[14/16] aarch64: inline __libc_mtag_new_tag
Commit Message
This is a common operation when heap tagging is enabled, so inline the
instructions instead of using an extern call.
---
sysdeps/aarch64/Makefile | 1 -
sysdeps/aarch64/__mtag_new_tag.S | 37 --------------------------------
sysdeps/aarch64/libc-mtag.h | 14 +++++++++---
3 files changed, 11 insertions(+), 41 deletions(-)
delete mode 100644 sysdeps/aarch64/__mtag_new_tag.S
@@ -41,7 +41,6 @@ endif
ifeq ($(subdir),misc)
sysdep_headers += sys/ifunc.h
sysdep_routines += __mtag_tag_zero_region \
- __mtag_new_tag \
__mtag_tag_region
endif
deleted file mode 100644
@@ -1,37 +0,0 @@
-/* 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. */
-
-#define ptr x0
-#define xset x1
-
-ENTRY(__libc_mtag_new_tag)
- // Guarantee that the new tag is not the same as now.
- gmi xset, ptr, xzr
- irg ptr, ptr, xset
- ret
-END (__libc_mtag_new_tag)
-#endif /* USE_MTAG */
@@ -52,9 +52,17 @@ __libc_mtag_address_get_tag (void *p)
}
/* Assign a new (random) tag to a pointer P (does not adjust the tag on
- the memory addressed).
- void *__libc_mtag_new_tag (void*) */
-void *__libc_mtag_new_tag (void *);
+ the memory addressed). */
+static __always_inline void *
+__libc_mtag_new_tag (void *p)
+{
+ register void *x0 asm ("x0") = p;
+ register unsigned long x1 asm ("x1");
+ /* Guarantee that the new tag is not the same as now. */
+ asm (".inst 0x9adf1401 /* gmi x1, x0, xzr */\n"
+ ".inst 0x9ac11000 /* irg x0, x0, x1 */" : "+r" (x0), "=r" (x1));
+ return x0;
+}
#endif /* USE_MTAG */