[src/trunk]: src/sys/kern PR/44673: Arna Clauson: Latest MAXSSIZ bump broke n...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/64ab33ee28cb
branches:  trunk
changeset: 762867:64ab33ee28cb
user:      christos <christos%NetBSD.org@localhost>
date:      Fri Mar 04 04:25:58 2011 +0000

description:
PR/44673: Arna Clauson: Latest MAXSSIZ bump broke netbsd32 emulation on amd64.
- Use MAXSSIZ32 instead of MAXSSIZ for 32 bit binaries
- Default MAXXSIZ32 to a quarter of MAXSSIZ (good enough?)
- Add debugging
XXX: Note that:
        - sparc32 MAXSSIZ is larger than sparc64 MAXSSIZ
        - sparc64 MAXSSIZ32 != sparc32 MAXSSIZ

diffstat:

 sys/kern/exec_subr.c |  32 +++++++++++++++++++++++++++++---
 1 files changed, 29 insertions(+), 3 deletions(-)

diffs (81 lines):

diff -r 24023ae318d2 -r 64ab33ee28cb sys/kern/exec_subr.c
--- a/sys/kern/exec_subr.c      Fri Mar 04 04:17:12 2011 +0000
+++ b/sys/kern/exec_subr.c      Fri Mar 04 04:25:58 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exec_subr.c,v 1.67 2011/01/17 07:13:31 uebayasi Exp $  */
+/*     $NetBSD: exec_subr.c,v 1.68 2011/03/04 04:25:58 christos Exp $  */
 
 /*
  * Copyright (c) 1993, 1994, 1996 Christopher G. Demetriou
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: exec_subr.c,v 1.67 2011/01/17 07:13:31 uebayasi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: exec_subr.c,v 1.68 2011/03/04 04:25:58 christos Exp $");
 
 #include "opt_pax.h"
 
@@ -64,6 +64,12 @@
 VMCMD_EVCNT_DECL(extends);
 VMCMD_EVCNT_DECL(kills);
 
+#ifdef DEBUG_STACK
+#define DPRINTF(a) uprintf a
+#else
+#define DPRINTF(a)
+#endif
+
 /*
  * new_vmcmd():
  *     create a new vmcmd structure and fill in its fields based
@@ -382,14 +388,22 @@
 #ifndef        USRSTACK32
 #define USRSTACK32     (0x00000000ffffffffL&~PGOFSET)
 #endif
+#ifndef MAXSSIZ32
+#define MAXSSIZ32      (MAXSSIZ >> 2)
+#endif
 
        if (epp->ep_flags & EXEC_32) {
                epp->ep_minsaddr = USRSTACK32;
-               max_stack_size = MAXSSIZ;
+               max_stack_size = MAXSSIZ32;
        } else {
                epp->ep_minsaddr = USRSTACK;
                max_stack_size = MAXSSIZ;
        }
+
+       DPRINTF(("ep_minsaddr=%llx max_stack_size=%llx\n",
+           (unsigned long long)epp->ep_minsaddr,
+           (unsigned long long)max_stack_size));
+
        epp->ep_ssize = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur;
 
 #ifdef PAX_ASLR
@@ -401,6 +415,10 @@
        epp->ep_maxsaddr = (vaddr_t)STACK_GROW(epp->ep_minsaddr,
                max_stack_size);
 
+       DPRINTF(("ep_ssize=%llx ep_maxsaddr=%llx\n", 
+           (unsigned long long)epp->ep_ssize,
+           (unsigned long long)epp->ep_maxsaddr));
+
        /*
         * set up commands for stack.  note that this takes *two*, one to
         * map the part of the stack which we can access, and one to map
@@ -414,6 +432,14 @@
        noaccess_size = max_stack_size - access_size;
        noaccess_linear_min = (vaddr_t)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr,
            access_size), noaccess_size);
+
+       DPRINTF(("access_size=%llx, access_linear_min=%llx, "
+           "noaccess_size=%llx, noaccess_linear_min=%llx\n",
+           (unsigned long long)access_size,
+           (unsigned long long)access_linear_min,
+           (unsigned long long)noaccess_size,
+           (unsigned long long)noaccess_linear_min));
+
        if (noaccess_size > 0 && noaccess_size <= MAXSSIZ) {
                NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size,
                    noaccess_linear_min, NULL, 0, VM_PROT_NONE, VMCMD_STACK);