Re: Big stack HUGE coredump

[Mark Kettenis]

> Date: Sat, 23 Feb 2008 13:58:55 +0000
> From: Alexander Nasonov <[EMAIL PROTECTED]>
> 
> Hi,
> If I set a core limit to "unlimited" and a stack limit to 32768,
> then run a program with indefinite recursion, the system would
> generate 8G coredump file.

Does the attached diff fix your problem?

Index: uvm_unix.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_unix.c,v
retrieving revision 1.32
diff -u -p -r1.32 uvm_unix.c
--- uvm_unix.c  5 Jan 2008 00:36:13 -0000       1.32
+++ uvm_unix.c  25 Feb 2008 21:15:10 -0000
@@ -166,7 +166,7 @@ uvm_coredump(p, vp, cred, chdr)
        struct vmspace *vm = p->p_vmspace;
        vm_map_t map = &vm->vm_map;
        vm_map_entry_t entry;
-       vaddr_t start, end;
+       vaddr_t start, end, top;
        struct coreseg cseg;
        off_t offset;
        int flag, error = 0;
@@ -202,13 +202,17 @@ uvm_coredump(p, vp, cred, chdr)
 
 #ifdef MACHINE_STACK_GROWS_UP
                if (USRSTACK <= start && start < (USRSTACK + MAXSSIZ)) {
-                       end = round_page(USRSTACK + ptoa(vm->vm_ssize));
+                       top = round_page(USRSTACK + ptoa(vm->vm_ssize));
+                       if (end > top)
+                               end = top;
+
                        if (start >= end)
                                continue;
-                       start = USRSTACK;
 #else
                if (start >= (vaddr_t)vm->vm_maxsaddr) {
-                       start = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
+                       top = trunc_page(USRSTACK - ptoa(vm->vm_ssize));
+                       if (start < top)
+                               start = top;
 
                        if (start >= end)
                                continue;