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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106// SPDX-License-Identifier: GPL-2.0-only#ifndef _GNU_SOURCE#define _GNU_SOURCE#endif#include <link.h>#include <stdio.h>#include <stdlib.h>#include <stdbool.h>#include "kselftest.h"
struct Statistics { unsigned long long load_address; unsigned long long alignment; bool interp;};
int ExtractStatistics(struct dl_phdr_info *info, size_t size, void *data){ struct Statistics *stats = (struct Statistics *) data; int i;
if (info->dlpi_name != NULL && info->dlpi_name[0] != '\0') { // Ignore headers from other than the executable. return 2; }
stats->load_address = (unsigned long long) info->dlpi_addr; stats->alignment = 0;
for (i = 0; i < info->dlpi_phnum; i++) { unsigned long long align;
if (info->dlpi_phdr[i].p_type == PT_INTERP) { stats->interp = true; continue; }
if (info->dlpi_phdr[i].p_type != PT_LOAD) continue;
align = info->dlpi_phdr[i].p_align;
if (align > stats->alignment) stats->alignment = align; }
return 1; // Terminate dl_iterate_phdr.}
int main(int argc, char **argv){ struct Statistics extracted = { }; unsigned long long misalign, pow2; bool interp_needed; char buf[1024]; FILE *maps; int ret;
ksft_print_header(); ksft_set_plan(4);
/* Dump maps file for debugging reference. */ maps = fopen("/proc/self/maps", "r"); if (!maps) ksft_exit_fail_msg("FAILED: /proc/self/maps: %s\n", strerror(errno)); while (fgets(buf, sizeof(buf), maps)) { ksft_print_msg("%s", buf); } fclose(maps);
/* Walk the program headers. */ ret = dl_iterate_phdr(ExtractStatistics, &extracted); if (ret != 1) ksft_exit_fail_msg("FAILED: dl_iterate_phdr\n");
/* Report our findings. */ ksft_print_msg("load_address=%#llx alignment=%#llx\n", extracted.load_address, extracted.alignment);
/* If we're named with ".static." we expect no INTERP. */ interp_needed = strstr(argv[0], ".static.") == NULL;
/* Were we built as expected? */ ksft_test_result(interp_needed == extracted.interp, "%s INTERP program header %s\n", interp_needed ? "Wanted" : "Unwanted", extracted.interp ? "seen" : "missing");
/* Did we find an alignment? */ ksft_test_result(extracted.alignment != 0, "Alignment%s found\n", extracted.alignment ? "" : " NOT");
/* Is the alignment sane? */ pow2 = extracted.alignment & (extracted.alignment - 1); ksft_test_result(pow2 == 0, "Alignment is%s a power of 2: %#llx\n", pow2 == 0 ? "" : " NOT", extracted.alignment);
/* Is the load address aligned? */ misalign = extracted.load_address & (extracted.alignment - 1); ksft_test_result(misalign == 0, "Load Address is %saligned (%#llx)\n", misalign ? "MIS" : "", misalign);
ksft_finished();}