[PATCH v4 6/6] aarch64: Add aarch64-specific files for memory tagging support
Richard Earnshaw
Richard.Earnshaw@foss.arm.com
Mon Dec 21 12:50:03 GMT 2020
On 21/12/2020 12:44, Szabolcs Nagy via Libc-alpha wrote:
> The 12/18/2020 19:29, Richard Earnshaw wrote:
>> This final patch provides the architecture-specific implementation of
>> the memory-tagging support hooks for aarch64.
>
> i see some gnu style issues in libc-mtag.h otherwise it looks ok.
>
> Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
>
>> ---
>> sysdeps/aarch64/Makefile | 5 +++
>> sysdeps/aarch64/__mtag_address_get_tag.S | 32 +++++++++++++
>> sysdeps/aarch64/__mtag_memset_tag.S | 53 ++++++++++++++++++++++
>> sysdeps/aarch64/__mtag_new_tag.S | 37 +++++++++++++++
>> sysdeps/aarch64/__mtag_tag_region.S | 51 +++++++++++++++++++++
>> sysdeps/aarch64/libc-mtag.h | 57 ++++++++++++++++++++++++
>> 6 files changed, 235 insertions(+)
>> create mode 100644 sysdeps/aarch64/__mtag_address_get_tag.S
>> create mode 100644 sysdeps/aarch64/__mtag_memset_tag.S
>> create mode 100644 sysdeps/aarch64/__mtag_new_tag.S
>> create mode 100644 sysdeps/aarch64/__mtag_tag_region.S
>> create mode 100644 sysdeps/aarch64/libc-mtag.h
>>
>
>> diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile
>> index d8e06d27b2..d3ab37a40a 100644
>> --- a/sysdeps/aarch64/Makefile
>> +++ b/sysdeps/aarch64/Makefile
>> @@ -40,4 +40,9 @@ endif
>>
>> ifeq ($(subdir),misc)
>> sysdep_headers += sys/ifunc.h
>> +sysdep_routines += __mtag_address_get_tag \
>> + __mtag_memset_tag \
>> + __mtag_new_tag \
>> + __mtag_tag_region
>> +
>> endif
>> diff --git a/sysdeps/aarch64/__mtag_address_get_tag.S b/sysdeps/aarch64/__mtag_address_get_tag.S
>> new file mode 100644
>> index 0000000000..4ffe884c95
>> --- /dev/null
>> +++ b/sysdeps/aarch64/__mtag_address_get_tag.S
>> @@ -0,0 +1,32 @@
>> +/* Copyright (C) 2020 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
>> +#define ptr x0
>> +
>> + .arch armv8.5-a
>> + .arch_extension memtag
>> +
>> +ENTRY (__libc_mtag_address_get_tag)
>> +
>> + ldg ptr, [ptr]
>> + ret
>> +END (__libc_mtag_address_get_tag)
>> +#endif /* USE_MTAG */
>> diff --git a/sysdeps/aarch64/__mtag_memset_tag.S b/sysdeps/aarch64/__mtag_memset_tag.S
>> new file mode 100644
>> index 0000000000..6f78d91b79
>> --- /dev/null
>> +++ b/sysdeps/aarch64/__mtag_memset_tag.S
>> @@ -0,0 +1,53 @@
>> +/* Copyright (C) 2020 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
>> +
>> +/* Use the same register names and assignments as memset. */
>> +#include "memset-reg.h"
>> +
>> + .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. */
>> +
>> +ENTRY(__libc_mtag_memset_with_tag)
>> +
>> + and valw, valw, 255
>> + orr valw, valw, valw, lsl 8
>> + orr valw, valw, valw, lsl 16
>> + orr val, val, val, lsl 32
>> + mov dst, dstin
>> +
>> +L(loop):
>> + stgp val, val, [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_memset_with_tag)
>> +#endif /* USE_MTAG */
>> diff --git a/sysdeps/aarch64/__mtag_new_tag.S b/sysdeps/aarch64/__mtag_new_tag.S
>> new file mode 100644
>> index 0000000000..663e3a484f
>> --- /dev/null
>> +++ b/sysdeps/aarch64/__mtag_new_tag.S
>> @@ -0,0 +1,37 @@
>> +/* Copyright (C) 2020 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 */
>> diff --git a/sysdeps/aarch64/__mtag_tag_region.S b/sysdeps/aarch64/__mtag_tag_region.S
>> new file mode 100644
>> index 0000000000..7af4f0fa0a
>> --- /dev/null
>> +++ b/sysdeps/aarch64/__mtag_tag_region.S
>> @@ -0,0 +1,51 @@
>> +/* Copyright (C) 2020 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
>> +
>> +/* Use the same register names and assignments as memset. */
>> +
>> + .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 better than
>> + this for larger values of COUNT. */
>> +
>> +#define dstin x0
>> +#define count x1
>> +#define dst x2
>> +
>> +ENTRY_ALIGN(__libc_mtag_tag_region, 6)
>> +
>> + mov dst, dstin
>> +L(loop):
>> + stg 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_region)
>> +#endif /* USE_MTAG */
>> diff --git a/sysdeps/aarch64/libc-mtag.h b/sysdeps/aarch64/libc-mtag.h
>> new file mode 100644
>> index 0000000000..0e9b63e95b
>> --- /dev/null
>> +++ b/sysdeps/aarch64/libc-mtag.h
>> @@ -0,0 +1,57 @@
>> +/* libc-internal interface for tagged (colored) memory support.
>> + Copyright (C) 2020 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/>. */
>> +
>> +#ifndef _AARCH64_LIBC_MTAG_H
>> +#define _AARCH64_LIBC_MTAG_H 1
>> +
>> +#ifndef USE_MTAG
>> +/* Generic bindings for systems that do not support memory tagging. */
>> +#include_next "libc-mtag.h"
>> +#else
>> +
>> +/* Used to ensure additional alignment when objects need to have distinct
>> + tags. */
>> +#define __MTAG_GRANULE_SIZE 16
>> +
>> +/* Non-zero if memory obtained via morecore (sbrk) is not tagged. */
>> +#define __MTAG_SBRK_UNTAGGED 1
>> +
>> +/* Extra flags to pass to mmap to get tagged pages. */
>> +#define __MTAG_MMAP_FLAGS PROT_MTE
>> +
>> +/* Set the tags for a region of memory, which must have size and alignment
>> + that are multiples of __MTAG_GRANULE_SIZE. Size cannot be zero.
>> + void *__libc_mtag_tag_region (const void *, size_t) */
>> +void *__libc_mtag_tag_region (void *, size_t);
>> +
>> +/* Optimized equivalent to __libc_mtag_tag_region followed by memset. */
>> +void *__libc_mtag_memset_with_tag(void *, int, size_t);
>> +
>> +/* Convert address P to a pointer that is tagged correctly for that
>> + location.
>> + void *__libc_mtag_address_get_tag (void*) */
>> +void *__libc_mtag_address_get_tag(void *);
>> +
>> +/* 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 *);
>
> missing spaces before (
Oops, fixed.
>
>> +
>> +#endif /* USE_MTAG */
>> +
>> +#endif /* _AARCH64_LIBC_MTAG_H */
R.
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