Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Alexei Starovoitov says:

====================
pull-request: bpf 2022-04-06

We've added 8 non-merge commits during the last 8 day(s) which contain
a total of 9 files changed, 139 insertions(+), 36 deletions(-).

The main changes are:

1) rethook related fixes, from Jiri and Masami.

2) Fix the case when tracing bpf prog is attached to struct_ops, from Martin.

3) Support dual-stack sockets in bpf_tcp_check_syncookie, from Maxim.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Adjust bpf_tcp_check_syncookie selftest to test dual-stack sockets
  bpf: Support dual-stack sockets in bpf_tcp_check_syncookie
  bpf: selftests: Test fentry tracing a struct_ops program
  bpf: Resolve to prog->aux->dst_prog->type only for BPF_PROG_TYPE_EXT
  rethook: Fix to use WRITE_ONCE() for rethook:: Handler
  selftests/bpf: Fix warning comparing pointer to 0
  bpf: Fix sparse warnings in kprobe_multi_resolve_syms
  bpftool: Explicit errno handling in skeletons
====================

Link: https://lore.kernel.org/r/20220407031245.73026-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

include/linux/bpf_verifier.h

@@ -570,9 +570,11 @@ static inline u32 type_flag(u32 type)
 	return type & ~BPF_BASE_TYPE_MASK;
 }
 
+/* only use after check_attach_btf_id() */
 static inline enum bpf_prog_type resolve_prog_type(struct bpf_prog *prog)
 {
-	return prog->aux->dst_prog ? prog->aux->dst_prog->type : prog->type;
+	return prog->type == BPF_PROG_TYPE_EXT ?
+		prog->aux->dst_prog->type : prog->type;
 }
 
 #endif /* _LINUX_BPF_VERIFIER_H */

kernel/trace/bpf_trace.c

@@ -2349,11 +2349,11 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long entry_ip,
 }
 
 static int
-kprobe_multi_resolve_syms(const void *usyms, u32 cnt,
+kprobe_multi_resolve_syms(const void __user *usyms, u32 cnt,
 			  unsigned long *addrs)
 {
 	unsigned long addr, size;
-	const char **syms;
+	const char __user **syms;
 	int err = -ENOMEM;
 	unsigned int i;
 	char *func;

kernel/trace/rethook.c

@@ -65,7 +65,7 @@ static void rethook_free_rcu(struct rcu_head *head)
  */
 void rethook_free(struct rethook *rh)
 {
-	rcu_assign_pointer(rh->handler, NULL);
+	WRITE_ONCE(rh->handler, NULL);
 
 	call_rcu(&rh->rcu, rethook_free_rcu);
 }

net/core/filter.c

@@ -7016,24 +7016,33 @@ BPF_CALL_5(bpf_tcp_check_syncookie, struct sock *, sk, void *, iph, u32, iph_len
 	if (!th->ack || th->rst || th->syn)
 		return -ENOENT;
 
+	if (unlikely(iph_len < sizeof(struct iphdr)))
+		return -EINVAL;
+
 	if (tcp_synq_no_recent_overflow(sk))
 		return -ENOENT;
 
 	cookie = ntohl(th->ack_seq) - 1;
 
-	switch (sk->sk_family) {
-	case AF_INET:
-		if (unlikely(iph_len < sizeof(struct iphdr)))
+	/* Both struct iphdr and struct ipv6hdr have the version field at the
+	 * same offset so we can cast to the shorter header (struct iphdr).
+	 */
+	switch (((struct iphdr *)iph)->version) {
+	case 4:
+		if (sk->sk_family == AF_INET6 && ipv6_only_sock(sk))
 			return -EINVAL;
 
 		ret = __cookie_v4_check((struct iphdr *)iph, th, cookie);
 		break;
 
 #if IS_BUILTIN(CONFIG_IPV6)
-	case AF_INET6:
+	case 6:
 		if (unlikely(iph_len < sizeof(struct ipv6hdr)))
 			return -EINVAL;
 
