linux-stable/kernel/trace/bpf_trace.c
Linus Torvalds 9ff9b0d392 networking changes for the 5.10 merge window
Add redirect_neigh() BPF packet redirect helper, allowing to limit stack
 traversal in common container configs and improving TCP back-pressure.
 Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.
 
 Expand netlink policy support and improve policy export to user space.
 (Ge)netlink core performs request validation according to declared
 policies. Expand the expressiveness of those policies (min/max length
 and bitmasks). Allow dumping policies for particular commands.
 This is used for feature discovery by user space (instead of kernel
 version parsing or trial and error).
 
 Support IGMPv3/MLDv2 multicast listener discovery protocols in bridge.
 
 Allow more than 255 IPv4 multicast interfaces.
 
 Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
 packets of TCPv6.
 
 In Multi-patch TCP (MPTCP) support concurrent transmission of data
 on multiple subflows in a load balancing scenario. Enhance advertising
 addresses via the RM_ADDR/ADD_ADDR options.
 
 Support SMC-Dv2 version of SMC, which enables multi-subnet deployments.
 
 Allow more calls to same peer in RxRPC.
 
 Support two new Controller Area Network (CAN) protocols -
 CAN-FD and ISO 15765-2:2016.
 
 Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
 kernel problem.
 
 Add TC actions for implementing MPLS L2 VPNs.
 
 Improve nexthop code - e.g. handle various corner cases when nexthop
 objects are removed from groups better, skip unnecessary notifications
 and make it easier to offload nexthops into HW by converting
 to a blocking notifier.
 
 Support adding and consuming TCP header options by BPF programs,
 opening the doors for easy experimental and deployment-specific
 TCP option use.
 
 Reorganize TCP congestion control (CC) initialization to simplify life
 of TCP CC implemented in BPF.
 
 Add support for shipping BPF programs with the kernel and loading them
 early on boot via the User Mode Driver mechanism, hence reusing all the
 user space infra we have.
 
 Support sleepable BPF programs, initially targeting LSM and tracing.
 
 Add bpf_d_path() helper for returning full path for given 'struct path'.
 
 Make bpf_tail_call compatible with bpf-to-bpf calls.
 
 Allow BPF programs to call map_update_elem on sockmaps.
 
 Add BPF Type Format (BTF) support for type and enum discovery, as
 well as support for using BTF within the kernel itself (current use
 is for pretty printing structures).
 
 Support listing and getting information about bpf_links via the bpf
 syscall.
 
 Enhance kernel interfaces around NIC firmware update. Allow specifying
 overwrite mask to control if settings etc. are reset during update;
 report expected max time operation may take to users; support firmware
 activation without machine reboot incl. limits of how much impact
 reset may have (e.g. dropping link or not).
 
 Extend ethtool configuration interface to report IEEE-standard
 counters, to limit the need for per-vendor logic in user space.
 
 Adopt or extend devlink use for debug, monitoring, fw update
 in many drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw,
 mv88e6xxx, dpaa2-eth).
 
 In mlxsw expose critical and emergency SFP module temperature alarms.
 Refactor port buffer handling to make the defaults more suitable and
 support setting these values explicitly via the DCBNL interface.
 
 Add XDP support for Intel's igb driver.
 
 Support offloading TC flower classification and filtering rules to
 mscc_ocelot switches.
 
 Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
 fixed interval period pulse generator and one-step timestamping in
 dpaa-eth.
 
 Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
 offload.
 
 Add Lynx PHY/PCS MDIO module, and convert various drivers which have
 this HW to use it. Convert mvpp2 to split PCS.
 
 Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
 7-port Mediatek MT7531 IP.
 
 Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
 and wcn3680 support in wcn36xx.
 
 Improve performance for packets which don't require much offloads
 on recent Mellanox NICs by 20% by making multiple packets share
 a descriptor entry.
 
 Move chelsio inline crypto drivers (for TLS and IPsec) from the crypto
 subtree to drivers/net. Move MDIO drivers out of the phy directory.
 
 Clean up a lot of W=1 warnings, reportedly the actively developed
 subsections of networking drivers should now build W=1 warning free.
 
 Make sure drivers don't use in_interrupt() to dynamically adapt their
 code. Convert tasklets to use new tasklet_setup API (sadly this
 conversion is not yet complete).
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:

 - Add redirect_neigh() BPF packet redirect helper, allowing to limit
   stack traversal in common container configs and improving TCP
   back-pressure.

   Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain.

 - Expand netlink policy support and improve policy export to user
   space. (Ge)netlink core performs request validation according to
   declared policies. Expand the expressiveness of those policies
   (min/max length and bitmasks). Allow dumping policies for particular
   commands. This is used for feature discovery by user space (instead
   of kernel version parsing or trial and error).

 - Support IGMPv3/MLDv2 multicast listener discovery protocols in
   bridge.

 - Allow more than 255 IPv4 multicast interfaces.

 - Add support for Type of Service (ToS) reflection in SYN/SYN-ACK
   packets of TCPv6.

 - In Multi-patch TCP (MPTCP) support concurrent transmission of data on
   multiple subflows in a load balancing scenario. Enhance advertising
   addresses via the RM_ADDR/ADD_ADDR options.

 - Support SMC-Dv2 version of SMC, which enables multi-subnet
   deployments.

 - Allow more calls to same peer in RxRPC.

 - Support two new Controller Area Network (CAN) protocols - CAN-FD and
   ISO 15765-2:2016.

 - Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit
   kernel problem.

 - Add TC actions for implementing MPLS L2 VPNs.

 - Improve nexthop code - e.g. handle various corner cases when nexthop
   objects are removed from groups better, skip unnecessary
   notifications and make it easier to offload nexthops into HW by
   converting to a blocking notifier.

 - Support adding and consuming TCP header options by BPF programs,
   opening the doors for easy experimental and deployment-specific TCP
   option use.

 - Reorganize TCP congestion control (CC) initialization to simplify
   life of TCP CC implemented in BPF.

 - Add support for shipping BPF programs with the kernel and loading
   them early on boot via the User Mode Driver mechanism, hence reusing
   all the user space infra we have.

 - Support sleepable BPF programs, initially targeting LSM and tracing.

 - Add bpf_d_path() helper for returning full path for given 'struct
   path'.

 - Make bpf_tail_call compatible with bpf-to-bpf calls.

 - Allow BPF programs to call map_update_elem on sockmaps.

 - Add BPF Type Format (BTF) support for type and enum discovery, as
   well as support for using BTF within the kernel itself (current use
   is for pretty printing structures).

 - Support listing and getting information about bpf_links via the bpf
   syscall.

 - Enhance kernel interfaces around NIC firmware update. Allow
   specifying overwrite mask to control if settings etc. are reset
   during update; report expected max time operation may take to users;
   support firmware activation without machine reboot incl. limits of
   how much impact reset may have (e.g. dropping link or not).

 - Extend ethtool configuration interface to report IEEE-standard
   counters, to limit the need for per-vendor logic in user space.

 - Adopt or extend devlink use for debug, monitoring, fw update in many
   drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx,
   dpaa2-eth).

 - In mlxsw expose critical and emergency SFP module temperature alarms.
   Refactor port buffer handling to make the defaults more suitable and
   support setting these values explicitly via the DCBNL interface.

 - Add XDP support for Intel's igb driver.

 - Support offloading TC flower classification and filtering rules to
   mscc_ocelot switches.

 - Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as
   fixed interval period pulse generator and one-step timestamping in
   dpaa-eth.

 - Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3)
   offload.

 - Add Lynx PHY/PCS MDIO module, and convert various drivers which have
   this HW to use it. Convert mvpp2 to split PCS.

 - Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as
   7-port Mediatek MT7531 IP.

 - Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver,
   and wcn3680 support in wcn36xx.

 - Improve performance for packets which don't require much offloads on
   recent Mellanox NICs by 20% by making multiple packets share a
   descriptor entry.

 - Move chelsio inline crypto drivers (for TLS and IPsec) from the
   crypto subtree to drivers/net. Move MDIO drivers out of the phy
   directory.

 - Clean up a lot of W=1 warnings, reportedly the actively developed
   subsections of networking drivers should now build W=1 warning free.

 - Make sure drivers don't use in_interrupt() to dynamically adapt their
   code. Convert tasklets to use new tasklet_setup API (sadly this
   conversion is not yet complete).

* tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits)
  Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH"
  net, sockmap: Don't call bpf_prog_put() on NULL pointer
  bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo
  bpf, sockmap: Add locking annotations to iterator
  netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements
  net: fix pos incrementment in ipv6_route_seq_next
  net/smc: fix invalid return code in smcd_new_buf_create()
  net/smc: fix valid DMBE buffer sizes
  net/smc: fix use-after-free of delayed events
  bpfilter: Fix build error with CONFIG_BPFILTER_UMH
  cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr
  net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info
  bpf: Fix register equivalence tracking.
  rxrpc: Fix loss of final ack on shutdown
  rxrpc: Fix bundle counting for exclusive connections
  netfilter: restore NF_INET_NUMHOOKS
  ibmveth: Identify ingress large send packets.
  ibmveth: Switch order of ibmveth_helper calls.
  cxgb4: handle 4-tuple PEDIT to NAT mode translation
  selftests: Add VRF route leaking tests
  ...
2020-10-15 18:42:13 -07:00

2234 lines
58 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
* Copyright (c) 2016 Facebook
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/bpf.h>
#include <linux/bpf_perf_event.h>
#include <linux/btf.h>
#include <linux/filter.h>
#include <linux/uaccess.h>
#include <linux/ctype.h>
#include <linux/kprobes.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
#include <linux/error-injection.h>
#include <linux/btf_ids.h>
#include <uapi/linux/bpf.h>
#include <uapi/linux/btf.h>
#include <asm/tlb.h>
#include "trace_probe.h"
#include "trace.h"
#define CREATE_TRACE_POINTS
#include "bpf_trace.h"
#define bpf_event_rcu_dereference(p) \
rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
#ifdef CONFIG_MODULES
struct bpf_trace_module {
struct module *module;
struct list_head list;
};
static LIST_HEAD(bpf_trace_modules);
static DEFINE_MUTEX(bpf_module_mutex);
static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
{
struct bpf_raw_event_map *btp, *ret = NULL;
struct bpf_trace_module *btm;
unsigned int i;
mutex_lock(&bpf_module_mutex);
list_for_each_entry(btm, &bpf_trace_modules, list) {
for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
btp = &btm->module->bpf_raw_events[i];
if (!strcmp(btp->tp->name, name)) {
if (try_module_get(btm->module))
ret = btp;
goto out;
}
}
}
out:
mutex_unlock(&bpf_module_mutex);
return ret;
}
#else
static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
{
return NULL;
}
#endif /* CONFIG_MODULES */
u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
u64 flags, const struct btf **btf,
s32 *btf_id);
/**
* trace_call_bpf - invoke BPF program
* @call: tracepoint event
* @ctx: opaque context pointer
*
* kprobe handlers execute BPF programs via this helper.
* Can be used from static tracepoints in the future.
*
* Return: BPF programs always return an integer which is interpreted by
* kprobe handler as:
* 0 - return from kprobe (event is filtered out)
* 1 - store kprobe event into ring buffer
* Other values are reserved and currently alias to 1
*/
unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
{
unsigned int ret;
if (in_nmi()) /* not supported yet */
return 1;
cant_sleep();
if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
/*
* since some bpf program is already running on this cpu,
* don't call into another bpf program (same or different)
* and don't send kprobe event into ring-buffer,
* so return zero here
*/
ret = 0;
goto out;
}
/*
* Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
* to all call sites, we did a bpf_prog_array_valid() there to check
* whether call->prog_array is empty or not, which is
* a heurisitc to speed up execution.
*
* If bpf_prog_array_valid() fetched prog_array was
* non-NULL, we go into trace_call_bpf() and do the actual
* proper rcu_dereference() under RCU lock.
* If it turns out that prog_array is NULL then, we bail out.
* For the opposite, if the bpf_prog_array_valid() fetched pointer
* was NULL, you'll skip the prog_array with the risk of missing
* out of events when it was updated in between this and the
* rcu_dereference() which is accepted risk.
*/
ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN);
out:
__this_cpu_dec(bpf_prog_active);
return ret;
}
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
{
regs_set_return_value(regs, rc);
override_function_with_return(regs);
return 0;
}
static const struct bpf_func_proto bpf_override_return_proto = {
.func = bpf_override_return,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
};
#endif
static __always_inline int
bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
{
int ret;
ret = copy_from_user_nofault(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
memset(dst, 0, size);
return ret;
}
BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
const void __user *, unsafe_ptr)
{
return bpf_probe_read_user_common(dst, size, unsafe_ptr);
}
const struct bpf_func_proto bpf_probe_read_user_proto = {
.func = bpf_probe_read_user,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
};
static __always_inline int
bpf_probe_read_user_str_common(void *dst, u32 size,
const void __user *unsafe_ptr)
{
int ret;
ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
memset(dst, 0, size);
return ret;
}
BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
const void __user *, unsafe_ptr)
{
return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
}
const struct bpf_func_proto bpf_probe_read_user_str_proto = {
.func = bpf_probe_read_user_str,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
};
static __always_inline int
bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
{
int ret = security_locked_down(LOCKDOWN_BPF_READ);
if (unlikely(ret < 0))
goto fail;
ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
goto fail;
return ret;
fail:
memset(dst, 0, size);
return ret;
}
BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
const void *, unsafe_ptr)
{
return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
}
const struct bpf_func_proto bpf_probe_read_kernel_proto = {
.func = bpf_probe_read_kernel,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
};
static __always_inline int
bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
{
int ret = security_locked_down(LOCKDOWN_BPF_READ);
if (unlikely(ret < 0))
goto fail;
/*
* The strncpy_from_kernel_nofault() call will likely not fill the
* entire buffer, but that's okay in this circumstance as we're probing
* arbitrary memory anyway similar to bpf_probe_read_*() and might
* as well probe the stack. Thus, memory is explicitly cleared
* only in error case, so that improper users ignoring return
* code altogether don't copy garbage; otherwise length of string
* is returned that can be used for bpf_perf_event_output() et al.
*/
ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
goto fail;
return ret;
fail:
memset(dst, 0, size);
return ret;
}
BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
const void *, unsafe_ptr)
{
return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
}
const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
.func = bpf_probe_read_kernel_str,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
};
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
const void *, unsafe_ptr)
{
if ((unsigned long)unsafe_ptr < TASK_SIZE) {
return bpf_probe_read_user_common(dst, size,
(__force void __user *)unsafe_ptr);
}
return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
}
static const struct bpf_func_proto bpf_probe_read_compat_proto = {
