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4e4136c644
Test gen_prologue and gen_epilogue that generate kfuncs that have not
been seen in the main program.
The main bpf program and return value checks are identical to
pro_epilogue.c introduced in commit 47e69431b5 ("selftests/bpf: Test
gen_prologue and gen_epilogue"). However, now when bpf_testmod_st_ops
detects a program name with prefix "test_kfunc_", it generates slightly
different prologue and epilogue: They still add 1000 to args->a in
prologue, add 10000 to args->a and set r0 to 2 * args->a in epilogue,
but involve kfuncs.
At high level, the alternative version of prologue and epilogue look
like this:
cgrp = bpf_cgroup_from_id(0);
if (cgrp)
bpf_cgroup_release(cgrp);
else
/* Perform what original bpf_testmod_st_ops prologue or
* epilogue does
*/
Since 0 is never a valid cgroup id, the original prologue or epilogue
logic will be performed. As a result, the __retval check should expect
the exact same return value.
Signed-off-by: Amery Hung <ameryhung@gmail.com>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250225233545.285481-2-ameryhung@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
62 lines
1.8 KiB
C
62 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
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#include <test_progs.h>
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#include "pro_epilogue.skel.h"
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#include "epilogue_tailcall.skel.h"
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#include "pro_epilogue_goto_start.skel.h"
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#include "epilogue_exit.skel.h"
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#include "pro_epilogue_with_kfunc.skel.h"
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struct st_ops_args {
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__u64 a;
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};
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static void test_tailcall(void)
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{
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LIBBPF_OPTS(bpf_test_run_opts, topts);
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struct epilogue_tailcall *skel;
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struct st_ops_args args;
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int err, prog_fd;
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skel = epilogue_tailcall__open_and_load();
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if (!ASSERT_OK_PTR(skel, "epilogue_tailcall__open_and_load"))
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return;
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topts.ctx_in = &args;
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topts.ctx_size_in = sizeof(args);
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skel->links.epilogue_tailcall =
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bpf_map__attach_struct_ops(skel->maps.epilogue_tailcall);
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if (!ASSERT_OK_PTR(skel->links.epilogue_tailcall, "attach_struct_ops"))
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goto done;
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/* Both test_epilogue_tailcall and test_epilogue_subprog are
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* patched with epilogue. When syscall_epilogue_tailcall()
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* is run, test_epilogue_tailcall() is triggered.
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* It executes a tail call and control is transferred to
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* test_epilogue_subprog(). Only test_epilogue_subprog()
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* does args->a += 1, thus final args.a value of 10001
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* guarantees that only the epilogue of the
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* test_epilogue_subprog is executed.
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*/
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memset(&args, 0, sizeof(args));
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prog_fd = bpf_program__fd(skel->progs.syscall_epilogue_tailcall);
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err = bpf_prog_test_run_opts(prog_fd, &topts);
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ASSERT_OK(err, "bpf_prog_test_run_opts");
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ASSERT_EQ(args.a, 10001, "args.a");
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ASSERT_EQ(topts.retval, 10001 * 2, "topts.retval");
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done:
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epilogue_tailcall__destroy(skel);
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}
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void test_pro_epilogue(void)
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{
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RUN_TESTS(pro_epilogue);
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RUN_TESTS(pro_epilogue_goto_start);
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RUN_TESTS(epilogue_exit);
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RUN_TESTS(pro_epilogue_with_kfunc);
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if (test__start_subtest("tailcall"))
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test_tailcall();
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}
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