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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_functions.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 'kernel/trace/trace_functions.c')
-rw-r--r-- | kernel/trace/trace_functions.c | 974 |
1 files changed, 974 insertions, 0 deletions
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c new file mode 100644 index 000000000..9f1bfbe10 --- /dev/null +++ b/kernel/trace/trace_functions.c @@ -0,0 +1,974 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * ring buffer based function tracer + * + * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> + * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> + * + * Based on code from the latency_tracer, that is: + * + * Copyright (C) 2004-2006 Ingo Molnar + * Copyright (C) 2004 Nadia Yvette Chambers + */ +#include <linux/ring_buffer.h> +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/ftrace.h> +#include <linux/slab.h> +#include <linux/fs.h> + +#include "trace.h" + +static void tracing_start_function_trace(struct trace_array *tr); +static void tracing_stop_function_trace(struct trace_array *tr); +static void +function_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs); +static void +function_stack_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs); +static void +function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs); +static void +function_stack_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, + struct ftrace_regs *fregs); +static struct tracer_flags func_flags; + +/* Our option */ +enum { + + TRACE_FUNC_NO_OPTS = 0x0, /* No flags set. */ + TRACE_FUNC_OPT_STACK = 0x1, + TRACE_FUNC_OPT_NO_REPEATS = 0x2, + + /* Update this to next highest bit. */ + TRACE_FUNC_OPT_HIGHEST_BIT = 0x4 +}; + +#define TRACE_FUNC_OPT_MASK (TRACE_FUNC_OPT_HIGHEST_BIT - 1) + +int ftrace_allocate_ftrace_ops(struct trace_array *tr) +{ + struct ftrace_ops *ops; + + /* The top level array uses the "global_ops" */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) + return 0; + + ops = kzalloc(sizeof(*ops), GFP_KERNEL); + if (!ops) + return -ENOMEM; + + /* Currently only the non stack version is supported */ + ops->func = function_trace_call; + ops->flags = FTRACE_OPS_FL_PID; + + tr->ops = ops; + ops->private = tr; + + return 0; +} + +void ftrace_free_ftrace_ops(struct trace_array *tr) +{ + kfree(tr->ops); + tr->ops = NULL; +} + +int ftrace_create_function_files(struct trace_array *tr, + struct dentry *parent) +{ + /* + * The top level array uses the "global_ops", and the files are + * created on boot up. + */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) + return 0; + + if (!tr->ops) + return -EINVAL; + + ftrace_create_filter_files(tr->ops, parent); + + return 0; +} + +void ftrace_destroy_function_files(struct trace_array *tr) +{ + ftrace_destroy_filter_files(tr->ops); + ftrace_free_ftrace_ops(tr); +} + +static ftrace_func_t select_trace_function(u32 flags_val) +{ + switch (flags_val & TRACE_FUNC_OPT_MASK) { + case TRACE_FUNC_NO_OPTS: + return function_trace_call; + case TRACE_FUNC_OPT_STACK: + return function_stack_trace_call; + case TRACE_FUNC_OPT_NO_REPEATS: + return function_no_repeats_trace_call; + case TRACE_FUNC_OPT_STACK | TRACE_FUNC_OPT_NO_REPEATS: + return function_stack_no_repeats_trace_call; + default: + return NULL; + } +} + +static bool handle_func_repeats(struct trace_array *tr, u32 flags_val) +{ + if (!tr->last_func_repeats && + (flags_val & TRACE_FUNC_OPT_NO_REPEATS)) { + tr->last_func_repeats = alloc_percpu(struct trace_func_repeats); + if (!tr->last_func_repeats) + return false; + } + + return true; +} + +static int function_trace_init(struct trace_array *tr) +{ + ftrace_func_t func; + /* + * Instance trace_arrays get their ops allocated + * at instance creation. Unless it failed + * the allocation. + */ + if (!tr->ops) + return -ENOMEM; + + func = select_trace_function(func_flags.val); + if (!func) + return -EINVAL; + + if (!handle_func_repeats(tr, func_flags.val)) + return -ENOMEM; + + ftrace_init_array_ops(tr, func); + + tr->array_buffer.cpu = raw_smp_processor_id(); + + tracing_start_cmdline_record(); + tracing_start_function_trace(tr); + return 0; +} + +static void function_trace_reset(struct trace_array *tr) +{ + tracing_stop_function_trace(tr); + tracing_stop_cmdline_record(); + ftrace_reset_array_ops(tr); +} + +static void function_trace_start(struct trace_array *tr) +{ + tracing_reset_online_cpus(&tr->array_buffer); +} + +static void +function_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) +{ + struct trace_array *tr = op->private; + struct trace_array_cpu *data; + unsigned int trace_ctx; + int bit; + int cpu; + + if (unlikely(!tr->function_enabled)) + return; + + bit = ftrace_test_recursion_trylock(ip, parent_ip); + if (bit < 0) + return; + + trace_ctx = tracing_gen_ctx(); + + cpu = smp_processor_id(); + data = per_cpu_ptr(tr->array_buffer.data, cpu); + if (!atomic_read(&data->disabled)) + trace_function(tr, ip, parent_ip, trace_ctx); + + ftrace_test_recursion_unlock(bit); +} + +#ifdef CONFIG_UNWINDER_ORC +/* + * Skip 2: + * + * function_stack_trace_call() + * ftrace_call() + */ +#define STACK_SKIP 2 +#else +/* + * Skip 3: + * __trace_stack() + * function_stack_trace_call() + * ftrace_call() + */ +#define STACK_SKIP 3 +#endif + +static void +function_stack_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, struct ftrace_regs *fregs) +{ + struct trace_array *tr = op->private; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + unsigned int trace_ctx; + + if (unlikely(!tr->function_enabled)) + return; + + /* + * Need to use raw, since this must be called before the + * recursive protection is performed. + */ + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = per_cpu_ptr(tr->array_buffer.data, cpu); + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) { + trace_ctx = tracing_gen_ctx_flags(flags); + trace_function(tr, ip, parent_ip, trace_ctx); + __trace_stack(tr, trace_ctx, STACK_SKIP); + } + + atomic_dec(&data->disabled); + local_irq_restore(flags); +} + +static inline bool is_repeat_check(struct trace_array *tr, + struct trace_func_repeats *last_info, + unsigned long ip, unsigned long parent_ip) +{ + if (last_info->ip == ip && + last_info->parent_ip == parent_ip && + last_info->count < U16_MAX) { + last_info->ts_last_call = + ring_buffer_time_stamp(tr->array_buffer.buffer); + last_info->count++; + return true; + } + + return false; +} + +static inline void process_repeats(struct trace_array *tr, + unsigned long ip, unsigned long parent_ip, + struct trace_func_repeats *last_info, + unsigned int trace_ctx) +{ + if (last_info->count) { + trace_last_func_repeats(tr, last_info, trace_ctx); + last_info->count = 0; + } + + last_info->ip = ip; + last_info->parent_ip = parent_ip; +} + +static void +function_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, + struct ftrace_regs *fregs) +{ + struct trace_func_repeats *last_info; + struct trace_array *tr = op->private; + struct trace_array_cpu *data; + unsigned int trace_ctx; + unsigned long flags; + int bit; + int cpu; + + if (unlikely(!tr->function_enabled)) + return; + + bit = ftrace_test_recursion_trylock(ip, parent_ip); + if (bit < 0) + return; + + cpu = smp_processor_id(); + data = per_cpu_ptr(tr->array_buffer.data, cpu); + if (atomic_read(&data->disabled)) + goto out; + + /* + * An interrupt may happen at any place here. But as far as I can see, + * the only damage that this can cause is to mess up the repetition + * counter without valuable data being lost. + * TODO: think about a solution that is better than just hoping to be + * lucky. + */ + last_info = per_cpu_ptr(tr->last_func_repeats, cpu); + if (is_repeat_check(tr, last_info, ip, parent_ip)) + goto