aarch64, arm: decode extra padded compat struct statfs64

According to arch/arm/kernel/sys_oabi-compat.c,
struct statfs64 has extra padding with EABI.

* statfs.c [AARCH64 || defined ARM] (COMPAT_STATFS64_PADDED_SIZE):
Define.
(do_statfs64_fstatfs64): New function, factored out from sys_statfs64.
[COMPAT_STATFS64_PADDED_SIZE]: Check it in addition to
sizeof(struct compat_statfs64).
(sys_statfs64, sys_fstatfs64): Use do_statfs64_fstatfs64.

Reported-and-tested-by: Elliott Hughes <enh@google.com>

diff --git a/statfs.c b/statfs.c
index f1e9fc38427b25f7f0d25bc636f4bfdb898fb0fb..214e6b2a813a29f70f20eb297eec57c127c26d26 100644 (file)
--- a/statfs.c
+++ b/statfs.c
@@ -128,6 +128,10 @@ struct compat_statfs64 {
   __attribute__ ((packed, aligned(4)))
 #endif
 ;
+#if defined AARCH64 || defined ARM
+/* See arch/arm/kernel/sys_oabi-compat.c for details. */
+# define COMPAT_STATFS64_PADDED_SIZE (sizeof(struct compat_statfs64) + 4)
+#endif
 
 static void
 printcompat_statfs64(struct tcb *tcp, const long addr)
@@ -157,16 +161,19 @@ printcompat_statfs64(struct tcb *tcp, const long addr)
        tprintf(", f_flags=%lu}", (unsigned long)statbuf.f_frsize);
 }
 
-int
-sys_statfs64(struct tcb *tcp)
+static int
+do_statfs64_fstatfs64(struct tcb *tcp)
 {
        if (entering(tcp)) {
-               printpath(tcp, tcp->u_arg[0]);
                tprintf(", %lu, ", tcp->u_arg[1]);
        } else {
                if (tcp->u_arg[1] == sizeof(struct statfs64))
                        printstatfs64(tcp, tcp->u_arg[2]);
-               else if (tcp->u_arg[1] == sizeof(struct compat_statfs64))
+               else if (tcp->u_arg[1] == sizeof(struct compat_statfs64)
+#ifdef COMPAT_STATFS64_PADDED_SIZE
+                        || tcp->u_arg[1] == COMPAT_STATFS64_PADDED_SIZE
+#endif
+                                                                       )
                        printcompat_statfs64(tcp, tcp->u_arg[2]);
                else
                        tprints("{???}");
@@ -174,21 +181,20 @@ sys_statfs64(struct tcb *tcp)
        return 0;
 }
 
+int
+sys_statfs64(struct tcb *tcp)
+{
+       if (entering(tcp))
+               printpath(tcp, tcp->u_arg[0]);
+       return do_statfs64_fstatfs64(tcp);
+}
+
 int
 sys_fstatfs64(struct tcb *tcp)
 {
-       if (entering(tcp)) {
+       if (entering(tcp))
                printfd(tcp, tcp->u_arg[0]);
-               tprintf(", %lu, ", tcp->u_arg[1]);
-       } else {
-               if (tcp->u_arg[1] == sizeof(struct statfs64))
-                       printstatfs64(tcp, tcp->u_arg[2]);
-               else if (tcp->u_arg[1] == sizeof(struct compat_statfs64))
-                       printcompat_statfs64(tcp, tcp->u_arg[2]);
-               else
-                       tprints("{???}");
-       }
-       return 0;
+       return do_statfs64_fstatfs64(tcp);
 }
 #endif /* HAVE_STRUCT_STATFS64 */