Centos-kernel-stream-9/tools/testing/selftests/bpf/prog_tests/jit_probe_mem.c

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selftests/bpf: Add verifier test exercising jit PROBE_MEM logic Bugzilla: https://bugzilla.redhat.com/2178930 commit 59fe41b5255f7b8a19a3347ec4b03fd830d6f4aa Author: Dave Marchevsky <davemarchevsky@fb.com> Date: Fri Dec 16 13:43:19 2022 -0800 selftests/bpf: Add verifier test exercising jit PROBE_MEM logic This patch adds a test exercising logic that was fixed / improved in the previous patch in the series, as well as general sanity checking for jit's PROBE_MEM logic which should've been unaffected by the previous patch. The added verifier test does the following: * Acquire a referenced kptr to struct prog_test_ref_kfunc using existing net/bpf/test_run.c kfunc * Helper returns ptr to a specific prog_test_ref_kfunc whose first two fields - both ints - have been prepopulated w/ vals 42 and 108, respectively * kptr_xchg the acquired ptr into an arraymap * Do a direct map_value load of the just-added ptr * Goal of all this setup is to get an unreferenced kptr pointing to struct with ints of known value, which is the result of this step * Using unreferenced kptr obtained in previous step, do loads of prog_test_ref_kfunc.a (offset 0) and .b (offset 4) * Then incr the kptr by 8 and load prog_test_ref_kfunc.a again (this time at offset -8) * Add all the loaded ints together and return Before the PROBE_MEM fixes in previous patch, the loads at offset 0 and 4 would succeed, while the load at offset -8 would incorrectly fail runtime check emitted by the JIT and 0 out dst reg as a result. This confirmed by retval of 150 for this test before previous patch - since second .a read is 0'd out - and a retval of 192 with the fixed logic. The test exercises the two optimizations to fixed logic added in last patch as well: * First load, with insn "r8 = *(u32 *)(r9 + 0)" exercises "insn->off is 0, no need to add / sub from src_reg" optimization * Third load, with insn "r9 = *(u32 *)(r9 - 8)" exercises "src_reg == dst_reg, no need to restore src_reg after load" optimization Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20221216214319.3408356-2-davemarchevsky@fb.com Signed-off-by: Viktor Malik <vmalik@redhat.com>
2023-05-04 11:22:36 +00:00
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */
#include <test_progs.h>
#include <network_helpers.h>
#include "jit_probe_mem.skel.h"
void test_jit_probe_mem(void)
{
LIBBPF_OPTS(bpf_test_run_opts, opts,
.data_in = &pkt_v4,
.data_size_in = sizeof(pkt_v4),
.repeat = 1,
);
struct jit_probe_mem *skel;
int ret;
skel = jit_probe_mem__open_and_load();
if (!ASSERT_OK_PTR(skel, "jit_probe_mem__open_and_load"))
return;
ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.test_jit_probe_mem), &opts);
ASSERT_OK(ret, "jit_probe_mem ret");
ASSERT_OK(opts.retval, "jit_probe_mem opts.retval");
ASSERT_EQ(skel->data->total_sum, 192, "jit_probe_mem total_sum");
jit_probe_mem__destroy(skel);
}