tests += \
tst-rseq-tls-range \
tst-rseq-tls-range-4096 \
+ tst-thp-align \
# tests
tests-static += \
tst-rseq-tls-range-4096-static \
# tests-static
modules-names += \
tst-rseq-tls-range-mod \
+ tst-thp-size-mod \
# modules-names
CFLAGS-tst-rseq-tls-range.c += -DMAIN_TLS_ALIGN=4
CFLAGS-tst-rseq-tls-range-4096.c += -DMAIN_TLS_ALIGN=4096
CFLAGS-tst-rseq-tls-range-static.c += -DMAIN_TLS_ALIGN=4
CFLAGS-tst-rseq-tls-range-4096-static.c += -DMAIN_TLS_ALIGN=4096
+LDFLAGS-tst-thp-size-mod.so += -Wl,-z,noseparate-code
$(objpfx)tst-rseq-tls-range.out: $(objpfx)tst-rseq-tls-range-mod.so
$(objpfx)tst-rseq-tls-range-4096.out: $(objpfx)tst-rseq-tls-range-mod.so
$(objpfx)tst-rseq-tls-range-static.out: $(objpfx)tst-rseq-tls-range-mod.so
$(objpfx)tst-rseq-tls-range-4096-static.out: $(objpfx)tst-rseq-tls-range-mod.so
+$(objpfx)tst-thp-align.out: $(objpfx)tst-thp-size-mod.so
tst-rseq-tls-range-static-ENV = LD_LIBRARY_PATH=$(objpfx):$(common-objpfx)
tst-rseq-tls-range-4096-static-ENV = LD_LIBRARY_PATH=$(objpfx):$(common-objpfx)
+tst-thp-align-ENV = GLIBC_TUNABLES=glibc.elf.thp=1
test-internal-extras += tst-nolink-libc
ifeq ($(run-built-tests),yes)
--- /dev/null
+/* Test the THP compatible alignment of PT_LOAD segments.
+
+ Copyright (C) 2026 Free Software Foundation, Inc.
+
+ 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 <fcntl.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <intprops.h>
+#include <inttypes.h>
+#include <support/check.h>
+#include <support/xdlfcn.h>
+#include <support/xstdio.h>
+#include <support/xunistd.h>
+
+#define THP_SIZE_MOD_NAME "tst-thp-size-mod.so"
+#define MAX_THP_PAGESIZE (32 * 1024 * 1024)
+
+enum thp_mode_t
+{
+ thp_mode_always,
+ thp_mode_madvise,
+ thp_mode_never,
+ thp_mode_not_supported
+};
+
+static unsigned long int
+get_thp_size (void)
+{
+ int fd = open ("/sys/kernel/mm/transparent_hugepage/hpage_pmd_size",
+ O_RDONLY, 0);
+ if (fd == -1)
+ return 0;
+
+ char str[INT_BUFSIZE_BOUND (unsigned long int)];
+ ssize_t s = read (fd, str, sizeof (str));
+ close (fd);
+ if (s < 0)
+ return 0;
+
+ unsigned long int r = 0;
+ for (ssize_t i = 0; i < s; i++)
+ {
+ if (str[i] == '\n')
+ break;
+ r *= 10;
+ r += str[i] - '0';
+ }
+ return r;
+}
+
+static enum thp_mode_t
+get_thp_mode (void)
+{
+ int fd = open ("/sys/kernel/mm/transparent_hugepage/enabled", O_RDONLY, 0);
+ if (fd == -1)
+ return thp_mode_not_supported;
+
+ static const char mode_always[] = "[always] madvise never\n";
+ static const char mode_madvise[] = "always [madvise] never\n";
+ static const char mode_never[] = "always madvise [never]\n";
+
+ char str[sizeof(mode_always)];
+ ssize_t s = read (fd, str, sizeof (str));
+ if (s >= sizeof str || s < 0)
+ return thp_mode_not_supported;
+ str[s] = '\0';
+ close (fd);
+
+ if (s == sizeof (mode_always) - 1)
+ {
+ if (strcmp (str, mode_always) == 0)
+ return thp_mode_always;
+ else if (strcmp (str, mode_madvise) == 0)
+ return thp_mode_madvise;
+ else if (strcmp (str, mode_never) == 0)
+ return thp_mode_never;
+ }
+ return thp_mode_not_supported;
+}
+
+static void
+check_align (void)
+{
+ unsigned long int thp_size = get_thp_size ();
+ enum thp_mode_t thp_mode = get_thp_mode ();
+
+ if (thp_size == 0)
+ {
+ FAIL_UNSUPPORTED ("unable to get THP size.\n");
+ return;
+ }
+
+ if (thp_size > MAX_THP_PAGESIZE)
+ {
+ FAIL_UNSUPPORTED ("THP size exceeds MAX_THP_PAGESIZE.\n");
+ return;
+ }
+
+ if (thp_mode != thp_mode_always)
+ {
+ FAIL_UNSUPPORTED ("THP mode is not always.\n");
+ return;
+ }
+
+ FILE *f = xfopen ("/proc/self/maps", "r");
+ char *line = NULL;
+ size_t len;
+
+ while (xgetline (&line, &len, f))
+ {
+ uintptr_t from, to;
+ char *prot = NULL, *path = NULL;
+ int r = sscanf (line, "%" SCNxPTR "-%" SCNxPTR "%ms%*s%*s%*s%ms",
+ &from, &to, &prot, &path);
+
+ TEST_VERIFY (r == 3 || r == 4);
+
+ if (strstr (prot, "x") && strstr (path, THP_SIZE_MOD_NAME))
+ TEST_COMPARE (from % thp_size, 0);
+
+ free (path);
+ }
+
+ free (line);
+ xfclose (f);
+}
+
+static int
+do_test (void)
+{
+ void *dl;
+
+ dl = xdlopen (THP_SIZE_MOD_NAME, RTLD_NOW);
+ check_align ();
+ xdlclose (dl);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
--- /dev/null
+/* A module that provides THP code size for testing.
+
+ Copyright (C) 2026 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/>. */
+
+ .globl thp_size
+thp_size:
+ .space 32 * 1024 * 1024
projects / thirdparty / glibc.git / commitdiff