out; + + local_save_flags(flags); + trace_ctx = tracing_gen_ctx_flags(flags); + process_repeats(tr, ip, parent_ip, last_info, trace_ctx); + + trace_function(tr, ip, parent_ip, trace_ctx); + +out: + ftrace_test_recursion_unlock(bit); +} + +static void +function_stack_no_repeats_trace_call(unsigned long ip, unsigned long parent_ip, + struct ftrace_ops *op, + struct ftrace_regs *fregs) +{ + struct trace_func_repeats *last_info; + struct trace_array *tr = op->private; + struct trace_array_cpu *data; + unsigned long flags; + long disabled; + int cpu; + unsigned int trace_ctx; + + if (unlikely(!tr->function_enabled)) + return; + + /* + * Need to use raw, since this must be called before the + * recursive protection is performed. + */ + local_irq_save(flags); + cpu = raw_smp_processor_id(); + data = per_cpu_ptr(tr->array_buffer.data, cpu); + disabled = atomic_inc_return(&data->disabled); + + if (likely(disabled == 1)) { + last_info = per_cpu_ptr(tr->last_func_repeats, cpu); + if (is_repeat_check(tr, last_info, ip, parent_ip)) + goto out; + + trace_ctx = tracing_gen_ctx_flags(flags); + process_repeats(tr, ip, parent_ip, last_info, trace_ctx); + + trace_function(tr, ip, parent_ip, trace_ctx); + __trace_stack(tr, trace_ctx, STACK_SKIP); + } + + out: + atomic_dec(&data->disabled); + local_irq_restore(flags); +} + +static struct tracer_opt func_opts[] = { +#ifdef CONFIG_STACKTRACE + { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, +#endif + { TRACER_OPT(func-no-repeats, TRACE_FUNC_OPT_NO_REPEATS) }, + { } /* Always set a last empty entry */ +}; + +static struct tracer_flags func_flags = { + .val = TRACE_FUNC_NO_OPTS, /* By default: all flags disabled */ + .opts = func_opts +}; + +static void tracing_start_function_trace(struct trace_array *tr) +{ + tr->function_enabled = 0; + register_ftrace_function(tr->ops); + tr->function_enabled = 1; +} + +static void tracing_stop_function_trace(struct trace_array *tr) +{ + tr->function_enabled = 0; + unregister_ftrace_function(tr->ops); +} + +static struct tracer function_trace; + +static int +func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set) +{ + ftrace_func_t func; + u32 new_flags; + + /* Do nothing if already set. */ + if (!!set == !!(func_flags.val & bit)) + return 0; + + /* We can change this flag only when not running. */ + if (tr->current_trace != &function_trace) + return 0; + + new_flags = (func_flags.val & ~bit) | (set ? bit : 0); + func = select_trace_function(new_flags); + if (!func) + return -EINVAL; + + /* Check if there's anything to change. */ + if (tr->ops->func == func) + return 0; + + if (!handle_func_repeats(tr, new_flags)) + return -ENOMEM; + + unregister_ftrace_function(tr->ops); + tr->ops->func = func; + register_ftrace_function(tr->ops); + + return 0; +} + +static struct tracer function_trace __tracer_data = +{ + .name = "function", + .init = function_trace_init, + .reset = function_trace_reset, + .start = function_trace_start, + .flags = &func_flags, + .set_flag = func_set_flag, + .allow_instances = true, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_function, +#endif +}; + +#ifdef CONFIG_DYNAMIC_FTRACE +static void update_traceon_count(struct ftrace_probe_ops *ops, + unsigned long ip, + struct trace_array *tr, bool on, + void *data) +{ + struct ftrace_func_mapper *mapper = data; + long *count; + long old_count; + + /* + * Tracing gets disabled (or enabled) once per count. + * This function can be called at the same time on multiple CPUs. + * It is fine if both disable (or enable) tracing, as disabling + * (or enabling) the second time doesn't do anything as the + * state of the tracer is already disabled (or enabled). + * What needs to be synchronized in this case is that the count + * only gets decremented once, even if the tracer is disabled + * (or enabled) twice, as the second one is really a nop. + * + * The memory barriers