.func = bpf_probe_read_compat,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
const void *, unsafe_ptr)
{
if ((unsigned long)unsafe_ptr < TASK_SIZE) {
return bpf_probe_read_user_str_common(dst, size,
(__force void __user *)unsafe_ptr);
}
return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
}
static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
.func = bpf_probe_read_compat_str,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
};
#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
BPF_CALL_3(bpf_probe_write_user, void __user *, unsafe_ptr, const void *, src,
u32, size)
{
/*
* Ensure we're in user context which is safe for the helper to
* run. This helper has no business in a kthread.
*
* access_ok() should prevent writing to non-user memory, but in
* some situations (nommu, temporary switch, etc) access_ok() does
* not provide enough validation, hence the check on KERNEL_DS.
*
* nmi_uaccess_okay() ensures the probe is not run in an interim
* state, when the task or mm are switched. This is specifically
* required to prevent the use of temporary mm.
*/
if (unlikely(in_interrupt() ||
current->flags & (PF_KTHREAD | PF_EXITING)))
return -EPERM;
if (unlikely(uaccess_kernel()))
return -EPERM;
if (unlikely(!nmi_uaccess_okay()))
return -EPERM;
return copy_to_user_nofault(unsafe_ptr, src, size);
}
static const struct bpf_func_proto bpf_probe_write_user_proto = {
.func = bpf_probe_write_user,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
.arg2_type = ARG_PTR_TO_MEM,
.arg3_type = ARG_CONST_SIZE,
};
static const struct bpf_func_proto *bpf_get_probe_write_proto(void)
{
if (!capable(CAP_SYS_ADMIN))
return NULL;
pr_warn_ratelimited("%s[%d] is installing a program with bpf_probe_write_user helper that may corrupt user memory!",
current->comm, task_pid_nr(current));
return &bpf_probe_write_user_proto;
}
static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
size_t bufsz)
{
void __user *user_ptr = (__force void __user *)unsafe_ptr;
buf[0] = 0;
switch (fmt_ptype) {
case 's':
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
if ((unsigned long)unsafe_ptr < TASK_SIZE) {
strncpy_from_user_nofault(buf, user_ptr, bufsz);
break;
}
fallthrough;
#endif
case 'k':
strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz);
break;
case 'u':
strncpy_from_user_nofault(buf, user_ptr, bufsz);
break;
}
}
static DEFINE_RAW_SPINLOCK(trace_printk_lock);
#define BPF_TRACE_PRINTK_SIZE 1024
static __printf(1, 0) int bpf_do_trace_printk(const char *fmt, ...)
{
static char buf[BPF_TRACE_PRINTK_SIZE];
unsigned long flags;
va_list ap;
int ret;
raw_spin_lock_irqsave(&trace_printk_lock, flags);
va_start(ap, fmt);
ret = vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
/* vsnprintf() will not append null for zero-length strings */
if (ret == 0)
buf[0] = '\0';
trace_bpf_trace_printk(buf);
raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
return ret;
}
/*
* Only limited trace_printk() conversion specifiers allowed:
* %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pB %pks %pus %s
*/
BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
u64, arg2, u64, arg3)
{
int i, mod[3] = {}, fmt_cnt = 0;
char buf[64], fmt_ptype;
void *unsafe_ptr = NULL;
bool str_seen = false;
/*
* bpf_check()->check_func_arg()->check_stack_boundary()
* guarantees that fmt points to bpf program stack,
* fmt_size bytes of it were initialized and fmt_size > 0
*/
if (fmt[--fmt_size] != 0)
return -EINVAL;
/* check format string for allowed specifiers */
for (i = 0; i < fmt_size; i++) {
if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i]))
return -EINVAL;
if (fmt[i] != '%')
continue;
if (fmt_cnt >= 3)
return -EINVAL;
/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
i++;
if (fmt[i] == 'l') {
mod[fmt_cnt]++;
i++;
} else if (fmt[i] == 'p') {
mod[fmt_cnt]++;
if ((fmt[i + 1] == 'k' ||
fmt[i + 1] == 'u') &&
fmt[i + 2] == 's') {
fmt_ptype = fmt[i + 1];
i += 2;
goto fmt_str;
}
if (fmt[i + 1] == 'B') {
i++;
goto fmt_next;
}
/* disallow any further format extensions */
if (fmt[i + 1] != 0 &&
!isspace(fmt[i + 1]) &&
!ispunct(fmt[i + 1]))
return -EINVAL;
goto fmt_next;
} else if (fmt[i] == 's') {
mod[fmt_cnt]++;
fmt_ptype = fmt[i];
fmt_str:
if (str_seen)
/* allow only one '%s' per fmt string */
return -EINVAL;
str_seen = true;
if (fmt[i + 1] != 0 &&
!isspace(fmt[i + 1]) &&
!ispunct(fmt[i + 1]))
return -EINVAL;
switch (fmt_cnt) {
case 0:
unsafe_ptr = (void *)(long)arg1;
arg1 = (long)buf;
break;
case 1:
unsafe_ptr = (void *)(long)arg2;
arg2 = (long)buf;
break;
case 2:
unsafe_ptr = (void *)(long)arg3;
arg3 = (long)buf;
break;
}
bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype,
sizeof(buf));
goto fmt_next;
}
if (fmt[i] == 'l') {
mod[fmt_cnt]++;
i++;
}
if (fmt[i] != 'i' && fmt[i] != 'd' &&
fmt[i] != 'u' && fmt[i] != 'x')
return -EINVAL;
fmt_next:
fmt_cnt++;
}
/* Horrid workaround for getting va_list handling working with different
* argument type combinations generically for 32 and 64 bit archs.
*/
#define __BPF_TP_EMIT() __BPF_ARG3_TP()
#define __BPF_TP(...) \
bpf_do_trace_printk(fmt, ##__VA_ARGS__)
#define __BPF_ARG1_TP(...) \
((mod[0] == 2 || (mod[0] == 1 && __BITS_PER_LONG == 64)) \
? __BPF_TP(arg1, ##__VA_ARGS__) \
: ((mod[0] == 1 || (mod[0] == 0 && __BITS_PER_LONG == 32)) \
? __BPF_TP((long)arg1, ##__VA_ARGS__) \
: __BPF_TP((u32)arg1, ##__VA_ARGS__)))
#define __BPF_ARG2_TP(...) \
((mod[1] == 2 || (mod[1] == 1 && __BITS_PER_LONG == 64)) \
? __BPF_ARG1_TP(arg2, ##__VA_ARGS__) \
: ((mod[1] == 1 || (mod[1] == 0 && __BITS_PER_LONG == 32)) \
? __BPF_ARG1_TP((long)arg2, ##__VA_ARGS__) \
: __BPF_ARG1_TP((u32)arg2, ##__VA_ARGS__)))
#define __BPF_ARG3_TP(...) \
((mod[2] == 2 || (mod[2] == 1 && __BITS_PER_LONG == 64)) \
? __BPF_ARG2_TP(arg3, ##__VA_ARGS__) \
: ((mod[2] == 1 || (mod[2] == 0 && __BITS_PER_LONG == 32)) \
? __BPF_ARG2_TP((long)arg3, ##__VA_ARGS__) \
: __BPF_ARG2_TP((u32)arg3, ##__VA_ARGS__)))
return __BPF_TP_EMIT();
}
static const struct bpf_func_proto bpf_trace_printk_proto = {
.func = bpf_trace_printk,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM,
.arg2_type = ARG_CONST_SIZE,
};
const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
{
/*
* This program might be calling bpf_trace_printk,
* so enable the associated bpf_trace/bpf_trace_printk event.
* Repeat this each time as it is possible a user has
* disabled bpf_trace_printk events. By loading a program
* calling bpf_trace_printk() however the user has expressed
* the intent to see such events.
*/
if (trace_set_clr_event("bpf_trace", "bpf_trace_printk", 1))
pr_warn_ratelimited("could not enable bpf_trace_printk events");
return &bpf_trace_printk_proto;
}
#define MAX_SEQ_PRINTF_VARARGS 12
#define MAX_SEQ_PRINTF_MAX_MEMCPY 6
#define MAX_SEQ_PRINTF_STR_LEN 128
struct bpf_seq_printf_buf {
char buf[MAX_SEQ_PRINTF_MAX_MEMCPY][MAX_SEQ_PRINTF_STR_LEN];
};
static DEFINE_PER_CPU(struct bpf_seq_printf_buf, bpf_seq_printf_buf);
static DEFINE_PER_CPU(int, bpf_seq_printf_buf_used);
BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
const void *, data, u32, data_len)
{
int err = -EINVAL, fmt_cnt = 0, memcpy_cnt = 0;
int i, buf_used, copy_size, num_args;
u64 params[MAX_SEQ_PRINTF_VARARGS];
struct bpf_seq_printf_buf *bufs;
const u64 *args = data;
buf_used = this_cpu_inc_return(bpf_seq_printf_buf_used);
if (WARN_ON_ONCE(buf_used > 1)) {
err = -EBUSY;
goto out;
}
bufs = this_cpu_ptr(&bpf_seq_printf_buf);
/*
* bpf_check()->check_func_arg()->check_stack_boundary()
* guarantees that fmt points to bpf program stack,
* fmt_size bytes of it were initialized and fmt_size > 0
*/
if (fmt[--fmt_size] != 0)
goto out;
if (data_len & 7)
goto out;
for (i = 0; i < fmt_size; i++) {
