From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- kernel/bpf/stackmap.c | 668 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 668 insertions(+) create mode 100644 kernel/bpf/stackmap.c (limited to 'kernel/bpf/stackmap.c') diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c new file mode 100644 index 000000000..aecea7451 --- /dev/null +++ b/kernel/bpf/stackmap.c @@ -0,0 +1,668 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2016 Facebook + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include "percpu_freelist.h" +#include "mmap_unlock_work.h" + +#define STACK_CREATE_FLAG_MASK \ + (BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY | \ + BPF_F_STACK_BUILD_ID) + +struct stack_map_bucket { + struct pcpu_freelist_node fnode; + u32 hash; + u32 nr; + u64 data[]; +}; + +struct bpf_stack_map { + struct bpf_map map; + void *elems; + struct pcpu_freelist freelist; + u32 n_buckets; + struct stack_map_bucket *buckets[]; +}; + +static inline bool stack_map_use_build_id(struct bpf_map *map) +{ + return (map->map_flags & BPF_F_STACK_BUILD_ID); +} + +static inline int stack_map_data_size(struct bpf_map *map) +{ + return stack_map_use_build_id(map) ? + sizeof(struct bpf_stack_build_id) : sizeof(u64); +} + +static int prealloc_elems_and_freelist(struct bpf_stack_map *smap) +{ + u64 elem_size = sizeof(struct stack_map_bucket) + + (u64)smap->map.value_size; + int err; + + smap->elems = bpf_map_area_alloc(elem_size * smap->map.max_entries, + smap->map.numa_node); + if (!smap->elems) + return -ENOMEM; + + err = pcpu_freelist_init(&smap->freelist); + if (err) + goto free_elems; + + pcpu_freelist_populate(&smap->freelist, smap->elems, elem_size, + smap->map.max_entries); + return 0; + +free_elems: + bpf_map_area_free(smap->elems); + return err; +} + +/* Called from syscall */ +static struct bpf_map *stack_map_alloc(union bpf_attr *attr) +{ + u32 value_size = attr->value_size; + struct bpf_stack_map *smap; + u64 cost, n_buckets; + int err; + + if (!bpf_capable()) + return ERR_PTR(-EPERM); + + if (attr->map_flags & ~STACK_CREATE_FLAG_MASK) + return ERR_PTR(-EINVAL); + + /* check sanity of attributes */ + if (attr->max_entries == 0 || attr->key_size != 4 || + value_size < 8 || value_size % 8) + return ERR_PTR(-EINVAL); + + BUILD_BUG_ON(sizeof(struct bpf_stack_build_id) % sizeof(u64)); + if (attr->map_flags & BPF_F_STACK_BUILD_ID) { + if (value_size % sizeof(struct bpf_stack_build_id) || + value_size / sizeof(struct bpf_stack_build_id) + > sysctl_perf_event_max_stack) + return ERR_PTR(-EINVAL); + } else if (value_size / 8 > sysctl_perf_event_max_stack) + return ERR_PTR(-EINVAL); + + /* hash table size must be power of 2 */ + n_buckets = roundup_pow_of_two(attr->max_entries); + if (!n_buckets) + return ERR_PTR(-E2BIG); + + cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap); + smap = bpf_map_area_alloc(cost, bpf_map_attr_numa_node(attr)); + if (!smap) + return ERR_PTR(-ENOMEM); + + bpf_map_init_from_attr(&smap->map, attr); + smap->n_buckets = n_buckets; + + err = get_callchain_buffers(sysctl_perf_event_max_stack); + if (err) + goto free_smap; + + err = prealloc_elems_and_freelist(smap); + if (err) + goto put_buffers; + + return &smap->map; + +put_buffers: + put_callchain_buffers(); +free_smap: + bpf_map_area_free(smap); + return ERR_PTR(err); +} + +static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, + u64 *ips, u32 trace_nr, bool user) +{ + int i; + struct mmap_unlock_irq_work *work = NULL; + bool