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// 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();
}
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