Date: Tue, 12 May 2026 16:55:27 +0000 From: Andrew Turner <andrew@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Cc: Sarah Walker <sarah.walker2@arm.com> Subject: git: cd2512eaab5c - main - vm: Add flags for unprotected allocations Message-ID: <6a035b7f.3e1ba.1c3bccb@gitrepo.freebsd.org>
index | next in thread | raw e-mail
The branch main has been updated by andrew: URL: https://cgit.FreeBSD.org/src/commit/?id=cd2512eaab5cd402a0177a8078b9234b215b39bd commit cd2512eaab5cd402a0177a8078b9234b215b39bd Author: Sarah Walker <sarah.walker2@arm.com> AuthorDate: 2026-05-12 12:16:00 +0000 Commit: Andrew Turner <andrew@FreeBSD.org> CommitDate: 2026-05-12 16:54:40 +0000 vm: Add flags for unprotected allocations Unprotected allocations are intended to be accessible outside of the current VM on systems such as Arm CCA. Reviewed by: markj Sponsored by: Arm Ltd Differential Revision: https://reviews.freebsd.org/D56518 --- sys/sys/malloc.h | 1 + sys/vm/pmap.h | 1 + sys/vm/vm_kern.c | 23 ++++++++++++++++++++--- 3 files changed, 22 insertions(+), 3 deletions(-) diff --git a/sys/sys/malloc.h b/sys/sys/malloc.h index 9b281da4b4d4..68dffb395534 100644 --- a/sys/sys/malloc.h +++ b/sys/sys/malloc.h @@ -61,6 +61,7 @@ #define M_EXEC 0x4000 /* allocate executable space */ #define M_NEXTFIT 0x8000 /* only for vmem, follow cursor */ #define M_NEVERFREED 0x10000 /* chunk will never get freed */ +#define M_UNPROTECTED 0x20000 /* alloc out of unprotected memory */ #define M_VERSION 2024073001 diff --git a/sys/vm/pmap.h b/sys/vm/pmap.h index e6dcd47d32f6..868bb787dc98 100644 --- a/sys/vm/pmap.h +++ b/sys/vm/pmap.h @@ -104,6 +104,7 @@ extern vm_offset_t kernel_vm_end; #define PMAP_ENTER_NOSLEEP 0x00000100 #define PMAP_ENTER_WIRED 0x00000200 #define PMAP_ENTER_LARGEPAGE 0x00000400 +#define PMAP_ENTER_UNPROTECTED 0x00000800 #define PMAP_ENTER_RESERVED 0xFF000000 /* diff --git a/sys/vm/vm_kern.c b/sys/vm/vm_kern.c index fc5d0de424bd..41ba07373976 100644 --- a/sys/vm/vm_kern.c +++ b/sys/vm/vm_kern.c @@ -270,6 +270,7 @@ kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, vm_size_t asize; int pflags; vm_prot_t prot; + u_int pmap_enter_flags; object = kernel_object; asize = round_page(size); @@ -279,6 +280,11 @@ kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, offset = addr - VM_MIN_KERNEL_ADDRESS; pflags = malloc2vm_flags(flags) | VM_ALLOC_WIRED; prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; + + pmap_enter_flags = prot | PMAP_ENTER_WIRED; + if ((flags & M_UNPROTECTED) != 0) + pmap_enter_flags |= PMAP_ENTER_UNPROTECTED; + VM_OBJECT_WLOCK(object); for (i = 0; i < asize; i += PAGE_SIZE) { m = kmem_alloc_contig_pages(object, atop(offset + i), @@ -296,7 +302,7 @@ kmem_alloc_attr_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, pmap_zero_page(m); vm_page_valid(m); pmap_enter(kernel_pmap, addr + i, m, prot, - prot | PMAP_ENTER_WIRED, 0); + pmap_enter_flags, 0); } VM_OBJECT_WUNLOCK(object); kmem_alloc_san(addr, size, asize, flags); @@ -363,6 +369,7 @@ kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, vm_size_t asize; u_long npages; int pflags; + u_int pmap_enter_flags; object = kernel_object; asize = round_page(size); @@ -385,12 +392,17 @@ kmem_alloc_contig_domain(int domain, vm_size_t size, int flags, vm_paddr_t low, vm_page_domain(m), domain)); end_m = m + npages; tmp = addr; + + pmap_enter_flags = VM_PROT_RW | PMAP_ENTER_WIRED; + if ((flags & M_UNPROTECTED) != 0) + pmap_enter_flags |= PMAP_ENTER_UNPROTECTED; + for (; m < end_m; m++) { if ((flags & M_ZERO) && (m->flags & PG_ZERO) == 0) pmap_zero_page(m); vm_page_valid(m); pmap_enter(kernel_pmap, tmp, m, VM_PROT_RW, - VM_PROT_RW | PMAP_ENTER_WIRED, 0); + pmap_enter_flags, 0); tmp += PAGE_SIZE; } VM_OBJECT_WUNLOCK(object); @@ -549,6 +561,7 @@ kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, vm_page_t m; vm_prot_t prot; int pflags; + u_int pmap_enter_flags; KASSERT(object == kernel_object, ("kmem_back_domain: only supports kernel object.")); @@ -560,6 +573,10 @@ kmem_back_domain(int domain, vm_object_t object, vm_offset_t addr, pflags |= VM_ALLOC_WAITFAIL; prot = (flags & M_EXEC) != 0 ? VM_PROT_ALL : VM_PROT_RW; + pmap_enter_flags = prot | PMAP_ENTER_WIRED; + if ((flags & M_UNPROTECTED) != 0) + pmap_enter_flags |= PMAP_ENTER_UNPROTECTED; + i = 0; vm_page_iter_init(&pages, object); VM_OBJECT_WLOCK(object); @@ -589,7 +606,7 @@ retry: ("kmem_malloc: page %p is managed", m)); vm_page_valid(m); pmap_enter(kernel_pmap, addr + i, m, prot, - prot | PMAP_ENTER_WIRED, 0); + pmap_enter_flags, 0); if (__predict_false((prot & VM_PROT_EXECUTE) != 0)) m->oflags |= VPO_KMEM_EXEC; }home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6a035b7f.3e1ba.1c3bccb>