static long zerofill(unsigned long start, unsigned long end, int prot)
{
unsigned long pg_start = PAGE_NEXT(start),
pg_end = PAGE_NEXT(end),
padd_len = pg_start-start;
if (start > end)
return -1;
if (prot & PROT_WRITE)
memset((void *)start, 0, padd_len);
return do_mmap2(pg_start, pg_end-pg_start, prot,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0);
}
static unsigned long get_mmap_base(elf_bin_t *elf)
{
unsigned long addr, pg_start, pg_end, mmap_min = ULONG_MAX, mmap_max = 0;
int i;
for (i=0; i<elf->hdr.e_phnum; i++)
if ( elf->phdr[i].p_type == PT_LOAD)
{
pg_start = PAGE_BASE(elf->phdr[i].p_vaddr);
pg_end = PAGE_NEXT(elf->phdr[i].p_vaddr + elf->phdr[i].p_memsz);
if (pg_start < mmap_min)
mmap_min = pg_start;
if (pg_end > mmap_max)
mmap_max = pg_end;
}
if (mmap_min > mmap_max)
mmap_min = mmap_max;
addr = do_mmap2(mmap_min, mmap_max-mmap_min, PROT_NONE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
if (addr & PG_MASK) /* not on page boundary -> error code */
return addr;
sys_munmap(addr, mmap_max-mmap_min);
return addr-mmap_min;
}
/** ユーザ空間へのアクセス許可があることを確認する(実装部)
@param[in] as 検査対象の仮想アドレス空間
@param[in] start 検査開始アドレス
@param[in] count 検査範囲のアドレス長(単位:バイト)
@param[in] prot 検査するアクセス権(仮想メモリ領域の保護属性)
@retval true 対象範囲に物理ページが存在し, 必要なアクセス権がある
@retval false 対象範囲に物理ページが存在しないか, 必要なアクセス権がない
*/
static bool
user_area_can_access_nolock(vm *as, void *start, size_t count, vma_prot prot) {
int rc;
void *pg_start;
void *pg_end;
vma *vmap;
kassert( as != NULL );
pg_start = (void *)PAGE_START((uintptr_t)start);
pg_end = ( PAGE_ALIGNED( (uintptr_t)(start + count) ) ?
( start + count ) : ( (void *)PAGE_NEXT( (uintptr_t)(start + count) ) ) );
rc = _vm_find_vma_nolock(as, pg_start, &vmap);
if ( rc != 0 )
goto can_not_access;
if ( vmap->end < pg_end )
goto can_not_access;
if ( !( vmap->prot & prot ) )
goto can_not_access;
return true;
can_not_access:
return false;
}
static char unmap_page(char *previous, char *mem, char *next)
{
if (!has_one_page_available())
return (0);
if (previous)
*PAGE_NEXT(previous) = next;
else
get_page_list(0, next);
munmap((void *)mem, *PAGE_SIZE(mem));
return (0);
}
/** sbrkシステムコールの実処理
@param[in] sbrk sbrkメッセージ
@param[in] src 呼出元エンドポイント
@retval 0 正常に更新した
@retval -ENOMEM メモリ不足により更新に失敗した
*/
static int
handle_sbrk(vm_sys_sbrk *sbrk,endpoint src) {
int rc;
thread *thr;
void *cur_end;
void *new_end;
intrflags flags;
acquire_all_thread_lock( &flags );
thr = thr_find_thread_by_tid_nolock(src);
if ( thr == NULL ) {
rc = -ENOENT;
goto unlock_out;
}
rc = proc_expand_heap(thr->p, NULL, &cur_end);
if ( rc != 0 )
goto unlock_out;
if ( sbrk->inc == 0 ) {
rc = 0;
goto success_out;
}
new_end = ( PAGE_ALIGNED( (uintptr_t)(cur_end + sbrk->inc) ) ) ?
