Add sysentvec->sv_fixlimits() hook so that we can catch cases on 64 bit

systems where the data/stack/etc limits are too big for a 32 bit process.

Move the 5 or so identical instances of ELF_RTLD_ADDR() into imgact_elf.c.

Supply an ia32_fixlimits function.  Export the clip/default values to
sysctl under the compat.ia32 heirarchy.

Have mmap(0, ...) respect the current p->p_limits[RLIMIT_DATA].rlim_max
value rather than the sysctl tweakable variable.  This allows mmap to
place mappings at sensible locations when limits have been reduced.

Have the imgact_elf.c ld-elf.so.1 placement algorithm use the same
method as mmap(0, ...) now does.

Note that we cannot remove all references to the sysctl tweakable
maxdsiz etc variables because /etc/login.conf specifies a datasize
of 'unlimited'.  And that causes exec etc to fail since it can no
longer find space to mmap things.

1 files changed, 9 insertions, 0 deletions

diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 8ff2dda..5b0d44f 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -842,6 +842,15 @@ exec_new_vmspace(imgp, sv)
 	EVENTHANDLER_INVOKE(process_exec, p);
 
 	/*
+	 * Here is as good a place as any to do any resource limit cleanups.
+	 * This is needed if a 64 bit binary exec's a 32 bit binary - the
+	 * data size limit may need to be changed to a value that makes
+	 * sense for the 32 bit binary.
+	 */
+	if (sv->sv_fixlimits)
+		sv->sv_fixlimits(imgp);
+
+	/*
 	 * Blow away entire process VM, if address space not shared,
 	 * otherwise, create a new VM space so that other threads are
 	 * not disrupted