Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2023-07-13

We've added 67 non-merge commits during the last 15 day(s) which contain
a total of 106 files changed, 4444 insertions(+), 619 deletions(-).

The main changes are:

1) Fix bpftool build in presence of stale vmlinux.h,
   from Alexander Lobakin.

2) Introduce bpf_me_mcache_free_rcu() and fix OOM under stress,
   from Alexei Starovoitov.

3) Teach verifier actual bounds of bpf_get_smp_processor_id()
   and fix perf+libbpf issue related to custom section handling,
   from Andrii Nakryiko.

4) Introduce bpf map element count, from Anton Protopopov.

5) Check skb ownership against full socket, from Kui-Feng Lee.

6) Support for up to 12 arguments in BPF trampoline, from Menglong Dong.

7) Export rcu_request_urgent_qs_task, from Paul E. McKenney.

8) Fix BTF walking of unions, from Yafang Shao.

9) Extend link_info for kprobe_multi and perf_event links,
   from Yafang Shao.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (67 commits)
  selftests/bpf: Add selftest for PTR_UNTRUSTED
  bpf: Fix an error in verifying a field in a union
  selftests/bpf: Add selftests for nested_trust
  bpf: Fix an error around PTR_UNTRUSTED
  selftests/bpf: add testcase for TRACING with 6+ arguments
  bpf, x86: allow function arguments up to 12 for TRACING
  bpf, x86: save/restore regs with BPF_DW size
  bpftool: Use "fallthrough;" keyword instead of comments
  bpf: Add object leak check.
  bpf: Convert bpf_cpumask to bpf_mem_cache_free_rcu.
  bpf: Introduce bpf_mem_free_rcu() similar to kfree_rcu().
  selftests/bpf: Improve test coverage of bpf_mem_alloc.
  rcu: Export rcu_request_urgent_qs_task()
  bpf: Allow reuse from waiting_for_gp_ttrace list.
  bpf: Add a hint to allocated objects.
  bpf: Change bpf_mem_cache draining process.
  bpf: Further refactor alloc_bulk().
  bpf: Factor out inc/dec of active flag into helpers.
  bpf: Refactor alloc_bulk().
  bpf: Let free_all() return the number of freed elements.
  ...
====================

Link: https://lore.kernel.org/r/20230714020910.80794-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 51 insertions, 14 deletions

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 5f2dcabad202..c92eb8c6ff08 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2369,9 +2369,13 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
 	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;
+		/* We allow NULL pointer for tracepoint */
+		if (fd_type)
+			*fd_type = BPF_FD_TYPE_TRACEPOINT;
+		if (probe_offset)
+			*probe_offset = 0x0;
+		if (probe_addr)
+			*probe_addr = 0x0;
 	} else {
 		/* kprobe/uprobe */
 		err = -EOPNOTSUPP;
@@ -2384,7 +2388,7 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
 #ifdef CONFIG_UPROBE_EVENTS
 		if (flags & TRACE_EVENT_FL_UPROBE)
 			err = bpf_get_uprobe_info(event, fd_type, buf,
-						  probe_offset,
+						  probe_offset, probe_addr,
 						  event->attr.type == PERF_TYPE_TRACEPOINT);
 #endif
 	}
@@ -2469,6 +2473,7 @@ struct bpf_kprobe_multi_link {
 	u32 cnt;
 	u32 mods_cnt;
 	struct module **mods;
+	u32 flags;
 };
 
 struct bpf_kprobe_multi_run_ctx {
@@ -2558,9 +2563,44 @@ static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link)
 	kfree(kmulti_link);
 }
 
+static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,
+						struct bpf_link_info *info)
+{
+	u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);
+	struct bpf_kprobe_multi_link *kmulti_link;
+	u32 ucount = info->kprobe_multi.count;
+	int err = 0, i;
+
+	if (!uaddrs ^ !ucount)
+		return -EINVAL;
+
+	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);
+	info->kprobe_multi.count = kmulti_link->cnt;
+	info->kprobe_multi.flags = kmulti_link->flags;
+
+	if (!uaddrs)
+		return 0;
+	if (ucount < kmulti_link->cnt)
+		err = -ENOSPC;
+	else
+		ucount = kmulti_link->cnt;
+
+	if (kallsyms_show_value(current_cred())) {
+		if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))
+			return -EFAULT;
+	} else {
+		for (i = 0; i < ucount; i++) {
+			if (put_user(0, uaddrs + i))
+				return -EFAULT;
+		}
+	}
+	return err;
+}
+
 static const struct bpf_link_ops bpf_kprobe_multi_link_lops = {
 	.release = bpf_kprobe_multi_link_release,
 	.dealloc = bpf_kprobe_multi_link_dealloc,
+	.fill_link_info = bpf_kprobe_multi_link_fill_link_info,
 };
 
 static void bpf_kprobe_multi_cookie_swap(void *a, void *b, int size, const void *priv)
@@ -2874,6 +2914,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
 	link->addrs = addrs;
 	link->cookies = cookies;
 	link->cnt = cnt;
+	link->flags = flags;
 
 	if (cookies) {
 		/*
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 23dba01831f7..17c21c0b2dd1 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1561,15 +1561,10 @@ int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
 
 	*fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
 					      : BPF_FD_TYPE_KPROBE;
-	if (tk->symbol) {
-		*symbol = tk->symbol;
-		*probe_offset = tk->rp.kp.offset;
-		*probe_addr = 0;
-	} else {
-		*symbol = NULL;
-		*probe_offset = 0;
-		*probe_addr = (unsigned long)tk->rp.kp.addr;
-	}
+	*probe_offset = tk->rp.kp.offset;
+	*probe_addr = kallsyms_show_value(current_cred()) ?
+		      (unsigned long)tk->rp.kp.addr : 0;
+	*symbol = tk->symbol;
 	return 0;
 }
 #endif	/* CONFIG_PERF_EVENTS */
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index fa09b33ee731..eaa800530e92 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1417,7 +1417,7 @@ static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
 
 int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
 			const char **filename, u64 *probe_offset,
-			bool perf_type_tracepoint)
+			u64 *probe_addr, bool perf_type_tracepoint)
 {
 	const char *pevent = trace_event_name(event->tp_event);
 	const char *group = event->tp_event->class->system;
@@ -1434,6 +1434,7 @@ int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
 				    : BPF_FD_TYPE_UPROBE;
 	*filename = tu->filename;
 	*probe_offset = tu->offset;
+	*probe_addr = 0;
 	return 0;
 }
 #endif	/* CONFIG_PERF_EVENTS */