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linuxdebug/kernel/trace/bpf_trace.c

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null pointer error
2024-07-16 15:50:57 +02:00
// 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 <linux/bpf_lsm.h>
#include <linux/fprobe.h>
#include <linux/bsearch.h>
#include <linux/sort.h>
#include <linux/key.h>
#include <linux/verification.h>
#include <net/bpf_sk_storage.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);
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
/**
* 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;
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 heuristic 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.
*/
rcu_read_lock();
ret = bpf_prog_run_array(rcu_dereference(call->prog_array),
ctx, bpf_prog_run);
rcu_read_unlock();
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;
/*
* NB: We rely on strncpy_from_user() not copying junk past the NUL
* terminator into `dst`.
*
* strncpy_from_user() does long-sized strides in the fast path. If the
* strncpy does not mask out the bytes after the NUL in `unsafe_ptr`,
* then there could be junk after the NUL in `dst`. If user takes `dst`
* and keys a hash map with it, then semantically identical strings can
* occupy multiple entries in the map.
*/
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;
ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
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;
/*
* 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))
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(!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 | MEM_RDONLY,
.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 DEFINE_RAW_SPINLOCK(trace_printk_lock);
#define MAX_TRACE_PRINTK_VARARGS 3
#define BPF_TRACE_PRINTK_SIZE 1024
BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,
u64, arg2, u64, arg3)
{
u64 args[MAX_TRACE_PRINTK_VARARGS] = { arg1, arg2, arg3 };
u32 *bin_args;
static char buf[BPF_TRACE_PRINTK_SIZE];
unsigned long flags;
int ret;
ret = bpf_bprintf_prepare(fmt, fmt_size, args, &bin_args,
MAX_TRACE_PRINTK_VARARGS);
if (ret < 0)
return ret;
raw_spin_lock_irqsave(&trace_printk_lock, flags);
ret = bstr_printf(buf, sizeof(buf), fmt, bin_args);
trace_bpf_trace_printk(buf);
raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
bpf_bprintf_cleanup();
return ret;
}
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 | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
};
static void __set_printk_clr_event(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");
}
const struct bpf_func_proto *bpf_get_trace_printk_proto(void)
{
__set_printk_clr_event();
return &bpf_trace_printk_proto;
}
BPF_CALL_4(bpf_trace_vprintk, char *, fmt, u32, fmt_size, const void *, data,
u32, data_len)
{
static char buf[BPF_TRACE_PRINTK_SIZE];
unsigned long flags;
int ret, num_args;
u32 *bin_args;
if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
(data_len && !data))
return -EINVAL;
num_args = data_len / 8;
ret = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args);
if (ret < 0)
return ret;
raw_spin_lock_irqsave(&trace_printk_lock, flags);
ret = bstr_printf(buf, sizeof(buf), fmt, bin_args);
trace_bpf_trace_printk(buf);
raw_spin_unlock_irqrestore(&trace_printk_lock, flags);
bpf_bprintf_cleanup();
return ret;
}
static const struct bpf_func_proto bpf_trace_vprintk_proto = {
.func = bpf_trace_vprintk,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg2_type = ARG_CONST_SIZE,
.arg3_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE_OR_ZERO,
};
const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void)
{
__set_printk_clr_event();
return &bpf_trace_vprintk_proto;
}
BPF_CALL_5(bpf_seq_printf, struct seq_file *, m, char *, fmt, u32, fmt_size,
const void *, data, u32, data_len)
{
int err, num_args;
u32 *bin_args;
if (data_len & 7 || data_len > MAX_BPRINTF_VARARGS * 8 ||
(data_len && !data))
return -EINVAL;
num_args = data_len / 8;
err = bpf_bprintf_prepare(fmt, fmt_size, data, &bin_args, num_args);
if (err < 0)
return err;
seq_bprintf(m, fmt, bin_args);
bpf_bprintf_cleanup();
return seq_has_overflowed(m) ? -EOVERFLOW : 0;
}
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 | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
