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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596// SPDX-License-Identifier: GPL-2.0/* * Test the static transparent flag 'T' of binfmt_misc. A magic-matched * binary is dispatched to an interpreter with the argument vector left * untouched, the binary passed through AT_EXECFD and mm->exe_file labeled * with the binary. The asserting interpreter (binfmt_transparent_interp) * verifies the constructed identity from inside the process and exits 0. * * Needs root for the registration; no bpf toolchain involved. */#define _GNU_SOURCE#include <stdio.h>#include <stdlib.h>
#include "binfmt_misc_common.h"#include "kselftest_harness.h"
#define MAGIC "#TRANSPARENT-SELFTEST#"#define TARGET_PATH "/tmp/binfmt_transparent_target"#define INTERP_PATH "/tmp/binfmt_transparent_interp"#define ENTRY "test_transparent"#define RULE(flags) ":" ENTRY ":M:0:" MAGIC "::" INTERP_PATH ":" flags
/* The target only has to carry the magic; it is never actually loaded. */static int create_target(void){ char buf[128] = MAGIC "\n"; int fd;
unlink(TARGET_PATH); fd = open(TARGET_PATH, O_WRONLY | O_CREAT | O_EXCL, 0755); if (fd < 0) return -1; if (write(fd, buf, sizeof(buf)) != (ssize_t)sizeof(buf)) { close(fd); return -1; } close(fd); return 0;}
FIXTURE(transparent) {};
FIXTURE_SETUP(transparent){ char src[PATH_MAX];
if (getuid() != 0) SKIP(return, "test must be run as root"); if (!binfmt_misc_available()) SKIP(return, "no binfmt_misc");
ASSERT_EQ(artifact_path(src, sizeof(src), "binfmt_transparent_interp"), 0); ASSERT_EQ(copy_file(src, INTERP_PATH), 0); ASSERT_EQ(create_target(), 0);
/* Skip the whole suite on a kernel that does not know 'T'. */ if (!binfmt_flag_supported('T')) { ASSERT_EQ(errno, EINVAL); SKIP(return, "kernel without the 'T' flag"); }}
FIXTURE_TEARDOWN(transparent){ unregister(ENTRY); unlink(TARGET_PATH); unlink(INTERP_PATH);}
/* Grammar sanity check: the same entry without 'T' has to register. */TEST_F(transparent, plain_entry_registers){ ASSERT_EQ(write_reg(RULE("")), 0);}
/* 'T' preserves the whole argv, so combining it with 'P' is rejected. */TEST_F(transparent, rejects_preserve_argv0){ ASSERT_NE(write_reg(RULE("TP")), 0); EXPECT_EQ(errno, EINVAL);}
/* The interpreter asserts the identity the kernel built for it. */TEST_F(transparent, dispatch){ ASSERT_EQ(write_reg(RULE("T")), 0);
setenv("BINFMT_TEST_BINARY", TARGET_PATH, 1); setenv("BINFMT_TEST_ARGV0", PAYLOAD_ARGV0, 1); EXPECT_EQ(run_payload(TARGET_PATH), 0);}
TEST_HARNESS_MAIN