[PATCH v2] target/ppc/kvm: Skip current and parent directories in kvmppc_find_cpu_dt

[Murilo Opsfelder Araujo <muriloo@linux.ibm.com>]

Some systems have /proc/device-tree/cpus/../clock-frequency. However,
this is not the expected path for a CPU device tree directory.

Signed-off-by: Murilo Opsfelder Araujo <muriloo@linux.ibm.com>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
---
v2:
- Skip current and parent directories.

v1: https://lore.kernel.org/qemu-devel/20220711193743.51456-1-muriloo@linux.ibm.com/

 target/ppc/kvm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 6eed466f80..466d0d2f4c 100644
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -1877,6 +1877,12 @@ static int kvmppc_find_cpu_dt(char *buf, int buf_len)
     buf[0] = '\0';
     while ((dirp = readdir(dp)) != NULL) {
         FILE *f;
+
+        /* Don't accidentally read from the current and parent directories */
+        if (strcmp(dirp->d_name, ".") == 0 || strcmp(dirp->d_name, "..") == 0) {
+            continue;
+        }
+
         snprintf(buf, buf_len, "%s%s/clock-frequency", PROC_DEVTREE_CPU,
                  dirp->d_name);
         f = fopen(buf, "r");
-- 
2.36.1