diff options
Diffstat (limited to 'sysdeps/aarch64/__mtag_tag_zero_region.S')
| -rw-r--r-- | sysdeps/aarch64/__mtag_tag_zero_region.S | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/sysdeps/aarch64/__mtag_tag_zero_region.S b/sysdeps/aarch64/__mtag_tag_zero_region.S new file mode 100644 index 0000000000..74d398bba5 --- /dev/null +++ b/sysdeps/aarch64/__mtag_tag_zero_region.S @@ -0,0 +1,49 @@ +/* Copyright (C) 2020-2021 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 + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + +#ifdef USE_MTAG + + .arch armv8.5-a + .arch_extension memtag + +/* NB, only supported on variants with 64-bit pointers. */ + +/* FIXME: This is a minimal implementation. We could do much better than + this for large values of COUNT. */ + +#define dstin x0 +#define count x1 +#define dst x2 + +ENTRY(__libc_mtag_tag_zero_region) + + mov dst, dstin +L(loop): + stzg dst, [dst], #16 + subs count, count, 16 + bne L(loop) +#if 0 + /* This is not currently needed, since for now we are only called + to tag memory that is taggable. */ + ldg dstin, [dstin] // Recover the tag created (might be untagged). +#endif + ret +END (__libc_mtag_tag_zero_region) +#endif /* USE_MTAG */ |