Commit 361d3202 authored by Yauheni Kaliuta's avatar Yauheni Kaliuta Committed by Andrii Nakryiko
Browse files

selftests/bpf: Pass page size from userspace in sockopt_sk 



Since there is no convenient way for bpf program to get PAGE_SIZE
from inside of the kernel, pass the value from userspace.

Zero-initialize the variable in bpf prog, otherwise it will cause
problems on some versions of Clang.

Signed-off-by: default avatarYauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210408061310.95877-3-yauheni.kaliuta@redhat.com
parent cad99cce

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

+2 −0
Original line number Diff line number Diff line
@@ -200,6 +200,8 @@ static void run_test(int cgroup_fd) 
	if (!ASSERT_OK_PTR(skel, "skel_load"))

		goto cleanup;



	skel->bss->page_size = getpagesize();



	skel->links._setsockopt =

		bpf_program__attach_cgroup(skel->progs._setsockopt, cgroup_fd);

	if (!ASSERT_OK_PTR(skel->links._setsockopt, "setsockopt_link"))

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

+4 −6
Original line number Diff line number Diff line
@@ -7,9 +7,7 @@ 


char _license[] SEC("license") = "GPL";



#ifndef PAGE_SIZE

#define PAGE_SIZE 4096

#endif

int page_size = 0; /* userspace should set it */



#ifndef SOL_TCP

#define SOL_TCP IPPROTO_TCP
@@ -89,7 +87,7 @@ int _getsockopt(struct bpf_sockopt *ctx) 
		 * program can only see the first PAGE_SIZE

		 * bytes of data.

		 */

		if (optval_end - optval != PAGE_SIZE)

		if (optval_end - optval != page_size)

			return 0; /* EPERM, unexpected data size */



		return 1;
@@ -160,7 +158,7 @@ int _setsockopt(struct bpf_sockopt *ctx) 


	if (ctx->level == SOL_IP && ctx->optname == IP_FREEBIND) {

		/* Original optlen is larger than PAGE_SIZE. */

		if (ctx->optlen != PAGE_SIZE * 2)

		if (ctx->optlen != page_size * 2)

			return 0; /* EPERM, unexpected data size */



		if (optval + 1 > optval_end)
@@ -174,7 +172,7 @@ int _setsockopt(struct bpf_sockopt *ctx) 
		 * program can only see the first PAGE_SIZE

		 * bytes of data.

		 */

		if (optval_end - optval != PAGE_SIZE)

		if (optval_end - optval != page_size)

			return 0; /* EPERM, unexpected data size */



		return 1;