Enhance capget and capset syscalls decoding

* system.c (cap_version): New xlat structure.
(print_cap_header, print_cap_data): New functions.
(sys_capget, sys_capset): Use them.

diff --git a/system.c b/system.c
index 4fdfa6f3e518b7e0c5ce7588b6067531765da0d4..cf66b13e94eefd3b7c64d514177858edbc984ccc 100644 (file)
--- a/system.c
+++ b/system.c
@@ -494,45 +494,75 @@ static const struct xlat capabilities[] = {
        { 0,            NULL            },
 };
 
+#ifndef _LINUX_CAPABILITY_VERSION_1
+# define _LINUX_CAPABILITY_VERSION_1 0x19980330
+#endif
+#ifndef _LINUX_CAPABILITY_VERSION_2
+# define _LINUX_CAPABILITY_VERSION_2 0x20071026
+#endif
+#ifndef _LINUX_CAPABILITY_VERSION_3
+# define _LINUX_CAPABILITY_VERSION_3 0x20080522
+#endif
+
+static const struct xlat cap_version[] = {
+       { _LINUX_CAPABILITY_VERSION_1,  "_LINUX_CAPABILITY_VERSION_1"   },
+       { _LINUX_CAPABILITY_VERSION_2,  "_LINUX_CAPABILITY_VERSION_3"   },
+       { _LINUX_CAPABILITY_VERSION_3,  "_LINUX_CAPABILITY_VERSION_3"   },
+       { 0,                            NULL                            }
+};
+
+static void
+print_cap_header(struct tcb *tcp, unsigned long addr)
+{
+       union { cap_user_header_t p; long *a; char *c; } arg;
+       long a[sizeof(*arg.p) / sizeof(long) + 1];
+       arg.a = a;
+
+       if (!addr)
+               tprints("NULL");
+       else if (!verbose(tcp) ||
+                umoven(tcp, addr, sizeof(*arg.p), arg.c) < 0)
+               tprintf("%#lx", addr);
+       else {
+               tprints("{");
+               printxval(cap_version, arg.p->version,
+                         "_LINUX_CAPABILITY_VERSION_???");
+               tprintf(", %d}", arg.p->pid);
+       }
+}
+
+static void
+print_cap_data(struct tcb *tcp, unsigned long addr)
+{
+       union { cap_user_data_t p; long *a; char *c; } arg;
+       long a[sizeof(*arg.p) / sizeof(long) + 1];
+       arg.a = a;
+
+       if (!addr)
+               tprints("NULL");
+       else if (!verbose(tcp) ||
+                (exiting(tcp) && syserror(tcp)) ||
+                umoven(tcp, addr, sizeof(*arg.p), arg.c) < 0)
+               tprintf("%#lx", addr);
+       else {
+               tprints("{");
+               printflags(capabilities, arg.p->effective, "CAP_???");
+               tprints(", ");
+               printflags(capabilities, arg.p->permitted, "CAP_???");
+               tprints(", ");
+               printflags(capabilities, arg.p->inheritable, "CAP_???");
+               tprints("}");
+       }
+}
+
 int
 sys_capget(struct tcb *tcp)
 {
-       /* cap_user_ types are _pointers_ to (small) structs. */
-       /* Structs themselves have no names defined. */
-       /* Have to use ugly hack to place them on stack. */
-       union { cap_user_header_t p; long *a; char *c; } arg0;
-       union { cap_user_data_t p; long *a; char *c; } arg1;
-       long a0[sizeof(*arg0.p) / sizeof(long) + 1];
-       long a1[sizeof(*arg1.p) / sizeof(long) + 1];
-       arg0.a = a0;
-       arg1.a = a1;
-
-       if (!entering(tcp)) {
-               if (!tcp->u_arg[0])
-                       tprints("NULL");
-               else if (!verbose(tcp))
-                       tprintf("%#lx", tcp->u_arg[0]);
-               else if (umoven(tcp, tcp->u_arg[0], sizeof(*arg0.p), arg0.c) < 0)
-                       tprints("???");
-               else {
-                       tprintf("%#x, %d", arg0.p->version, arg0.p->pid);
-               }
+       if (entering(tcp)) {
+               print_cap_header(tcp, tcp->u_arg[0]);
                tprints(", ");
-               if (!tcp->u_arg[1])
-                       tprints("NULL");
-               else if (!verbose(tcp))
-                       tprintf("%#lx", tcp->u_arg[1]);
-               else if (umoven(tcp, tcp->u_arg[1], sizeof(*arg1.p), arg1.c) < 0)
-                       tprints("???");
-               else {
-                       tprints("{");
-                       printflags(capabilities, arg1.p->effective, "CAP_???");
-                       tprints(", ");
-                       printflags(capabilities, arg1.p->permitted, "CAP_???");
-                       tprints(", ");
-                       printflags(capabilities, arg1.p->inheritable, "CAP_???");
-                       tprints("}");
-               }
+       } else {
+               print_cap_data(tcp, tcp->u_arg[1]);
        }
        return 0;
 }
@@ -540,39 +570,10 @@ sys_capget(struct tcb *tcp)
 int
 sys_capset(struct tcb *tcp)
 {
-       union { cap_user_header_t p; long *a; char *c; } arg0;
-       union { cap_user_data_t p; long *a; char *c; } arg1;
-       long a0[sizeof(*arg0.p) / sizeof(long) + 1];
-       long a1[sizeof(*arg1.p) / sizeof(long) + 1];
-       arg0.a = a0;
-       arg1.a = a1;
-
        if (entering(tcp)) {
-               if (!tcp->u_arg[0])
-                       tprints("NULL");
-               else if (!verbose(tcp))
-                       tprintf("%#lx", tcp->u_arg[0]);
-               else if (umoven(tcp, tcp->u_arg[0], sizeof(*arg0.p), arg0.c) < 0)
-                       tprints("???");
-               else {
-                       tprintf("%#x, %d", arg0.p->version, arg0.p->pid);
-               }
+               print_cap_header(tcp, tcp->u_arg[0]);
                tprints(", ");
-               if (!tcp->u_arg[1])
-                       tprints("NULL");
-               else if (!verbose(tcp))
-                       tprintf("%#lx", tcp->u_arg[1]);
-               else if (umoven(tcp, tcp->u_arg[1], sizeof(*arg1.p), arg1.c) < 0)
-                       tprints("???");
-               else {
-                       tprints("{");
-                       printflags(capabilities, arg1.p->effective, "CAP_???");
-                       tprints(", ");
-                       printflags(capabilities, arg1.p->permitted, "CAP_???");
-                       tprints(", ");
-                       printflags(capabilities, arg1.p->inheritable, "CAP_???");
-                       tprints("}");
-               }
+               print_cap_data(tcp, tcp->u_arg[1]);
        }
        return 0;
 }