svn commit: r228261 - head/usr.bin/truss

[Konstantin Belousov]

Author: kib
Date: Sun Dec  4 18:43:09 2011
New Revision: 228261
URL: http://svn.freebsd.org/changeset/base/228261

Log:
  Use explicit information from the kernel to detect the traps due to
  syscall entry and leave.
  
  Based on submision by:	Dan Nelson <dnelson allantgroup com>
  MFC after:	1 month

Modified:
  head/usr.bin/truss/setup.c

Modified: head/usr.bin/truss/setup.c
==============================================================================
--- head/usr.bin/truss/setup.c	Sun Dec  4 16:33:04 2011	(r228260)
+++ head/usr.bin/truss/setup.c	Sun Dec  4 18:43:09 2011	(r228261)
@@ -202,9 +202,19 @@ waitevent(struct trussinfo *info)
 		find_thread(info, lwpinfo.pl_lwpid);
 		switch(WSTOPSIG(waitval)) {
 		case SIGTRAP:
-			info->pr_why = info->curthread->in_syscall?S_SCX:S_SCE;
-			info->curthread->in_syscall = 1 - info->curthread->in_syscall;
-			break;
+			if (lwpinfo.pl_flags & PL_FLAG_SCE) {
+				info->pr_why = S_SCE;
+				info->curthread->in_syscall = 1;
+				break;
+			} else if (lwpinfo.pl_flags & PL_FLAG_SCX) {
+				info->pr_why = S_SCX;
+				info->curthread->in_syscall = 0;
+				break;
+			} else {
+				errx(1,
+		   "pl_flags %x contains neither PL_FLAG_SCE nor PL_FLAG_SCX",
+				    lwpinfo.pl_flags);
+			}
 		default:
 			info->pr_why = S_SIG;
 			info->pr_data = WSTOPSIG(waitval);