irq_work_busy = bpf_mmap_unlock_get_irq_work(&work); + struct vm_area_struct *vma, *prev_vma = NULL; + const char *prev_build_id; + + /* If the irq_work is in use, fall back to report ips. Same + * fallback is used for kernel stack (!user) on a stackmap with + * build_id. + */ + if (!user || !current || !current->mm || irq_work_busy || + !mmap_read_trylock(current->mm)) { + /* cannot access current->mm, fall back to ips */ + for (i = 0; i < trace_nr; i++) { + id_offs[i].status = BPF_STACK_BUILD_ID_IP; + id_offs[i].ip = ips[i]; + memset(id_offs[i].build_id, 0, BUILD_ID_SIZE_MAX); + } + return; + } + + for (i = 0; i < trace_nr; i++) { + if (range_in_vma(prev_vma, ips[i], ips[i])) { + vma = prev_vma; + memcpy(id_offs[i].build_id, prev_build_id, + BUILD_ID_SIZE_MAX); + goto build_id_valid; + } + vma = find_vma(current->mm, ips[i]); + if (!vma || build_id_parse(vma, id_offs[i].build_id, NULL)) { + /* per entry fall back to ips */ + id_offs[i].status = BPF_STACK_BUILD_ID_IP; + id_offs[i].ip = ips[i]; + memset(id_offs[i].build_id, 0, BUILD_ID_SIZE_MAX); + continue; + } +build_id_valid: + id_offs[i].offset = (vma->vm_pgoff << PAGE_SHIFT) + ips[i] + - vma->vm_start; + id_offs[i].status = BPF_STACK_BUILD_ID_VALID; + prev_vma = vma; + prev_build_id = id_offs[i].build_id; + } + bpf_mmap_unlock_mm(work, current->mm); +} + +static struct perf_callchain_entry * +get_callchain_entry_for_task(struct task_struct *task, u32 max_depth) +{ +#ifdef CONFIG_STACKTRACE + struct perf_callchain_entry *entry; + int rctx; + + entry = get_callchain_entry(&rctx); + + if (!entry) + return NULL; + + entry->nr = stack_trace_save_tsk(task, (unsigned long *)entry->ip, + max_depth, 0); + + /* stack_trace_save_tsk() works on unsigned long array, while + * perf_callchain_entry uses u64 array. For 32-bit systems, it is + * necessary to fix this mismatch. + */ + if (__BITS_PER_LONG != 64) { + unsigned long *from = (unsigned long *) entry->ip; + u64 *to = entry->ip; + int i; + + /* copy data from the end to avoid using extra buffer */ + for (i = entry->nr - 1; i >= 0; i--) + to[i] = (u64)(from[i]); + } + + put_callchain_entry(rctx); + + return entry; +#else /* CONFIG_STACKTRACE */ + return NULL; +#endif +} + +static long __bpf_get_stackid(struct bpf_map *map, + struct perf_callchain_entry *trace, u64 flags) +{ + struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); + struct stack_map_bucket *bucket, *new_bucket, *old_bucket; + u32 skip = flags & BPF_F_SKIP_FIELD_MASK; + u32 hash, id, trace_nr, trace_len; + bool user = flags & BPF_F_USER_STACK; + u64 *ips; + bool hash_matches; + + if (trace->nr <= skip) + /* skipping more than usable stack trace */ + return -EFAULT; + + trace_nr = trace->nr - skip; + trace_len = trace_nr * sizeof(u64); + ips = trace->ip + skip; + hash = jhash2((u32 *)ips, trace_len / sizeof(u32), 0); + id = hash & (smap->n_buckets - 1); + bucket = READ_ONCE(smap->buckets[id]); + + hash_matches = bucket && bucket->hash == hash; + /* fast cmp */ + if (hash_matches && flags & BPF_F_FAST_STACK_CMP) + return id; + + if (stack_map_use_build_id(map)) { + /* for build_id+offset, pop a bucket before slow cmp */ + new_bucket = (struct stack_map_bucket *) + pcpu_freelist_pop(&smap->freelist); + if (unlikely(!new_bucket)) + return -ENOMEM; + new_bucket->nr = trace_nr; + stack_map_get_build_id_offset( + (struct bpf_stack_build_id *)new_bucket->data, + ips, trace_nr, user); + trace_len = trace_nr * sizeof(struct bpf_stack_build_id); + if (hash_matches && bucket->nr == trace_nr && + memcmp(bucket->data, new_bucket->data, trace_len) == 0) { + pcpu_freelist_push(&smap->freelist, &new_bucket->fnode); + return id; + } + if (bucket && !