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-rw-r--r--linux-user/elfload.c10
-rw-r--r--linux-user/main.c16
-rw-r--r--linux-user/syscall.c28
3 files changed, 31 insertions, 23 deletions
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 7e7f642332..fe9dfe795d 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -2134,12 +2134,15 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk,
             /* we have run out of space */
             return -1;
         } else {
-            int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE | MAP_FIXED;
+            int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE |
+                MAP_FIXED_NOREPLACE;
             void * mmap_start = mmap((void *) align_start, guest_size,
                                      PROT_NONE, flags, -1, 0);
             if (mmap_start != MAP_FAILED) {
                 munmap((void *) align_start, guest_size);
-                return (uintptr_t) mmap_start + offset;
+                if (MAP_FIXED_NOREPLACE || mmap_start == (void *) align_start) {
+                    return (uintptr_t) mmap_start + offset;
+                }
             }
             base += qemu_host_page_size;
         }
@@ -2307,9 +2310,8 @@ static void pgb_reserved_va(const char *image_name, abi_ulong guest_loaddr,
     /* Widen the "image" to the entire reserved address space. */
     pgb_static(image_name, 0, reserved_va, align);
 
-#ifdef MAP_FIXED_NOREPLACE
+    /* osdep.h defines this as 0 if it's missing */
     flags |= MAP_FIXED_NOREPLACE;
-#endif
 
     /* Reserve the memory on the host. */
     assert(guest_base != 0);
diff --git a/linux-user/main.c b/linux-user/main.c
index 3597e99bb1..75c9785157 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -758,15 +758,27 @@ int main(int argc, char **argv, char **envp)
 
         if ((fp = fopen("/proc/sys/vm/mmap_min_addr", "r")) != NULL) {
             unsigned long tmp;
-            if (fscanf(fp, "%lu", &tmp) == 1) {
+            if (fscanf(fp, "%lu", &tmp) == 1 && tmp != 0) {
                 mmap_min_addr = tmp;
-                qemu_log_mask(CPU_LOG_PAGE, "host mmap_min_addr=0x%lx\n", mmap_min_addr);
+                qemu_log_mask(CPU_LOG_PAGE, "host mmap_min_addr=0x%lx\n",
+                              mmap_min_addr);
             }
             fclose(fp);
         }
     }
 
     /*
+     * We prefer to not make NULL pointers accessible to QEMU.
+     * If we're in a chroot with no /proc, fall back to 1 page.
+     */
+    if (mmap_min_addr == 0) {
+        mmap_min_addr = qemu_host_page_size;
+        qemu_log_mask(CPU_LOG_PAGE,
+                      "host mmap_min_addr=0x%lx (fallback)\n",
+                      mmap_min_addr);
+    }
+
+    /*
      * Prepare copy of argv vector for target.
      */
     target_argc = argc - optind;
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 1211e759c2..945fc25279 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -388,14 +388,7 @@ static bitmask_transtbl fcntl_flags_tbl[] = {
   { 0, 0, 0, 0 }
 };
 
-static int sys_getcwd1(char *buf, size_t size)
-{
-  if (getcwd(buf, size) == NULL) {
-      /* getcwd() sets errno */
-      return (-1);
-  }
-  return strlen(buf)+1;
-}
+_syscall2(int, sys_getcwd1, char *, buf, size_t, size)
 
 #ifdef TARGET_NR_utimensat
 #if defined(__NR_utimensat)
@@ -8868,7 +8861,9 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
             unlock_user(p, arg1, 0);
             if (arg3) {
                 puts = &uts;
-                target_to_host_timespec(puts, arg3);
+                if (target_to_host_timespec(puts, arg3)) {
+                    return -TARGET_EFAULT;
+                }
             } else {
                 puts = NULL;
             }
@@ -11831,16 +11826,15 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1,
         target_to_host_timespec(&ts, arg3);
         ret = get_errno(safe_clock_nanosleep(arg1, arg2,
                                              &ts, arg4 ? &ts : NULL));
-        if (arg4)
+        /*
+         * if the call is interrupted by a signal handler, it fails
+         * with error -TARGET_EINTR and if arg4 is not NULL and arg2 is not
+         * TIMER_ABSTIME, it returns the remaining unslept time in arg4.
+         */
+        if (ret == -TARGET_EINTR && arg4 && arg2 != TIMER_ABSTIME) {
             host_to_target_timespec(arg4, &ts);
-
-#if defined(TARGET_PPC)
-        /* clock_nanosleep is odd in that it returns positive errno values.
-         * On PPC, CR0 bit 3 should be set in such a situation. */
-        if (ret && ret != -TARGET_ERESTARTSYS) {
-            ((CPUPPCState *)cpu_env)->crf[0] |= 1;
         }
-#endif
+
         return ret;
     }
 #endif