glibc/sysdeps/unix/sysv/linux/dl-mseal.c

52 lines
1.6 KiB
C

/* Memory sealing. Linux version.
Copyright (C) 2025 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 <atomic.h>
#include <dl-mseal.h>
#include <dl-tunables.h>
#include <ldsodefs.h>
#include <libintl.h>
void
_dl_mseal (void *addr, size_t len, const char *object)
{
int r = 0;
bool fail = false;
#if __ASSUME_MSEAL
r = INTERNAL_SYSCALL_CALL (mseal, addr, len, 0);
fail = r != 0;
#else
static int mseal_supported = true;
/* Avoid issuing mseal again if it is not supported by the kernel. */
if (atomic_load_relaxed (&mseal_supported))
{
int r = INTERNAL_SYSCALL_CALL (mseal, addr, len, 0);
if (r == -ENOSYS)
atomic_store_relaxed (&mseal_supported, false);
else
fail = r != 0;
}
#endif
if (fail)
{
static const char errstring[] = N_("\
cannot apply memory sealing");
_dl_signal_error (-r, DSO_FILENAME (object), NULL, errstring);
}
}