Add a tool to track down fd leaks.
Add a hook that's called upon file descriptor creation to libc, and a
library that uses it to capture backtraces for file descriptor creation,
to make it easier to hunt down file descriptor leaks.
Currently, this doesn't capture all of the ways of creating a file
descriptor, but completeness isn't required for this to be useful as
long as leaked file descriptors are created with a function that is
tracked. The primary unhandled case is binder, which receives file
descriptors as a payload in a not-trivially-parsable byte blob, but
there's a chance that the leak we're currently trying to track down
isn't of a file descriptor received over binder, so leave that for
later.
Bug: http://b/140703823
Test: manual
Change-Id: I308a14c2e234cdba4207157b634ab6b8bc539dd9
diff --git a/libc/bionic/open.cpp b/libc/bionic/open.cpp
index 222e5d3..bd8685a 100644
--- a/libc/bionic/open.cpp
+++ b/libc/bionic/open.cpp
@@ -31,6 +31,7 @@
#include <stdlib.h>
#include <unistd.h>
+#include "private/bionic_fdtrack.h"
#include "private/bionic_fortify.h"
extern "C" int __openat(int, const char*, int, int);
@@ -62,13 +63,13 @@
va_end(args);
}
- return __openat(AT_FDCWD, pathname, force_O_LARGEFILE(flags), mode);
+ return FDTRACK_CREATE(__openat(AT_FDCWD, pathname, force_O_LARGEFILE(flags), mode));
}
__strong_alias(open64, open);
int __open_2(const char* pathname, int flags) {
if (needs_mode(flags)) __fortify_fatal("open: called with O_CREAT/O_TMPFILE but no mode");
- return __openat(AT_FDCWD, pathname, force_O_LARGEFILE(flags), 0);
+ return FDTRACK_CREATE_NAME("open", __openat(AT_FDCWD, pathname, force_O_LARGEFILE(flags), 0));
}
int openat(int fd, const char *pathname, int flags, ...) {
@@ -81,11 +82,11 @@
va_end(args);
}
- return __openat(fd, pathname, force_O_LARGEFILE(flags), mode);
+ return FDTRACK_CREATE_NAME("openat", __openat(fd, pathname, force_O_LARGEFILE(flags), mode));
}
__strong_alias(openat64, openat);
int __openat_2(int fd, const char* pathname, int flags) {
if (needs_mode(flags)) __fortify_fatal("open: called with O_CREAT/O_TMPFILE but no mode");
- return __openat(fd, pathname, force_O_LARGEFILE(flags), 0);
+ return FDTRACK_CREATE_NAME("openat", __openat(fd, pathname, force_O_LARGEFILE(flags), 0));
}