linux-user: Fix qemu-arm to run static armhf binaries

qemu-user crashes immediately when running static binaries on the armhf
architecture. The problem is the memory layout where the executable is
loaded before the interpreter library, in which case the reserved brk
region clashes with the interpreter code and is released before qemu
tries to start the program.

At load time qemu calculates a brk value for interpreter and executable
each.  The fix is to choose the higher one of both.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Andreas Schwab <schwab@suse.de>
Cc: qemu-stable@nongnu.org
Reported-by:  Venkata.Pyla@toshiba-tsip.com
Closes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1040981

linux-user/elfload.c

@@ -3615,6 +3615,13 @@ int load_elf_binary(struct linux_binprm *bprm, struct image_info *info)
 
     if (elf_interpreter) {
         load_elf_interp(elf_interpreter, &interp_info, bprm->buf);
+        /*
+         * adjust brk address if the interpreter was loaded above the main
+         * executable, e.g. happens with static binaries on armhf
+         */
+        if (interp_info.brk > info->brk) {
+            info->brk = interp_info.brk;
+        }
 
         /* If the program interpreter is one of these two, then assume
            an iBCS2 image.  Otherwise assume a native linux image.  */