syscall_emul: Argument retrieval bug fix

This commit fixes a stack-buffer underflow
by fixing the way the array is indexed.

Change-Id: I44400e2b99a2f8e1f48f673cd110b9dcd6480a72
Reviewed-on: https://gem5-review.googlesource.com/3040
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Maintainer: Brandon Potter <Brandon.Potter@amd.com>

diff --git a/src/sim/syscall_desc.cc b/src/sim/syscall_desc.cc
index 13b519081fc311cca71005aae0d723447e75e0c2..3696c1719734644139ce1dc3f997b49cb5e83875 100644 (file)
--- a/src/sim/syscall_desc.cc
+++ b/src/sim/syscall_desc.cc
@@ -54,11 +54,11 @@ SyscallDesc::doSyscall(int callnum, Process *process, ThreadContext *tc,
     /**
      * Step through the first six parameters for the system call and
      * retrieve their values. Note that index is incremented as a
-     * side-effect of the getSyscallArg method which is why the LHS
-     * needs the "-1".
+     * side-effect of the getSyscallArg method.
      */
-    for (int index = 0; index < 6; )
-        arg[index - 1] = process->getSyscallArg(tc, index);
+    int index = 0;
+    for (int i = 0; i < 6; i++)
+        arg[i] = process->getSyscallArg(tc, index);
 
     /**
      * Linux supports up to six system call arguments through registers