.arg4_type = ARG_PTR_TO_MEM | PTR_MAYBE_NULL | MEM_RDONLY,
.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 | MEM_RDONLY,
.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 | MEM_RDONLY,
.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;
struct perf_raw_record raw = {
.frag = {
.size = size,
.data = data,
},
};
struct perf_sample_data *sd;
int nest_level, err;
preempt_disable();
sds = this_cpu_ptr(&bpf_trace_sds);
nest_level = this_cpu_inc_return(bpf_trace_nest_level);
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;
sd->sample_flags |= PERF_SAMPLE_RAW;
err = __bpf_perf_event_output(regs, map, flags, sd);
out:
this_cpu_dec(bpf_trace_nest_level);
preempt_enable();
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 | MEM_RDONLY,
.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)
{
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;
int nest_level;
u64 ret;
preempt_disable();
nest_level = this_cpu_inc_return(bpf_event_output_nest_level);
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;
sd->sample_flags |= PERF_SAMPLE_RAW;
ret = __bpf_perf_event_output(regs, map, flags, sd);
out:
this_cpu_dec(bpf_event_output_nest_level);
preempt_enable();
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_0(bpf_get_current_task_btf)
{
return (unsigned long) current;
}
const struct bpf_func_proto bpf_get_current_task_btf_proto = {
.func = bpf_get_current_task_btf,
.gpl_only = true,
.ret_type = RET_PTR_TO_BTF_ID,
.ret_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
};
BPF_CALL_1(bpf_task_pt_regs, struct task_struct *, task)
{
return (unsigned long) task_pt_regs(task);
}
BTF_ID_LIST(bpf_task_pt_regs_ids)
BTF_ID(struct, pt_regs)
const struct bpf_func_proto bpf_task_pt_regs_proto = {
.func = bpf_task_pt_regs,
.gpl_only = true,
.arg1_type = ARG_PTR_TO_BTF_ID,
.arg1_btf_id = &btf_tracing_ids[BTF_TRACING_TYPE_TASK],
.ret_type = RET_PTR_TO_BTF_ID,
.ret_btf_id = &bpf_task_pt_regs_ids[0],
};
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);
put_task_struct(work->task);
}
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(!nmi_uaccess_okay()))
return -EPERM;
/* Task should not be pid=1 to avoid kernel panic. */
if (unlikely(is_global_init(current)))
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 (irq_work_is_busy(&work->irq_work))
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 = get_task_struct(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)
{
struct path copy;
long len;
char *p;
if (!sz)
return 0;
/*
* The path pointer is verified as trusted and safe to use,
* but let's double check it's valid anyway to workaround
* potentially broken verifier.
*/
len = copy_from_kernel_nofault(&copy, path, sizeof(*path));
if (len < 0)
return len;
p = d_path(&copy, 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)
{
if (prog->type == BPF_PROG_TYPE_TRACING &&
prog->expected_attach_type == BPF_TRACE_ITER)
return true;
if (prog->type == BPF_PROG_TYPE_LSM)
return bpf_lsm_is_sleepable_hook(prog->aux->attach_btf_id);
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 IS_ERR(*btf) ? PTR_ERR(*btf) : -EINVAL;
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 | MEM_RDONLY,
.arg4_type = ARG_CONST_SIZE,
.arg5_type = ARG_ANYTHING,
};
BPF_CALL_1(bpf_get_func_ip_tracing, void *, ctx)
{
/* This helper call is inlined by verifier. */
return ((u64 *)ctx)[-2];
}
static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = {
.func = bpf_get_func_ip_tracing,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
#ifdef CONFIG_X86_KERNEL_IBT
static unsigned long get_entry_ip(unsigned long fentry_ip)
{
u32 instr;
/* Being extra safe in here in case entry ip is on the page-edge. */
if (get_kernel_nofault(instr, (u32 *) fentry_ip - 1))
return fentry_ip;
if (is_endbr(instr))
fentry_ip -= ENDBR_INSN_SIZE;
return fentry_ip;
}
#else
#define get_entry_ip(fentry_ip) fentry_ip
#endif
BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
{
struct kprobe *kp = kprobe_running();
if (!kp || !(kp->flags & KPROBE_FLAG_ON_FUNC_ENTRY))
return 0;
return get_entry_ip((uintptr_t)kp->addr);
}
static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
.func = bpf_get_func_ip_kprobe,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs)
{