+		if (sk->sk_family != AF_INET6)
+			return -EINVAL;
+
 		ret = __cookie_v6_check((struct ipv6hdr *)iph, th, cookie);
 		break;
 #endif /* CONFIG_IPV6 */

tools/bpf/bpftool/gen.c

@@ -828,8 +828,10 @@ codegen_maps_skeleton(struct bpf_object *obj, size_t map_cnt, bool mmaped)
 			s->map_cnt = %zu;			    \n\
 			s->map_skel_sz = sizeof(*s->maps);	    \n\
 			s->maps = (struct bpf_map_skeleton *)calloc(s->map_cnt, s->map_skel_sz);\n\
-			if (!s->maps)				    \n\
+			if (!s->maps) {				    \n\
+				err = -ENOMEM;			    \n\
 				goto err;			    \n\
+			}					    \n\
 		",
 		map_cnt
 	);
@@ -870,8 +872,10 @@ codegen_progs_skeleton(struct bpf_object *obj, size_t prog_cnt, bool populate_li
 			s->prog_cnt = %zu;			    \n\
 			s->prog_skel_sz = sizeof(*s->progs);	    \n\
 			s->progs = (struct bpf_prog_skeleton *)calloc(s->prog_cnt, s->prog_skel_sz);\n\
-			if (!s->progs)				    \n\
+			if (!s->progs) {			    \n\
+				err = -ENOMEM;			    \n\
 				goto err;			    \n\
+			}					    \n\
 		",
 		prog_cnt
 	);
@@ -1182,10 +1186,13 @@ static int do_skeleton(int argc, char **argv)
 		%1$s__create_skeleton(struct %1$s *obj)			    \n\
 		{							    \n\
 			struct bpf_object_skeleton *s;			    \n\
+			int err;					    \n\
 									    \n\
 			s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));\n\
-			if (!s)						    \n\
+			if (!s)	{					    \n\
+				err = -ENOMEM;				    \n\
 				goto err;				    \n\
+			}						    \n\
 									    \n\
 			s->sz = sizeof(*s);				    \n\
 			s->name = \"%1$s\";				    \n\
@@ -1206,7 +1213,7 @@ static int do_skeleton(int argc, char **argv)
 			return 0;					    \n\
 		err:							    \n\
 			bpf_object__destroy_skeleton(s);		    \n\
-			return -ENOMEM;					    \n\
+			return err;					    \n\
 		}							    \n\
 									    \n\
 		static inline const void *%2$s__elf_bytes(size_t *sz)	    \n\
@@ -1466,12 +1473,12 @@ static int do_subskeleton(int argc, char **argv)
 									    \n\
 			obj = (struct %1$s *)calloc(1, sizeof(*obj));	    \n\
 			if (!obj) {					    \n\
-				errno = ENOMEM;				    \n\
+				err = -ENOMEM;				    \n\
 				goto err;				    \n\
 			}						    \n\
 			s = (struct bpf_object_subskeleton *)calloc(1, sizeof(*s));\n\
 			if (!s) {					    \n\
-				errno = ENOMEM;				    \n\
+				err = -ENOMEM;				    \n\
 				goto err;				    \n\
 			}						    \n\
 			s->sz = sizeof(*s);				    \n\
@@ -1483,7 +1490,7 @@ static int do_subskeleton(int argc, char **argv)
 			s->var_cnt = %2$d;				    \n\
 			s->vars = (struct bpf_var_skeleton *)calloc(%2$d, sizeof(*s->vars));\n\
 			if (!s->vars) {					    \n\
-				errno = ENOMEM;				    \n\
+				err = -ENOMEM;				    \n\
 				goto err;				    \n\
 			}						    \n\
 		",
@@ -1538,6 +1545,7 @@ static int do_subskeleton(int argc, char **argv)
 			return obj;					    \n\
 		err:							    \n\
 			%1$s__destroy(obj);				    \n\
+			errno = -err;					    \n\
 			return NULL;					    \n\
 		}							    \n\
 									    \n\

tools/testing/selftests/bpf/prog_tests/dummy_st_ops.c

@@ -2,6 +2,7 @@
 /* Copyright (C) 2021. Huawei Technologies Co., Ltd */
 #include <test_progs.h>
 #include "dummy_st_ops.skel.h"
+#include "trace_dummy_st_ops.skel.h"
 
