// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com
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* Copyright (c) 2016 Facebook
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/bpf.h>
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#include <linux/bpf_perf_event.h>
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#include <linux/btf.h>
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#include <linux/filter.h>
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#include <linux/uaccess.h>
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#include <linux/ctype.h>
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#include <linux/kprobes.h>
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#include <linux/spinlock.h>
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#include <linux/syscalls.h>
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#include <linux/error-injection.h>
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#include <linux/btf_ids.h>
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#include <uapi/linux/bpf.h>
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#include <uapi/linux/btf.h>
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#include <asm/tlb.h>
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#include "trace_probe.h"
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#include "trace.h"
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#define CREATE_TRACE_POINTS
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#include "bpf_trace.h"
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#define bpf_event_rcu_dereference(p) \
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rcu_dereference_protected(p, lockdep_is_held(&bpf_event_mutex))
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#ifdef CONFIG_MODULES
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struct bpf_trace_module {
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struct module *module;
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struct list_head list;
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};
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static LIST_HEAD(bpf_trace_modules);
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static DEFINE_MUTEX(bpf_module_mutex);
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static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
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{
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struct bpf_raw_event_map *btp, *ret = NULL;
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struct bpf_trace_module *btm;
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unsigned int i;
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mutex_lock(&bpf_module_mutex);
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list_for_each_entry(btm, &bpf_trace_modules, list) {
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for (i = 0; i < btm->module->num_bpf_raw_events; ++i) {
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btp = &btm->module->bpf_raw_events[i];
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if (!strcmp(btp->tp->name, name)) {
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if (try_module_get(btm->module))
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ret = btp;
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goto out;
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}
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}
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}
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out:
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mutex_unlock(&bpf_module_mutex);
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return ret;
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}
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#else
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static struct bpf_raw_event_map *bpf_get_raw_tracepoint_module(const char *name)
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{
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return NULL;
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}
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#endif /* CONFIG_MODULES */
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u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
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static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
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u64 flags, const struct btf **btf,
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s32 *btf_id);
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/**
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* trace_call_bpf - invoke BPF program
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* @call: tracepoint event
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* @ctx: opaque context pointer
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*
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* kprobe handlers execute BPF programs via this helper.
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* Can be used from static tracepoints in the future.
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*
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* Return: BPF programs always return an integer which is interpreted by
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* kprobe handler as:
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* 0 - return from kprobe (event is filtered out)
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* 1 - store kprobe event into ring buffer
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* Other values are reserved and currently alias to 1
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*/
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unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
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{
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unsigned int ret;
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cant_sleep();
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if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) {
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/*
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* since some bpf program is already running on this cpu,
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* don't call into another bpf program (same or different)
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* and don't send kprobe event into ring-buffer,
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* so return zero here
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*/
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ret = 0;
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goto out;
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}
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/*
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* Instead of moving rcu_read_lock/rcu_dereference/rcu_read_unlock
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* to all call sites, we did a bpf_prog_array_valid() there to check
|
* whether call->prog_array is empty or not, which is
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* a heurisitc to speed up execution.
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*
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* If bpf_prog_array_valid() fetched prog_array was
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* non-NULL, we go into trace_call_bpf() and do the actual
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* proper rcu_dereference() under RCU lock.
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* If it turns out that prog_array is NULL then, we bail out.
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* For the opposite, if the bpf_prog_array_valid() fetched pointer
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* was NULL, you'll skip the prog_array with the risk of missing
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* out of events when it was updated in between this and the
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* rcu_dereference() which is accepted risk.
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*/
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ret = BPF_PROG_RUN_ARRAY_CHECK(call->prog_array, ctx, BPF_PROG_RUN);
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out:
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__this_cpu_dec(bpf_prog_active);
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return ret;
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}
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#ifdef CONFIG_BPF_KPROBE_OVERRIDE
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BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
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{
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regs_set_return_value(regs, rc);
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override_function_with_return(regs);
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return 0;
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}
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static const struct bpf_func_proto bpf_override_return_proto = {
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.func = bpf_override_return,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_CTX,
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.arg2_type = ARG_ANYTHING,
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};
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#endif
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static __always_inline int
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bpf_probe_read_user_common(void *dst, u32 size, const void __user *unsafe_ptr)
|
{
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int ret;
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ret = copy_from_user_nofault(dst, unsafe_ptr, size);
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if (unlikely(ret < 0))
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memset(dst, 0, size);
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return ret;
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}
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BPF_CALL_3(bpf_probe_read_user, void *, dst, u32, size,
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const void __user *, unsafe_ptr)
|
{
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return bpf_probe_read_user_common(dst, size, unsafe_ptr);
|
}
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|
const struct bpf_func_proto bpf_probe_read_user_proto = {
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.func = bpf_probe_read_user,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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static __always_inline int
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bpf_probe_read_user_str_common(void *dst, u32 size,
|
const void __user *unsafe_ptr)
|
{
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int ret;
|
|
/*
|
* NB: We rely on strncpy_from_user() not copying junk past the NUL
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* 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.
