/* Copyright (c) 2011-2015 PLUMgrid, http://plumgrid.com * Copyright (c) 2016 Facebook * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public * License as published by the Free Software Foundation. */#include <linux/kernel.h>#include <linux/types.h>#include <linux/slab.h>#include <linux/bpf.h>#include <linux/bpf_perf_event.h>#include <linux/filter.h>#include <linux/uaccess.h>#include <linux/ctype.h>#include "trace.h" /** * trace_call_bpf - invoke BPF program * @prog: BPF program * @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 bpf_prog *prog, void *ctx){	unsigned int ret; 	if (in_nmi()) /* not supported yet */		return 1; 	preempt_disable(); 	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;	} 	rcu_read_lock();	ret = BPF_PROG_RUN(prog, ctx);	rcu_read_unlock();  out:	__this_cpu_dec(bpf_prog_active);	preempt_enable(); 	return ret;}EXPORT_SYMBOL_GPL(trace_call_bpf); BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr){	int ret; 	ret = probe_kernel_read(dst, unsafe_ptr, size);	if (unlikely(ret < 0))		memset(dst, 0, size); 	return ret;} static const struct bpf_func_proto bpf_probe_read_proto = {	.func		= bpf_probe_read,	.gpl_only	= true,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,	.arg2_type	= ARG_CONST_SIZE,	.arg3_type	= ARG_ANYTHING,}; BPF_CALL_3(bpf_probe_write_user, void *, 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.	 */ 	if (unlikely(in_interrupt() ||		     current->flags & (PF_KTHREAD | PF_EXITING)))		return -EPERM;	if (unlikely(uaccess_kernel()))		return -EPERM;	if (!access_ok(VERIFY_WRITE, unsafe_ptr, size))		return -EPERM; 	return probe_kernel_write(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){	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;} /* * Only limited trace_printk() conversion specifiers allowed: * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %s */BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1,	   u64, arg2, u64, arg3){	bool str_seen = false;	int mod[3] = {};	int fmt_cnt = 0;	u64 unsafe_addr;	char buf[64];	int i; 	/*	 * 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' || fmt[i] == 's') {			mod[fmt_cnt]++;			i++;			if (!isspace(fmt[i]) && !ispunct(fmt[i]) && fmt[i] != 0)				return -EINVAL;			fmt_cnt++;			if (fmt[i - 1] == 's') {				if (str_seen)					/* allow only one '%s' per fmt string */					return -EINVAL;				str_seen = true; 				switch (fmt_cnt) {				case 1:					unsafe_addr = arg1;					arg1 = (long) buf;					break;				case 2:					unsafe_addr = arg2;					arg2 = (long) buf;					break;				case 3:					unsafe_addr = arg3;					arg3 = (long) buf;					break;				}				buf[0] = 0;				strncpy_from_unsafe(buf,						    (void *) (long) unsafe_addr,						    sizeof(buf));			}			continue;		} 		if (fmt[i] == 'l') {			mod[fmt_cnt]++;			i++;		} 		if (fmt[i] != 'i' && fmt[i] != 'd' &&		    fmt[i] != 'u' && fmt[i] != 'x')			return -EINVAL;		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(...)							\	__trace_printk(1 /* Fake ip will not be printed. */,		\		       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 allocate per-cpu printk buffers	 */	trace_printk_init_buffers(); 	return &bpf_trace_printk_proto;} BPF_CALL_2(bpf_perf_event_read, struct bpf_map *, map, u64, flags){	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;	u64 value = 0;	int err; 	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; 	err = perf_event_read_local(ee->event, &value);	/*	 * 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,}; static DEFINE_PER_CPU(struct perf_sample_data, bpf_sd); static __always_inline u64__bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,			u64 flags, struct perf_raw_record *raw){	struct bpf_array *array = container_of(map, struct bpf_array, map);	struct perf_sample_data *sd = this_cpu_ptr(&bpf_sd);	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; 	perf_sample_data_init(sd, 0, 0);	sd->raw = raw;	perf_event_output(event, sd, regs);	return 0;} BPF_CALL_5(bpf_perf_event_output, struct pt_regs *, regs, struct bpf_map *, map,	   u64, flags, void *, data, u64, size){	struct perf_raw_record raw = {		.frag = {			.size = size,			.data = data,		},	}; 	if (unlikely(flags & ~(BPF_F_INDEX_MASK)))		return -EINVAL; 	return __bpf_perf_event_output(regs, map, flags, &raw);} 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,}; static DEFINE_PER_CPU(struct pt_regs, bpf_pt_regs); 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 pt_regs *regs = this_cpu_ptr(&bpf_pt_regs);	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,		},	}; 	perf_fetch_caller_regs(regs); 	return __bpf_perf_event_output(regs, map, flags, &raw);} BPF_CALL_0(bpf_get_current_task){	return (long) current;} static 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(in_interrupt()))		return -EINVAL;	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,}; BPF_CALL_3(bpf_probe_read_str, void *, dst, u32, size,	   const void *, unsafe_ptr){	int ret; 	/*	 * The strncpy_from_unsafe() 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_unsafe(dst, unsafe_ptr, size);	if (unlikely(ret < 0))		memset(dst, 0, size); 	return ret;} static const struct bpf_func_proto bpf_probe_read_str_proto = {	.func		= bpf_probe_read_str,	.gpl_only	= true,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,	.arg2_type	= ARG_CONST_SIZE,	.arg3_type	= ARG_ANYTHING,}; static const struct bpf_func_proto *tracing_func_proto(enum bpf_func_id func_id){	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_probe_read:		return &bpf_probe_read_proto;	case BPF_FUNC_ktime_get_ns:		return &bpf_ktime_get_ns_proto;	case BPF_FUNC_tail_call:		return &bpf_tail_call_proto;	case BPF_FUNC_get_current_pid_tgid:		return &bpf_get_current_pid_tgid_proto;	case BPF_FUNC_get_current_task:		return &bpf_get_current_task_proto;	case BPF_FUNC_get_current_uid_gid:		return &bpf_get_current_uid_gid_proto;	case BPF_FUNC_get_current_comm:		return &bpf_get_current_comm_proto;	case BPF_FUNC_trace_printk:		return bpf_get_trace_printk_proto();	case BPF_FUNC_get_smp_processor_id:		return &bpf_get_smp_processor_id_proto;	case BPF_FUNC_get_numa_node_id:		return &bpf_get_numa_node_id_proto;	case BPF_FUNC_perf_event_read:		return &bpf_perf_event_read_proto;	case BPF_FUNC_probe_write_user:		return bpf_get_probe_write_proto();	case BPF_FUNC_current_task_under_cgroup:		return &bpf_current_task_under_cgroup_proto;	case BPF_FUNC_get_prandom_u32:		return &bpf_get_prandom_u32_proto;	case BPF_FUNC_probe_read_str:		return &bpf_probe_read_str_proto;	default:		return NULL;	}} static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func_id){	switch (func_id) {	case BPF_FUNC_perf_event_output:		return &bpf_perf_event_output_proto;	case BPF_FUNC_get_stackid:

Lines 1–500 of 669. Load more