guarantee that we only decrement the + * counter once. First the count is read to a local variable + * and a read barrier is used to make sure that it is loaded + * before checking if the tracer is in the state we want. + * If the tracer is not in the state we want, then the count + * is guaranteed to be the old count. + * + * Next the tracer is set to the state we want (disabled or enabled) + * then a write memory barrier is used to make sure that + * the new state is visible before changing the counter by + * one minus the old counter. This guarantees that another CPU + * executing this code will see the new state before seeing + * the new counter value, and would not do anything if the new + * counter is seen. + * + * Note, there is no synchronization between this and a user + * setting the tracing_on file. But we currently don't care + * about that. + */ + count = (long *)ftrace_func_mapper_find_ip(mapper, ip); + old_count = *count; + + if (old_count <= 0) + return; + + /* Make sure we see count before checking tracing state */ + smp_rmb(); + + if (on == !!tracer_tracing_is_on(tr)) + return; + + if (on) + tracer_tracing_on(tr); + else + tracer_tracing_off(tr); + + /* Make sure tracing state is visible before updating count */ + smp_wmb(); + + *count = old_count - 1; +} + +static void +ftrace_traceon_count(unsigned long ip, unsigned long parent_ip, + struct trace_array *tr, struct ftrace_probe_ops *ops, + void *data) +{ + update_traceon_count(ops, ip, tr, 1, data); +} + +static void +ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip, + struct trace_array *tr, struct ftrace_probe_ops *ops, + void *data) +{ + update_traceon_count(ops, ip, tr, 0, data); +} + +static void +ftrace_traceon(unsigned long ip, unsigned long parent_ip, + struct trace_array *tr, struct ftrace_probe_ops *ops, + void *data) +{ + if (tracer_tracing_is_on(tr)) + return; + + tracer_tracing_on(tr); +} + +static void +ftrace_traceoff(unsigned long ip, unsigned long parent_ip, + struct trace_array *tr, struct ftrace_probe_ops *ops, + void *data) +{ + if (!tracer_tracing_is_on(tr)) + return; + + tracer_tracing_off(tr); +} + +#ifdef CONFIG_UNWINDER_ORC +/* + * Skip 3: + * + * function_trace_probe_call() + * ftrace_ops_assist_func() + * ftrace_call() + */ +#define FTRACE_STACK_SKIP 3 +#else +/* + * Skip 5: + * + * __trace_stack() + * ftrace_stacktrace() + * function_trace_probe_call() + * ftrace_ops_assist_func() + * ftrace_call() + */ +#define FTRACE_STACK_SKIP 5 +#endif + +static __always_inline void trace_stack(struct trace_array *tr) +{ + unsigned int trace_ctx; + + trace_ctx = tracing_gen_ctx(); + + __trace_stack(tr, trace_ctx, FTRACE_STACK_SKIP); +} + +static void +ftrace_stacktrace(unsigned long ip, unsigned long parent_ip, + struct trace_array *tr, struct ftrace_probe_ops *ops, + void *data) +{ + trace_stack(tr); +} + +static void +ftrace_stacktrace_count(unsigned long ip, unsigned long parent_ip, + struct trace_array *tr, struct ftrace_probe_ops *ops, + void *data) +{ + struct ftrace_func_mapper *mapper = data; + long *count; + long old_count; + long new_count; + + if (!tracing_is_on()) + return; + + /* unlimited? */ + if (!mapper) { + trace_stack(tr); + return; + } + + count = (long *)ftrace_func_mapper_find_ip(mapper, ip); + + /* + * Stack traces should only execute the number of times the + * user specified in the counter. + */ + do { + old_count = *count; + + if (!old_count) + return; + + new_count = old_count - 1; + new_count = cmpxchg(count, old_count, new_count); + if (new_count == old_count) + trace_stack(tr); + + if (!tracing_is_on()) + return; + + } while (new_count != old_count); +} + +static int update_count(struct ftrace_probe_ops *ops, unsigned long ip, + void *data) +{ + struct ftrace_func_mapper *mapper = data; + long *count = NULL; + + if (mapper) + count = (long *)ftrace_func_mapper_find_ip(mapper, ip); + + if (count) { + if (*count <= 0) + return 0; + (*count)--; + } + + return 1; +} + +static void +ftrace_dump_probe(unsigned long ip, unsigned long parent_ip, + struct trace_array *tr, struct ftrace_probe_ops *ops, + void *data) +{ + if (update_count(ops, ip, data)) + ftrace_dump(DUMP_ALL); +} + +/* Only dump the current CPU buffer. */ +static void +ftrace_cpudump_probe(unsigned long ip, unsigned long parent_ip, + struct trace_array *tr, struct ftrace_probe_ops *ops, + void *data) +{ + if (update_count(ops, ip, data)) + ftrace_dump(DUMP_ORIG); +} + +static int +ftrace_probe_print(const char *name, struct seq_file *m, + unsigned long ip, struct ftrace_probe_ops *ops, + void *data) +{ + struct ftrace_func_mapper *mapper = data; + long *count = NULL; + + seq_printf(m, "%ps:%s", (void *)ip, name); + + if (mapper) + count = (long *)ftrace_func_mapper_find_ip(mapper, ip); + + if (count) + seq_printf(m, ":count=%ld\n", *count); + else + seq_puts(m, ":unlimited\n"); + + return 0; +} + +static int +ftrace_traceon_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, + void *data) +{ + return ftrace_probe_print("traceon", m, ip, ops, data); +} + +static int +ftrace_traceoff_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *data) +{ + return ftrace_probe_print("traceoff", m, ip, ops, data); +} + +static int +ftrace_stacktrace_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *data) +{ + return ftrace_probe_print("stacktrace", m, ip, ops, data); +} + +static int +ftrace_dump_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *data) +{ + return ftrace_probe_print("dump", m, ip, ops, data); +} + +static int +ftrace_cpudump_print(struct seq_file *m, unsigned long ip, + struct ftrace_probe_ops *ops, void *data) +{ + return ftrace_probe_print("cpudump", m, ip, ops, data); +} + + +static int +ftrace_count_init(struct ftrace_probe_ops *ops, struct trace_array *tr, + unsigned long ip, void *init_data, void **data) +{ + struct ftrace_func_mapper *mapper = *data; + + if (!mapper) { + mapper = allocate_ftrace_func_mapper(); + if (!mapper) + return -ENOMEM; + *data = mapper; + } + + return ftrace_func_mapper_add_ip(mapper, ip, init_data); +} + +static void +ftrace_count_free(struct ftrace_probe_ops *ops, struct trace_array *tr, + unsigned long ip, void *data) +{ + struct ftrace_func_mapper *mapper = data; + + if (!ip) { + free_ftrace_func_mapper(mapper, NULL); + return; + } + + ftrace_func_mapper_remove_ip(mapper, ip); +} + +static struct ftrace_probe_ops traceon_count_probe_ops = { + .func = ftrace_traceon_count, + .print = ftrace_traceon_print, + .init = ftrace_count_init, + .free = ftrace_count_free, +}; + +static struct ftrace_probe_ops traceoff_count_probe_ops = { + .func = ftrace_traceoff_count, + .print = ftrace_traceoff_print, + .init = ftrace_count_init, + .free = ftrace_count_free, +}; + +static struct ftrace_probe_ops stacktrace_count_probe_ops = { + .func = ftrace_stacktrace_count, + .print = ftrace_stacktrace_print, + .init = ftrace_count_init, + .free = ftrace_count_free, +}; + +static struct ftrace_probe_ops dump_probe_ops = { + .func = ftrace_dump_probe, + .print = ftrace_dump_print, + .init = ftrace_count_init, + .free = ftrace_count_free, +}; + +static struct ftrace_probe_ops cpudump_probe_ops = { + .func = ftrace_cpudump_probe, + .print = ftrace_cpudump_print, +}; + +static struct ftrace_probe_ops traceon_probe_ops = { + .func = ftrace_traceon, + .print = ftrace_traceon_print, +}; + +static struct ftrace_probe_ops traceoff_probe_ops = { + .func = ftrace_traceoff, + .print = ftrace_traceoff_print, +}; + +static struct ftrace_probe_ops stacktrace_probe_ops = { + .func = ftrace_stacktrace, + .print = ftrace_stacktrace_print, +}; + +static int +ftrace_trace_probe_callback(struct trace_array *tr, + struct ftrace_probe_ops *ops, + struct ftrace_hash *hash, char *glob, + char *cmd, char *param, int