On 4/27/23 1:04 PM, Stanislav Fomichev wrote:
Instead of assuming EFAULT, let's assume the BPF program's
output is ignored.
Remove "getsockopt: deny arbitrary ctx->retval" because it
was actually testing optlen. We have separate set of tests
for retval.
Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
---
.../selftests/bpf/prog_tests/sockopt.c | 80 +++++++++++++++++--
1 file changed, 74 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt.c b/tools/testing/selftests/bpf/prog_tests/sockopt.c
index aa4debf62fc6..8dad30ce910e 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockopt.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockopt.c
@@ -273,10 +273,30 @@ static struct sockopt_test {
.error = EFAULT_GETSOCKOPT,
},
{
- .descr = "getsockopt: deny arbitrary ctx->retval",
+ .descr = "getsockopt: ignore >PAGE_SIZE optlen",
.insns = {
- /* ctx->retval = 123 */
- BPF_MOV64_IMM(BPF_REG_0, 123),
+ /* write 0xFF to the first optval byte */
+
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+ /* r2 = ctx->optval */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
+ /* r6 = ctx->optval + 1 */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 1),
+
+ /* r7 = ctx->optval_end */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval_end)),
+
+ /* if (ctx->optval + 1 <= ctx->optval_end) { */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
+ /* ctx->optval[0] = 0xF0 */
+ BPF_ST_MEM(BPF_B, BPF_REG_2, 0, 0xFF),
+ /* } */
+
+ /* ctx->retval = 0 */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
offsetof(struct bpf_sockopt, retval)),
@@ -287,9 +307,10 @@ static struct sockopt_test {
.attach_type = BPF_CGROUP_GETSOCKOPT,
.expected_attach_type = BPF_CGROUP_GETSOCKOPT,
- .get_optlen = 64,
-
- .error = EFAULT_GETSOCKOPT,
+ .get_level = 1234,
+ .get_optname = 5678,
+ .get_optval = {}, /* the changes are ignored */
+ .get_optlen = 4096 + 1,
The patchset looks good. Thanks for taking care of it.
One question, is it safe to the assume 4096 page size for all platforms in the
selftests?