return bpf_kprobe_multi_entry_ip(current->bpf_ctx);
}
static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = {
.func = bpf_get_func_ip_kprobe_multi,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs)
{
return bpf_kprobe_multi_cookie(current->bpf_ctx);
}
static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
.func = bpf_get_attach_cookie_kprobe_multi,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
{
struct bpf_trace_run_ctx *run_ctx;
run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
return run_ctx->bpf_cookie;
}
static const struct bpf_func_proto bpf_get_attach_cookie_proto_trace = {
.func = bpf_get_attach_cookie_trace,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_1(bpf_get_attach_cookie_pe, struct bpf_perf_event_data_kern *, ctx)
{
return ctx->event->bpf_cookie;
}
static const struct bpf_func_proto bpf_get_attach_cookie_proto_pe = {
.func = bpf_get_attach_cookie_pe,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_1(bpf_get_attach_cookie_tracing, void *, ctx)
{
struct bpf_trace_run_ctx *run_ctx;
run_ctx = container_of(current->bpf_ctx, struct bpf_trace_run_ctx, run_ctx);
return run_ctx->bpf_cookie;
}
static const struct bpf_func_proto bpf_get_attach_cookie_proto_tracing = {
.func = bpf_get_attach_cookie_tracing,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
BPF_CALL_3(bpf_get_branch_snapshot, void *, buf, u32, size, u64, flags)
{
#ifndef CONFIG_X86
return -ENOENT;
#else
static const u32 br_entry_size = sizeof(struct perf_branch_entry);
u32 entry_cnt = size / br_entry_size;
entry_cnt = static_call(perf_snapshot_branch_stack)(buf, entry_cnt);
if (unlikely(flags))
return -EINVAL;
if (!entry_cnt)
return -ENOENT;
return entry_cnt * br_entry_size;
#endif
}
static const struct bpf_func_proto bpf_get_branch_snapshot_proto = {
.func = bpf_get_branch_snapshot,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_UNINIT_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
};
BPF_CALL_3(get_func_arg, void *, ctx, u32, n, u64 *, value)
{
/* This helper call is inlined by verifier. */
u64 nr_args = ((u64 *)ctx)[-1];
if ((u64) n >= nr_args)
return -EINVAL;
*value = ((u64 *)ctx)[n];
return 0;
}
static const struct bpf_func_proto bpf_get_func_arg_proto = {
.func = get_func_arg,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_PTR_TO_LONG,
};
BPF_CALL_2(get_func_ret, void *, ctx, u64 *, value)
{
/* This helper call is inlined by verifier. */
u64 nr_args = ((u64 *)ctx)[-1];
*value = ((u64 *)ctx)[nr_args];
return 0;
}
static const struct bpf_func_proto bpf_get_func_ret_proto = {
.func = get_func_ret,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
.arg2_type = ARG_PTR_TO_LONG,
};
BPF_CALL_1(get_func_arg_cnt, void *, ctx)
{
/* This helper call is inlined by verifier. */
return ((u64 *)ctx)[-1];
}
static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = {
.func = get_func_arg_cnt,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_CTX,
};
#ifdef CONFIG_KEYS
__diag_push();
__diag_ignore_all("-Wmissing-prototypes",
"kfuncs which will be used in BPF programs");
/**
* bpf_lookup_user_key - lookup a key by its serial
* @serial: key handle serial number
* @flags: lookup-specific flags
*
* Search a key with a given *serial* and the provided *flags*.
* If found, increment the reference count of the key by one, and
* return it in the bpf_key structure.
*
* The bpf_key structure must be passed to bpf_key_put() when done
* with it, so that the key reference count is decremented and the
* bpf_key structure is freed.
*
* Permission checks are deferred to the time the key is used by
* one of the available key-specific kfuncs.
*
* Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested
* special keyring (e.g. session keyring), if it doesn't yet exist.
* Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting
* for the key construction, and to retrieve uninstantiated keys (keys
* without data attached to them).
*
* Return: a bpf_key pointer with a valid key pointer if the key is found, a
* NULL pointer otherwise.
*/
struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)
{
key_ref_t key_ref;
struct bpf_key *bkey;
if (flags & ~KEY_LOOKUP_ALL)
return NULL;
/*
* Permission check is deferred until the key is used, as the
* intent of the caller is unknown here.