enable) +{ + void *count = (void *)-1; + char *number; + int ret; + + /* hash funcs only work with set_ftrace_filter */ + if (!enable) + return -EINVAL; + + if (glob[0] == '!') + return unregister_ftrace_function_probe_func(glob+1, tr, ops); + + if (!param) + goto out_reg; + + number = strsep(¶m, ":"); + + if (!strlen(number)) + goto out_reg; + + /* + * We use the callback data field (which is a pointer) + * as our counter. + */ + ret = kstrtoul(number, 0, (unsigned long *)&count); + if (ret) + return ret; + + out_reg: + ret = register_ftrace_function_probe(glob, tr, ops, count); + + return ret < 0 ? ret : 0; +} + +static int +ftrace_trace_onoff_callback(struct trace_array *tr, struct ftrace_hash *hash, + char *glob, char *cmd, char *param, int enable) +{ + struct ftrace_probe_ops *ops; + + if (!tr) + return -ENODEV; + + /* we register both traceon and traceoff to this callback */ + if (strcmp(cmd, "traceon") == 0) + ops = param ? &traceon_count_probe_ops : &traceon_probe_ops; + else + ops = param ? &traceoff_count_probe_ops : &traceoff_probe_ops; + + return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd, + param, enable); +} + +static int +ftrace_stacktrace_callback(struct trace_array *tr, struct ftrace_hash *hash, + char *glob, char *cmd, char *param, int enable) +{ + struct ftrace_probe_ops *ops; + + if (!tr) + return -ENODEV; + + ops = param ? &stacktrace_count_probe_ops : &stacktrace_probe_ops; + + return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd, + param, enable); +} + +static int +ftrace_dump_callback(struct trace_array *tr, struct ftrace_hash *hash, + char *glob, char *cmd, char *param, int enable) +{ + struct ftrace_probe_ops *ops; + + if (!tr) + return -ENODEV; + + ops = &dump_probe_ops; + + /* Only dump once. */ + return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd, + "1", enable); +} + +static int +ftrace_cpudump_callback(struct trace_array *tr, struct ftrace_hash *hash, + char *glob, char *cmd, char *param, int enable) +{ + struct ftrace_probe_ops *ops; + + if (!tr) + return -ENODEV; + + ops = &cpudump_probe_ops; + + /* Only dump once. */ + return ftrace_trace_probe_callback(tr, ops, hash, glob, cmd, + "1", enable); +} + +static struct ftrace_func_command ftrace_traceon_cmd = { + .name = "traceon", + .func = ftrace_trace_onoff_callback, +}; + +static struct ftrace_func_command ftrace_traceoff_cmd = { + .name = "traceoff", + .func = ftrace_trace_onoff_callback, +}; + +static struct ftrace_func_command ftrace_stacktrace_cmd = { + .name = "stacktrace", + .func = ftrace_stacktrace_callback, +}; + +static struct ftrace_func_command ftrace_dump_cmd = { + .name = "dump", + .func = ftrace_dump_callback, +}; + +static struct ftrace_func_command ftrace_cpudump_cmd = { + .name = "cpudump", + .func = ftrace_cpudump_callback, +}; + +static int __init init_func_cmd_traceon(void) +{ + int ret; + + ret = register_ftrace_command(&ftrace_traceoff_cmd); + if (ret) + return ret; + + ret = register_ftrace_command(&ftrace_traceon_cmd); + if (ret) + goto out_free_traceoff; + + ret = register_ftrace_command(&ftrace_stacktrace_cmd); + if (ret) + goto out_free_traceon; + + ret = register_ftrace_command(&ftrace_dump_cmd); + if (ret) + goto out_free_stacktrace; + + ret = register_ftrace_command(&ftrace_cpudump_cmd); + if (ret) + goto out_free_dump; + + return 0; + + out_free_dump: + unregister_ftrace_command(&ftrace_dump_cmd); + out_free_stacktrace: + unregister_ftrace_command(&ftrace_stacktrace_cmd); + out_free_traceon: + unregister_ftrace_command(&ftrace_traceon_cmd); + out_free_traceoff: + unregister_ftrace_command(&ftrace_traceoff_cmd); + + return ret; +} +#else +static inline int init_func_cmd_traceon(void) +{ + return 0; +} +#endif /* CONFIG_DYNAMIC_FTRACE */ + +__init int init_function_trace(void) +{ + init_func_cmd_traceon(); + return register_tracer(&function_trace); +} |