#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 {
}
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;
ret = pipe(retval_pipe);
if (ret < 0) {
perror("pipe");
+ retval.i = ret;
goto end;
}
run_as_data.data = data;
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;
}
/*
* 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;
+ retval.i = pid;
goto unmap_stack;
}
/* receive return value */
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]);
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;