatch %#lx\n", __func__, i); + continue; + } + + list_swap(&page_i->lru, &page_j->lru); + + pr_debug("%s: swap: %#lx -> %#lx\n", __func__, i, j); + + /* take it easy on the zone lock */ + if ((i % (100 * order_pages)) == 0) { + spin_unlock_irqrestore(&z->lock, flags); + cond_resched(); + spin_lock_irqsave(&z->lock, flags); + } + } + spin_unlock_irqrestore(&z->lock, flags); +} + +/* + * __shuffle_free_memory - reduce the predictability of the page allocator + * @pgdat: node page data + */ +void __meminit __shuffle_free_memory(pg_data_t *pgdat) +{ + struct zone *z; + + for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) + shuffle_zone(z); +} + +bool shuffle_pick_tail(void) +{ + static u64 rand; + static u8 rand_bits; + bool ret; + + /* + * The lack of locking is deliberate. If 2 threads race to + * update the rand state it just adds to the entropy. + */ + if (rand_bits == 0) { + rand_bits = 64; + rand = get_random_u64(); + } + + ret = rand & 1; + + rand_bits--; + rand >>= 1; + + return ret; +} |