( (void *)( cur_end + sbrk->inc ) ) :
( (void *)PAGE_NEXT( (uintptr_t)(cur_end + sbrk->inc) ) );
if ( new_end < thr->p->heap->start ) {
rc = -EINVAL;
goto unlock_out;
}
rc = proc_expand_heap(thr->p, new_end, &cur_end);
if ( rc != 0 )
goto unlock_out;
success_out:
release_all_thread_lock(&flags);
if ( rc == 0 )
sbrk->old_heap_end = cur_end;
return 0;
unlock_out:
release_all_thread_lock(&flags);
return rc;
}
static unsigned long set_brk(elf_bin_t *bin)
{
unsigned long new_brk = 0, v_end, i;
for (i=0; i<bin->hdr.e_phnum; i++)
if ( bin->phdr[i].p_type == PT_LOAD)
{
v_end = PAGE_NEXT(bin->phdr[i].p_vaddr+bin->phdr[i].p_memsz);
if ( (bin->phdr[i].p_type == PT_LOAD) && (new_brk < v_end) )
new_brk = v_end;
}
return (new_brk == set_brk_min(new_brk)) ? 0 : -1;
}
static char has_one_page_available()
{
char *mem;
char av;
av = 0;
mem = get_page_list(0, (void *)-1);
while (mem && av != 3)
{
if (*PAGE_SIZE(mem) == get_alloc_size(TINY))
av |= 1;
else if (*PAGE_SIZE(mem) == get_alloc_size(SMALL))
av |= 2;
mem = *PAGE_NEXT(mem);
}
return (av == 3);
}
static char delete_ptrs_page(char *ptr)
{
char *mem;
char *previous;
char *next;
previous = NULL;
mem = get_page_list(0, (void *)-1);
while (mem)
{
next = *PAGE_NEXT(mem);
if (ptr >= mem + PAGE_META && ptr < mem + *PAGE_SIZE(mem))
return (evaluate_freeable(ptr, previous, mem, next));
previous = mem;
mem = next;
}
return (0);
}
static long mmap_prog_section(elf_bin_t *elf, Elf32_Phdr *p)
{
unsigned long base = elf->base, brk_, bss, addr, pg_off, size;
int prot = 0;
if (p->p_flags & PF_R)
prot |= PROT_READ;
if (p->p_flags & PF_W)
prot |= PROT_WRITE;
if (p->p_flags & PF_X)
prot |= PROT_EXEC;
addr = PAGE_BASE(base+p->p_vaddr);
size = PAGE_NEXT(base+p->p_vaddr + p->p_filesz) - addr;
pg_off = p->p_offset/PG_SIZE;
bss = base + p->p_vaddr + p->p_filesz;
brk_ = base + p->p_vaddr + p->p_memsz;
if ( ((p->p_vaddr-p->p_offset) & PG_MASK) || (bss > brk_) )
return -1;
addr = do_mmap2(addr, size, prot, MAP_PRIVATE|MAP_FIXED, elf->fd, pg_off);
if (addr & PG_MASK) /* not on page boundary -> error code */
return addr;
if (elf->brk < brk_)
elf->brk = brk_;
if (elf->bss < bss)
elf->bss = bss;
/* linux does not fill in bss sections
* between load segments for interpreters;
* makes no difference to the standard ld.so
*/
addr = zerofill(bss, brk_, prot);
if (addr & PG_MASK) /* not on page boundary -> error code */
return addr;
return 0;
}
/* relocate the stack */
static long get_stack_random_shift(long *auxv)
{
return 0x1000000 - (PAGE_NEXT((long)get_aux(auxv, AT_EXECFN)) & 0xfff000);
}
/** プロセス間でデータをコピーする
@param[in] dest_as コピー先の仮想アドレス空間
@param[in] src_as コピー元の仮想アドレス空間
@param[in] dest コピー先のアドレス
@param[in] src コピー元のアドレス
@param[in] count コピーするバイト数
@return コピーしたバイト数
@return -ENOMEM バッファページが獲得できない
@return -EFAULT ページが存在しない
@note カーネルストレートマップ領域間でメモリコピーを行うことで
アドレス空間の切り替えを行わないようにする