|
*/
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ret = strncpy_from_user_nofault(dst, unsafe_ptr, size);
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if (unlikely(ret < 0))
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memset(dst, 0, size);
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return ret;
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}
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BPF_CALL_3(bpf_probe_read_user_str, void *, dst, u32, size,
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const void __user *, unsafe_ptr)
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{
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return bpf_probe_read_user_str_common(dst, size, unsafe_ptr);
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}
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const struct bpf_func_proto bpf_probe_read_user_str_proto = {
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.func = bpf_probe_read_user_str,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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static __always_inline int
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bpf_probe_read_kernel_common(void *dst, u32 size, const void *unsafe_ptr)
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{
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int ret;
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ret = copy_from_kernel_nofault(dst, unsafe_ptr, size);
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if (unlikely(ret < 0))
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memset(dst, 0, size);
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return ret;
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}
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BPF_CALL_3(bpf_probe_read_kernel, void *, dst, u32, size,
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const void *, unsafe_ptr)
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{
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return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
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}
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const struct bpf_func_proto bpf_probe_read_kernel_proto = {
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.func = bpf_probe_read_kernel,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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|
static __always_inline int
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bpf_probe_read_kernel_str_common(void *dst, u32 size, const void *unsafe_ptr)
|
{
|
int ret;
|
|
/*
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* The strncpy_from_kernel_nofault() call will likely not fill the
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* entire buffer, but that's okay in this circumstance as we're probing
|
* arbitrary memory anyway similar to bpf_probe_read_*() and might
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* as well probe the stack. Thus, memory is explicitly cleared
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* only in error case, so that improper users ignoring return
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* code altogether don't copy garbage; otherwise length of string
|
* is returned that can be used for bpf_perf_event_output() et al.
|
*/
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ret = strncpy_from_kernel_nofault(dst, unsafe_ptr, size);
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if (unlikely(ret < 0))
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memset(dst, 0, size);
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return ret;
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}
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BPF_CALL_3(bpf_probe_read_kernel_str, void *, dst, u32, size,
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const void *, unsafe_ptr)
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{
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return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
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}
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const struct bpf_func_proto bpf_probe_read_kernel_str_proto = {
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.func = bpf_probe_read_kernel_str,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
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BPF_CALL_3(bpf_probe_read_compat, void *, dst, u32, size,
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const void *, unsafe_ptr)
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{
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if ((unsigned long)unsafe_ptr < TASK_SIZE) {
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return bpf_probe_read_user_common(dst, size,
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(__force void __user *)unsafe_ptr);
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}
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return bpf_probe_read_kernel_common(dst, size, unsafe_ptr);
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}
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static const struct bpf_func_proto bpf_probe_read_compat_proto = {
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.func = bpf_probe_read_compat,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE_OR_ZERO,
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.arg3_type = ARG_ANYTHING,
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};
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|
BPF_CALL_3(bpf_probe_read_compat_str, void *, dst, u32, size,
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const void *, unsafe_ptr)
|
{
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if ((unsigned long)unsafe_ptr < TASK_SIZE) {
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return bpf_probe_read_user_str_common(dst, size,
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(__force void __user *)unsafe_ptr);
|
}
|
return bpf_probe_read_kernel_str_common(dst, size, unsafe_ptr);
|
}
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|
static const struct bpf_func_proto bpf_probe_read_compat_str_proto = {
|
.func = bpf_probe_read_compat_str,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.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 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,
|
.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_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) < 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) < 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) < 0 ?
|
NULL : &bpf_probe_read_compat_proto;
|
case BPF_FUNC_probe_read_str:
|
return security_locked_down(LOCKDOWN_BPF_READ) < 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;
|
#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_per_cpu_ptr:
|
return &bpf_per_cpu_ptr_proto;
|
case BPF_FUNC_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)
|
{
|
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 -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;
|
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;
|
|
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();
|
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_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,
|
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 */
|
