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- /* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
- /* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */
- /* Copyright (C) 2014 OSCAR lab, Stony Brook University
- This file is part of Graphene Library OS.
- Graphene Library OS is free software: you can redistribute it and/or
- modify it under the terms of the GNU General Public License
- as published by the Free Software Foundation, either version 3 of the
- License, or (at your option) any later version.
- Graphene Library OS is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- #include <pal.h>
- #include <pal_error.h>
- #include <linux_list.h>
- #include <atomic.h>
- #include <linux/futex.h>
- #include <errno.h>
- #include "sgx_internal.h"
- #define MUTEX_SPINLOCK_TIMES 20
- static int _DkMutexLock (struct mutex_handle * mut)
- {
- int i, c = 0;
- int ret;
- struct atomic_int * m = &mut->value;
- /* Spin and try to take lock */
- for (i = 0; i < MUTEX_SPINLOCK_TIMES; i++) {
- c = atomic_dec_and_test(m);
- if (c)
- goto success;
- cpu_relax();
- }
- /* The lock is now contended */
- while (!c) {
- int val = atomic_read(m);
- if (val == 1)
- goto again;
- ret = INLINE_SYSCALL(futex, 6, m, FUTEX_WAIT, val, NULL, NULL, 0);
- if (IS_ERR(ret) &&
- ERRNO(ret) != EWOULDBLOCK &&
- ERRNO(ret) != EINTR) {
- ret = -PAL_ERROR_DENIED;
- goto out;
- }
- again:
- /* Upon wakeup, we still need to check whether mutex is unlocked or
- * someone else took it.
- * If c==0 upon return from xchg (i.e., the older value of m==0), we
- * will exit the loop. Else, we sleep again (through a futex call).
- */
- c = atomic_dec_and_test(m);
- }
- success:
- ret = 0;
- out:
- return ret;
- }
- static int _DkMutexUnlock (struct mutex_handle * mut)
- {
- int ret = 0;
- int must_wake = 0;
- struct atomic_int * m = &mut->value;
- /* Unlock, and if not contended then exit. */
- if (atomic_read(m) < 0)
- must_wake = 1;
- atomic_set(m, 1);
- if (must_wake) {
- /* We need to wake someone up */
- ret = INLINE_SYSCALL(futex, 6, m, FUTEX_WAKE, 1, NULL, NULL, 0);
- }
- if (IS_ERR(ret)) {
- ret = -PAL_ERROR_TRYAGAIN;
- goto out;
- }
- ret = 0;
- out:
- return ret;
- }
- static struct mutex_handle slabmgr_lock;
- static void * untrusted_slabmgr = NULL;
- #define system_lock() _DkMutexLock(&slabmgr_lock)
- #define system_unlock() _DkMutexUnlock(&slabmgr_lock)
- #define PAGE_SIZE (pagesize)
- #define STARTUP_SIZE 8
- static inline void * __malloc (int size)
- {
- void * addr = NULL;
- addr = (void *) INLINE_SYSCALL(mmap, 6, NULL, size,
- PROT_READ | PROT_WRITE,
- MAP_PRIVATE | MAP_ANONYMOUS,
- -1, 0);
- if (IS_ERR_P(addr))
- return NULL;
- return addr;
- }
- #define system_malloc(size) __malloc(size)
- static inline void __free (void * addr, int size)
- {
- INLINE_SYSCALL(munmap, 2, addr, size);
- }
- #define system_free(addr, size) __free(addr, size)
- #include "slabmgr.h"
- int init_untrusted_allocator (struct pal_sec * pal_sec)
- {
- if (!untrusted_slabmgr) {
- untrusted_slabmgr = create_slab_mgr();
- if (!untrusted_slabmgr)
- return -PAL_ERROR_NOMEM;
- }
- pal_sec->untrusted_allocator.alignment = pagesize;
- pal_sec->untrusted_allocator.slabmgr = untrusted_slabmgr;
- pal_sec->untrusted_allocator.lock = &slabmgr_lock;
- return 0;
- }
- void * malloc_untrusted (int size)
- {
- void * ptr = slab_alloc((SLAB_MGR) untrusted_slabmgr, size);
- /* the slab manger will always remain at least one byte of padding,
- so we can feel free to assign an offset at the byte prior to
- the pointer */
- if (ptr)
- *(((unsigned char *) ptr) - 1) = 0;
- return ptr;
- }
- void free_untrusted (void * ptr)
- {
- ptr -= *(((unsigned char *) ptr) - 1);
- slab_free((SLAB_MGR) untrusted_slabmgr, ptr);
- }
- int _DkEventSet (PAL_HANDLE event, int wakeup)
- {
- int ret = 0;
- if (event->event.isnotification) {
- // Leave it signaled, wake all
- if (atomic_cmpxchg(&event->event.signaled, 0, 1) == 0) {
- int nwaiters = atomic_read(&event->event.nwaiters);
- if (nwaiters) {
- if (wakeup != -1 && nwaiters > wakeup)
- nwaiters = wakeup;
- ret = INLINE_SYSCALL(futex, 6, &event->event.signaled,
- FUTEX_WAKE, nwaiters, NULL, NULL, 0);
- if (IS_ERR(ret))
- atomic_set(&event->event.signaled, 0);
- }
- }
- } else {
- // Only one thread wakes up, leave unsignaled
- ret = INLINE_SYSCALL(futex, 6, &event->event.signaled, FUTEX_WAKE, 1,
- NULL, NULL, 0);
- }
- return IS_ERR(ret) ? PAL_ERROR_TRYAGAIN : ret;
- }
- int _DkEventWait (PAL_HANDLE event)
- {
- int ret = 0;
- if (!event->event.isnotification || !atomic_read(&event->event.signaled)) {
- atomic_inc(&event->event.nwaiters);
- do {
- ret = INLINE_SYSCALL(futex, 6, &event->event.signaled, FUTEX_WAIT,
- 0, NULL, NULL, 0);
- if (IS_ERR(ret)) {
- if (ERRNO(ret) == EWOULDBLOCK) {
- ret = 0;
- } else {
- ret = -PAL_ERROR_DENIED;
- break;
- }
- }
- } while (event->event.isnotification &&
- !atomic_read(&event->event.signaled));
- atomic_dec(&event->event.nwaiters);
- }
- return ret;
- }
- #define PRINTBUF_SIZE 256
- struct printbuf {
- int idx; // current buffer index
- int cnt; // total bytes printed so far
- char buf[PRINTBUF_SIZE];
- };
- static void
- fputch(void * f, int ch, struct printbuf * b)
- {
- b->buf[b->idx++] = ch;
- if (b->idx == PRINTBUF_SIZE-1) {
- INLINE_SYSCALL(write, 3, 2, b->buf, b->idx);
- b->idx = 0;
- }
- b->cnt++;
- }
- static int
- vprintf(const char * fmt, va_list *ap)
- {
- struct printbuf b;
- b.idx = 0;
- b.cnt = 0;
- vfprintfmt((void *) &fputch, NULL, &b, fmt, ap);
- INLINE_SYSCALL(write, 3, 2, b.buf, b.idx);
- return b.cnt;
- }
- int
- pal_printf(const char * fmt, ...)
- {
- va_list ap;
- int cnt;
- va_start(ap, fmt);
- cnt = vprintf(fmt, &ap);
- va_end(ap);
- return cnt;
- }
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