また、自プロセスの空間のmutexを取ると互いの空間のロック待ちで
デッドロックするため, プリエンプションを禁止にして自プロセス内の
他のスレッドが割り込まないようにし, 自プロセスのアドレス空間の
mutexを取らないようにする。
*/
static int
inter_user_copy(vm *dest_as, vm *src_as, void *dest, const void *src, size_t count) {
int rc;
size_t len;
uintptr_t src_kvaddr;
vma_prot src_prot;
uintptr_t dest_kvaddr;
vma_prot dest_prot;
void *saddr;
void *daddr;
size_t src_len;
size_t dest_len;
size_t cpy_len;
void *new_page;
vma *vmap;
kassert( src_as != NULL );
kassert( src_as->p != NULL );
kassert( dest_as != NULL );
kassert( dest_as->p != NULL );
/* アドレス空間とアドレスの範囲がユーザ空間に収まることを確認 */
if ( ( (uintptr_t)src >= KERN_VMA_BASE ) || ( (uintptr_t)dest >= KERN_VMA_BASE ) )
return -EFAULT;
if ( ( dest_as->p == hal_refer_kernel_proc() ) ||
( src_as->p == hal_refer_kernel_proc() ) )
return -EFAULT;
/* 自CPUの同一プロセス内のスレッドがアドレス空間を操作
* しないことを保証するためにプリエンプションを抑止
*/
ti_disable_dispatch();
/* 相手の空間のロック(mutex)を取る */
if ( ¤t->p->vm == dest_as )
mutex_lock( &src_as->asmtx );
else
mutex_lock( &dest_as->asmtx );
saddr = (void *)src;
daddr = dest;
for( len = count; len > 0; ) {
/*
* コピー元/コピー先ページを取得する
*/
if ( src_as->p == hal_refer_kernel_proc() )
src_kvaddr = PAGE_START(saddr);
else {
rc = hal_translate_user_page(src_as, (uintptr_t)saddr,
&src_kvaddr, &src_prot);
if ( rc != 0 ) {
/*
* ページ未割り当て時はページを割当てる
*/
rc = _vm_find_vma_nolock(src_as, saddr, &vmap);
if ( rc != 0 )
goto unlock_out;
if ( vmap->prot == VMA_PROT_NONE )
goto unlock_out;
rc = get_free_page(&new_page);
if ( rc != 0 )
goto unlock_out;
memset(new_page, 0, PAGE_SIZE);
rc = hal_map_user_page(src_as, (uintptr_t)saddr,
(uintptr_t)new_page, vmap->prot );
if ( rc != 0 ) {
free_page(new_page);
goto unlock_out;
}
}
}
if ( dest_as->p == hal_refer_kernel_proc() )
dest_kvaddr = PAGE_START(daddr);
else {
rc = hal_translate_user_page(dest_as, (uintptr_t)daddr,
&dest_kvaddr, &dest_prot);
if ( rc != 0 ) {
/*
* ページ未割り当て時はページを割当てる
*/
rc = _vm_find_vma_nolock(dest_as, daddr, &vmap);
if ( rc != 0 )
goto unlock_out;
if ( vmap->prot == VMA_PROT_NONE )
goto unlock_out;
rc = get_free_page(&new_page);
if ( rc != 0 )
goto unlock_out;
memset(new_page, 0, PAGE_SIZE);
rc = hal_map_user_page(dest_as, (uintptr_t)daddr,
(uintptr_t)new_page, vmap->prot );
if ( rc != 0 ) {
free_page(new_page);
goto unlock_out;
}
}
}
/*
* src/destともページ内に収まる分だけコピーする
*/
src_len = PAGE_NEXT(saddr) - (uintptr_t)saddr;
dest_len = PAGE_NEXT(daddr) - (uintptr_t)daddr;
cpy_len = ( src_len <= dest_len ) ? ( src_len ) : ( dest_len );
if ( cpy_len > len )
cpy_len = len;
len -= cpy_len;
while( cpy_len > 0 ) {
*(char *)(dest_kvaddr + ( (uintptr_t)daddr - PAGE_START(daddr) ) )
= *(char *)(src_kvaddr +
( (uintptr_t)saddr - PAGE_START(saddr) ) );
--cpy_len;
++saddr;
++daddr;
}
}
rc = count - len;
unlock_out:
if ( ¤t->p->vm == dest_as )
mutex_unlock( &src_as->asmtx );
else
mutex_unlock( &dest_as->asmtx );
ti_enable_dispatch();
return rc;
}