if (fmt[i] == '%') {
if (fmt[i + 1] == '%')
i++;
else if (!data || !data_len)
goto out;
}
}
num_args = data_len / 8;
/* check format string for allowed specifiers */
for (i = 0; i < fmt_size; i++) {
/* only printable ascii for now. */
if ((!isprint(fmt[i]) && !isspace(fmt[i])) || !isascii(fmt[i])) {
err = -EINVAL;
goto out;
}
if (fmt[i] != '%')
continue;
if (fmt[i + 1] == '%') {
i++;
continue;
}
if (fmt_cnt >= MAX_SEQ_PRINTF_VARARGS) {
err = -E2BIG;
goto out;
}
if (fmt_cnt >= num_args) {
err = -EINVAL;
goto out;
}
/* fmt[i] != 0 && fmt[last] == 0, so we can access fmt[i + 1] */
i++;
/* skip optional "[0 +-][num]" width formating field */
while (fmt[i] == '0' || fmt[i] == '+' || fmt[i] == '-' ||
fmt[i] == ' ')
i++;
if (fmt[i] >= '1' && fmt[i] <= '9') {
i++;
while (fmt[i] >= '0' && fmt[i] <= '9')
i++;
}
if (fmt[i] == 's') {
void *unsafe_ptr;
/* try our best to copy */
if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
err = -E2BIG;
goto out;
}
unsafe_ptr = (void *)(long)args[fmt_cnt];
err = strncpy_from_kernel_nofault(bufs->buf[memcpy_cnt],
unsafe_ptr, MAX_SEQ_PRINTF_STR_LEN);
if (err < 0)
bufs->buf[memcpy_cnt][0] = '\0';
params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
fmt_cnt++;
memcpy_cnt++;
continue;
}
if (fmt[i] == 'p') {
if (fmt[i + 1] == 0 ||
fmt[i + 1] == 'K' ||
fmt[i + 1] == 'x' ||
fmt[i + 1] == 'B') {
/* just kernel pointers */
params[fmt_cnt] = args[fmt_cnt];
fmt_cnt++;
continue;
}
/* only support "%pI4", "%pi4", "%pI6" and "%pi6". */
if (fmt[i + 1] != 'i' && fmt[i + 1] != 'I') {
err = -EINVAL;
goto out;
}
if (fmt[i + 2] != '4' && fmt[i + 2] != '6') {
err = -EINVAL;
goto out;
}
if (memcpy_cnt >= MAX_SEQ_PRINTF_MAX_MEMCPY) {
err = -E2BIG;
goto out;
}
copy_size = (fmt[i + 2] == '4') ? 4 : 16;
err = copy_from_kernel_nofault(bufs->buf[memcpy_cnt],
(void *) (long) args[fmt_cnt],
copy_size);
if (err < 0)
memset(bufs->buf[memcpy_cnt], 0, copy_size);
params[fmt_cnt] = (u64)(long)bufs->buf[memcpy_cnt];
i += 2;
fmt_cnt++;
memcpy_cnt++;
continue;
}
if (fmt[i] == 'l') {
i++;
if (fmt[i] == 'l')
i++;
}
if (fmt[i] != 'i' && fmt[i] != 'd' &&
fmt[i] != 'u' && fmt[i] != 'x' &&
fmt[i] != 'X') {
err = -EINVAL;
goto out;
}
params[fmt_cnt] = args[fmt_cnt];
fmt_cnt++;
}
/* Maximumly we can have MAX_SEQ_PRINTF_VARARGS parameter, just give
* all of them to seq_printf().
*/
seq_printf(m, fmt, params[0], params[1], params[2], params[3],
params[4], params[5], params[6], params[7], params[8],
params[9], params[10], params[11]);
err = seq_has_overflowed(m) ? -EOVERFLOW : 0;
out:
this_cpu_dec(bpf_seq_printf_buf_used);
return err;
}
BTF_ID_LIST_SINGLE(btf_seq_file_ids, struct, seq_file)
static const struct bpf_func_proto bpf_seq_printf_proto = {
.func = bpf_seq_printf,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &btf_seq_file_ids[0],
.arg2_type = ARG_PTR_TO_MEM,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_PTR_TO_MEM_OR_NULL,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
BPF_CALL_3(bpf_seq_write, struct seq_file *, m, const void *, data, u32, len)
{
return seq_write(m, data, len) ? -EOVERFLOW : 0;
}
static const struct bpf_func_proto bpf_seq_write_proto = {
.func = bpf_seq_write,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &btf_seq_file_ids[0],
.arg2_type = ARG_PTR_TO_MEM,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
};
BPF_CALL_4(bpf_seq_printf_btf, struct seq_file *, m, struct btf_ptr *, ptr,
u32, btf_ptr_size, u64, flags)
{
const struct btf *btf;
s32 btf_id;
int ret;
ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
if (ret)
return ret;
return btf_type_seq_show_flags(btf, btf_id, ptr->ptr, m, flags);
}
static const struct bpf_func_proto bpf_seq_printf_btf_proto = {
.func = bpf_seq_printf_btf,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &btf_seq_file_ids[0],
.arg2_type = ARG_PTR_TO_MEM,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.arg4_type = ARG_ANYTHING,
};
static __always_inline int
get_map_perf_counter(struct bpf_map *map, u64 flags,
u64 *value, u64 *enabled, u64 *running)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
unsigned int cpu = smp_processor_id();
u64 index = flags & BPF_F_INDEX_MASK;
struct bpf_event_entry *ee;
if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
return -EINVAL;
if (index == BPF_F_CURRENT_CPU)
index = cpu;
if (unlikely(index >= array->map.max_entries))
return -E2BIG;
ee = READ_ONCE(array->ptrs[index]);
if (!ee)
return -ENOENT;
return perf_event_read_local(ee->event, value, enabled, running);
}
BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags)
{
u64 value = 0;
int err;
err = get_map_perf_counter(map, flags, &value, NULL, NULL);
/*
* this api is ugly since we miss [-22..-2] range of valid
* counter values, but that's uapi
*/
if (err)
return err;
return value;
}
static const struct bpf_func_proto bpf_perf_event_read_proto = {
.func = bpf_perf_event_read,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_perf_event_read_value, struct bpf_map *, map, u64, flags,
struct bpf_perf_event_value *, buf, u32, size)
{
int err = -EINVAL;
if (unlikely(size != sizeof(struct bpf_perf_event_value)))
goto clear;
err = get_map_perf_counter(map, flags, &buf->counter, &buf->enabled,
&buf->running);
if (unlikely(err))
goto clear;
return 0;
clear:
memset(buf, 0, size);
return err;
}
static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
.func = bpf_perf_event_read_value,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_PTR_TO_UNINIT_MEM,
.arg4_type = ARG_CONST_SIZE,
};
static __always_inline u64
__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
u64 flags, struct perf_sample_data *sd)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
unsigned int cpu = smp_processor_id();
u64 index = flags & BPF_F_INDEX_MASK;
struct bpf_event_entry *ee;
struct perf_event *event;
if (index == BPF_F_CURRENT_CPU)
index = cpu;
if (unlikely(index >= array->map.max_entries))
return -E2BIG;
ee = READ_ONCE(array->ptrs[index]);
if (!ee)
return -ENOENT;
event = ee->event;
if (unlikely(event->attr.type != PERF_TYPE_SOFTWARE ||
event->attr.config != PERF_COUNT_SW_BPF_OUTPUT))
return -EINVAL;
if (unlikely(event->oncpu != cpu))
return -EOPNOTSUPP;
return perf_event_output(event, sd, regs);
}
/*
* Support executing tracepoints in normal, irq, and nmi context that each call
* bpf_perf_event_output
*/
struct bpf_trace_sample_data {
struct perf_sample_data sds[3];
};
static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_trace_sds);
static DEFINE_PER_CPU(int, bpf_trace_nest_level);
BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,
u64, flags, void *, data, u64, size)
{
struct bpf_trace_sample_data *sds = this_cpu_ptr(&bpf_trace_sds);
int nest_level = this_cpu_inc_return(bpf_trace_nest_level);
struct perf_raw_record raw = {
.frag = {
.size = size,
.data = data,
},
};
struct perf_sample_data *sd;
int err;
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(sds->sds))) {
err = -EBUSY;
goto out;
}
sd = &sds->sds[nest_level - 1];
if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
err = -EINVAL;
goto out;
}
perf_sample_data_init(sd, 0, 0);
sd->raw = &raw;
err = __bpf_perf_event_output(regs, map, flags, sd);
out:
this_cpu_dec(bpf_trace_nest_level);
return err;
}
static const struct bpf_func_proto bpf_perf_event_output_proto = {
.func = bpf_perf_event_output,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_MEM,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
static DEFINE_PER_CPU(int, bpf_event_output_nest_level);
struct bpf_nested_pt_regs {
struct pt_regs regs[3];
};
static DEFINE_PER_CPU(struct bpf_nested_pt_regs, bpf_pt_regs);
static DEFINE_PER_CPU(struct bpf_trace_sample_data, bpf_misc_sds);
