Fix compiler warnings about breaking strict-aliasing rules
* system.c (sys_capget, sys_capset): Use proxy unions to cast long*
pointers to cap_user_header_t and cap_user_data_t pointers without
breaking strict-aliasing rules.
Reported-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/system.c b/system.c
index 5498449..c44a016 100644
--- a/system.c
+++ b/system.c
@@ -501,37 +501,37 @@
/* cap_user_ types are _pointers_ to (small) structs. */
/* Structs themselves have no names defined. */
/* Have to use ugly hack to place them on stack. */
- cap_user_header_t arg0;
- cap_user_data_t arg1;
- long a0[sizeof(*arg0) / sizeof(long) + 1];
- long a1[sizeof(*arg1) / sizeof(long) + 1];
- arg0 = (cap_user_header_t) a0;
- arg1 = (cap_user_data_t ) a1;
+ 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), (char *) arg0) < 0)
+ else if (umoven(tcp, tcp->u_arg[0], sizeof(*arg0.p), arg0.c) < 0)
tprints("???");
else {
- tprintf("%#x, %d", arg0->version, arg0->pid);
+ tprintf("%#x, %d", arg0.p->version, arg0.p->pid);
}
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), (char *) arg1) < 0)
+ else if (umoven(tcp, tcp->u_arg[1], sizeof(*arg1.p), arg1.c) < 0)
tprints("???");
else {
tprints("{");
- printflags(capabilities, arg1->effective, "CAP_???");
+ printflags(capabilities, arg1.p->effective, "CAP_???");
tprints(", ");
- printflags(capabilities, arg1->permitted, "CAP_???");
+ printflags(capabilities, arg1.p->permitted, "CAP_???");
tprints(", ");
- printflags(capabilities, arg1->inheritable, "CAP_???");
+ printflags(capabilities, arg1.p->inheritable, "CAP_???");
tprints("}");
}
}
@@ -541,37 +541,37 @@
int
sys_capset(struct tcb *tcp)
{
- cap_user_header_t arg0;
- cap_user_data_t arg1;
- long a0[sizeof(*arg0) / sizeof(long) + 1];
- long a1[sizeof(*arg1) / sizeof(long) + 1];
- arg0 = (cap_user_header_t) a0;
- arg1 = (cap_user_data_t ) a1;
+ 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), (char *) arg0) < 0)
+ else if (umoven(tcp, tcp->u_arg[0], sizeof(*arg0.p), arg0.c) < 0)
tprints("???");
else {
- tprintf("%#x, %d", arg0->version, arg0->pid);
+ tprintf("%#x, %d", arg0.p->version, arg0.p->pid);
}
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), (char *) arg1) < 0)
+ else if (umoven(tcp, tcp->u_arg[1], sizeof(*arg1.p), arg1.c) < 0)
tprints("???");
else {
tprints("{");
- printflags(capabilities, arg1->effective, "CAP_???");
+ printflags(capabilities, arg1.p->effective, "CAP_???");
tprints(", ");
- printflags(capabilities, arg1->permitted, "CAP_???");
+ printflags(capabilities, arg1.p->permitted, "CAP_???");
tprints(", ");
- printflags(capabilities, arg1->inheritable, "CAP_???");
+ printflags(capabilities, arg1.p->inheritable, "CAP_???");
tprints("}");
}
}