Author: jhibbits
Date: Sun Nov 17 01:01:02 2019
New Revision: 354783
URL: https://svnweb.freebsd.org/changeset/base/354783

Log:
  powerpc: Return SIGILL if DSCR does not exist in m{f,t}spr emulation
  
  Guard against programs written for one powerpc target running on another,
  and panicking the system due to not having the DSCR register.

Modified:
  head/sys/powerpc/powerpc/exec_machdep.c

Modified: head/sys/powerpc/powerpc/exec_machdep.c
==============================================================================
--- head/sys/powerpc/powerpc/exec_machdep.c     Sun Nov 17 00:52:58 2019        
(r354782)
+++ head/sys/powerpc/powerpc/exec_machdep.c     Sun Nov 17 01:01:02 2019        
(r354783)
@@ -1086,15 +1086,17 @@ emulate_mfspr(int spr, int reg, struct trapframe *fram
        td = curthread;
 
        if (spr == SPR_DSCR || spr == SPR_DSCRP) {
+               if (!(cpu_features2 & PPC_FEATURE2_DSCR))
+                       return (SIGILL);
                // If DSCR was never set, get the default DSCR
                if ((td->td_pcb->pcb_flags & PCB_CDSCR) == 0)
                        td->td_pcb->pcb_dscr = mfspr(SPR_DSCRP);
 
                frame->fixreg[reg] = td->td_pcb->pcb_dscr;
                frame->srr0 += 4;
-               return 0;
+               return (0);
        } else
-               return SIGILL;
+               return (SIGILL);
 }
 
 static int
@@ -1104,13 +1106,15 @@ emulate_mtspr(int spr, int reg, struct trapframe *fram
        td = curthread;
 
        if (spr == SPR_DSCR || spr == SPR_DSCRP) {
+               if (!(cpu_features2 & PPC_FEATURE2_DSCR))
+                       return (SIGILL);
                td->td_pcb->pcb_flags |= PCB_CDSCR;
                td->td_pcb->pcb_dscr = frame->fixreg[reg];
                mtspr(SPR_DSCRP, frame->fixreg[reg]);
                frame->srr0 += 4;
-               return 0;
+               return (0);
        } else
-               return SIGILL;
+               return (SIGILL);
 }
 
 #define XFX 0xFC0007FF
_______________________________________________
svn-src-all@freebsd.org mailing list
https://lists.freebsd.org/mailman/listinfo/svn-src-all
To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"

Reply via email to