u64 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
{
int nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
struct perf_raw_frag frag = {
.copy = ctx_copy,
.size = ctx_size,
.data = ctx,
};
struct perf_raw_record raw = {
.frag = {
{
.next = ctx_size ? &frag : NULL,
},
.size = meta_size,
.data = meta,
},
};
struct perf_sample_data *sd;
struct pt_regs *regs;
u64 ret;
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bpf_misc_sds.sds))) {
ret = -EBUSY;
goto out;
}
sd = this_cpu_ptr(&bpf_misc_sds.sds[nest_level - 1]);
regs = this_cpu_ptr(&bpf_pt_regs.regs[nest_level - 1]);
perf_fetch_caller_regs(regs);
perf_sample_data_init(sd, 0, 0);
sd->raw = &raw;
ret = __bpf_perf_event_output(regs, map, flags, sd);
out:
this_cpu_dec(bpf_event_output_nest_level);
return ret;
}
BPF_CALL_0(bpf_get_current_task)
{
return (long) current;
}
const struct bpf_func_proto bpf_get_current_task_proto = {
.func = bpf_get_current_task,
.gpl_only = true,
.ret_type = RET_INTEGER,
};
BPF_CALL_2(bpf_current_task_under_cgroup, struct bpf_map *, map, u32, idx)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
struct cgroup *cgrp;
if (unlikely(idx >= array->map.max_entries))
return -E2BIG;
cgrp = READ_ONCE(array->ptrs[idx]);
if (unlikely(!cgrp))
return -EAGAIN;
return task_under_cgroup_hierarchy(current, cgrp);
}
static const struct bpf_func_proto bpf_current_task_under_cgroup_proto = {
.func = bpf_current_task_under_cgroup,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_ANYTHING,
};
struct send_signal_irq_work {
struct irq_work irq_work;
struct task_struct *task;
u32 sig;
enum pid_type type;
};
static DEFINE_PER_CPU(struct send_signal_irq_work, send_signal_work);
static void do_bpf_send_signal(struct irq_work *entry)
{
struct send_signal_irq_work *work;
work = container_of(entry, struct send_signal_irq_work, irq_work);
group_send_sig_info(work->sig, SEND_SIG_PRIV, work->task, work->type);
}
static int bpf_send_signal_common(u32 sig, enum pid_type type)
{
struct send_signal_irq_work *work = NULL;
/* Similar to bpf_probe_write_user, task needs to be
* in a sound condition and kernel memory access be
* permitted in order to send signal to the current
* task.
*/
if (unlikely(current->flags & (PF_KTHREAD | PF_EXITING)))
return -EPERM;
if (unlikely(uaccess_kernel()))
return -EPERM;
if (unlikely(!nmi_uaccess_okay()))
return -EPERM;
if (irqs_disabled()) {
/* Do an early check on signal validity. Otherwise,
* the error is lost in deferred irq_work.
*/
if (unlikely(!valid_signal(sig)))
return -EINVAL;
work = this_cpu_ptr(&send_signal_work);
if (atomic_read(&work->irq_work.flags) & IRQ_WORK_BUSY)
return -EBUSY;
/* Add the current task, which is the target of sending signal,
* to the irq_work. The current task may change when queued
* irq works get executed.
*/
work->task = current;
work->sig = sig;
work->type = type;
irq_work_queue(&work->irq_work);
return 0;
}
return group_send_sig_info(sig, SEND_SIG_PRIV, current, type);
}
BPF_CALL_1(bpf_send_signal, u32, sig)
{
return bpf_send_signal_common(sig, PIDTYPE_TGID);
}
static const struct bpf_func_proto bpf_send_signal_proto = {
.func = bpf_send_signal,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
};
BPF_CALL_1(bpf_send_signal_thread, u32, sig)
{
return bpf_send_signal_common(sig, PIDTYPE_PID);
}
static const struct bpf_func_proto bpf_send_signal_thread_proto = {
.func = bpf_send_signal_thread,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_d_path, struct path *, path, char *, buf, u32, sz)
{
long len;
char *p;
if (!sz)
return 0;
p = d_path(path, buf, sz);
if (IS_ERR(p)) {
len = PTR_ERR(p);
} else {
len = buf + sz - p;
memmove(buf, p, len);
}
return len;
}
BTF_SET_START(btf_allowlist_d_path)
#ifdef CONFIG_SECURITY
BTF_ID(func, security_file_permission)
BTF_ID(func, security_inode_getattr)
BTF_ID(func, security_file_open)
#endif
#ifdef CONFIG_SECURITY_PATH
BTF_ID(func, security_path_truncate)
#endif
BTF_ID(func, vfs_truncate)
BTF_ID(func, vfs_fallocate)
BTF_ID(func, dentry_open)
BTF_ID(func, vfs_getattr)
BTF_ID(func, filp_close)
BTF_SET_END(btf_allowlist_d_path)
static bool bpf_d_path_allowed(const struct bpf_prog *prog)
{
return btf_id_set_contains(&btf_allowlist_d_path, prog->aux->attach_btf_id);
}
BTF_ID_LIST_SINGLE(bpf_d_path_btf_ids, struct, path)
static const struct bpf_func_proto bpf_d_path_proto = {
.func = bpf_d_path,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &bpf_d_path_btf_ids[0],
.arg2_type = ARG_PTR_TO_MEM,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.allowed = bpf_d_path_allowed,
};
#define BTF_F_ALL (BTF_F_COMPACT | BTF_F_NONAME | \
BTF_F_PTR_RAW | BTF_F_ZERO)
static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
u64 flags, const struct btf **btf,
s32 *btf_id)
{
const struct btf_type *t;
if (unlikely(flags & ~(BTF_F_ALL)))
return -EINVAL;
if (btf_ptr_size != sizeof(struct btf_ptr))
return -EINVAL;
*btf = bpf_get_btf_vmlinux();
if (IS_ERR_OR_NULL(*btf))
return PTR_ERR(*btf);
if (ptr->type_id > 0)
*btf_id = ptr->type_id;
else
return -EINVAL;
if (*btf_id > 0)
t = btf_type_by_id(*btf, *btf_id);
if (*btf_id <= 0 || !t)
return -ENOENT;
return 0;
}
BPF_CALL_5(bpf_snprintf_btf, char *, str, u32, str_size, struct btf_ptr *, ptr,
u32, btf_ptr_size, u64, flags)
{
const struct btf *btf;
s32 btf_id;
int ret;
ret = bpf_btf_printf_prepare(ptr, btf_ptr_size, flags, &btf, &btf_id);
if (ret)
return ret;
return btf_type_snprintf_show(btf, btf_id, ptr->ptr, str, str_size,
flags);
}
const struct bpf_func_proto bpf_snprintf_btf_proto = {
.func = bpf_snprintf_btf,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM,
.arg2_type = ARG_CONST_SIZE,
.arg3_type = ARG_PTR_TO_MEM,
.arg4_type = ARG_CONST_SIZE,
.arg5_type = ARG_ANYTHING,
};
const struct bpf_func_proto *
bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_map_lookup_elem:
return &bpf_map_lookup_elem_proto;
case BPF_FUNC_map_update_elem:
return &bpf_map_update_elem_proto;
case BPF_FUNC_map_delete_elem:
return &bpf_map_delete_elem_proto;
case BPF_FUNC_map_push_elem:
return &bpf_map_push_elem_proto;
case BPF_FUNC_map_pop_elem:
return &bpf_map_pop_elem_proto;
case BPF_FUNC_map_peek_elem:
return &bpf_map_peek_elem_proto;
case BPF_FUNC_ktime_get_ns:
return &bpf_ktime_get_ns_proto;
case BPF_FUNC_ktime_get_boot_ns:
return &bpf_ktime_get_boot_ns_proto;
case BPF_FUNC_tail_call:
return &bpf_tail_call_proto;
case BPF_FUNC_get_current_pid_tgid:
return &bpf_get_current_pid_tgid_proto;
case BPF_FUNC_get_current_task:
return &bpf_get_current_task_proto;
case BPF_FUNC_get_current_uid_gid:
return &bpf_get_current_uid_gid_proto;
case BPF_FUNC_get_current_comm:
return &bpf_get_current_comm_proto;
case BPF_FUNC_trace_printk:
return bpf_get_trace_printk_proto();
case BPF_FUNC_get_smp_processor_id:
return &bpf_get_smp_processor_id_proto;
case BPF_FUNC_get_numa_node_id:
return &bpf_get_numa_node_id_proto;
case BPF_FUNC_perf_event_read:
return &bpf_perf_event_read_proto;
case BPF_FUNC_probe_write_user:
return bpf_get_probe_write_proto();
case BPF_FUNC_current_task_under_cgroup:
return &bpf_current_task_under_cgroup_proto;
case BPF_FUNC_get_prandom_u32:
return &bpf_get_prandom_u32_proto;
case BPF_FUNC_probe_read_user:
return &bpf_probe_read_user_proto;
case BPF_FUNC_probe_read_kernel:
return &bpf_probe_read_kernel_proto;
case BPF_FUNC_probe_read_user_str:
return &bpf_probe_read_user_str_proto;
case BPF_FUNC_probe_read_kernel_str:
return &bpf_probe_read_kernel_str_proto;
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
case BPF_FUNC_probe_read:
return &bpf_probe_read_compat_proto;
case BPF_FUNC_probe_read_str:
return &bpf_probe_read_compat_str_proto;
#endif
#ifdef CONFIG_CGROUPS
case BPF_FUNC_get_current_cgroup_id:
return &bpf_get_current_cgroup_id_proto;
#endif
case BPF_FUNC_send_signal:
return &bpf_send_signal_proto;
case BPF_FUNC_send_signal_thread:
return &bpf_send_signal_thread_proto;
case BPF_FUNC_perf_event_read_value:
return &bpf_perf_event_read_value_proto;
case BPF_FUNC_get_ns_current_pid_tgid:
return &bpf_get_ns_current_pid_tgid_proto;
case BPF_FUNC_ringbuf_output:
return &bpf_ringbuf_output_proto;
case BPF_FUNC_ringbuf_reserve:
return &bpf_ringbuf_reserve_proto;
case BPF_FUNC_ringbuf_submit:
return &bpf_ringbuf_submit_proto;
case BPF_FUNC_ringbuf_discard:
return &bpf_ringbuf_discard_proto;
case BPF_FUNC_ringbuf_query:
return &bpf_ringbuf_query_proto;
case BPF_FUNC_jiffies64:
return &bpf_jiffies64_proto;
case BPF_FUNC_get_task_stack:
return &bpf_get_task_stack_proto;
case BPF_FUNC_copy_from_user:
return prog->aux->sleepable ? &bpf_copy_from_user_proto : NULL;
case BPF_FUNC_snprintf_btf:
return &bpf_snprintf_btf_proto;
case BPF_FUNC_bpf_per_cpu_ptr:
return &bpf_per_cpu_ptr_proto;
case BPF_FUNC_bpf_this_cpu_ptr:
return &bpf_this_cpu_ptr_proto;
default:
return NULL;
}
}
static const struct bpf_func_proto *
kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_perf_event_output:
return &bpf_perf_event_output_proto;
case BPF_FUNC_get_stackid:
return &bpf_get_stackid_proto;
case BPF_FUNC_get_stack:
return &bpf_get_stack_proto;
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
case BPF_FUNC_override_return:
return &bpf_override_return_proto;
#endif
default:
return bpf_tracing_func_proto(func_id, prog);
}
}
/* bpf+kprobe programs can access fields of 'struct pt_regs' */
static bool kprobe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
if (off < 0 || off >= sizeof(struct pt_regs))
return false;
if (type != BPF_READ)
return false;
if (off % size != 0)
return false;
/*
* Assertion for 32 bit to make sure last 8 byte access
* (BPF_DW) to the last 4 byte member is disallowed.
*/
if (off + size > sizeof(struct pt_regs))
return false;
return true;
}
const struct bpf_verifier_ops kprobe_verifier_ops = {
.get_func_proto = kprobe_prog_func_proto,
.is_valid_access = kprobe_prog_is_valid_access,
};
const struct bpf_prog_ops kprobe_prog_ops = {
};
BPF_CALL_5(bpf_perf_event_output_tp, void *, tp_buff, struct bpf_map *, map,
u64, flags, void *, data, u64, size)
{
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
/*
* r1 points to perf tracepoint buffer where first 8 bytes are hidden
* from bpf program and contain a pointer to 'struct pt_regs'. Fetch it
* from there and call the same bpf_perf_event_output() helper inline.
*/
return ____bpf_perf_event_output(regs, map, flags, data, size);
}
static const struct bpf_func_proto bpf_perf_event_output_proto_tp = {
.func = bpf_perf_event_output_tp,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_MEM,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
u64, flags)
{
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
/*
* Same comment as in bpf_perf_event_output_tp(), only that this time
* the other helper's function body cannot be inlined due to being
* external, thus we need to call raw helper function.
*/
return bpf_get_stackid((unsigned long) regs, (unsigned long) map,
flags, 0, 0);
}
static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
.func = bpf_get_stackid_tp,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_get_stack_tp, void *, tp_buff, void *, buf, u32, size,
u64, flags)
{
struct pt_regs *regs = *(struct pt_regs **)tp_buff;
return bpf_get_stack((unsigned long) regs, (unsigned long) buf,
(unsigned long) size, flags, 0);
}
static const struct bpf_func_proto bpf_get_stack_proto_tp = {
.func = bpf_get_stack_tp,
.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,
};
static const struct bpf_func_proto *
tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_perf_event_output:
return &bpf_perf_event_output_proto_tp;
case BPF_FUNC_get_stackid:
return &bpf_get_stackid_proto_tp;
case BPF_FUNC_get_stack:
return &bpf_get_stack_proto_tp;
default:
return bpf_tracing_func_proto(func_id, prog);
}
}
static bool tp_prog_is_valid_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
if (off < sizeof(void *) || off >= PERF_MAX_TRACE_SIZE)
return false;
if (type != BPF_READ)
return false;
if (off % size != 0)
return false;
BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(__u64));
return true;
}
const struct bpf_verifier_ops tracepoint_verifier_ops = {
.get_func_proto = tp_prog_func_proto,
.is_valid_access = tp_prog_is_valid_access,
};
const struct bpf_prog_ops tracepoint_prog_ops = {
};
BPF_CALL_3(bpf_perf_prog_read_value, struct bpf_perf_event_data_kern *, ctx,
struct bpf_perf_event_value *, buf, u32, size)
{
int err = -EINVAL;
if (unlikely(size != sizeof(struct bpf_perf_event_value)))
goto clear;
err = perf_event_read_local(ctx->event, &buf->counter, &buf->enabled,
&buf->running);
if (unlikely(err))
goto clear;
return 0;
clear:
memset(buf, 0, size);
return err;
}
static const struct bpf_func_proto bpf_perf_prog_read_value_proto = {
.func = bpf_perf_prog_read_value,
.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,
};
BPF_CALL_4(bpf_read_branch_records, struct bpf_perf_event_data_kern *, ctx,
void *, buf, u32, size, u64, flags)
{
#ifndef CONFIG_X86
return -ENOENT;
#else
static const u32 br_entry_size = sizeof(struct perf_branch_entry);
struct perf_branch_stack *br_stack = ctx->data->br_stack;
u32 to_copy;
if (unlikely(flags & ~BPF_F_GET_BRANCH_RECORDS_SIZE))
return -EINVAL;
if (unlikely(!br_stack))
return -EINVAL;
if (flags & BPF_F_GET_BRANCH_RECORDS_SIZE)
return br_stack->nr * br_entry_size;
if (!buf || (size % br_entry_size != 0))
return -EINVAL;
to_copy = min_t(u32, br_stack->nr * br_entry_size, size);
memcpy(buf, br_stack->entries, to_copy);
return to_copy;
#endif
}
static const struct bpf_func_proto bpf_read_branch_records_proto = {
.func = bpf_read_branch_records,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_PTR_TO_MEM_OR_NULL,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.arg4_type = ARG_ANYTHING,
};
static const struct bpf_func_proto *
pe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_perf_event_output:
return &bpf_perf_event_output_proto_tp;
case BPF_FUNC_get_stackid:
return &bpf_get_stackid_proto_pe;
case BPF_FUNC_get_stack:
return &bpf_get_stack_proto_pe;
case BPF_FUNC_perf_prog_read_value:
return &bpf_perf_prog_read_value_proto;
case BPF_FUNC_read_branch_records:
return &bpf_read_branch_records_proto;
default:
return bpf_tracing_func_proto(func_id, prog);
}
}
/*
* bpf_raw_tp_regs are separate from bpf_pt_regs used from skb/xdp
* to avoid potential recursive reuse issue when/if tracepoints are added
* inside bpf_*_event_output, bpf_get_stackid and/or bpf_get_stack.
*
* Since raw tracepoints run despite bpf_prog_active, support concurrent usage
* in normal, irq, and nmi context.
*/
struct bpf_raw_tp_regs {
struct pt_regs regs[3];
};
static DEFINE_PER_CPU(struct bpf_raw_tp_regs, bpf_raw_tp_regs);
static DEFINE_PER_CPU(int, bpf_raw_tp_nest_level);
static struct pt_regs *get_bpf_raw_tp_regs(void)
{
struct bpf_raw_tp_regs *tp_regs = this_cpu_ptr(&bpf_raw_tp_regs);
int nest_level = this_cpu_inc_return(bpf_raw_tp_nest_level);
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(tp_regs->regs))) {
this_cpu_dec(bpf_raw_tp_nest_level);
return ERR_PTR(-EBUSY);
}
return &tp_regs->regs[nest_level - 1];
}
static void put_bpf_raw_tp_regs(void)
{
this_cpu_dec(bpf_raw_tp_nest_level);
}
BPF_CALL_5(bpf_perf_event_output_raw_tp, struct bpf_raw_tracepoint_args *, args,
struct bpf_map *, map, u64, flags, void *, data, u64, size)
{
struct pt_regs *regs = get_bpf_raw_tp_regs();
int ret;
if (IS_ERR(regs))
