X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Frunas.c;h=e0c317c4e40347fb7001b74fb9900e9bcfafe32f;hp=07912a7d68bf7ce97cf7ba765194fd66e28334c8;hb=e71aad1fa4b06a5f91ddceace42366f3d79bd77e;hpb=ca4537d385628d3568a918409d909d3042ca7a38

diff --git a/src/common/runas.c b/src/common/runas.c
index 07912a7d6..e0c317c4e 100644
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -28,16 +28,29 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <sched.h>
-#include <sys/mman.h>
+#include <sys/signal.h>
 
 #include <common/error.h>
+#include <common/compat/mman.h>
+#include <common/compat/clone.h>
 
 #include "runas.h"
 
 #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 {
@@ -154,14 +167,14 @@ int child_run_as(void *_data)
 	if (data->gid != getegid()) {
 		ret = setegid(data->gid);
 		if (ret < 0) {
-			perror("setegid");
+			PERROR("setegid");
 			return EXIT_FAILURE;
 		}
 	}
 	if (data->uid != geteuid()) {
 		ret = seteuid(data->uid);
 		if (ret < 0) {
-			perror("seteuid");
+			PERROR("seteuid");
 			return EXIT_FAILURE;
 		}
 	}
@@ -177,7 +190,7 @@ int child_run_as(void *_data)
 		writelen = write(data->retval_pipe, &sendret.c[index],
 				writeleft);
 		if (writelen < 0) {
-			perror("write");
+			PERROR("write");
 			return EXIT_FAILURE;
 		}
 		writeleft -= writelen;
@@ -187,7 +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;
@@ -214,7 +227,8 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
 
 	ret = pipe(retval_pipe);
 	if (ret < 0) {
-		perror("pipe");
+		PERROR("pipe");
+		retval.i = ret;
 		goto end;
 	}
 	run_as_data.data = data;
@@ -224,23 +238,22 @@ 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;
+		PERROR("mmap");
+		retval.i = -ENOMEM;
 		goto close_pipe;
 	}
 	/*
 	 * Pointing to the middle of the stack to support architectures
 	 * where the stack grows up (HPPA).
 	 */
-	pid = clone(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2),
-		CLONE_FILES | SIGCHLD,
-		&run_as_data, NULL);
+	pid = lttng_clone_files(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2),
+		&run_as_data);
 	if (pid < 0) {
-		perror("clone");
-		ret = pid;
+		PERROR("clone");
+		retval.i = pid;
 		goto unmap_stack;
 	}
 	/* receive return value */
@@ -249,7 +262,7 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid)
 	do {
 		readlen = read(retval_pipe[0], &retval.c[index], readleft);
 		if (readlen < 0) {
-			perror("read");
+			PERROR("read");
 			ret = -1;
 			break;
 		}
@@ -263,21 +276,51 @@ 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;
+		PERROR("wait");
+		retval.i = -1;
 	}
 unmap_stack:
 	ret = munmap(child_stack, RUNAS_CHILD_STACK_SIZE);
 	if (ret < 0) {
-		perror("munmap");
+		PERROR("munmap");
+		retval.i = ret;
 	}
 close_pipe:
-	close(retval_pipe[0]);
-	close(retval_pipe[1]);
+	ret = close(retval_pipe[0]);
+	if (ret) {
+		PERROR("close");
+	}
+	ret = close(retval_pipe[1]);
+	if (ret) {
+		PERROR("close");
+	}
 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;