*/
key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
if (IS_ERR(key_ref))
return NULL;
bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
if (!bkey) {
key_put(key_ref_to_ptr(key_ref));
return NULL;
}
bkey->key = key_ref_to_ptr(key_ref);
bkey->has_ref = true;
return bkey;
}
/**
* bpf_lookup_system_key - lookup a key by a system-defined ID
* @id: key ID
*
* Obtain a bpf_key structure with a key pointer set to the passed key ID.
* The key pointer is marked as invalid, to prevent bpf_key_put() from
* attempting to decrement the key reference count on that pointer. The key
* pointer set in such way is currently understood only by
* verify_pkcs7_signature().
*
* Set *id* to one of the values defined in include/linux/verification.h:
* 0 for the primary keyring (immutable keyring of system keys);
* VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring
* (where keys can be added only if they are vouched for by existing keys
* in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform
* keyring (primarily used by the integrity subsystem to verify a kexec'ed
* kerned image and, possibly, the initramfs signature).
*
* Return: a bpf_key pointer with an invalid key pointer set from the
* pre-determined ID on success, a NULL pointer otherwise
*/
struct bpf_key *bpf_lookup_system_key(u64 id)
{
struct bpf_key *bkey;
if (system_keyring_id_check(id) < 0)
return NULL;
bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC);
if (!bkey)
return NULL;
bkey->key = (struct key *)(unsigned long)id;
bkey->has_ref = false;
return bkey;
}
/**
* bpf_key_put - decrement key reference count if key is valid and free bpf_key
* @bkey: bpf_key structure
*
* Decrement the reference count of the key inside *bkey*, if the pointer
* is valid, and free *bkey*.
*/
void bpf_key_put(struct bpf_key *bkey)
{
if (bkey->has_ref)
key_put(bkey->key);
kfree(bkey);
}
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
/**
* bpf_verify_pkcs7_signature - verify a PKCS#7 signature
* @data_ptr: data to verify
* @sig_ptr: signature of the data
* @trusted_keyring: keyring with keys trusted for signature verification
*
* Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr*
* with keys in a keyring referenced by *trusted_keyring*.
*
* Return: 0 on success, a negative value on error.
*/
int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
struct bpf_dynptr_kern *sig_ptr,
struct bpf_key *trusted_keyring)
{
int ret;
if (trusted_keyring->has_ref) {
/*
* Do the permission check deferred in bpf_lookup_user_key().
* See bpf_lookup_user_key() for more details.
*
* A call to key_task_permission() here would be redundant, as
* it is already done by keyring_search() called by
* find_asymmetric_key().
*/
ret = key_validate(trusted_keyring->key);
if (ret < 0)
return ret;
}
return verify_pkcs7_signature(data_ptr->data,
bpf_dynptr_get_size(data_ptr),
sig_ptr->data,
bpf_dynptr_get_size(sig_ptr),
trusted_keyring->key,
VERIFYING_UNSPECIFIED_SIGNATURE, NULL,
NULL);
}
#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
__diag_pop();
BTF_SET8_START(key_sig_kfunc_set)
BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
#endif
BTF_SET8_END(key_sig_kfunc_set)
static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
.owner = THIS_MODULE,
.set = &key_sig_kfunc_set,
};
static int __init bpf_key_sig_kfuncs_init(void)
{
return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
&bpf_key_sig_kfunc_set);
}
late_initcall(bpf_key_sig_kfuncs_init);
#endif /* CONFIG_KEYS */
static 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_map_lookup_percpu_elem:
return &bpf_map_lookup_percpu_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_task_btf:
return &bpf_get_current_task_btf_proto;
case BPF_FUNC_task_pt_regs:
return &bpf_task_pt_regs_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_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_write_user:
return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ?
NULL : bpf_get_probe_write_proto();
case BPF_FUNC_probe_read_user:
return &bpf_probe_read_user_proto;
case BPF_FUNC_probe_read_kernel:
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
NULL : &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 security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
NULL : &bpf_probe_read_kernel_str_proto;
#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
case BPF_FUNC_probe_read:
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
NULL : &bpf_probe_read_compat_proto;
case BPF_FUNC_probe_read_str:
return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ?
