Commit 206e22f0 authored by Chris Kennelly's avatar Chris Kennelly Committed by Linus Torvalds

tools/testing/selftests: add self-test for verifying load alignment

This produces a PIE binary with a variety of p_align requirements,
suitable for verifying that the load address meets that alignment
requirement.
Signed-off-by: default avatarChris Kennelly <ckennelly@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Fangrui Song <maskray@google.com>
Cc: Hugh Dickens <hughd@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Link: https://lkml.kernel.org/r/20200820170541.1132271-3-ckennelly@google.com
Link: https://lkml.kernel.org/r/20200821233848.3904680-3-ckennelly@google.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ce81bb25
...@@ -7,6 +7,7 @@ execveat.moved ...@@ -7,6 +7,7 @@ execveat.moved
execveat.path.ephemeral execveat.path.ephemeral
execveat.ephemeral execveat.ephemeral
execveat.denatured execveat.denatured
/load_address_*
/recursion-depth /recursion-depth
xxxxxxxx* xxxxxxxx*
pipe pipe
......
...@@ -4,7 +4,7 @@ CFLAGS += -Wno-nonnull ...@@ -4,7 +4,7 @@ CFLAGS += -Wno-nonnull
CFLAGS += -D_GNU_SOURCE CFLAGS += -D_GNU_SOURCE
TEST_PROGS := binfmt_script non-regular TEST_PROGS := binfmt_script non-regular
TEST_GEN_PROGS := execveat TEST_GEN_PROGS := execveat load_address_4096 load_address_2097152 load_address_16777216
TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir pipe TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir pipe
# Makefile is a run-time dependency, since it's accessed by the execveat test # Makefile is a run-time dependency, since it's accessed by the execveat test
TEST_FILES := Makefile TEST_FILES := Makefile
...@@ -27,4 +27,9 @@ $(OUTPUT)/execveat.symlink: $(OUTPUT)/execveat ...@@ -27,4 +27,9 @@ $(OUTPUT)/execveat.symlink: $(OUTPUT)/execveat
$(OUTPUT)/execveat.denatured: $(OUTPUT)/execveat $(OUTPUT)/execveat.denatured: $(OUTPUT)/execveat
cp $< $@ cp $< $@
chmod -x $@ chmod -x $@
$(OUTPUT)/load_address_4096: load_address.c
$(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x1000 -pie $< -o $@
$(OUTPUT)/load_address_2097152: load_address.c
$(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x200000 -pie $< -o $@
$(OUTPUT)/load_address_16777216: load_address.c
$(CC) $(CFLAGS) $(LDFLAGS) -Wl,-z,max-page-size=0x1000000 -pie $< -o $@
// SPDX-License-Identifier: GPL-2.0-only
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <link.h>
#include <stdio.h>
#include <stdlib.h>
struct Statistics {
unsigned long long load_address;
unsigned long long alignment;
};
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++) {
if (info->dlpi_phdr[i].p_type != PT_LOAD)
continue;
if (info->dlpi_phdr[i].p_align > stats->alignment)
stats->alignment = info->dlpi_phdr[i].p_align;
}
return 1; // Terminate dl_iterate_phdr.
}
int main(int argc, char **argv)
{
struct Statistics extracted;
unsigned long long misalign;
int ret;
ret = dl_iterate_phdr(ExtractStatistics, &extracted);
if (ret != 1) {
fprintf(stderr, "FAILED\n");
return 1;
}
if (extracted.alignment == 0) {
fprintf(stderr, "No alignment found\n");
return 1;
} else if (extracted.alignment & (extracted.alignment - 1)) {
fprintf(stderr, "Alignment is not a power of 2\n");
return 1;
}
misalign = extracted.load_address & (extracted.alignment - 1);
if (misalign) {
printf("alignment = %llu, load_address = %llu\n",
extracted.alignment, extracted.load_address);
fprintf(stderr, "FAILED\n");
return 1;
}
fprintf(stderr, "PASS\n");
return 0;
}
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