X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Frunas.c;h=4742a792eca105f35f1a8e2d194db9aeecd55a66;hb=2d85a600590b23ca5ca1e182187d08f44808ef80;hp=86db9b8682c343efaee59a08bee72123fc518d60;hpb=89831a7431103178268b5f1dccbf094e7c4f4095;p=lttng-tools.git

diff --git a/src/common/runas.c b/src/common/runas.c
index 86db9b868..4742a792e 100644
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -38,8 +38,19 @@
 
 #define RUNAS_CHILD_STACK_SIZE	10485760
 
-#ifndef MAP_STACK
-#define MAP_STACK		0
+#ifdef __FreeBSD__
+/* FreeBSD MAP_STACK always return -ENOMEM */
+#define LTTNG_MAP_STACK		0
+#else
+#define LTTNG_MAP_STACK		MAP_STACK
+#endif
+
+#ifndef MAP_GROWSDOWN
+#define MAP_GROWSDOWN		0
+#endif
+
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS		MAP_ANON
 #endif
 
 struct run_as_data {
@@ -189,7 +200,7 @@ int child_run_as(void *_data)
 }
 
 static
-int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+int run_as_clone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
 {
 	struct run_as_data run_as_data;
 	int ret = 0;
@@ -217,6 +228,7 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
 	ret = pipe(retval_pipe);
 	if (ret < 0) {
 		perror("pipe");
+		retval.i = ret;
 		goto end;
 	}
 	run_as_data.data = data;
@@ -226,11 +238,11 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
 	run_as_data.retval_pipe = retval_pipe[1];	/* write end */
 	child_stack = mmap(NULL, RUNAS_CHILD_STACK_SIZE,
 		PROT_WRITE | PROT_READ,
-		MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | MAP_STACK,
+		MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | LTTNG_MAP_STACK,
 		-1, 0);
 	if (child_stack == MAP_FAILED) {
 		perror("mmap");
-		ret = -ENOMEM;
+		retval.i = -ENOMEM;
 		goto close_pipe;
 	}
 	/*
@@ -241,7 +253,7 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
 		&run_as_data);
 	if (pid < 0) {
 		perror("clone");
-		ret = pid;
+		retval.i = pid;
 		goto unmap_stack;
 	}
 	/* receive return value */
@@ -265,12 +277,13 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
 	pid = waitpid(pid, &status, 0);
 	if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 		perror("wait");
-		ret = -1;
+		retval.i = -1;
 	}
 unmap_stack:
 	ret = munmap(child_stack, RUNAS_CHILD_STACK_SIZE);
 	if (ret < 0) {
 		perror("munmap");
+		retval.i = ret;
 	}
 close_pipe:
 	close(retval_pipe[0]);
@@ -279,6 +292,29 @@ end:
 	return retval.i;
 }
 
+/*
+ * To be used on setups where gdb has issues debugging programs using
+ * clone/rfork. Note that this is for debuging ONLY, and should not be
+ * considered secure.
+ */
+static
+int run_as_noclone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+{
+	return cmd(data);
+}
+
+static
+int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
+{
+	if (!getenv("LTTNG_DEBUG_NOCLONE")) {
+		DBG("Using run_as_clone");
+		return run_as_clone(cmd, data, uid, gid);
+	} else {
+		DBG("Using run_as_noclone");
+		return run_as_noclone(cmd, data, uid, gid);
+	}
+}
+
 int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
 {
 	struct run_as_mkdir_data data;