NULL : &bpf_probe_read_compat_str_proto;
#endif
#ifdef CONFIG_CGROUPS
case BPF_FUNC_get_current_cgroup_id:
return &bpf_get_current_cgroup_id_proto;
case BPF_FUNC_get_current_ancestor_cgroup_id:
return &bpf_get_current_ancestor_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_copy_from_user_task:
return prog->aux->sleepable ? &bpf_copy_from_user_task_proto : NULL;
case BPF_FUNC_snprintf_btf:
return &bpf_snprintf_btf_proto;
case BPF_FUNC_per_cpu_ptr:
return &bpf_per_cpu_ptr_proto;
case BPF_FUNC_this_cpu_ptr:
return &bpf_this_cpu_ptr_proto;
case BPF_FUNC_task_storage_get:
return &bpf_task_storage_get_proto;
case BPF_FUNC_task_storage_delete:
return &bpf_task_storage_delete_proto;
case BPF_FUNC_for_each_map_elem:
return &bpf_for_each_map_elem_proto;
case BPF_FUNC_snprintf:
return &bpf_snprintf_proto;
case BPF_FUNC_get_func_ip:
return &bpf_get_func_ip_proto_tracing;
case BPF_FUNC_get_branch_snapshot:
return &bpf_get_branch_snapshot_proto;
case BPF_FUNC_find_vma:
return &bpf_find_vma_proto;
case BPF_FUNC_trace_vprintk:
return bpf_get_trace_vprintk_proto();
default:
return bpf_base_func_proto(func_id);
}
}
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
case BPF_FUNC_get_func_ip:
return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
&bpf_get_func_ip_proto_kprobe_multi :
&bpf_get_func_ip_proto_kprobe;
case BPF_FUNC_get_attach_cookie:
return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
&bpf_get_attach_cookie_proto_kmulti :
&bpf_get_attach_cookie_proto_trace;
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 | MEM_RDONLY,
.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;
case BPF_FUNC_get_attach_cookie:
return &bpf_get_attach_cookie_proto_trace;
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)
{
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(!(ctx->data->sample_flags & PERF_SAMPLE_BRANCH_STACK)))
return -ENOENT;
if (unlikely(!br_stack))
return -ENOENT;
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;
}
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;
case BPF_FUNC_get_attach_cookie:
return &bpf_get_attach_cookie_proto_pe;
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 | MEM_RDONLY,
.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;
extern const struct bpf_func_proto bpf_xdp_get_buff_len_trace_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 | MEM_RDONLY,
.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)
{
const struct bpf_func_proto *fn;
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;
case BPF_FUNC_skc_to_unix_sock:
return &bpf_skc_to_unix_sock_proto;
case BPF_FUNC_skc_to_mptcp_sock:
return &bpf_skc_to_mptcp_sock_proto;
case BPF_FUNC_sk_storage_get:
return &bpf_sk_storage_get_tracing_proto;
case BPF_FUNC_sk_storage_delete:
return &bpf_sk_storage_delete_tracing_proto;
case BPF_FUNC_sock_from_file:
return &bpf_sock_from_file_proto;
case BPF_FUNC_get_socket_cookie:
return &bpf_get_socket_ptr_cookie_proto;
case BPF_FUNC_xdp_get_buff_len:
return &bpf_xdp_get_buff_len_trace_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;
case BPF_FUNC_get_func_arg:
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_proto : NULL;
case BPF_FUNC_get_func_ret:
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_ret_proto : NULL;
case BPF_FUNC_get_func_arg_cnt:
return bpf_prog_has_trampoline(prog) ? &bpf_get_func_arg_cnt_proto : NULL;
case BPF_FUNC_get_attach_cookie:
return bpf_prog_has_trampoline(prog) ? &bpf_get_attach_cookie_proto_tracing : NULL;
default:
fn = raw_tp_prog_func_proto(func_id, prog);
if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
fn = bpf_iter_get_func_proto(func_id, prog);
return fn;
}
}
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)
{
return bpf_tracing_ctx_access(off, size, type);
}
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)
{
return bpf_tracing_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,
u64 bpf_cookie)
{
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, bpf_cookie, &new_array);
if (ret < 0)
goto unlock;
/* set the new array to event->tp_event and set event->prog */
event->prog = prog;
event->bpf_cookie = bpf_cookie;
