Date: Thu, 10 Aug 2023 18:14:03 GMT From: John Baldwin <jhb@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 9795f14ec40a - main - netlink: Align allocations on __max_align_t, not uint64_t. Message-ID: <202308101814.37AIE3gK010376@gitrepo.freebsd.org>
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The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=9795f14ec40acbab93aabedf05d70e0256ce9bf5 commit 9795f14ec40acbab93aabedf05d70e0256ce9bf5 Author: John Baldwin <jhb@FreeBSD.org> AuthorDate: 2023-08-10 18:12:52 +0000 Commit: John Baldwin <jhb@FreeBSD.org> CommitDate: 2023-08-10 18:12:52 +0000 netlink: Align allocations on __max_align_t, not uint64_t. uint64_t is not sufficient alignment for allocators on all platforms. On a CHERI platform pointers require 16 byte alignment, but also if a type contained a uint128_t or long double it would not be aligned correctly either. C11 added max_align_t precisely to provide a portable type for allocators to use. Reviewed by: melifaro Obtained from: CheriBSD Sponsored by: DARPA Differential Revision: https://reviews.freebsd.org/D41301 --- sys/netlink/netlink_message_parser.h | 4 ++-- sys/netlink/netlink_snl.h | 5 +++-- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/sys/netlink/netlink_message_parser.h b/sys/netlink/netlink_message_parser.h index 0934057ac49f..0242177fdd26 100644 --- a/sys/netlink/netlink_message_parser.h +++ b/sys/netlink/netlink_message_parser.h @@ -41,12 +41,12 @@ struct linear_buffer { char *base; /* Base allocated memory pointer */ uint32_t offset; /* Currently used offset */ uint32_t size; /* Total buffer size */ -}; +} __aligned(_Alignof(__max_align_t)); static inline void * lb_alloc(struct linear_buffer *lb, int len) { - len = roundup2(len, sizeof(uint64_t)); + len = roundup2(len, _Alignof(__max_align_t)); if (lb->offset + len > lb->size) return (NULL); void *data = (void *)(lb->base + lb->offset); diff --git a/sys/netlink/netlink_snl.h b/sys/netlink/netlink_snl.h index 0292725bd135..8bb7b076b7b7 100644 --- a/sys/netlink/netlink_snl.h +++ b/sys/netlink/netlink_snl.h @@ -33,6 +33,7 @@ #include <assert.h> #include <errno.h> +#include <stdalign.h> #include <stddef.h> #include <stdbool.h> #include <stdint.h> @@ -74,7 +75,7 @@ struct linear_buffer { uint32_t offset; /* Currently used offset */ uint32_t size; /* Total buffer size */ struct linear_buffer *next; /* Buffer chaining */ -}; +} __aligned(alignof(__max_align_t)); static inline struct linear_buffer * lb_init(uint32_t size) @@ -98,7 +99,7 @@ lb_free(struct linear_buffer *lb) static inline char * lb_allocz(struct linear_buffer *lb, int len) { - len = roundup2(len, sizeof(uint64_t)); + len = roundup2(len, alignof(__max_align_t)); if (lb->offset + len > lb->size) return (NULL); void *data = (void *)(lb->base + lb->offset);
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