svn commit: r257858 - head/sys/i386/i386

[Konstantin Belousov]

Author: kib
Date: Fri Nov  8 16:57:55 2013
New Revision: 257858
URL: http://svnweb.freebsd.org/changeset/base/257858

Log:
  Fix signal delivery for the iBCS2 binaries.  The iBCS2 sysvec uses
  current FreeBSD signal trampoline, but does not specifies
  sv_sigcode_base, since shared page is not mapped.  This results in the
  zero %eip for the signal frame.  Fall back to calculating %eip as
  offset from the psstrings when sv_sigcode_base is not initialized.
  
  Reported by:	Rich Naill <rich at enterprisesystems.net>
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week

Modified:
  head/sys/i386/i386/machdep.c

Modified: head/sys/i386/i386/machdep.c
==============================================================================
--- head/sys/i386/i386/machdep.c	Fri Nov  8 16:56:13 2013	(r257857)
+++ head/sys/i386/i386/machdep.c	Fri Nov  8 16:57:55 2013	(r257858)
@@ -757,6 +757,8 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, 
 
 	regs->tf_esp = (int)sfp;
 	regs->tf_eip = p->p_sysent->sv_sigcode_base;
+	if (regs->tf_eip == 0)
+		regs->tf_eip = p->p_sysent->sv_psstrings - szsigcode;
 	regs->tf_eflags &= ~(PSL_T | PSL_D);
 	regs->tf_cs = _ucodesel;
 	regs->tf_ds = _udatasel;