Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-04-23

The following pull-request contains BPF updates for your *net-next* tree.

We've added 69 non-merge commits during the last 22 day(s) which contain
a total of 69 files changed, 3141 insertions(+), 866 deletions(-).

The main changes are:

1) Add BPF static linker support for extern resolution of global, from Andrii.

2) Refine retval for bpf_get_task_stack helper, from Dave.

3) Add a bpf_snprintf helper, from Florent.

4) A bunch of miscellaneous improvements from many developers.
====================

Signed-off-by: David S. Miller <[email protected]>

1 files changed, 55 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/linked_vars2.c b/tools/testing/selftests/bpf/progs/linked_vars2.c
new file mode 100644
index 000000000000..e4f5bd388a3c
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/linked_vars2.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+extern int LINUX_KERNEL_VERSION __kconfig;
+/* when an extern is defined as both strong and weak, resulting symbol will be strong */
+extern bool CONFIG_BPF_SYSCALL __kconfig;
+extern const void __start_BTF __ksym;
+
+int input_bss2;
+int input_data2 = 2;
+const volatile int input_rodata2 = 22;
+
+int input_bss_weak __weak;
+/* these two weak variables should lose */
+int input_data_weak __weak = 20;
+const volatile int input_rodata_weak __weak = 200;
+
+extern int input_bss1;
+extern int input_data1;
+extern const int input_rodata1;
+
+int output_bss2;
+int output_data2;
+int output_rodata2;
+
+int output_sink2;
+
+static __noinline int get_data_res(void)
+{
+	/* just make sure all the relocations work against .text as well */
+	return input_data1 + input_data2 + input_data_weak;
+}
+
+SEC("raw_tp/sys_enter")
+int BPF_PROG(handler2)
+{
+	output_bss2 = input_bss1 + input_bss2 + input_bss_weak;
+	output_data2 = get_data_res();
+	output_rodata2 = input_rodata1 + input_rodata2 + input_rodata_weak;
+
+	/* make sure we actually use above special externs, otherwise compiler
+	 * will optimize them out
+	 */
+	output_sink2 = LINUX_KERNEL_VERSION
+		       + CONFIG_BPF_SYSCALL
+		       + (long)&__start_BTF;
+
+	return 0;
+}
+
+char LICENSE[] SEC("license") = "GPL";