(flags & BPF_F_REUSE_STACKID)) { + pcpu_freelist_push(&smap->freelist, &new_bucket->fnode); + return -EEXIST; + } + } else { + if (hash_matches && bucket->nr == trace_nr && + memcmp(bucket->data, ips, trace_len) == 0) + return id; + if (bucket && !(flags & BPF_F_REUSE_STACKID)) + return -EEXIST; + + new_bucket = (struct stack_map_bucket *) + pcpu_freelist_pop(&smap->freelist); + if (unlikely(!new_bucket)) + return -ENOMEM; + memcpy(new_bucket->data, ips, trace_len); + } + + new_bucket->hash = hash; + new_bucket->nr = trace_nr; + + old_bucket = xchg(&smap->buckets[id], new_bucket); + if (old_bucket) + pcpu_freelist_push(&smap->freelist, &old_bucket->fnode); + return id; +} + +BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map, + u64, flags) +{ + u32 max_depth = map->value_size / stack_map_data_size(map); + u32 skip = flags & BPF_F_SKIP_FIELD_MASK; + bool user = flags & BPF_F_USER_STACK; + struct perf_callchain_entry *trace; + bool kernel = !user; + + if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | + BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID))) + return -EINVAL; + + max_depth += skip; + if (max_depth > sysctl_perf_event_max_stack) + max_depth = sysctl_perf_event_max_stack; + + trace = get_perf_callchain(regs, 0, kernel, user, max_depth, + false, false); + + if (unlikely(!trace)) + /* couldn't fetch the stack trace */ + return -EFAULT; + + return __bpf_get_stackid(map, trace, flags); +} + +const struct bpf_func_proto bpf_get_stackid_proto = { + .func = bpf_get_stackid, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_ANYTHING, +}; + +static __u64 count_kernel_ip(struct perf_callchain_entry *trace) +{ + __u64 nr_kernel = 0; + + while (nr_kernel < trace->nr) { + if (trace->ip[nr_kernel] == PERF_CONTEXT_USER) + break; + nr_kernel++; + } + return nr_kernel; +} + +BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx, + struct bpf_map *, map, u64, flags) +{ + struct perf_event *event = ctx->event; + struct perf_callchain_entry *trace; + bool kernel, user; + __u64 nr_kernel; + int ret; + + /* perf_sample_data doesn't have callchain, use bpf_get_stackid */ + if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)) + return bpf_get_stackid((unsigned long)(ctx->regs), + (unsigned long) map, flags, 0, 0); + + if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | + BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID))) + return -EINVAL; + + user = flags & BPF_F_USER_STACK; + kernel = !user; + + trace = ctx->data->callchain; + if (unlikely(!trace)) + return -EFAULT; + + nr_kernel = count_kernel_ip(trace); + + if (kernel) { + __u64 nr = trace->nr; + + trace->nr = nr_kernel; + ret = __bpf_get_stackid(map, trace, flags); + + /* restore nr */ + trace->nr = nr; + } else { /* user */ + u64 skip = flags & BPF_F_SKIP_FIELD_MASK; + + skip += nr_kernel; + if (skip > BPF_F_SKIP_FIELD_MASK) + return -EFAULT; + + flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip; + ret = __bpf_get_stackid(map, trace, flags); + } + return ret; +} + +const struct bpf_func_proto bpf_get_stackid_proto_pe = { + .func = bpf_get_stackid_pe, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_CONST_MAP_PTR, + .arg3_type = ARG_ANYTHING, +}; + +static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task, + struct