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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 /kernel/trace/trace_recursion_record.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 '')
-rw-r--r-- | kernel/trace/trace_recursion_record.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/kernel/trace/trace_recursion_record.c b/kernel/trace/trace_recursion_record.c new file mode 100644 index 000000000..a520b11af --- /dev/null +++ b/kernel/trace/trace_recursion_record.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/seq_file.h> +#include <linux/kallsyms.h> +#include <linux/module.h> +#include <linux/ftrace.h> +#include <linux/fs.h> + +#include "trace_output.h" + +struct recursed_functions { + unsigned long ip; + unsigned long parent_ip; +}; + +static struct recursed_functions recursed_functions[CONFIG_FTRACE_RECORD_RECURSION_SIZE]; +static atomic_t nr_records; + +/* + * Cache the last found function. Yes, updates to this is racey, but + * so is memory cache ;-) + */ +static unsigned long cached_function; + +void ftrace_record_recursion(unsigned long ip, unsigned long parent_ip) +{ + int index = 0; + int i; + unsigned long old; + + again: + /* First check the last one recorded */ + if (ip == cached_function) + return; + + i = atomic_read(&nr_records); + /* nr_records is -1 when clearing records */ + smp_mb__after_atomic(); + if (i < 0) + return; + + /* + * If there's two writers and this writer comes in second, + * the cmpxchg() below to update the ip will fail. Then this + * writer will try again. It is possible that index will now + * be greater than nr_records. This is because the writer + * that succeeded has not updated the nr_records yet. + * This writer could keep trying again until the other writer + * updates nr_records. But if the other writer takes an + * interrupt, and that interrupt locks up that CPU, we do + * not want this CPU to lock up due to the recursion protection, + * and have a bug report showing this CPU as the cause of + * locking up the computer. To not lose this record, this + * writer will simply use the next position to update the + * recursed_functions, and it will update the nr_records + * accordingly. + */ + if (index < i) + index = i; + if (index >= CONFIG_FTRACE_RECORD_RECURSION_SIZE) + return; + + for (i = index - 1; i >= 0; i--) { + if (recursed_functions[i].ip == ip) { + cached_function = ip; + return; + } + } + + cached_function = ip; + + /* + * We only want to add a function if it hasn't been added before. + * Add to the current location before incrementing the count. + * If it fails to add, then increment the index (save in i) + * and try again. + */ + old = cmpxchg(&recursed_functions[index].ip, 0, ip); + if (old != 0) { + /* Did something else already added this for us? */ + if (old == ip) + return; + /* Try the next location (use i for the next index) */ + index++; + goto again; + } + + recursed_functions[index].parent_ip = parent_ip; + + /* + * It's still possible that we could race with the clearing + * CPU0 CPU1 + * ---- ---- + * ip = func + * nr_records = -1; + * recursed_functions[0] = 0; + * i = -1 + * if (i < 0) + * nr_records = 0; + * (new recursion detected) + * recursed_functions[0] = func + * cmpxchg(recursed_functions[0], + * func, 0) + * + * But the worse that could happen is that we get a zero in + * the recursed_functions array, and it's likely that "func" will + * be recorded again. + */ + i = atomic_read(&nr_records); + smp_mb__after_atomic(); + if (i < 0) + cmpxchg(&recursed_functions[index].ip, ip, 0); + else if (i <= index) + atomic_cmpxchg(&nr_records, i, index + 1); +} +EXPORT_SYMBOL_GPL(ftrace_record_recursion); + +static DEFINE_MUTEX(recursed_function_lock); +static struct trace_seq *tseq; + +static void *recursed_function_seq_start(struct seq_file *m, loff_t *pos) +{ + void *ret = NULL; + int index; + + mutex_lock(&recursed_function_lock); + index = atomic_read(&nr_records); + if (*pos < index) { + ret = &recursed_functions[*pos]; + } + + tseq = kzalloc(sizeof(*tseq), GFP_KERNEL); + if (!tseq) + return ERR_PTR(-ENOMEM); + + trace_seq_init(tseq); + + return ret; +} + +static void *recursed_function_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + int index; + int p; + + index = atomic_read(&nr_records); + p = ++(*pos); + + return p < index ? &recursed_functions[p] : NULL; +} + +static void recursed_function_seq_stop(struct seq_file *m, void *v) +{ + kfree(tseq); + mutex_unlock(&recursed_function_lock); +} + +static int recursed_function_seq_show(struct seq_file *m, void *v) +{ + struct recursed_functions *record = v; + int ret = 0; + + if (record) { + trace_seq_print_sym(tseq, record->parent_ip, true); + trace_seq_puts(tseq, ":\t"); + trace_seq_print_sym(tseq, record->ip, true); + trace_seq_putc(tseq, '\n'); + ret = trace_print_seq(m, tseq); + } + + return ret; +} + +static const struct seq_operations recursed_function_seq_ops = { + .start = recursed_function_seq_start, + .next = recursed_function_seq_next, + .stop = recursed_function_seq_stop, + .show = recursed_function_seq_show +}; + +static int recursed_function_open(struct inode *inode, struct file *file) +{ + int ret = 0; + + mutex_lock(&recursed_function_lock); + /* If this file was opened for write, then erase contents */ + if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { + /* disable updating records */ + atomic_set(&nr_records, -1); + smp_mb__after_atomic(); + memset(recursed_functions, 0, sizeof(recursed_functions)); + smp_wmb(); + /* enable them again */ + atomic_set(&nr_records, 0); + } + if (file->f_mode & FMODE_READ) + ret = seq_open(file, &recursed_function_seq_ops); + mutex_unlock(&recursed_function_lock); + + return ret; +} + +static ssize_t recursed_function_write(struct file *file, + const char __user *buffer, + size_t count, loff_t *ppos) +{ + return count; +} + +static int recursed_function_release(struct inode *inode, struct file *file) +{ + if (file->f_mode & FMODE_READ) + seq_release(inode, file); + return 0; +} + +static const struct file_operations recursed_functions_fops = { + .open = recursed_function_open, + .write = recursed_function_write, + .read = seq_read, + .llseek = seq_lseek, + .release = recursed_function_release, +}; + +__init static int create_recursed_functions(void) +{ + + trace_create_file("recursed_functions", TRACE_MODE_WRITE, + NULL, NULL, &recursed_functions_fops); + return 0; +} + +fs_initcall(create_recursed_functions); |