return PTR_ERR(regs);
perf_fetch_caller_regs(regs);
ret = ____bpf_perf_event_output(regs, map, flags, data, size);
put_bpf_raw_tp_regs();
return ret;
}
static const struct bpf_func_proto bpf_perf_event_output_proto_raw_tp = {
.func = bpf_perf_event_output_raw_tp,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_MEM,
.arg5_type = ARG_CONST_SIZE_OR_ZERO,
};
extern const struct bpf_func_proto bpf_skb_output_proto;
extern const struct bpf_func_proto bpf_xdp_output_proto;
BPF_CALL_3(bpf_get_stackid_raw_tp, struct bpf_raw_tracepoint_args *, args,
struct bpf_map *, map, u64, flags)
{
struct pt_regs *regs = get_bpf_raw_tp_regs();
int ret;
if (IS_ERR(regs))
return PTR_ERR(regs);
perf_fetch_caller_regs(regs);
/* similar to bpf_perf_event_output_tp, but pt_regs fetched differently */
ret = bpf_get_stackid((unsigned long) regs, (unsigned long) map,
flags, 0, 0);
put_bpf_raw_tp_regs();
return ret;
}
static const struct bpf_func_proto bpf_get_stackid_proto_raw_tp = {
.func = bpf_get_stackid_raw_tp,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_CONST_MAP_PTR,
.arg3_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_get_stack_raw_tp, struct bpf_raw_tracepoint_args *, args,
void *, buf, u32, size, u64, flags)
{
struct pt_regs *regs = get_bpf_raw_tp_regs();
int ret;
if (IS_ERR(regs))
return PTR_ERR(regs);
perf_fetch_caller_regs(regs);
ret = bpf_get_stack((unsigned long) regs, (unsigned long) buf,
(unsigned long) size, flags, 0);
put_bpf_raw_tp_regs();
return ret;
}
static const struct bpf_func_proto bpf_get_stack_proto_raw_tp = {
.func = bpf_get_stack_raw_tp,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_PTR_TO_MEM,
.arg3_type = ARG_CONST_SIZE_OR_ZERO,
.arg4_type = ARG_ANYTHING,
};
static const struct bpf_func_proto *
raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_perf_event_output:
return &bpf_perf_event_output_proto_raw_tp;
case BPF_FUNC_get_stackid:
return &bpf_get_stackid_proto_raw_tp;
case BPF_FUNC_get_stack:
return &bpf_get_stack_proto_raw_tp;
default:
return bpf_tracing_func_proto(func_id, prog);
}
}
const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
#ifdef CONFIG_NET
case BPF_FUNC_skb_output:
return &bpf_skb_output_proto;
case BPF_FUNC_xdp_output:
return &bpf_xdp_output_proto;
case BPF_FUNC_skc_to_tcp6_sock:
return &bpf_skc_to_tcp6_sock_proto;
case BPF_FUNC_skc_to_tcp_sock:
return &bpf_skc_to_tcp_sock_proto;
case BPF_FUNC_skc_to_tcp_timewait_sock:
return &bpf_skc_to_tcp_timewait_sock_proto;
case BPF_FUNC_skc_to_tcp_request_sock:
return &bpf_skc_to_tcp_request_sock_proto;
case BPF_FUNC_skc_to_udp6_sock:
return &bpf_skc_to_udp6_sock_proto;
#endif
case BPF_FUNC_seq_printf:
return prog->expected_attach_type == BPF_TRACE_ITER ?
&bpf_seq_printf_proto :
NULL;
case BPF_FUNC_seq_write:
return prog->expected_attach_type == BPF_TRACE_ITER ?
&bpf_seq_write_proto :
NULL;
case BPF_FUNC_seq_printf_btf:
return prog->expected_attach_type == BPF_TRACE_ITER ?
&bpf_seq_printf_btf_proto :
NULL;
case BPF_FUNC_d_path:
return &bpf_d_path_proto;
default:
return raw_tp_prog_func_proto(func_id, prog);
}
}
static bool raw_tp_prog_is_valid_access(int off, int size,
enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
return false;
if (type != BPF_READ)
return false;
if (off % size != 0)
return false;
return true;
}
static bool tracing_prog_is_valid_access(int off, int size,
enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
if (off < 0 || off >= sizeof(__u64) * MAX_BPF_FUNC_ARGS)
return false;
if (type != BPF_READ)
return false;
if (off % size != 0)
return false;
return btf_ctx_access(off, size, type, prog, info);
}
int __weak bpf_prog_test_run_tracing(struct bpf_prog *prog,
const union bpf_attr *kattr,
union bpf_attr __user *uattr)
{
return -ENOTSUPP;
}
const struct bpf_verifier_ops raw_tracepoint_verifier_ops = {
.get_func_proto = raw_tp_prog_func_proto,
.is_valid_access = raw_tp_prog_is_valid_access,
};
const struct bpf_prog_ops raw_tracepoint_prog_ops = {
#ifdef CONFIG_NET
.test_run = bpf_prog_test_run_raw_tp,
#endif
};
const struct bpf_verifier_ops tracing_verifier_ops = {
.get_func_proto = tracing_prog_func_proto,
.is_valid_access = tracing_prog_is_valid_access,
};
const struct bpf_prog_ops tracing_prog_ops = {
.test_run = bpf_prog_test_run_tracing,
};
static bool raw_tp_writable_prog_is_valid_access(int off, int size,
enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
if (off == 0) {
if (size != sizeof(u64) || type != BPF_READ)
return false;
info->reg_type = PTR_TO_TP_BUFFER;
}
return raw_tp_prog_is_valid_access(off, size, type, prog, info);
}
const struct bpf_verifier_ops raw_tracepoint_writable_verifier_ops = {
.get_func_proto = raw_tp_prog_func_proto,
.is_valid_access = raw_tp_writable_prog_is_valid_access,
};
const struct bpf_prog_ops raw_tracepoint_writable_prog_ops = {
};
static bool pe_prog_is_valid_access(int off, int size, enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
const int size_u64 = sizeof(u64);
if (off < 0 || off >= sizeof(struct bpf_perf_event_data))
return false;
if (type != BPF_READ)
return false;
if (off % size != 0) {
if (sizeof(unsigned long) != 4)
return false;
if (size != 8)
return false;
if (off % size != 4)
return false;
}
switch (off) {
case bpf_ctx_range(struct bpf_perf_event_data, sample_period):
bpf_ctx_record_field_size(info, size_u64);
if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
return false;
break;
case bpf_ctx_range(struct bpf_perf_event_data, addr):
bpf_ctx_record_field_size(info, size_u64);
if (!bpf_ctx_narrow_access_ok(off, size, size_u64))
return false;
break;
default:
if (size != sizeof(long))
return false;
}
return true;
}
static u32 pe_prog_convert_ctx_access(enum bpf_access_type type,
const struct bpf_insn *si,
struct bpf_insn *insn_buf,
struct bpf_prog *prog, u32 *target_size)
{
struct bpf_insn *insn = insn_buf;
switch (si->off) {
case offsetof(struct bpf_perf_event_data, sample_period):
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
data), si->dst_reg, si->src_reg,
offsetof(struct bpf_perf_event_data_kern, data));
*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
bpf_target_off(struct perf_sample_data, period, 8,
target_size));
break;
case offsetof(struct bpf_perf_event_data, addr):
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
data), si->dst_reg, si->src_reg,
offsetof(struct bpf_perf_event_data_kern, data));
*insn++ = BPF_LDX_MEM(BPF_DW, si->dst_reg, si->dst_reg,
bpf_target_off(struct perf_sample_data, addr, 8,
target_size));
break;
default:
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_perf_event_data_kern,
regs), si->dst_reg, si->src_reg,
offsetof(struct bpf_perf_event_data_kern, regs));
*insn++ = BPF_LDX_MEM(BPF_SIZEOF(long), si->dst_reg, si->dst_reg,
si->off);
break;
}
return insn - insn_buf;
}
const struct bpf_verifier_ops perf_event_verifier_ops = {
.get_func_proto = pe_prog_func_proto,
.is_valid_access = pe_prog_is_valid_access,
.convert_ctx_access = pe_prog_convert_ctx_access,
};
const struct bpf_prog_ops perf_event_prog_ops = {
};
static DEFINE_MUTEX(bpf_event_mutex);
#define BPF_TRACE_MAX_PROGS 64
int perf_event_attach_bpf_prog(struct perf_event *event,
struct bpf_prog *prog)
{
struct bpf_prog_array *old_array;
struct bpf_prog_array *new_array;
int ret = -EEXIST;
/*
* Kprobe override only works if they are on the function entry,
* and only if they are on the opt-in list.
*/
if (prog->kprobe_override &&
(!trace_kprobe_on_func_entry(event->tp_event) ||
!trace_kprobe_error_injectable(event->tp_event)))
return -EINVAL;
mutex_lock(&bpf_event_mutex);
if (event->prog)
goto unlock;
old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
if (old_array &&
