svn commit: r257143 - head/sys/cddl/contrib/opensolaris/uts/intel/dtrace

[Mark Johnston]

Author: markj
Date: Sat Oct 26 03:21:54 2013
New Revision: 257143
URL: http://svnweb.freebsd.org/changeset/base/257143

Log:
  Fix a couple of bugs in the fasttrap emulation of a "push %rbp" instruction:
  the code was trying to save the stack pointer rather than the frame pointer,
  and the arguments to copyout(9) were reversed, so nothing ended up being
  saved on the stack. This would cause process crashes when the pid provider
  was being used to instrument calls of a function starting with this
  instruction.
  
  Reported by:	symbolics at gmx.com
  Tested by:	symbolics at gmx.com (earlier version)
  MFC after:	2 weeks

Modified:
  head/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c

Modified: head/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c	Sat Oct 26 03:21:08 2013	(r257142)
+++ head/sys/cddl/contrib/opensolaris/uts/intel/dtrace/fasttrap_isa.c	Sat Oct 26 03:21:54 2013	(r257143)
@@ -104,6 +104,7 @@ uwrite(proc_t *p, void *kaddr, size_t le
 #define	r_rip	r_eip
 #define	r_rflags r_eflags
 #define	r_rsp	r_esp
+#define	r_rbp	r_ebp
 #endif
 
 /*
@@ -1394,29 +1395,27 @@ fasttrap_pid_probe(struct reg *rp)
 	case FASTTRAP_T_PUSHL_EBP:
 	{
 		int ret = 0;
-		uintptr_t addr = 0;
 
 #ifdef __amd64
 		if (p->p_model == DATAMODEL_NATIVE) {
-			addr = rp->r_rsp - sizeof (uintptr_t);
-			ret = fasttrap_sulword((void *)addr, &rp->r_rsp);
+			rp->r_rsp -= sizeof (uintptr_t);
+			ret = fasttrap_sulword(&rp->r_rbp, (void *)rp->r_rsp);
 		} else {
 #endif
 #ifdef __i386__
-			addr = rp->r_rsp - sizeof (uint32_t);
-			ret = fasttrap_suword32((void *)addr, &rp->r_rsp);
+			rp->r_rsp -= sizeof (uint32_t);
+			ret = fasttrap_suword32(&rp->r_rbp, (void *)rp->r_rsp);
 #endif
 #ifdef __amd64
 		}
 #endif
 
 		if (ret == -1) {
-			fasttrap_sigsegv(p, curthread, addr);
+			fasttrap_sigsegv(p, curthread, rp->r_rsp);
 			new_pc = pc;
 			break;
 		}
 
-		rp->r_rsp = addr;
 		new_pc = pc + tp->ftt_size;
 		break;
 	}