From patchwork Tue Feb 26 18:27:33 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Fix PR56344 X-Patchwork-Submitter: Marek Polacek X-Patchwork-Id: 223365 Message-Id: <20130226182733.GG25197@redhat.com> To: GCC Patches Date: Tue, 26 Feb 2013 19:27:33 +0100 From: Marek Polacek List-Id: This "fixes" PR56344 by prohibiting passing arguments by value of size >= 2^30 bytes. Probably no sane programmer would want to do that, but it's better to issue an error than to segfault. This would be a good opportunity to use __builtin_expect, but we don't use that much in the codebase... Regtested/bootstrapped on x86_64-linux, ok for trunk? Do we need a testcase for this (compiling it is quite slow)? 2013-02-26 Marek Polacek PR middle-end/56344 * calls.c (expand_call): Disallow passing huge arguments by value. Marek --- gcc/calls.c.mp 2013-02-26 17:04:33.159555349 +0100 +++ gcc/calls.c 2013-02-26 18:50:54.864084545 +0100 @@ -3037,6 +3037,14 @@ expand_call (tree exp, rtx target, int i { rtx before_arg = get_last_insn (); + /* We don't allow passing huge (> 2^30 B) arguments + by value. It would cause an overflow later on. */ + if (adjusted_args_size.constant >= (1 << 30)) + { + error ("passing too large argument on stack"); + continue; + } + if (store_one_arg (&args[i], argblock, flags, adjusted_args_size.var != 0, reg_parm_stack_space)