rcu_assign_pointer(event->tp_event->prog_array, new_array);
bpf_prog_array_free_sleepable(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, 0, &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_sleepable(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;
preempt_disable();
mod = __module_address((unsigned long)btp);
module_put(mod);
preempt_enable();
}
static __always_inline
void __bpf_trace_run(struct bpf_prog *prog, u64 *args)
{
cant_sleep();
if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
bpf_prog_inc_misses_counter(prog);
goto out;
}
rcu_read_lock();
(void) bpf_prog_run(prog, args);
rcu_read_unlock();
out:
this_cpu_dec(*(prog->active));
}
#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_may_exist(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, probe_addr,
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 */
#ifdef CONFIG_FPROBE
struct bpf_kprobe_multi_link {
struct bpf_link link;
struct fprobe fp;
unsigned long *addrs;
u64 *cookies;
u32 cnt;
};
struct bpf_kprobe_multi_run_ctx {
struct bpf_run_ctx run_ctx;
struct bpf_kprobe_multi_link *link;
unsigned long entry_ip;
};
struct user_syms {
const char **syms;
char *buf;
};
static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32 cnt)
{
unsigned long __user usymbol;
const char **syms = NULL;
char *buf = NULL, *p;
int err = -ENOMEM;
unsigned int i;
syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
if (!syms)
goto error;
buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
if (!buf)
goto error;
for (p = buf, i = 0; i < cnt; i++) {
if (__get_user(usymbol, usyms + i)) {
err = -EFAULT;
goto error;
}
err = strncpy_from_user(p, (const char __user *) usymbol, KSYM_NAME_LEN);
if (err == KSYM_NAME_LEN)
err = -E2BIG;
if (err < 0)
goto error;
syms[i] = p;
p += err + 1;
}
us->syms = syms;
us->buf = buf;
return 0;
error:
if (err) {
kvfree(syms);
kvfree(buf);
}
return err;
}
static void free_user_syms(struct user_syms *us)
{
kvfree(us->syms);
kvfree(us->buf);
}
static void bpf_kprobe_multi_link_release(struct bpf_link *link)
{
struct bpf_kprobe_multi_link *kmulti_link;
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
unregister_fprobe(&kmulti_link->fp);
}
static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
{
struct bpf_kprobe_multi_link *kmulti_link;
kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
kvfree(kmulti_link->addrs);
kvfree(kmulti_link->cookies);
kfree(kmulti_link);
}
static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
.release = bpf_kprobe_multi_link_release,
.dealloc = bpf_kprobe_multi_link_dealloc,
};
static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
{
const struct bpf_kprobe_multi_link *link = priv;
unsigned long *addr_a = a, *addr_b = b;
u64 *cookie_a, *cookie_b;
cookie_a = link->cookies + (addr_a - link->addrs);
cookie_b = link->cookies + (addr_b - link->addrs);
/* swap addr_a/addr_b and cookie_a/cookie_b values */
swap(*addr_a, *addr_b);
swap(*cookie_a, *cookie_b);
}
static int __bpf_kprobe_multi_cookie_cmp(const void *a, const void *b)
{
const unsigned long *addr_a = a, *addr_b = b;
if (*addr_a == *addr_b)
return 0;
return *addr_a < *addr_b ? -1 : 1;
}
static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void *priv)
{
return __bpf_kprobe_multi_cookie_cmp(a, b);
}
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
{
struct bpf_kprobe_multi_run_ctx *run_ctx;
struct bpf_kprobe_multi_link *link;
u64 *cookie, entry_ip;
unsigned long *addr;
if (WARN_ON_ONCE(!ctx))
return 0;
run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
link = run_ctx->link;
if (!link->cookies)
return 0;
entry_ip = run_ctx->entry_ip;
addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip),
__bpf_kprobe_multi_cookie_cmp);
if (!addr)
return 0;
cookie = link->cookies + (addr - link->addrs);
return *cookie;
}
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
{
struct bpf_kprobe_multi_run_ctx *run_ctx;
run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx);
return run_ctx->entry_ip;
}
static int
kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
unsigned long entry_ip, struct pt_regs *regs)
{
struct bpf_kprobe_multi_run_ctx run_ctx = {
