glibc/elf/tst-tunables.c
Adhemerval Zanella 2a969b53c0 elf: Do not duplicate the GLIBC_TUNABLES string
The tunable parsing duplicates the tunable environment variable so it
null-terminates each one since it simplifies the later parsing. It has
the drawback of adding another point of failure (__minimal_malloc
failing), and the memory copy requires tuning the compiler to avoid mem
operations calls.

The parsing now tracks the tunable start and its size. The
dl-tunable-parse.h adds helper functions to help parsing, like a strcmp
that also checks for size and an iterator for suboptions that are
comma-separated (used on hwcap parsing by x86, powerpc, and s390x).

Since the environment variable is allocated on the stack by the kernel,
it is safe to keep the references to the suboptions for later parsing
of string tunables (as done by set_hwcaps by multiple architectures).

Checked on x86_64-linux-gnu, powerpc64le-linux-gnu, and
aarch64-linux-gnu.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2023-12-19 13:25:45 -03:00

322 lines
6.6 KiB
C

/* Check GLIBC_TUNABLES parsing.
Copyright (C) 2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <array_length.h>
#include <dl-tunables.h>
#include <getopt.h>
#include <intprops.h>
#include <stdint.h>
#include <stdlib.h>
#include <support/capture_subprocess.h>
#include <support/check.h>
static int restart;
#define CMDLINE_OPTIONS \
{ "restart", no_argument, &restart, 1 },
static const struct test_t
{
const char *name;
const char *value;
int32_t expected_malloc_check;
size_t expected_mmap_threshold;
int32_t expected_perturb;
} tests[] =
{
/* Expected tunable format. */
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2",
2,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096",
2,
4096,
0,
},
/* Empty tunable are ignored. */
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2::glibc.malloc.mmap_threshold=4096",
2,
4096,
0,
},
/* As well empty values. */
{
"GLIBC_TUNABLES",
"glibc.malloc.check=:glibc.malloc.mmap_threshold=4096",
0,
4096,
0,
},
/* Tunable are processed from left to right, so last one is the one set. */
{
"GLIBC_TUNABLES",
"glibc.malloc.check=1:glibc.malloc.check=2",
2,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=1:glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096",
2,
4096,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096:glibc.malloc.check=1",
1,
4096,
0,
},
/* 0x800 is larger than tunable maxval (0xff), so the tunable is unchanged. */
{
"GLIBC_TUNABLES",
"glibc.malloc.perturb=0x800",
0,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.perturb=0x55",
0,
0,
0x55,
},
/* Out of range values are just ignored. */
{
"GLIBC_TUNABLES",
"glibc.malloc.perturb=0x800:glibc.malloc.mmap_threshold=4096",
0,
4096,
0,
},
/* Invalid keys are ignored. */
{
"GLIBC_TUNABLES",
":glibc.malloc.garbage=2:glibc.malloc.check=1",
1,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.perturb=0x800:not_valid.malloc.check=2:glibc.malloc.mmap_threshold=4096",
0,
4096,
0,
},
{
"GLIBC_TUNABLES",
"glibc.not_valid.check=2:glibc.malloc.mmap_threshold=4096",
0,
4096,
0,
},
{
"GLIBC_TUNABLES",
"not_valid.malloc.check=2:glibc.malloc.mmap_threshold=4096",
0,
4096,
0,
},
/* Invalid subkeys are ignored. */
{
"GLIBC_TUNABLES",
"glibc.malloc.garbage=2:glibc.maoc.mmap_threshold=4096:glibc.malloc.check=2",
2,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=4:glibc.malloc.garbage=2:glibc.maoc.mmap_threshold=4096",
0,
0,
0,
},
{
"GLIBC_TUNABLES",
"not_valid.malloc.check=2",
0,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.not_valid.check=2",
0,
0,
0,
},
/* An ill-formatted tunable in the for key=key=value will considere the
value as 'key=value' (which can not be parsed as an integer). */
{
"GLIBC_TUNABLES",
"glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096",
0,
0,
0,
},
/* Ill-formatted tunables string is not parsed. */
{
"GLIBC_TUNABLES",
"glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096:glibc.malloc.check=2",
0,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2=2",
0,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2=2:glibc.malloc.mmap_threshold=4096",
0,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2=2:glibc.malloc.check=2",
0,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096=4096",
0,
0,
0,
},
{
"GLIBC_TUNABLES",
"glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096=4096",
0,
0,
0,
},
/* Also check some tunable aliases. */
{
"MALLOC_CHECK_",
"2",
2,
0,
0,
},
{
"MALLOC_MMAP_THRESHOLD_",
"4096",
0,
4096,
0,
},
{
"MALLOC_PERTURB_",
"0x55",
0,
0,
0x55,
},
/* 0x800 is larger than tunable maxval (0xff), so the tunable is unchanged. */
{
"MALLOC_PERTURB_",
"0x800",
0,
0,
0,
},
};
static int
handle_restart (int i)
{
TEST_COMPARE (tests[i].expected_malloc_check,
TUNABLE_GET_FULL (glibc, malloc, check, int32_t, NULL));
TEST_COMPARE (tests[i].expected_mmap_threshold,
TUNABLE_GET_FULL (glibc, malloc, mmap_threshold, size_t, NULL));
TEST_COMPARE (tests[i].expected_perturb,
TUNABLE_GET_FULL (glibc, malloc, perturb, int32_t, NULL));
return 0;
}
static int
do_test (int argc, char *argv[])
{
/* We must have either:
- One our fource parameters left if called initially:
+ path to ld.so optional
+ "--library-path" optional
+ the library path optional
+ the application name
+ the test to check */
TEST_VERIFY_EXIT (argc == 2 || argc == 5);
if (restart)
return handle_restart (atoi (argv[1]));
char nteststr[INT_BUFSIZE_BOUND (int)];
char *spargv[10];
{
int i = 0;
for (; i < argc - 1; i++)
spargv[i] = argv[i + 1];
spargv[i++] = (char *) "--direct";
spargv[i++] = (char *) "--restart";
spargv[i++] = nteststr;
spargv[i] = NULL;
}
for (int i = 0; i < array_length (tests); i++)
{
snprintf (nteststr, sizeof nteststr, "%d", i);
printf ("[%d] Spawned test for %s=%s\n",
i,
tests[i].name,
tests[i].value);
setenv (tests[i].name, tests[i].value, 1);
struct support_capture_subprocess result
= support_capture_subprogram (spargv[0], spargv);
support_capture_subprocess_check (&result, "tst-tunables", 0,
sc_allow_stderr);
support_capture_subprocess_free (&result);
unsetenv (tests[i].name);
}
return 0;
}
#define TEST_FUNCTION_ARGV do_test
#include <support/test-driver.c>