Merge remote-tracking branch 'remotes/cminyard/tags/for-qemu-i2c-5' into staging

[mirror_qemu.git] / linux-user / elfload.c

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 475d243f3bd1207a1abb4b03874b2fcc1d4b58a1..7e7f642332dc9e3c8fe9a5695c7fa75912869543 100644 (file)
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -389,7 +389,7 @@ static bool init_guest_commpage(void)
 {
     void *want = g2h(ARM_COMMPAGE & -qemu_host_page_size);
     void *addr = mmap(want, qemu_host_page_size, PROT_READ | PROT_WRITE,
-                      MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+                      MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
 
     if (addr == MAP_FAILED) {
         perror("Allocating guest commpage");
@@ -2113,7 +2113,8 @@ static void pgb_have_guest_base(const char *image_name, abi_ulong guest_loaddr,
  * only dumbly iterate up the host address space seeing if the
  * allocation would work.
  */
-static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, long align)
+static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk,
+                                        long align, uintptr_t offset)
 {
     uintptr_t base;
 
@@ -2123,7 +2124,7 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, lon
     while (true) {
         uintptr_t align_start, end;
         align_start = ROUND_UP(base, align);
-        end = align_start + guest_size;
+        end = align_start + guest_size + offset;
 
         /* if brk is anywhere in the range give ourselves some room to grow. */
         if (align_start <= brk && brk < end) {
@@ -2138,7 +2139,7 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, lon
                                      PROT_NONE, flags, -1, 0);
             if (mmap_start != MAP_FAILED) {
                 munmap((void *) align_start, guest_size);
-                return (uintptr_t) mmap_start;
+                return (uintptr_t) mmap_start + offset;
             }
             base += qemu_host_page_size;
         }
@@ -2147,7 +2148,7 @@ static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk, lon
 
 /* Return value for guest_base, or -1 if no hole found. */
 static uintptr_t pgb_find_hole(uintptr_t guest_loaddr, uintptr_t guest_size,
-                               long align)
+                               long align, uintptr_t offset)
 {
     GSList *maps, *iter;
     uintptr_t this_start, this_end, next_start, brk;
@@ -2161,7 +2162,7 @@ static uintptr_t pgb_find_hole(uintptr_t guest_loaddr, uintptr_t guest_size,
     brk = (uintptr_t)sbrk(0);
 
     if (!maps) {
-        return pgd_find_hole_fallback(guest_size, brk, align);
+        return pgd_find_hole_fallback(guest_size, brk, align, offset);
     }
 
     /* The first hole is before the first map entry. */
@@ -2173,7 +2174,7 @@ static uintptr_t pgb_find_hole(uintptr_t guest_loaddr, uintptr_t guest_size,
 
         this_end = ((MapInfo *)iter->data)->start;
         next_start = ((MapInfo *)iter->data)->end;
-        align_start = ROUND_UP(this_start, align);
+        align_start = ROUND_UP(this_start + offset, align);
 
         /* Skip holes that are too small. */
         if (align_start >= this_end) {
@@ -2223,6 +2224,7 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr,
 {
     uintptr_t loaddr = orig_loaddr;
     uintptr_t hiaddr = orig_hiaddr;
+    uintptr_t offset = 0;
     uintptr_t addr;
 
     if (hiaddr != orig_hiaddr) {
@@ -2236,18 +2238,19 @@ static void pgb_static(const char *image_name, abi_ulong orig_loaddr,
     if (ARM_COMMPAGE) {
         /*
          * Extend the allocation to include the commpage.
-         * For a 64-bit host, this is just 4GiB; for a 32-bit host,
-         * the address arithmetic will wrap around, but the difference
-         * will produce the correct allocation size.
+         * For a 64-bit host, this is just 4GiB; for a 32-bit host we
+         * need to ensure there is space bellow the guest_base so we
+         * can map the commpage in the place needed when the address
+         * arithmetic wraps around.
          */
         if (sizeof(uintptr_t) == 8 || loaddr >= 0x80000000u) {
-            hiaddr = (uintptr_t)4 << 30;
+            hiaddr = (uintptr_t) 4 << 30;
         } else {
-            loaddr = ARM_COMMPAGE & -align;
+            offset = -(ARM_COMMPAGE & -align);
         }
     }
 
-    addr = pgb_find_hole(loaddr, hiaddr - loaddr, align);
+    addr = pgb_find_hole(loaddr, hiaddr - loaddr, align, offset);
     if (addr == -1) {
         /*
          * If ARM_COMMPAGE, there *might* be a non-consecutive allocation
@@ -2282,7 +2285,7 @@ static void pgb_dynamic(const char *image_name, long align)
          * just above that, and maximises the positive guest addresses.
          */
         commpage = ARM_COMMPAGE & -align;
-        addr = pgb_find_hole(commpage, -commpage, align);
+        addr = pgb_find_hole(commpage, -commpage, align, 0);
         assert(addr != -1);
         guest_base = addr;
     }
@@ -2291,7 +2294,7 @@ static void pgb_dynamic(const char *image_name, long align)
 static void pgb_reserved_va(const char *image_name, abi_ulong guest_loaddr,
                             abi_ulong guest_hiaddr, long align)
 {
-    const int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE;
+    int flags = MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE;
     void *addr, *test;
 
     if (guest_hiaddr > reserved_va) {
@@ -2304,15 +2307,19 @@ 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
+    flags |= MAP_FIXED_NOREPLACE;
+#endif
+
     /* Reserve the memory on the host. */
     assert(guest_base != 0);
     test = g2h(0);
     addr = mmap(test, reserved_va, PROT_NONE, flags, -1, 0);
     if (addr == MAP_FAILED) {
         error_report("Unable to reserve 0x%lx bytes of virtual address "
-                     "space for use as guest address space (check your "
+                     "space (%s) for use as guest address space (check your "
                      "virtual memory ulimit setting or reserve less "
-                     "using -R option)", reserved_va);
+                     "using -R option)", reserved_va, strerror(errno));
         exit(EXIT_FAILURE);
     }
     assert(addr == test);