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From: Martin KaFai Lau <martin.lau@linux.dev>
To: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
	Andrii Nakryiko <andrii@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Kui-Feng Lee <thinker.li@gmail.com>,
	kernel-team@meta.com
Subject: [PATCH v5 bpf-next 09/12] selftests/bpf: Test a uptr struct spanning across pages.
Date: Mon, 14 Oct 2024 17:49:59 -0700	[thread overview]
Message-ID: <20241015005008.767267-10-martin.lau@linux.dev> (raw)
In-Reply-To: <20241015005008.767267-1-martin.lau@linux.dev>

From: Martin KaFai Lau <martin.lau@kernel.org>

This patch tests the case when uptr has a struct spanning across two
pages. It is not supported now and EOPNOTSUPP is expected from the
syscall update_elem.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
 .../bpf/prog_tests/task_local_storage.c       | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/task_local_storage.c b/tools/testing/selftests/bpf/prog_tests/task_local_storage.c
index 4c8eadd1f083..9a081aaa26a3 100644
--- a/tools/testing/selftests/bpf/prog_tests/task_local_storage.c
+++ b/tools/testing/selftests/bpf/prog_tests/task_local_storage.c
@@ -8,6 +8,7 @@
 #include <sys/syscall.h>   /* For SYS_xxx definitions */
 #include <sys/types.h>
 #include <sys/eventfd.h>
+#include <sys/mman.h>
 #include <test_progs.h>
 #include "task_local_storage_helpers.h"
 #include "task_local_storage.skel.h"
@@ -367,6 +368,42 @@ static void test_uptr_basic(void)
 	close(parent_task_fd);
 }
 
+static void test_uptr_across_pages(void)
+{
+	int page_size = getpagesize();
+	struct value_type value = {};
+	struct task_ls_uptr *skel;
+	int err, task_fd, map_fd;
+	void *mem;
+
+	task_fd = sys_pidfd_open(getpid(), 0);
+	if (!ASSERT_OK_FD(task_fd, "task_fd"))
+		return;
+
+	mem = mmap(NULL, page_size * 2, PROT_READ | PROT_WRITE,
+		   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if (!ASSERT_OK_PTR(mem, "mmap(page_size * 2)")) {
+		close(task_fd);
+		return;
+	}
+
+	skel = task_ls_uptr__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_open_and_load"))
+		goto out;
+
+	map_fd = bpf_map__fd(skel->maps.datamap);
+	value.udata = mem + page_size - offsetof(struct user_data, b);
+	err = bpf_map_update_elem(map_fd, &task_fd, &value, 0);
+	if (!ASSERT_ERR(err, "update_elem(udata)"))
+		goto out;
+	ASSERT_EQ(errno, EOPNOTSUPP, "errno");
+
+out:
+	task_ls_uptr__destroy(skel);
+	close(task_fd);
+	munmap(mem, page_size * 2);
+}
+
 void test_task_local_storage(void)
 {
 	if (test__start_subtest("sys_enter_exit"))
@@ -379,4 +416,6 @@ void test_task_local_storage(void)
 		test_nodeadlock();
 	if (test__start_subtest("uptr_basic"))
 		test_uptr_basic();
+	if (test__start_subtest("uptr_across_pages"))
+		test_uptr_across_pages();
 }
-- 
2.43.5


  parent reply	other threads:[~2024-10-15  0:50 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-15  0:49 [PATCH v5 bpf-next 00/12] Share user memory to BPF program through task storage map Martin KaFai Lau
2024-10-15  0:49 ` [PATCH v5 bpf-next 01/12] bpf: Support __uptr type tag in BTF Martin KaFai Lau
2024-10-15  0:49 ` [PATCH v5 bpf-next 02/12] bpf: Handle BPF_UPTR in verifier Martin KaFai Lau
2024-10-15  0:49 ` [PATCH v5 bpf-next 03/12] bpf: Add "bool swap_uptrs" arg to bpf_local_storage_update() and bpf_selem_alloc() Martin KaFai Lau
2024-10-15  0:49 ` [PATCH v5 bpf-next 04/12] bpf: Postpone bpf_selem_free() in bpf_selem_unlink_storage_nolock() Martin KaFai Lau
2024-10-15  0:49 ` [PATCH v5 bpf-next 05/12] bpf: Postpone bpf_obj_free_fields to the rcu callback Martin KaFai Lau
2024-10-15  0:49 ` [PATCH v5 bpf-next 06/12] bpf: Add uptr support in the map_value of the task local storage Martin KaFai Lau
2024-10-22 23:07   ` Shakeel Butt
2024-10-23  0:57     ` Shakeel Butt
2024-10-24  0:44       ` Martin KaFai Lau
2024-10-15  0:49 ` [PATCH v5 bpf-next 07/12] libbpf: define __uptr Martin KaFai Lau
2024-10-15  0:49 ` [PATCH v5 bpf-next 08/12] selftests/bpf: Some basic __uptr tests Martin KaFai Lau
2024-10-15  0:49 ` Martin KaFai Lau [this message]
2024-10-15  0:50 ` [PATCH v5 bpf-next 10/12] selftests/bpf: Add update_elem failure test for task storage uptr Martin KaFai Lau
2024-10-15  0:50 ` [PATCH v5 bpf-next 11/12] selftests/bpf: Add uptr failure verifier tests Martin KaFai Lau
2024-10-15  0:50 ` [PATCH v5 bpf-next 12/12] selftests/bpf: Create task_local_storage map with invalid uptr's struct Martin KaFai Lau

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