This will be useful in later patches for tracking the paths associated
with mmap operations. This will be useful to the upcoming -dfilter
changes to track execution only certain libraries.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
---
linux-user/syscall.c | 59 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 54 insertions(+), 5 deletions(-)
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 9353268cc1..e191163c49 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -8557,6 +8557,58 @@ static int open_hardware(CPUArchState *cpu_env, int fd)
}
#endif
+/*
+ * Handle non-intercepted guest open operations. This gives us the
+ * opportunity to track some information
+ */
+
+static QemuMutex fd_tracking_lock;
+static GHashTable *fd_path;
+
+__attribute__((constructor))
+static void fd_tracking_init(void)
+{
+ qemu_mutex_init(&fd_tracking_lock);
+}
+
+static int do_plain_guest_openat(int dirfd, const char *pathname,
+ int flags, mode_t mode, bool safe)
+{
+ const char * real_path = path(pathname);
+ int fd;
+
+ if (safe) {
+ fd = safe_openat(dirfd, real_path, flags, mode);
+ } else {
+ fd = openat(dirfd, real_path, flags, mode);
+ }
+
+ /* If we opened an fd save some details */
+ if (fd >= 0) {
+ WITH_QEMU_LOCK_GUARD(&fd_tracking_lock) {
+ if (!fd_path) {
+ fd_path = g_hash_table_new(NULL, NULL);
+ }
+
+ if (!g_hash_table_insert(fd_path, GINT_TO_POINTER(fd),
g_strdup(real_path))) {
+ fprintf(stderr, "%s: duplicate fd %d in fd_path hash\n",
__func__, fd);
+ }
+ }
+ }
+
+ return fd;
+}
+
+static void fd_path_cleanup(int fd) {
+ WITH_QEMU_LOCK_GUARD(&fd_tracking_lock) {
+ /*
+ * Assume success, if we failed to cleanup its totally
+ * possible the guest got confused and closed something twice.
+ */
+ g_hash_table_remove(fd_path, GINT_TO_POINTER(fd));
+ }
+}
+
int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *fname,
int flags, mode_t mode, bool safe)
@@ -8643,11 +8695,7 @@ int do_guest_openat(CPUArchState *cpu_env, int dirfd,
const char *fname,
return fd;
}
- if (safe) {
- return safe_openat(dirfd, path(pathname), flags, mode);
- } else {
- return openat(dirfd, path(pathname), flags, mode);
- }
+ return do_plain_guest_openat(dirfd, pathname, flags, mode, safe);
}
ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz)
@@ -9355,6 +9403,7 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int
num, abi_long arg1,
return get_errno(pidfd_getfd(arg1, arg2, arg3));
#endif
case TARGET_NR_close:
+ fd_path_cleanup(arg1);
fd_trans_unregister(arg1);
return get_errno(close(arg1));
#if defined(__NR_close_range) && defined(TARGET_NR_close_range)
--
2.39.2
