return entry;#else /* CONFIG_STACKTRACE */	return NULL;#endif} static long __bpf_get_stackid(struct bpf_map *map,			      struct perf_callchain_entry *trace, u64 flags){	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);	struct stack_map_bucket *bucket, *new_bucket, *old_bucket;	u32 hash, id, trace_nr, trace_len, i, max_depth;	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;	bool user = flags & BPF_F_USER_STACK;	u64 *ips;	bool hash_matches; 	if (trace->nr <= skip)		/* skipping more than usable stack trace */		return -EFAULT; 	max_depth = stack_map_calculate_max_depth(map->value_size, stack_map_data_size(map), flags);	trace_nr = min_t(u32, trace->nr - skip, max_depth - skip);	trace_len = trace_nr * sizeof(u64);	ips = trace->ip + skip;	hash = jhash2((u32 *)ips, trace_len / sizeof(u32), 0);	id = hash & (smap->n_buckets - 1);	bucket = READ_ONCE(smap->buckets[id]); 	hash_matches = bucket && bucket->hash == hash;	/* fast cmp */	if (hash_matches && flags & BPF_F_FAST_STACK_CMP)		return id; 	if (stack_map_use_build_id(map)) {		struct bpf_stack_build_id *id_offs; 		/* for build_id+offset, pop a bucket before slow cmp */		new_bucket = (struct stack_map_bucket *)			pcpu_freelist_pop(&smap->freelist);		if (unlikely(!new_bucket))			return -ENOMEM;		new_bucket->nr = trace_nr;		id_offs = (struct bpf_stack_build_id *)new_bucket->data;		for (i = 0; i < trace_nr; i++)			id_offs[i].ip = ips[i];		stack_map_get_build_id_offset(id_offs, trace_nr, user, false /* !may_fault */);		trace_len = trace_nr * sizeof(struct bpf_stack_build_id);		if (hash_matches && bucket->nr == trace_nr &&		    memcmp(bucket->data, new_bucket->data, trace_len) == 0) {			pcpu_freelist_push(&smap->freelist, &new_bucket->fnode);			return id;		}		if (bucket && !(flags & BPF_F_REUSE_STACKID)) {			pcpu_freelist_push(&smap->freelist, &new_bucket->fnode);			return -EEXIST;		}	} else {		if (hash_matches && bucket->nr == trace_nr &&		    memcmp(bucket->data, ips, trace_len) == 0)			return id;		if (bucket && !(flags & BPF_F_REUSE_STACKID))			return -EEXIST; 		new_bucket = (struct stack_map_bucket *)			pcpu_freelist_pop(&smap->freelist);		if (unlikely(!new_bucket))			return -ENOMEM;		memcpy(new_bucket->data, ips, trace_len);	} 	new_bucket->hash = hash;	new_bucket->nr = trace_nr; 	old_bucket = xchg(&smap->buckets[id], new_bucket);	if (old_bucket)		pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);	return id;} BPF_CALL_3(bpf_get_stackid, struct pt_regs *, regs, struct bpf_map *, map,	   u64, flags){	u32 elem_size = stack_map_data_size(map);	bool user = flags & BPF_F_USER_STACK;	struct perf_callchain_entry *trace;	bool kernel = !user;	u32 max_depth; 	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |			       BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))		return -EINVAL; 	max_depth = stack_map_calculate_max_depth(map->value_size, elem_size, flags);	trace = get_perf_callchain(regs, kernel, user, max_depth,				   false, false, 0); 	if (unlikely(!trace))		/* couldn't fetch the stack trace */		return -EFAULT; 	return __bpf_get_stackid(map, trace, flags);} const struct bpf_func_proto bpf_get_stackid_proto = {	.func		= bpf_get_stackid,	.gpl_only	= true,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_CTX,	.arg2_type	= ARG_CONST_MAP_PTR,	.arg3_type	= ARG_ANYTHING,}; static __u64 count_kernel_ip(struct perf_callchain_entry *trace){	__u64 nr_kernel = 0; 	while (nr_kernel < trace->nr) {		if (trace->ip[nr_kernel] == PERF_CONTEXT_USER)			break;		nr_kernel++;	}	return nr_kernel;} BPF_CALL_3(bpf_get_stackid_pe, struct bpf_perf_event_data_kern *, ctx,	   struct bpf_map *, map, u64, flags){	struct perf_event *event = ctx->event;	struct perf_callchain_entry *trace;	bool kernel, user;	__u64 nr_kernel;	int ret; 	/* perf_sample_data doesn't have callchain, use bpf_get_stackid */	if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN))		return bpf_get_stackid((unsigned long)(ctx->regs),				       (unsigned long) map, flags, 0, 0); 	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |			       BPF_F_FAST_STACK_CMP | BPF_F_REUSE_STACKID)))		return -EINVAL; 	user = flags & BPF_F_USER_STACK;	kernel = !user; 	trace = ctx->data->callchain;	if (unlikely(!trace))		return -EFAULT; 	nr_kernel = count_kernel_ip(trace);	__u64 nr = trace->nr; /* save original */ 	if (kernel) {		trace->nr = nr_kernel;		ret = __bpf_get_stackid(map, trace, flags);	} else { /* user */		u64 skip = flags & BPF_F_SKIP_FIELD_MASK; 		skip += nr_kernel;		if (skip > BPF_F_SKIP_FIELD_MASK)			return -EFAULT; 		flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip;		ret = __bpf_get_stackid(map, trace, flags);	} 	/* restore nr */	trace->nr = nr; 	return ret;} const struct bpf_func_proto bpf_get_stackid_proto_pe = {	.func		= bpf_get_stackid_pe,	.gpl_only	= false,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_CTX,	.arg2_type	= ARG_CONST_MAP_PTR,	.arg3_type	= ARG_ANYTHING,}; static long __bpf_get_stack(struct pt_regs *regs, struct task_struct *task,			    struct perf_callchain_entry *trace_in,			    void *buf, u32 size, u64 flags, bool may_fault){	u32 trace_nr, copy_len, elem_size, max_depth;	bool user_build_id = flags & BPF_F_USER_BUILD_ID;	bool crosstask = task && task != current;	u32 skip = flags & BPF_F_SKIP_FIELD_MASK;	bool user = flags & BPF_F_USER_STACK;	struct perf_callchain_entry *trace;	bool kernel = !user;	int err = -EINVAL;	u64 *ips; 	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |			       BPF_F_USER_BUILD_ID)))		goto clear;	if (kernel && user_build_id)		goto clear; 	elem_size = user_build_id ? sizeof(struct bpf_stack_build_id) : sizeof(u64);	if (unlikely(size % elem_size))		goto clear; 	/* cannot get valid user stack for task without user_mode regs */	if (task && user && !user_mode(regs))		goto err_fault; 	/* get_perf_callchain does not support crosstask user stack walking	 * but returns an empty stack instead of NULL.	 */	if (crosstask && user) {		err = -EOPNOTSUPP;		goto clear;	} 	max_depth = stack_map_calculate_max_depth(size, elem_size, flags); 	if (may_fault)		rcu_read_lock(); /* need RCU for perf's callchain below */ 	if (trace_in) {		trace = trace_in;		trace->nr = min_t(u32, trace->nr, max_depth);	} else if (kernel && task) {		trace = get_callchain_entry_for_task(task, max_depth);	} else {		trace = get_perf_callchain(regs, kernel, user, max_depth,					   crosstask, false, 0);	} 	if (unlikely(!trace) || trace->nr < skip) {		if (may_fault)			rcu_read_unlock();		goto err_fault;	} 	trace_nr = trace->nr - skip;	copy_len = trace_nr * elem_size; 	ips = trace->ip + skip;	if (user_build_id) {		struct bpf_stack_build_id *id_offs = buf;		u32 i; 		for (i = 0; i < trace_nr; i++)			id_offs[i].ip = ips[i];	} else {		memcpy(buf, ips, copy_len);	} 	/* trace/ips should not be dereferenced after this point */	if (may_fault)		rcu_read_unlock(); 	if (user_build_id)		stack_map_get_build_id_offset(buf, trace_nr, user, may_fault); 	if (size > copy_len)		memset(buf + copy_len, 0, size - copy_len);	return copy_len; err_fault:	err = -EFAULT;clear:	memset(buf, 0, size);	return err;} BPF_CALL_4(bpf_get_stack, struct pt_regs *, regs, void *, buf, u32, size,	   u64, flags){	return __bpf_get_stack(regs, NULL, NULL, buf, size, flags, false /* !may_fault */);} const struct bpf_func_proto bpf_get_stack_proto = {	.func		= bpf_get_stack,	.gpl_only	= true,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_CTX,	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,	.arg4_type	= ARG_ANYTHING,}; BPF_CALL_4(bpf_get_stack_sleepable, struct pt_regs *, regs, void *, buf, u32, size,	   u64, flags){	return __bpf_get_stack(regs, NULL, NULL, buf, size, flags, true /* may_fault */);} const struct bpf_func_proto bpf_get_stack_sleepable_proto = {	.func		= bpf_get_stack_sleepable,	.