diff options
Diffstat (limited to 'sys/vm')
| -rw-r--r-- | sys/vm/vm_map.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c index 7b0656b..3dd4d01 100644 --- a/sys/vm/vm_map.c +++ b/sys/vm/vm_map.c @@ -30,9 +30,51 @@ #include <sys/param.h> #include <sys/types.h> #include <sys/errno.h> +#include <sys/proc.h> +#include <sys/syscall.h> +#include <sys/syslog.h> +#include <sys/mman.h> +#include <vm/dynalloc.h> +#include <vm/vm_pager.h> #include <vm/pmap.h> #include <vm/map.h> #include <vm/vm.h> +#include <assert.h> + +#define pr_trace(fmt, ...) kprintf("vm_map: " fmt, ##__VA_ARGS__) +#define pr_error(...) pr_trace(__VA_ARGS__) + +RBT_GENERATE(lgdr_entries, mmap_entry, hd, mmap_entrycmp); + +static inline void +mmap_dbg(void *addr, size_t len, int prot, int flags, int fildes, off_t off) +{ + pr_trace("addr=%p, len=%d, prot=%x\nflags=%x, fildes=%d, off=%d\n", + addr, len, prot, flags, fildes, off); +} + +/* + * Add a memory mapping to the mmap ledger. + * + * @td: Process to add mapping to. + * @ep: Memory map entry to add. + * @len: Length of memory mapping in bytes. + */ +static inline int +mmap_add(struct proc *td, struct mmap_entry *ep) +{ + struct mmap_entry *tmp; + struct mmap_lgdr *lp = td->mlgdr; + + if (ep->size == 0) { + return -EINVAL; + } + + tmp = RBT_INSERT(lgdr_entries, &lp->hd, ep); + __assert(tmp == NULL); + lp->nbytes += ep->size; + return 0; +} /* * Create/destroy virtual memory mappings in a specific @@ -85,6 +127,123 @@ vm_map_modify(struct vas vas, vaddr_t va, paddr_t pa, vm_prot_t prot, bool unmap } /* + * Create a physical to virtual memory mapping. + * + * @addr: Virtual address to map (NULL to be any). + * @len: The amount of bytes to map (must be page aligned) + * @prot: Protection flags (PROT_*) + * @fildes: File descriptor. + * @off: Offset. + * + * TODO: Fields to use: `fildes' and `off' + * XXX: Must be called after pid 1 is up and running to avoid + * crashes. + */ +void * +mmap_at(void *addr, size_t len, int prot, int flags, int fildes, off_t off) +{ + struct vm_object *map_obj; + struct vm_page *pg; + struct mmap_entry *ep; + struct proc *td; + struct vas vas; + int error, npgs; + paddr_t pa; + vaddr_t va; + size_t misalign; + + misalign = len & (DEFAULT_PAGESIZE - 1); + len = ALIGN_UP(len + misalign, DEFAULT_PAGESIZE); + npgs = len / DEFAULT_PAGESIZE; + + if (addr == NULL) { + pr_error("mmap: NULL addr not supported\n"); + return NULL; + } + + /* Validate flags */ + if (ISSET(flags, MAP_FIXED | MAP_SHARED)) { + pr_error("mmap: fixed/shared mappings not yet supported\n"); + mmap_dbg(addr, len, prot, flags, fildes, off); + return NULL; + } + map_obj = dynalloc(sizeof(*map_obj)); + if (map_obj == NULL) { + kprintf("mmap: failed to allocate map object\n"); + return NULL; + } + error = vm_obj_init(map_obj, &vm_anonops, 1); + if (error < 0) { + kprintf("mmap: vm_obj_init() returned %d\n", error); + kprintf("mmap: failed to init object\n"); + return NULL; + } + + /* XXX: Assuming private */ + vas = pmap_read_vas(); + va = ALIGN_DOWN((vaddr_t)addr, DEFAULT_PAGESIZE); + + for (int i = 0; i < npgs; ++i) { + pg = vm_pagealloc(map_obj, PALLOC_ZERO); + + if (pg == NULL) { + /* TODO */ + pr_error("mmap: failed to allocate page %d\n"); + return NULL; + } + + pa = pg->phys_addr; + error = vm_map(vas, va, pa, prot, len); + pr_trace("va=%p, len=%d\n", va, len); + if (error < 0) { + pr_error("mmap: failed to map page (retval=%x)\n", error); + return NULL; + } + } + + /* Add entry to ledger */ + td = this_td(); + ep = dynalloc(sizeof(*ep)); + if (ep == NULL) { + pr_error("mmap: failed to allocate mmap ledger entry\n"); + return NULL; + } + + ep->va_start = va; + ep->obj = map_obj; + ep->size = len; + mmap_add(td, ep); + return addr; +} + +/* + * mmap() syscall + * + * arg0 -> addr + * arg1 -> len + * arg2 -> prot + * arg3 -> flags + * arg4 -> fildes + * arg5 -> off + */ +scret_t +mmap(struct syscall_args *scargs) +{ + void *addr; + size_t len; + int prot, flags; + int fildes, off; + + addr = (void *)scargs->arg0; + len = scargs->arg1; + prot = scargs->arg2; + flags = scargs->arg3; + fildes = scargs->arg4; + off = scargs->arg5; + return (scret_t)mmap_at(addr, len, prot, flags, fildes, off); +} + +/* * Create a virtual memory mapping in a specific * address space. * @@ -130,3 +289,12 @@ vm_unmap(struct vas vas, vaddr_t va, size_t count) { return vm_map_modify(vas, va, 0, 0, true, count); } + +/* + * Helper for tree(3) and the mmap ledger. + */ +int +mmap_entrycmp(const struct mmap_entry *a, const struct mmap_entry *b) +{ + return (a->va_start < b->va_start) ? -1 : a->va_start > b->va_start; +} |