linux-user: Do early mmap placement only for reserved_va

For reserved_va, place all non-fixed maps then proceed
as for MAP_FIXED.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Helge Deller <deller@gmx.de>
Message-Id: <20240102015808.132373-21-richard.henderson@linaro.org>

diff --git a/linux-user/mmap.c b/linux-user/mmap.c
index cc983bedbd4f40b7987d1eefa6a5d0e3e2f29f26..1bbfeb25b147c0524d81e8d3f2bccf53f5909dfe 100644 (file)
--- a/linux-user/mmap.c
+++ b/linux-user/mmap.c
@@ -540,17 +540,19 @@ static abi_long target_mmap__locked(abi_ulong start, abi_ulong len,
     host_offset = offset & -host_page_size;
 
     /*
-     * If the user is asking for the kernel to find a location, do that
-     * before we truncate the length for mapping files below.
+     * For reserved_va, we are in full control of the allocation.
+     * Find a suitable hole and convert to MAP_FIXED.
      */
-    if (!(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) {
+    if (reserved_va && !(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) {
         host_len = len + offset - host_offset;
-        host_len = ROUND_UP(host_len, host_page_size);
-        start = mmap_find_vma(real_start, host_len, TARGET_PAGE_SIZE);
+        start = mmap_find_vma(real_start, host_len,
+                              MAX(host_page_size, TARGET_PAGE_SIZE));
         if (start == (abi_ulong)-1) {
             errno = ENOMEM;
             return -1;
         }
+        start += offset - host_offset;
+        flags |= MAP_FIXED;
     }
 
     /*