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 long __bpf_get_task_stack(struct task_struct *task, void *buf, u32 size,				 u64 flags, bool may_fault){	struct pt_regs *regs;	long res = -EINVAL; 	if (!try_get_task_stack(task))		return -EFAULT; 	regs = task_pt_regs(task);	if (regs)		res = __bpf_get_stack(regs, task, NULL, buf, size, flags, may_fault);	put_task_stack(task); 	return res;} BPF_CALL_4(bpf_get_task_stack, struct task_struct *, task, void *, buf,	   u32, size, u64, flags){	return __bpf_get_task_stack(task, buf, size, flags, false /* !may_fault */);} const struct bpf_func_proto bpf_get_task_stack_proto = {	.func		= bpf_get_task_stack,	.gpl_only	= false,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_BTF_ID,	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,	.arg4_type	= ARG_ANYTHING,}; BPF_CALL_4(bpf_get_task_stack_sleepable, struct task_struct *, task, void *, buf,	   u32, size, u64, flags){	return __bpf_get_task_stack(task, buf, size, flags, true /* !may_fault */);} const struct bpf_func_proto bpf_get_task_stack_sleepable_proto = {	.func		= bpf_get_task_stack_sleepable,	.gpl_only	= false,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_BTF_ID,	.arg1_btf_id	= &btf_tracing_ids[BTF_TRACING_TYPE_TASK],	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,	.arg4_type	= ARG_ANYTHING,}; BPF_CALL_4(bpf_get_stack_pe, struct bpf_perf_event_data_kern *, ctx,	   void *, buf, u32, size, u64, flags){	struct pt_regs *regs = (struct pt_regs *)(ctx->regs);	struct perf_event *event = ctx->event;	struct perf_callchain_entry *trace;	bool kernel, user;	int err = -EINVAL;	__u64 nr_kernel; 	if (!(event->attr.sample_type & PERF_SAMPLE_CALLCHAIN))		return __bpf_get_stack(regs, NULL, NULL, buf, size, flags, false /* !may_fault */); 	if (unlikely(flags & ~(BPF_F_SKIP_FIELD_MASK | BPF_F_USER_STACK |			       BPF_F_USER_BUILD_ID)))		goto clear; 	user = flags & BPF_F_USER_STACK;	kernel = !user; 	err = -EFAULT;	trace = ctx->data->callchain;	if (unlikely(!trace))		goto clear; 	nr_kernel = count_kernel_ip(trace); 	if (kernel) {		__u64 nr = trace->nr; 		trace->nr = nr_kernel;		err = __bpf_get_stack(regs, NULL, trace, buf, size, flags, false /* !may_fault */); 		/* restore nr */		trace->nr = nr;	} else { /* user */		u64 skip = flags & BPF_F_SKIP_FIELD_MASK; 		skip += nr_kernel;		if (skip > BPF_F_SKIP_FIELD_MASK)			goto clear; 		flags = (flags & ~BPF_F_SKIP_FIELD_MASK) | skip;		err = __bpf_get_stack(regs, NULL, trace, buf, size, flags, false /* !may_fault */);	}	return err; clear:	memset(buf, 0, size);	return err; } const struct bpf_func_proto bpf_get_stack_proto_pe = {	.func		= bpf_get_stack_pe,	.gpl_only	= true,	.ret_type	= RET_INTEGER,	.arg1_type	= ARG_PTR_TO_CTX,	.arg2_type	= ARG_PTR_TO_UNINIT_MEM,	.arg3_type	= ARG_CONST_SIZE_OR_ZERO,	.arg4_type	= ARG_ANYTHING,}; /* Called from eBPF program */static void *stack_map_lookup_elem(struct bpf_map *map, void *key){	return ERR_PTR(-EOPNOTSUPP);} /* Called from syscall */static int stack_map_lookup_and_delete_elem(struct bpf_map *map, void *key,					    void *value, u64 flags){	return bpf_stackmap_extract(map, key, value, true);} /* Called from syscall */int bpf_stackmap_extract(struct bpf_map *map, void *key, void *value,			 bool delete){	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);	struct stack_map_bucket *bucket, *old_bucket;	u32 id = *(u32 *)key, trace_len; 	if (unlikely(id >= smap->n_buckets))		return -ENOENT; 	bucket = xchg(&smap->buckets[id], NULL);	if (!bucket)		return -ENOENT; 	trace_len = bucket->nr * stack_map_data_size(map);	memcpy(value, bucket->data, trace_len);	memset(value + trace_len, 0, map->value_size - trace_len); 	if (delete)		old_bucket = bucket;	else		old_bucket = xchg(&smap->buckets[id], bucket);	if (old_bucket)		pcpu_freelist_push(&smap->freelist, &old_bucket->fnode);	return 0;} static int stack_map_get_next_key(struct bpf_map *map, void *key,				  void *next_key){	struct bpf_stack_map *smap = container_of(map,						  struct bpf_stack_map, map);	u32 id; 	WARN_ON_ONCE(!rcu_read_lock_held()); 	if (!key) {		id = 0;	} else {		id = *(u32 *)key;		if (id >= smap->n_buckets || !smap->buckets[id])			id = 0;		else			id++;	} 	while (id < smap->n_buckets && !smap->buckets[id])		id++; 	if (id >= smap->n_buckets)		return -ENOENT; 	*(u32 *)next_key = id;	return 0;} static long stack_map_update_elem(struct bpf_map *map, void *key, void *value,				  u64 map_flags){	return -EINVAL;} /* Called from syscall or from eBPF program */static long stack_map_delete_elem(struct bpf_map *map, void *key){	struct bpf_stack_map *smap = container_of(map, struct bpf_stack_map, map);	struct stack_map_bucket *old_bucket;	u32 id = *(u32 *)key; 

Lines 501–1000 of 1050. Previous lines Load more