bpf_prog_array_length(old_array) >= BPF_TRACE_MAX_PROGS) {
ret = -E2BIG;
goto unlock;
}
ret = bpf_prog_array_copy(old_array, NULL, prog, &new_array);
if (ret < 0)
goto unlock;
/* set the new array to event->tp_event and set event->prog */
event->prog = prog;
rcu_assign_pointer(event->tp_event->prog_array, new_array);
bpf_prog_array_free(old_array);
unlock:
mutex_unlock(&bpf_event_mutex);
return ret;
}
void perf_event_detach_bpf_prog(struct perf_event *event)
{
struct bpf_prog_array *old_array;
struct bpf_prog_array *new_array;
int ret;
mutex_lock(&bpf_event_mutex);
if (!event->prog)
goto unlock;
old_array = bpf_event_rcu_dereference(event->tp_event->prog_array);
ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);
if (ret == -ENOENT)
goto unlock;
if (ret < 0) {
bpf_prog_array_delete_safe(old_array, event->prog);
} else {
rcu_assign_pointer(event->tp_event->prog_array, new_array);
bpf_prog_array_free(old_array);
}
bpf_prog_put(event->prog);
event->prog = NULL;
unlock:
mutex_unlock(&bpf_event_mutex);
}
int perf_event_query_prog_array(struct perf_event *event, void __user *info)
{
struct perf_event_query_bpf __user *uquery = info;
struct perf_event_query_bpf query = {};
struct bpf_prog_array *progs;
u32 *ids, prog_cnt, ids_len;
int ret;
if (!perfmon_capable())
return -EPERM;
if (event->attr.type != PERF_TYPE_TRACEPOINT)
return -EINVAL;
if (copy_from_user(&query, uquery, sizeof(query)))
return -EFAULT;
ids_len = query.ids_len;
if (ids_len > BPF_TRACE_MAX_PROGS)
return -E2BIG;
ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
if (!ids)
return -ENOMEM;
/*
* The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
* is required when user only wants to check for uquery->prog_cnt.
* There is no need to check for it since the case is handled
* gracefully in bpf_prog_array_copy_info.
*/
mutex_lock(&bpf_event_mutex);
progs = bpf_event_rcu_dereference(event->tp_event->prog_array);
ret = bpf_prog_array_copy_info(progs, ids, ids_len, &prog_cnt);
mutex_unlock(&bpf_event_mutex);
if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
ret = -EFAULT;
kfree(ids);
return ret;
}
extern struct bpf_raw_event_map __start__bpf_raw_tp[];
extern struct bpf_raw_event_map __stop__bpf_raw_tp[];
struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name)
{
struct bpf_raw_event_map *btp = __start__bpf_raw_tp;
for (; btp < __stop__bpf_raw_tp; btp++) {
if (!strcmp(btp->tp->name, name))
return btp;
}
return bpf_get_raw_tracepoint_module(name);
}
void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp)
{
struct module *mod = __module_address((unsigned long)btp);
if (mod)
module_put(mod);
}
static __always_inline
void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
{
cant_sleep();
rcu_read_lock();
(void) BPF_PROG_RUN(prog, args);
rcu_read_unlock();
}
#define UNPACK(...) __VA_ARGS__
#define REPEAT_1(FN, DL, X, ...) FN(X)
#define REPEAT_2(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_1(FN, DL, __VA_ARGS__)
#define REPEAT_3(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_2(FN, DL, __VA_ARGS__)
#define REPEAT_4(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_3(FN, DL, __VA_ARGS__)
#define REPEAT_5(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_4(FN, DL, __VA_ARGS__)
#define REPEAT_6(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_5(FN, DL, __VA_ARGS__)
#define REPEAT_7(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_6(FN, DL, __VA_ARGS__)
#define REPEAT_8(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_7(FN, DL, __VA_ARGS__)
#define REPEAT_9(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_8(FN, DL, __VA_ARGS__)
#define REPEAT_10(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_9(FN, DL, __VA_ARGS__)
#define REPEAT_11(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_10(FN, DL, __VA_ARGS__)
#define REPEAT_12(FN, DL, X, ...) FN(X) UNPACK DL REPEAT_11(FN, DL, __VA_ARGS__)
#define REPEAT(X, FN, DL, ...) REPEAT_##X(FN, DL, __VA_ARGS__)
#define SARG(X) u64 arg##X
#define COPY(X) args[X] = arg##X
#define __DL_COM (,)
#define __DL_SEM (;)
#define __SEQ_0_11 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
#define BPF_TRACE_DEFN_x(x) \
void bpf_trace_run##x(struct bpf_prog *prog, \
REPEAT(x, SARG, __DL_COM, __SEQ_0_11)) \
{ \
u64 args[x]; \
REPEAT(x, COPY, __DL_SEM, __SEQ_0_11); \
__bpf_trace_run(prog, args); \
} \
EXPORT_SYMBOL_GPL(bpf_trace_run##x)
BPF_TRACE_DEFN_x(1);
BPF_TRACE_DEFN_x(2);
BPF_TRACE_DEFN_x(3);
BPF_TRACE_DEFN_x(4);
BPF_TRACE_DEFN_x(5);
BPF_TRACE_DEFN_x(6);
BPF_TRACE_DEFN_x(7);
BPF_TRACE_DEFN_x(8);
BPF_TRACE_DEFN_x(9);
BPF_TRACE_DEFN_x(10);
BPF_TRACE_DEFN_x(11);
BPF_TRACE_DEFN_x(12);
static int __bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
{
struct tracepoint *tp = btp->tp;
/*
* check that program doesn't access arguments beyond what's
* available in this tracepoint
*/
if (prog->aux->max_ctx_offset > btp->num_args * sizeof(u64))
return -EINVAL;
if (prog->aux->max_tp_access > btp->writable_size)
return -EINVAL;
return tracepoint_probe_register(tp, (void *)btp->bpf_func, prog);
}
int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
{
return __bpf_probe_register(btp, prog);
}
int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
{
return tracepoint_probe_unregister(btp->tp, (void *)btp->bpf_func, prog);
}
int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
u32 *fd_type, const char **buf,
u64 *probe_offset, u64 *probe_addr)
{
bool is_tracepoint, is_syscall_tp;
struct bpf_prog *prog;
int flags, err = 0;
prog = event->prog;
if (!prog)
return -ENOENT;
/* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
return -EOPNOTSUPP;
*prog_id = prog->aux->id;
flags = event->tp_event->flags;
is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
is_syscall_tp = is_syscall_trace_event(event->tp_event);
if (is_tracepoint || is_syscall_tp) {
*buf = is_tracepoint ? event->tp_event->tp->name
: event->tp_event->name;
*fd_type = BPF_FD_TYPE_TRACEPOINT;
*probe_offset = 0x0;
*probe_addr = 0x0;
} else {
/* kprobe/uprobe */
err = -EOPNOTSUPP;
#ifdef CONFIG_KPROBE_EVENTS
if (flags & TRACE_EVENT_FL_KPROBE)
err = bpf_get_kprobe_info(event, fd_type, buf,
probe_offset, probe_addr,
event->attr.type == PERF_TYPE_TRACEPOINT);
#endif
#ifdef CONFIG_UPROBE_EVENTS
if (flags & TRACE_EVENT_FL_UPROBE)
err = bpf_get_uprobe_info(event, fd_type, buf,
probe_offset,
event->attr.type == PERF_TYPE_TRACEPOINT);
#endif
}
return err;
}
static int __init send_signal_irq_work_init(void)
{
int cpu;
struct send_signal_irq_work *work;
for_each_possible_cpu(cpu) {
work = per_cpu_ptr(&send_signal_work, cpu);
init_irq_work(&work->irq_work, do_bpf_send_signal);
}
return 0;
}
subsys_initcall(send_signal_irq_work_init);
#ifdef CONFIG_MODULES
static int bpf_event_notify(struct notifier_block *nb, unsigned long op,
void *module)
{
struct bpf_trace_module *btm, *tmp;
struct module *mod = module;
int ret = 0;
if (mod->num_bpf_raw_events == 0 ||
(op != MODULE_STATE_COMING && op != MODULE_STATE_GOING))
goto out;
mutex_lock(&bpf_module_mutex);
switch (op) {
case MODULE_STATE_COMING:
btm = kzalloc(sizeof(*btm), GFP_KERNEL);
if (btm) {
btm->module = module;
list_add(&btm->list, &bpf_trace_modules);
} else {
ret = -ENOMEM;
}
break;
case MODULE_STATE_GOING:
list_for_each_entry_safe(btm, tmp, &bpf_trace_modules, list) {
if (btm->module == module) {
list_del(&btm->list);
kfree(btm);
break;
}
}
break;
}
mutex_unlock(&bpf_module_mutex);
out:
return notifier_from_errno(ret);
}
static struct notifier_block bpf_module_nb = {
.notifier_call = bpf_event_notify,
};
static int __init bpf_event_init(void)
{
register_module_notifier(&bpf_module_nb);
return 0;
}
fs_initcall(bpf_event_init);
#endif /* CONFIG_MODULES */