diff options
| author | reinoud <reinoud@NetBSD.org> | 2018-08-05 16:51:59 +0000 |
|---|---|---|
| committer | reinoud <reinoud@NetBSD.org> | 2018-08-05 16:51:59 +0000 |
| commit | 4a299273cb7cad27948411275d50ee63f5e7b2e9 (patch) | |
| tree | 78c9bb27974ce2ff3fccd16564b57834aa9a5412 | |
| parent | 08c361d0e4c7ebb90565de6914619a820418bcf3 (diff) | |
To avoid possible collisions between the NetBSD/userland kernel and possible
host kernel memory allocation schemes, allocate two dedicated pages for page
copying and page zeroing.
| -rw-r--r-- | sys/arch/usermode/usermode/pmap.c | 39 |
1 files changed, 20 insertions, 19 deletions
diff --git a/sys/arch/usermode/usermode/pmap.c b/sys/arch/usermode/usermode/pmap.c index 4bd1a310fa8..276ab5a3346 100644 --- a/sys/arch/usermode/usermode/pmap.c +++ b/sys/arch/usermode/usermode/pmap.c @@ -1,4 +1,4 @@ -/* $NetBSD: pmap.c,v 1.112 2018/08/03 11:18:22 reinoud Exp $ */ +/* $NetBSD: pmap.c,v 1.113 2018/08/05 16:51:59 reinoud Exp $ */ /*- * Copyright (c) 2011 Reinoud Zandijk <reinoud@NetBSD.org> @@ -27,7 +27,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.112 2018/08/03 11:18:22 reinoud Exp $"); +__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.113 2018/08/05 16:51:59 reinoud Exp $"); #include "opt_memsize.h" #include "opt_kmempages.h" @@ -101,6 +101,8 @@ static int pm_nentries = 0; static int pm_nl1 = 0; static int pm_l1_size = 0; static uint64_t pm_entries_size = 0; +static void *pm_tmp_p0; +static void *pm_tmp_p1; static struct pool pmap_pool; static struct pool pmap_pventry_pool; @@ -183,6 +185,11 @@ pmap_bootstrap(void) kmem_kvm_end = kmem_k_start - barrier_len; kmem_kvm_start = kmem_kvm_end - KVMSIZE; + /* allow some pmap scratch space */ + pm_tmp_p0 = (void *) (kmem_kvm_start); + pm_tmp_p1 = (void *) (kmem_kvm_start + PAGE_SIZE); + kmem_kvm_start += 2*PAGE_SIZE; + /* claim an area for userland (---/R--/RW-/RWX) */ kmem_user_start = vm_min_addr; kmem_user_end = kmem_kvm_start - barrier_len; @@ -1227,14 +1234,12 @@ pmap_zero_page(paddr_t pa) if (pa & (PAGE_SIZE-1)) panic("%s: unaligned address passed : %p\n", __func__, (void *) pa); - blob = thunk_mmap(NULL, PAGE_SIZE, + blob = thunk_mmap(pm_tmp_p0, PAGE_SIZE, THUNK_PROT_READ | THUNK_PROT_WRITE, - THUNK_MAP_FILE | THUNK_MAP_SHARED, + THUNK_MAP_FILE | THUNK_MAP_FIXED | THUNK_MAP_SHARED, mem_fh, pa); - if (!blob) + if (blob != pm_tmp_p0) panic("%s: couldn't get mapping", __func__); - if (blob < (char *) kmem_k_end) - panic("%s: mmap in illegal memory range", __func__); memset(blob, 0, PAGE_SIZE); @@ -1254,25 +1259,21 @@ pmap_copy_page(paddr_t src_pa, paddr_t dst_pa) thunk_printf_debug("pmap_copy_page: pa src %p, pa dst %p\n", (void *) src_pa, (void *) dst_pa); - /* XXX bug alart: can we allow the kernel to make a decision on this? */ - sblob = thunk_mmap(NULL, PAGE_SIZE, + /* source */ + sblob = thunk_mmap(pm_tmp_p0, PAGE_SIZE, THUNK_PROT_READ, - THUNK_MAP_FILE | THUNK_MAP_SHARED, + THUNK_MAP_FILE | THUNK_MAP_FIXED | THUNK_MAP_SHARED, mem_fh, src_pa); - if (!sblob) + if (sblob != pm_tmp_p0) panic("%s: couldn't get src mapping", __func__); - if (sblob < (char *) kmem_k_end) - panic("%s: mmap in illegal memory range", __func__); - /* XXX bug alart: can we allow the kernel to make a decision on this? */ - dblob = thunk_mmap(NULL, PAGE_SIZE, + /* destination */ + dblob = thunk_mmap(pm_tmp_p1, PAGE_SIZE, THUNK_PROT_READ | THUNK_PROT_WRITE, - THUNK_MAP_FILE | THUNK_MAP_SHARED, + THUNK_MAP_FILE | THUNK_MAP_FIXED | THUNK_MAP_SHARED, mem_fh, dst_pa); - if (!dblob) + if (dblob != pm_tmp_p1) panic("%s: couldn't get dst mapping", __func__); - if (dblob < (char *) kmem_k_end) - panic("%s: mmap in illegal memory range", __func__); memcpy(dblob, sblob, PAGE_SIZE); |
