Date: Wed, 13 Jan 2021 15:44:08 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: f9d85a082181 - main - Revert "x86 busdma_bounce: do not make assumptions about alignment of malloc(9) results." Message-ID: <202101131544.10DFi8wo078250@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=f9d85a082181a4eeec4200e42c3ffc1ac85f571c commit f9d85a082181a4eeec4200e42c3ffc1ac85f571c Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2021-01-13 15:40:54 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2021-01-13 15:44:00 +0000 Revert "x86 busdma_bounce: do not make assumptions about alignment of malloc(9) results." This reverts commit 8f54940f019ca586bcfbf189ef9974eeb0a8194a. The free needs to be called on the address returned by malloc, not the realigned address. Noted by: andrew Sponsored by: The FreeBSD Foundation --- sys/x86/x86/busdma_bounce.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/sys/x86/x86/busdma_bounce.c b/sys/x86/x86/busdma_bounce.c index fec6e2144a22..65fbbb7ec1a4 100644 --- a/sys/x86/x86/busdma_bounce.c +++ b/sys/x86/x86/busdma_bounce.c @@ -403,8 +403,6 @@ static int bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags, bus_dmamap_t *mapp) { - uintptr_t ma; - size_t malloc_sz; vm_memattr_t attr; int mflags; @@ -447,20 +445,19 @@ bounce_bus_dmamem_alloc(bus_dma_tag_t dmat, void **vaddr, int flags, * else allocate a block of contiguous pages because one or more of the * constraints is something that only the contig allocator can fulfill. * - * Warn the user if we get it wrong. + * NOTE: The (dmat->common.alignment <= dmat->maxsize) check + * below is just a quick hack. The exact alignment guarantees + * of malloc(9) need to be nailed down, and the code below + * should be rewritten to take that into account. + * + * In the meantime warn the user if malloc gets it wrong. */ if (dmat->common.maxsize <= PAGE_SIZE && + dmat->common.alignment <= dmat->common.maxsize && dmat->common.lowaddr >= ptoa((vm_paddr_t)Maxmem) && attr == VM_MEMATTR_DEFAULT) { - malloc_sz = roundup2(dmat->common.maxsize, - dmat->common.alignment); - ma = (uintptr_t)malloc_domainset(malloc_sz, M_DEVBUF, + *vaddr = malloc_domainset(dmat->common.maxsize, M_DEVBUF, DOMAINSET_PREF(dmat->common.domain), mflags); - if (ma != 0) { - *vaddr = (void *)roundup2(ma, dmat->common.alignment); - } else { - *vaddr = NULL; - } } else if (dmat->common.nsegments >= howmany(dmat->common.maxsize, MIN(dmat->common.maxsegsz, PAGE_SIZE)) &&
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202101131544.10DFi8wo078250>