 /* Need to keep consistent with definition in include/linux/bpf.h */
 struct bpf_dummy_ops_state {
@@ -56,6 +57,7 @@ static void test_dummy_init_ptr_arg(void)
 		.ctx_in = args,
 		.ctx_size_in = sizeof(args),
 	);
+	struct trace_dummy_st_ops *trace_skel;
 	struct dummy_st_ops *skel;
 	int fd, err;
 
@@ -64,12 +66,33 @@ static void test_dummy_init_ptr_arg(void)
 		return;
 
 	fd = bpf_program__fd(skel->progs.test_1);
+
+	trace_skel = trace_dummy_st_ops__open();
+	if (!ASSERT_OK_PTR(trace_skel, "trace_dummy_st_ops__open"))
+		goto done;
+
+	err = bpf_program__set_attach_target(trace_skel->progs.fentry_test_1,
+					     fd, "test_1");
+	if (!ASSERT_OK(err, "set_attach_target(fentry_test_1)"))
+		goto done;
+
+	err = trace_dummy_st_ops__load(trace_skel);
+	if (!ASSERT_OK(err, "load(trace_skel)"))
+		goto done;
+
+	err = trace_dummy_st_ops__attach(trace_skel);
+	if (!ASSERT_OK(err, "attach(trace_skel)"))
+		goto done;
+
 	err = bpf_prog_test_run_opts(fd, &attr);
 	ASSERT_OK(err, "test_run");
 	ASSERT_EQ(in_state.val, 0x5a, "test_ptr_ret");
 	ASSERT_EQ(attr.retval, exp_retval, "test_ret");
+	ASSERT_EQ(trace_skel->bss->val, exp_retval, "fentry_val");
 
+done:
 	dummy_st_ops__destroy(skel);
+	trace_dummy_st_ops__destroy(trace_skel);
 }
 
 static void test_dummy_multiple_args(void)

tools/testing/selftests/bpf/progs/map_ptr_kern.c

@@ -367,7 +367,7 @@ static inline int check_array_of_maps(void)
 
 	VERIFY(check_default(&array_of_maps->map, map));
 	inner_map = bpf_map_lookup_elem(array_of_maps, &key);
-	VERIFY(inner_map != 0);
+	VERIFY(inner_map != NULL);
 	VERIFY(inner_map->map.max_entries == INNER_MAX_ENTRIES);
 
 	return 1;
@@ -394,7 +394,7 @@ static inline int check_hash_of_maps(void)
 
 	VERIFY(check_default(&hash_of_maps->map, map));
 	inner_map = bpf_map_lookup_elem(hash_of_maps, &key);
-	VERIFY(inner_map != 0);
+	VERIFY(inner_map != NULL);
 	VERIFY(inner_map->map.max_entries == INNER_MAX_ENTRIES);
 
 	return 1;

tools/testing/selftests/bpf/progs/trace_dummy_st_ops.c

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+int val = 0;
+
+SEC("fentry/test_1")
+int BPF_PROG(fentry_test_1, __u64 *st_ops_ctx)
+{
+	__u64 state;
+
+	/* Read the traced st_ops arg1 which is a pointer */
+	bpf_probe_read_kernel(&state, sizeof(__u64), (void *)st_ops_ctx);
+	/* Read state->val */
+	bpf_probe_read_kernel(&val, sizeof(__u32), (void *)state);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";