perf_callchain_entry *trace_in, + void *buf, u32 size, u64 flags) +{ + u32 trace_nr, copy_len, elem_size, num_elem, max_depth; + bool user_build_id = flags & BPF_F_USER_BUILD_ID; + u32 skip = flags & BPF_F_SKIP_FIELD_MASK; + bool user = flags & BPF_F_USER_STACK; + struct perf_callchain_entry *trace; + bool kernel = !user; + int err = -EINVAL; + u64 *ips; + + if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | + BPF_F_USER_BUILD_ID))) + goto clear; + if (kernel && user_build_id) + goto clear; + + elem_size = (user && user_build_id) ? sizeof(struct bpf_stack_build_id) + : sizeof(u64); + if (unlikely(size % elem_size)) + goto clear; + + /* cannot get valid user stack for task without user_mode regs */ + if (task && user && !user_mode(regs)) + goto err_fault; + + num_elem = size / elem_size; + max_depth = num_elem + skip; + if (sysctl_perf_event_max_stack < max_depth) + max_depth = sysctl_perf_event_max_stack; + + if (trace_in) + trace = trace_in; + else if (kernel && task) + trace = get_callchain_entry_for_task(task, max_depth); + else + trace = get_perf_callchain(regs, 0, kernel, user, max_depth, + false, false); + if (unlikely(!trace)) + goto err_fault; + + if (trace->nr < skip) + goto err_fault; + + trace_nr = trace->nr - skip; + trace_nr = (trace_nr <= num_elem) ? trace_nr : num_elem; + copy_len = trace_nr * elem_size; + + ips = trace->ip + skip; + if (user && user_build_id) + stack_map_get_build_id_offset(buf, ips, trace_nr, user); + else + memcpy(buf, ips, copy_len); + + if (size > copy_len) + memset(buf + copy_len, 0, size - copy_len); + return copy_len; + +err_fault: + err = -EFAULT; +clear: + memset(buf, 0, size); + return err; +} + +BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size, + u64, flags) +{ + return __bpf_get_stack(regs, NULL, NULL, buf, size, flags); +} + +const struct bpf_func_proto bpf_get_stack_proto = { + .func = bpf_get_stack, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_UNINIT_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, + .arg4_type = ARG_ANYTHING, +}; + +BPF_CALL_4(bpf_get_task_stack, struct task_struct *, task, void *, buf, + u32, size, u64, flags) +{ + struct pt_regs *regs; + long res = -EINVAL; + + if (!try_get_task_stack(task)) + return -EFAULT; + + regs = task_pt_regs(task); + if (regs) + res = __bpf_get_stack(regs, task, NULL, buf, size, flags); + put_task_stack(task); + + return res; +} + +const struct bpf_func_proto bpf_get_task_stack_proto = { + .func = bpf_get_task_stack, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID, + .arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK], + .arg2_type = ARG_PTR_TO_UNINIT_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, + .arg4_type = ARG_ANYTHING, +}; + +BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx, + void *, buf, u32, size, u64, flags) +{ + struct pt_regs *regs = (struct pt_regs *)(ctx->regs); + struct perf_event *event = ctx->event; + struct perf_callchain_entry *trace; + bool kernel, user; + int err = -EINVAL; + __u64 nr_kernel; + + if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)) + return __bpf_get_stack(regs, NULL, NULL, buf, size, flags); + + if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK | + BPF_F_USER_BUILD_ID))) + goto clear; + + user = flags & BPF_F_USER_STACK; + kernel = !user; + + err = -EFAULT; + trace = ctx->data->callchain; + if (unlikely(!trace)) + goto clear; + + nr_kernel = count_kernel_ip(trace); + + if (kernel) { + __u64 nr = trace->nr; + + trace->nr = nr_kernel; + err = __bpf_get_stack(regs, NULL, trace, buf, size, flags); + + /* restore nr */ + trace->nr = nr; + } else { /* user */ + u64 skip = flags & BPF_F_SKIP_FIELD_MASK; + + skip += nr_kernel; + if (skip > BPF_F_SKIP_FIELD_MASK) + goto clear; + + flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip; + err = __bpf_get_stack(regs, NULL, trace, buf, size, flags); + } + return err; + +clear: + memset(buf, 0, size); + return err; + +} + +const struct bpf_func_proto bpf_get_stack_proto_pe = { + .func = bpf_get_stack_pe, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_PTR_TO_UNINIT_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, + .arg4_type = ARG_ANYTHING, +}; + +/* Called from eBPF program */ +static void *stack_map_lookup_elem(struct bpf_map *map, void *key) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +/* Called from syscall */ +int bpf_stackmap_copy(struct bpf_map *map, void *key, void *value) +{ + struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); + struct stack_map_bucket *bucket, *old_bucket; + u32 id = *(u32 *)key, trace_len; + + if (unlikely(id >= smap->n_buckets)) + return -ENOENT; + + bucket = xchg(&smap->buckets[id], NULL); + if (!bucket) + return -ENOENT; + + trace_len = bucket->nr * stack_map_data_size(map); + memcpy(value, bucket->data, trace_len); + memset(value + trace_len, 0, map->value_size - trace_len); + + old_bucket = xchg(&smap->buckets[id], bucket); + if (old_bucket) + pcpu_freelist_push(&smap->freelist, &old_bucket->fnode); + return 0; +} + +static int stack_map_get_next_key(struct bpf_map *map, void *key, + void *next_key) +{ + struct bpf_stack_map *smap = container_of(map, + struct bpf_stack_map, map); + u32 id; + + WARN_ON_ONCE(!rcu_read_lock_held()); + + if (!key) { + id = 0; + } else { + id = *(u32 *)key; + if (id >= smap->n_buckets || !smap->buckets[id]) + id = 0; + else + id++; + } + + while (id < smap->n_buckets && !smap->buckets[id]) + id++; + + if (id >= smap->n_buckets) + return -ENOENT; + + *(u32 *)next_key = id; + return 0; +} + +static int stack_map_update_elem(struct bpf_map *map, void *key, void *value, + u64 map_flags) +{ + return -EINVAL; +} + +/* Called from syscall or from eBPF program */ +static int stack_map_delete_elem(struct bpf_map *map, void *key) +{ + struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); + struct stack_map_bucket *old_bucket; + u32 id = *(u32 *)key; + + if (unlikely(id >= smap->n_buckets)) + return -E2BIG; + + old_bucket = xchg(&smap->buckets[id], NULL); + if (old_bucket) { + pcpu_freelist_push(&smap->freelist, &old_bucket->fnode); + return 0; + } else { + return -ENOENT; + } +} + +/* Called when map->refcnt goes to zero, either from workqueue or from syscall */ +static void stack_map_free(struct bpf_map *map) +{ + struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map); + + bpf_map_area_free(smap->elems); + pcpu_freelist_destroy(&smap->freelist); + bpf_map_area_free(smap); + put_callchain_buffers(); +} + +BTF_ID_LIST_SINGLE(stack_trace_map_btf_ids, struct, bpf_stack_map) +const struct bpf_map_ops stack_trace_map_ops = { + .map_meta_equal = bpf_map_meta_equal, + .map_alloc = stack_map_alloc, + .map_free = stack_map_free, + .map_get_next_key = stack_map_get_next_key, + .map_lookup_elem = stack_map_lookup_elem, + .map_update_elem = stack_map_update_elem, + .map_delete_elem = stack_map_delete_elem, + .map_check_btf = map_check_no_btf, + .map_btf_id = &stack_trace_map_btf_ids[0], +}; -- cgit v1.2.3