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

Daniel Borkmann says:

====================
pull-request: bpf 2024-06-24

We've added 12 non-merge commits during the last 10 day(s) which contain
a total of 10 files changed, 412 insertions(+), 16 deletions(-).

The main changes are:

1) Fix a BPF verifier issue validating may_goto with a negative offset,
   from Alexei Starovoitov.

2) Fix a BPF verifier validation bug with may_goto combined with jump to
   the first instruction, also from Alexei Starovoitov.

3) Fix a bug with overrunning reservations in BPF ring buffer,
   from Daniel Borkmann.

4) Fix a bug in BPF verifier due to missing proper var_off setting related
   to movsx instruction, from Yonghong Song.

5) Silence unnecessary syzkaller-triggered warning in __xdp_reg_mem_model(),
   from Daniil Dulov.

* tag 'for-netdev' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  xdp: Remove WARN() from __xdp_reg_mem_model()
  selftests/bpf: Add tests for may_goto with negative offset.
  bpf: Fix may_goto with negative offset.
  selftests/bpf: Add more ring buffer test coverage
  bpf: Fix overrunning reservations in ringbuf
  selftests/bpf: Tests with may_goto and jumps to the 1st insn
  bpf: Fix the corner case with may_goto and jump to the 1st insn.
  bpf: Update BPF LSM maintainer list
  bpf: Fix remap of arena.
  selftests/bpf: Add a few tests to cover
  bpf: Add missed var_off setting in coerce_subreg_to_size_sx()
  bpf: Add missed var_off setting in set_sext32_default_val()
====================

Link: https://patch.msgid.link/20240624124330.8401-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 56 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/ringbuf.c b/tools/testing/selftests/bpf/prog_tests/ringbuf.c
index 4c6f42dae409..da430df45aa4 100644
--- a/tools/testing/selftests/bpf/prog_tests/ringbuf.c
+++ b/tools/testing/selftests/bpf/prog_tests/ringbuf.c
@@ -12,9 +12,11 @@
 #include <sys/sysinfo.h>
 #include <linux/perf_event.h>
 #include <linux/ring_buffer.h>
+
 #include "test_ringbuf.lskel.h"
 #include "test_ringbuf_n.lskel.h"
 #include "test_ringbuf_map_key.lskel.h"
+#include "test_ringbuf_write.lskel.h"
 
 #define EDONE 7777
 
@@ -84,6 +86,58 @@ static void *poll_thread(void *input)
 	return (void *)(long)ring_buffer__poll(ringbuf, timeout);
 }
 
+static void ringbuf_write_subtest(void)
+{
+	struct test_ringbuf_write_lskel *skel;
+	int page_size = getpagesize();
+	size_t *mmap_ptr;
+	int err, rb_fd;
+
+	skel = test_ringbuf_write_lskel__open();
+	if (!ASSERT_OK_PTR(skel, "skel_open"))
+		return;
+
+	skel->maps.ringbuf.max_entries = 0x4000;
+
+	err = test_ringbuf_write_lskel__load(skel);
+	if (!ASSERT_OK(err, "skel_load"))
+		goto cleanup;
+
+	rb_fd = skel->maps.ringbuf.map_fd;
+
+	mmap_ptr = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, rb_fd, 0);
+	if (!ASSERT_OK_PTR(mmap_ptr, "rw_cons_pos"))
+		goto cleanup;
+	*mmap_ptr = 0x3000;
+	ASSERT_OK(munmap(mmap_ptr, page_size), "unmap_rw");
+
+	skel->bss->pid = getpid();
+
+	ringbuf = ring_buffer__new(rb_fd, process_sample, NULL, NULL);
+	if (!ASSERT_OK_PTR(ringbuf, "ringbuf_new"))
+		goto cleanup;
+
+	err = test_ringbuf_write_lskel__attach(skel);
+	if (!ASSERT_OK(err, "skel_attach"))
+		goto cleanup_ringbuf;
+
+	skel->bss->discarded = 0;
+	skel->bss->passed = 0;
+
+	/* trigger exactly two samples */
+	syscall(__NR_getpgid);
+	syscall(__NR_getpgid);
+
+	ASSERT_EQ(skel->bss->discarded, 2, "discarded");
+	ASSERT_EQ(skel->bss->passed, 0, "passed");
+
+	test_ringbuf_write_lskel__detach(skel);
+cleanup_ringbuf:
+	ring_buffer__free(ringbuf);
+cleanup:
+	test_ringbuf_write_lskel__destroy(skel);
+}
+
 static void ringbuf_subtest(void)
 {
 	const size_t rec_sz = BPF_RINGBUF_HDR_SZ + sizeof(struct sample);
@@ -451,4 +505,6 @@ void test_ringbuf(void)
 		ringbuf_n_subtest();
 	if (test__start_subtest("ringbuf_map_key"))
 		ringbuf_map_key_subtest();
+	if (test__start_subtest("ringbuf_write"))
+		ringbuf_write_subtest();
 }