| 1 | /* libc-internal interface for tagged (colored) memory support. |
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| 2 | Copyright (C) 2020-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <http://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #ifndef _GENERIC_LIBC_MTAG_H |
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| 20 | #define _GENERIC_LIBC_MTAG_H 1 |
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| 21 | |
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| 22 | /* Generic bindings for systems that do not support memory tagging. */ |
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| 23 | |
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| 24 | /* Used to ensure additional alignment when objects need to have distinct |
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| 25 | tags. */ |
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| 26 | #define __MTAG_GRANULE_SIZE 1 |
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| 27 | |
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| 28 | /* Non-zero if memory obtained via morecore (sbrk) is not tagged. */ |
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| 29 | #define __MTAG_SBRK_UNTAGGED 0 |
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| 30 | |
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| 31 | /* Extra flags to pass to mmap() to request a tagged region of memory. */ |
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| 32 | #define __MTAG_MMAP_FLAGS 0 |
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| 33 | |
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| 34 | /* Memory tagging target hooks are only called when memory tagging is |
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| 35 | enabled at runtime. The generic definitions here must not be used. */ |
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| 36 | void __libc_mtag_link_error (void); |
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| 37 | |
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| 38 | /* Set the tags for a region of memory, which must have size and alignment |
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| 39 | that are multiples of __MTAG_GRANULE_SIZE. Size cannot be zero. */ |
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| 40 | static inline void * |
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| 41 | __libc_mtag_tag_region (void *p, size_t n) |
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| 42 | { |
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| 43 | __libc_mtag_link_error (); |
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| 44 | return p; |
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| 45 | } |
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| 46 | |
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| 47 | /* Optimized equivalent to __libc_mtag_tag_region followed by memset to 0. */ |
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| 48 | static inline void * |
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| 49 | __libc_mtag_tag_zero_region (void *p, size_t n) |
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| 50 | { |
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| 51 | __libc_mtag_link_error (); |
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| 52 | return memset (s: p, c: 0, n: n); |
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| 53 | } |
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| 54 | |
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| 55 | /* Convert address P to a pointer that is tagged correctly for that |
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| 56 | location. */ |
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| 57 | static inline void * |
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| 58 | __libc_mtag_address_get_tag (void *p) |
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| 59 | { |
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| 60 | __libc_mtag_link_error (); |
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| 61 | return p; |
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| 62 | } |
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| 63 | |
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| 64 | /* Assign a new (random) tag to a pointer P (does not adjust the tag on |
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| 65 | the memory addressed). */ |
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| 66 | static inline void * |
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| 67 | __libc_mtag_new_tag (void *p) |
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| 68 | { |
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| 69 | __libc_mtag_link_error (); |
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| 70 | return p; |
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| 71 | } |
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| 72 | |
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| 73 | #endif /* _GENERIC_LIBC_MTAG_H */ |
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| 74 | |
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