svn commit: r327794 - head/cddl/contrib/opensolaris/lib/libdtrace/common

[Mark Johnston]

Author: markj
Date: Wed Jan 10 21:37:11 2018
New Revision: 327794
URL: https://svnweb.freebsd.org/changeset/base/327794

Log:
  Fix an off-by-one in dt_opt_setenv().
  
  The bug would cause incorrect behaviour when attempting to override
  an already set environment variable with -x setenv, as long as the
  variable is not the last one in the array.
  
  Reported by:	Samuel Lepetit <slepetit at apple.com>
  MFC after:	2 weeks

Modified:
  head/cddl/contrib/opensolaris/lib/libdtrace/common/dt_options.c

Modified: head/cddl/contrib/opensolaris/lib/libdtrace/common/dt_options.c
==============================================================================
--- head/cddl/contrib/opensolaris/lib/libdtrace/common/dt_options.c	Wed Jan 10 21:24:03 2018	(r327793)
+++ head/cddl/contrib/opensolaris/lib/libdtrace/common/dt_options.c	Wed Jan 10 21:37:11 2018	(r327794)
@@ -415,7 +415,7 @@ dt_opt_setenv(dtrace_hdl_t *dtp, const char *arg, uint
 {
 	char **p;
 	char *var;
-	int i;
+	int nvars;
 
 	/*
 	 * We can't effectively set environment variables from #pragma lines
@@ -430,7 +430,7 @@ dt_opt_setenv(dtrace_hdl_t *dtp, const char *arg, uint
 	if (!option && strchr(arg, '=') != NULL)
 		return (dt_set_errno(dtp, EDT_BADOPTVAL));
 
-	for (i = 1, p = dtp->dt_proc_env; *p != NULL; i++, p++)
+	for (nvars = 0, p = dtp->dt_proc_env; *p != NULL; nvars++, p++)
 		continue;
 
 	for (p = dtp->dt_proc_env; *p != NULL; p++) {
@@ -439,9 +439,9 @@ dt_opt_setenv(dtrace_hdl_t *dtp, const char *arg, uint
 			var = *p + strlen(*p);
 		if (strncmp(*p, arg, var - *p) == 0) {
 			dt_free(dtp, *p);
-			*p = dtp->dt_proc_env[i - 1];
-			dtp->dt_proc_env[i - 1] = NULL;
-			i--;
+			*p = dtp->dt_proc_env[nvars - 1];
+			dtp->dt_proc_env[nvars - 1] = NULL;
+			nvars--;
 		}
 	}
 
@@ -449,17 +449,18 @@ dt_opt_setenv(dtrace_hdl_t *dtp, const char *arg, uint
 		if ((var = strdup(arg)) == NULL)
 			return (dt_set_errno(dtp, EDT_NOMEM));
 
-		if ((p = dt_alloc(dtp, sizeof (char *) * (i + 1))) == NULL) {
+		nvars++;
+		if ((p = dt_alloc(dtp, sizeof(char *) * (nvars + 1))) == NULL) {
 			dt_free(dtp, var);
 			return (dt_set_errno(dtp, EDT_NOMEM));
 		}
 
-		bcopy(dtp->dt_proc_env, p, sizeof (char *) * i);
+		bcopy(dtp->dt_proc_env, p, sizeof(char *) * nvars);
 		dt_free(dtp, dtp->dt_proc_env);
 		dtp->dt_proc_env = p;
 
-		dtp->dt_proc_env[i - 1] = var;
-		dtp->dt_proc_env[i] = NULL;
+		dtp->dt_proc_env[nvars - 1] = var;
+		dtp->dt_proc_env[nvars] = NULL;
 	}
 
 	return (0);