Date: Wed, 01 Jul 2026 11:49:36 +0000
From: Brooks Davis <brooks@FreeBSD.org>
To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org
Subject: git: 17602eb3eae9 - main - CHERI: make mem{cpy,move}(9) CHERI compatible
Message-ID: <6a44fed0.1873e.696ad06@gitrepo.freebsd.org>
index | next in thread | raw e-mail
The branch main has been updated by brooks: URL: https://cgit.FreeBSD.org/src/commit/?id=17602eb3eae95a53c973a5ceb4fc3134a770e8d6 commit 17602eb3eae95a53c973a5ceb4fc3134a770e8d6 Author: Brooks Davis <brooks@FreeBSD.org> AuthorDate: 2026-07-01 11:46:55 +0000 Commit: Brooks Davis <brooks@FreeBSD.org> CommitDate: 2026-07-01 11:49:10 +0000 CHERI: make mem{cpy,move}(9) CHERI compatible - Use intptr_t in place of long as the word type in the core copying loop where aligned words a copied. This preserved the provenance of any copied pointers. - When working with the address of src or dst use ptraddr_t rather than uintptr_t. This avoid ambigious provenance in expressions involving multiple addresses. As a minor tweak, rename the function to memmove since that is the interface it implements (overlapping src and dst are permitted) and make memcpy the alias rather than the other way around. Reviewed by: kib, markj Effort: CHERI upstreaming Sponsored by: Innovate UK Differential Revision: https://reviews.freebsd.org/D57965 --- sys/libkern/bcopy.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/sys/libkern/bcopy.c b/sys/libkern/bcopy.c index 8df260809a02..be26443ef884 100644 --- a/sys/libkern/bcopy.c +++ b/sys/libkern/bcopy.c @@ -35,7 +35,9 @@ #include <sys/param.h> #ifdef _KERNEL #include <sys/systm.h> +#include <sys/stddef.h> #else +#include <stddef.h> #include <string.h> #endif @@ -46,7 +48,7 @@ * sizeof(word) MUST BE A POWER OF TWO * SO THAT wmask BELOW IS ALL ONES */ -typedef long word; /* "word" used for optimal copy speed */ +typedef intptr_t word; /* "word" used for optimal copy speed */ #define wsize sizeof(word) #define wmask (wsize - 1) @@ -57,7 +59,7 @@ typedef long word; /* "word" used for optimal copy speed */ * (the portable versions of) bcopy, memcpy, and memmove. */ void * -memcpy(void *dst0, const void *src0, size_t length) +memmove(void *dst0, const void *src0, size_t length) { char *dst; const char *src; @@ -76,18 +78,18 @@ memcpy(void *dst0, const void *src0, size_t length) #define TLOOP(s) if (t) TLOOP1(s) #define TLOOP1(s) do { s; } while (--t) - if ((unsigned long)dst < (unsigned long)src) { + if ((ptraddr_t)dst < (ptraddr_t)src) { /* * Copy forward. */ t = (size_t)src; /* only need low bits */ - if ((t | (uintptr_t)dst) & wmask) { + if ((t | (ptraddr_t)dst) & wmask) { /* * Try to align operands. This cannot be done * unless the low bits match. */ - if ((t ^ (uintptr_t)dst) & wmask || length < wsize) { + if ((t ^ (ptraddr_t)dst) & wmask || length < wsize) { t = length; } else { t = wsize - (t & wmask); @@ -112,10 +114,10 @@ memcpy(void *dst0, const void *src0, size_t length) */ src += length; dst += length; - t = (uintptr_t)src; + t = (size_t)src; - if ((t | (uintptr_t)dst) & wmask) { - if ((t ^ (uintptr_t)dst) & wmask || length <= wsize) { + if ((t | (ptraddr_t)dst) & wmask) { + if ((t ^ (ptraddr_t)dst) & wmask || length <= wsize) { t = length; } else { t &= wmask; @@ -134,4 +136,4 @@ done: return (dst0); } -__strong_reference(memcpy, memmove); +__strong_reference(memmove, memcpy);home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6a44fed0.1873e.696ad06>