diff options
| -rw-r--r-- | sys/kern/kern_exec.c | 24 | ||||
| -rw-r--r-- | sys/vm/vm_map.c | 94 | ||||
| -rw-r--r-- | sys/vm/vm_map.h | 2 | ||||
| -rw-r--r-- | sys/vm/vm_mmap.c | 4 |
4 files changed, 68 insertions, 56 deletions
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c index 5b0d44f..4dfb9a1 100644 --- a/sys/kern/kern_exec.c +++ b/sys/kern/kern_exec.c @@ -835,8 +835,6 @@ exec_new_vmspace(imgp, sv) GIANT_REQUIRED; - stack_addr = sv->sv_usrstack - maxssiz; - imgp->vmspace_destroyed = 1; EVENTHANDLER_INVOKE(process_exec, p); @@ -871,24 +869,20 @@ exec_new_vmspace(imgp, sv) } /* Allocate a new stack */ + stack_addr = sv->sv_usrstack - maxssiz; error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz, - sv->sv_stackprot, VM_PROT_ALL, 0); + sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN); if (error) return (error); #ifdef __ia64__ - { - /* - * Allocate backing store. We really need something - * similar to vm_map_stack which can allow the backing - * store to grow upwards. This will do for now. - */ - vm_offset_t bsaddr; - bsaddr = p->p_sysent->sv_usrstack - 2 * maxssiz; - error = vm_map_find(map, 0, 0, &bsaddr, - regstkpages * PAGE_SIZE, 0, VM_PROT_ALL, VM_PROT_ALL, 0); - FIRST_THREAD_IN_PROC(p)->td_md.md_bspstore = bsaddr; - } + /* Allocate a new register stack */ + stack_addr = sv->sv_usrstack - 2 * maxssiz; + error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz, + sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_UP); + if (error) + return (error); + FIRST_THREAD_IN_PROC(p)->td_md.md_bspstore = stack_addr; #endif /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c index c299e92..4492f9b 100644 --- a/sys/vm/vm_map.c +++ b/sys/vm/vm_map.c @@ -2500,22 +2500,28 @@ vmspace_fork(struct vmspace *vm1) } int -vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, - vm_prot_t prot, vm_prot_t max, int cow) +vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, + vm_prot_t prot, vm_prot_t max, int cow) { - vm_map_entry_t prev_entry; - vm_map_entry_t new_stack_entry; - vm_size_t init_ssize; - int rv; + vm_map_entry_t new_entry, prev_entry; + vm_offset_t bot, top; + vm_size_t init_ssize; + int orient, rv; - if (addrbos < vm_map_min(map)) - return (KERN_NO_SPACE); - if (addrbos > map->max_offset) + /* + * The stack orientation is piggybacked with the cow argument. + * Extract it into orient and mask the cow argument so that we + * don't pass it around further. + * NOTE: We explicitly allow bi-directional stacks. + */ + orient = cow & (MAP_STACK_GROWS_DOWN|MAP_STACK_GROWS_UP); + cow &= ~orient; + KASSERT(orient != 0, ("No stack grow direction")); + + if (addrbos < vm_map_min(map) || addrbos > map->max_offset) return (KERN_NO_SPACE); - if (max_ssize < sgrowsiz) - init_ssize = max_ssize; - else - init_ssize = sgrowsiz; + + init_ssize = (max_ssize < sgrowsiz) ? max_ssize : sgrowsiz; vm_map_lock(map); @@ -2532,13 +2538,14 @@ vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, return (KERN_NO_SPACE); } - /* If we can't accomodate max_ssize in the current mapping, - * no go. However, we need to be aware that subsequent user - * mappings might map into the space we have reserved for - * stack, and currently this space is not protected. - * - * Hopefully we will at least detect this condition - * when we try to grow the stack. + /* + * If we can't accomodate max_ssize in the current mapping, no go. + * However, we need to be aware that subsequent user mappings might + * map into the space we have reserved for stack, and currently this + * space is not protected. + * + * Hopefully we will at least detect this condition when we try to + * grow the stack. */ if ((prev_entry->next != &map->header) && (prev_entry->next->start < addrbos + max_ssize)) { @@ -2546,29 +2553,38 @@ vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize, return (KERN_NO_SPACE); } - /* We initially map a stack of only init_ssize. We will - * grow as needed later. Since this is to be a grow - * down stack, we map at the top of the range. + /* + * We initially map a stack of only init_ssize. We will grow as + * needed later. Depending on the orientation of the stack (i.e. + * the grow direction) we either map at the top of the range, the + * bottom of the range or in the middle. * - * Note: we would normally expect prot and max to be - * VM_PROT_ALL, and cow to be 0. Possibly we should - * eliminate these as input parameters, and just - * pass these values here in the insert call. + * Note: we would normally expect prot and max to be VM_PROT_ALL, + * and cow to be 0. Possibly we should eliminate these as input + * parameters, and just pass these values here in the insert call. */ - rv = vm_map_insert(map, NULL, 0, addrbos + max_ssize - init_ssize, - addrbos + max_ssize, prot, max, cow); + if (orient == MAP_STACK_GROWS_DOWN) + bot = addrbos + max_ssize - init_ssize; + else if (orient == MAP_STACK_GROWS_UP) + bot = addrbos; + else + bot = round_page(addrbos + max_ssize/2 - init_ssize/2); + top = bot + init_ssize; + rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow); - /* Now set the avail_ssize amount */ - if (rv == KERN_SUCCESS){ + /* Now set the avail_ssize amount. */ + if (rv == KERN_SUCCESS) { if (prev_entry != &map->header) - vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize); - new_stack_entry = prev_entry->next; - if (new_stack_entry->end != addrbos + max_ssize || - new_stack_entry->start != addrbos + max_ssize - init_ssize) - panic ("Bad entry start/end for new stack entry"); + vm_map_clip_end(map, prev_entry, bot); + new_entry = prev_entry->next; + if (new_entry->end != top || new_entry->start != bot) + panic("Bad entry start/end for new stack entry"); - new_stack_entry->avail_ssize = max_ssize - init_ssize; - new_stack_entry->eflags |= MAP_ENTRY_GROWS_DOWN; + new_entry->avail_ssize = max_ssize - init_ssize; + if (orient & MAP_STACK_GROWS_DOWN) + new_entry->eflags |= MAP_ENTRY_GROWS_DOWN; + if (orient & MAP_STACK_GROWS_UP) + new_entry->eflags |= MAP_ENTRY_GROWS_UP; } vm_map_unlock(map); @@ -2648,7 +2664,7 @@ Retry: KASSERT(addr > stack_entry->end, ("foo")); end = (next_entry != &map->header) ? next_entry->start : stack_entry->end + stack_entry->avail_ssize; - grow_amount = roundup(addr - stack_entry->end, PAGE_SIZE); + grow_amount = roundup(addr + 1 - stack_entry->end, PAGE_SIZE); max_grow = end - stack_entry->end; } diff --git a/sys/vm/vm_map.h b/sys/vm/vm_map.h index a720298..d1aff1f 100644 --- a/sys/vm/vm_map.h +++ b/sys/vm/vm_map.h @@ -302,6 +302,8 @@ long vmspace_resident_count(struct vmspace *vmspace); #define MAP_DISABLE_SYNCER 0x0020 #define MAP_DISABLE_COREDUMP 0x0100 #define MAP_PREFAULT_MADVISE 0x0200 /* from (user) madvise request */ +#define MAP_STACK_GROWS_DOWN 0x1000 +#define MAP_STACK_GROWS_UP 0x2000 /* * vm_fault option flags diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c index 933e580..1bda10e 100644 --- a/sys/vm/vm_mmap.c +++ b/sys/vm/vm_mmap.c @@ -1320,8 +1320,8 @@ vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot, *addr = pmap_addr_hint(object, *addr, size); if (flags & MAP_STACK) - rv = vm_map_stack (map, *addr, size, prot, - maxprot, docow); + rv = vm_map_stack(map, *addr, size, prot, maxprot, + docow | MAP_STACK_GROWS_DOWN); else rv = vm_map_find(map, object, foff, addr, size, fitit, prot, maxprot, docow); |