.link = link,
.entry_ip = entry_ip,
};
struct bpf_run_ctx *old_run_ctx;
int err;
if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
err = 0;
goto out;
}
migrate_disable();
rcu_read_lock();
old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
err = bpf_prog_run(link->link.prog, regs);
bpf_reset_run_ctx(old_run_ctx);
rcu_read_unlock();
migrate_enable();
out:
__this_cpu_dec(bpf_prog_active);
return err;
}
static void
kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
struct pt_regs *regs)
{
struct bpf_kprobe_multi_link *link;
link = container_of(fp, struct bpf_kprobe_multi_link, fp);
kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs);
}
static int symbols_cmp_r(const void *a, const void *b, const void *priv)
{
const char **str_a = (const char **) a;
const char **str_b = (const char **) b;
return strcmp(*str_a, *str_b);
}
struct multi_symbols_sort {
const char **funcs;
u64 *cookies;
};
static void symbols_swap_r(void *a, void *b, int size, const void *priv)
{
const struct multi_symbols_sort *data = priv;
const char **name_a = a, **name_b = b;
swap(*name_a, *name_b);
/* If defined, swap also related cookies. */
if (data->cookies) {
u64 *cookie_a, *cookie_b;
cookie_a = data->cookies + (name_a - data->funcs);
cookie_b = data->cookies + (name_b - data->funcs);
swap(*cookie_a, *cookie_b);
}
}
int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
struct bpf_kprobe_multi_link *link = NULL;
struct bpf_link_primer link_primer;
void __user *ucookies;
unsigned long *addrs;
u32 flags, cnt, size;
void __user *uaddrs;
u64 *cookies = NULL;
void __user *usyms;
int err;
/* no support for 32bit archs yet */
if (sizeof(u64) != sizeof(void *))
return -EOPNOTSUPP;
if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI)
return -EINVAL;
flags = attr->link_create.kprobe_multi.flags;
if (flags & ~BPF_F_KPROBE_MULTI_RETURN)
return -EINVAL;
uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs);
usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms);
if (!!uaddrs == !!usyms)
return -EINVAL;
cnt = attr->link_create.kprobe_multi.cnt;
if (!cnt)
return -EINVAL;
size = cnt * sizeof(*addrs);
addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
if (!addrs)
return -ENOMEM;
ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
if (ucookies) {
cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
if (!cookies) {
err = -ENOMEM;
goto error;
}
if (copy_from_user(cookies, ucookies, size)) {
err = -EFAULT;
goto error;
}
}
if (uaddrs) {
if (copy_from_user(addrs, uaddrs, size)) {
err = -EFAULT;
goto error;
}
} else {
struct multi_symbols_sort data = {
.cookies = cookies,
};
struct user_syms us;
err = copy_user_syms(&us, usyms, cnt);
if (err)
goto error;
if (cookies)
data.funcs = us.syms;
sort_r(us.syms, cnt, sizeof(*us.syms), symbols_cmp_r,
symbols_swap_r, &data);
err = ftrace_lookup_symbols(us.syms, cnt, addrs);
free_user_syms(&us);
if (err)
goto error;
}
link = kzalloc(sizeof(*link), GFP_KERNEL);
if (!link) {
err = -ENOMEM;
goto error;
}
bpf_link_init(&link->link, BPF_LINK_TYPE_KPROBE_MULTI,
&bpf_kprobe_multi_link_lops, prog);
err = bpf_link_prime(&link->link, &link_primer);
if (err)
goto error;
if (flags & BPF_F_KPROBE_MULTI_RETURN)
link->fp.exit_handler = kprobe_multi_link_handler;
else
link->fp.entry_handler = kprobe_multi_link_handler;
link->addrs = addrs;
link->cookies = cookies;
link->cnt = cnt;
if (cookies) {
/*
* Sorting addresses will trigger sorting cookies as well
* (check bpf_kprobe_multi_cookie_swap). This way we can
* find cookie based on the address in bpf_get_attach_cookie
* helper.
*/
sort_r(addrs, cnt, sizeof(*addrs),
bpf_kprobe_multi_cookie_cmp,
bpf_kprobe_multi_cookie_swap,
link);
}
err = register_fprobe_ips(&link->fp, addrs, cnt);
if (err) {
bpf_link_cleanup(&link_primer);
return err;
}
return bpf_link_settle(&link_primer);
error:
kfree(link);
kvfree(addrs);
kvfree(cookies);
return err;
}
#else /* !CONFIG_FPROBE */
int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
return -EOPNOTSUPP;
}
static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx)
{
return 0;
}
static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
{
return 0;
}
#endif