implement prctl() for COMPAT_LINUX

ok pirofti@

1 files changed, 83 insertions, 1 deletions

diff --git a/sys/compat/linux/linux_misc.c b/sys/compat/linux/linux_misc.c
index 57020d126fa..ffa718dc1be 100644
--- a/sys/compat/linux/linux_misc.c
+++ b/sys/compat/linux/linux_misc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: linux_misc.c,v 1.72 2011/07/09 00:10:52 deraadt Exp $	*/
+/*	$OpenBSD: linux_misc.c,v 1.73 2011/12/14 08:33:18 robert Exp $	*/
 /*	$NetBSD: linux_misc.c,v 1.27 1996/05/20 01:59:21 fvdl Exp $	*/
 
 /*-
@@ -1481,3 +1481,85 @@ linux_sys_swapon(struct proc *p, void *v, register_t *retval)
 	SCARG(&ua, misc) = 0;	/* priority */
 	return (sys_swapctl(p, &ua, retval));
 }
+
+int
+linux_sys_prctl(struct proc *p, void *v, register_t *retval)
+{
+	int error = 0, max_size, pdeath_signal;
+	char comm[LINUX_MAX_COMM_LEN];
+	struct linux_emuldata *ed = (struct linux_emuldata*)p->p_emuldata;
+
+	struct linux_sys_prctl_args /* {
+		int option;
+		unsigned long arg2;
+		unsigned long arg3;
+		unsigned long arg4;
+		unsigned long arg5;
+	} */ *uap = v;
+
+	switch (SCARG(uap, option)) {
+	case LINUX_PR_SET_PDEATHSIG:
+		if (SCARG(uap, arg2) < 0 || SCARG(uap, arg2) >= LINUX__NSIG)
+			return (EINVAL);
+		ed->pdeath_signal = SCARG(uap, arg2);
+		break;
+	case LINUX_PR_GET_PDEATHSIG:
+		pdeath_signal = ed->pdeath_signal;
+		error = copyout(&pdeath_signal, (void *)SCARG(uap, arg2),
+		    sizeof(pdeath_signal));
+		break;
+	case LINUX_PR_GET_KEEPCAPS:
+		/*
+		 * Indicate that we always clear the effective and
+		 * permitted capability sets when the user id becomes
+		 * non-zero (actually the capability sets are simply
+		 * always zero in the current implementation).
+		 */
+		*retval = 0;
+		break;
+	case LINUX_PR_SET_KEEPCAPS:
+		 /* Ignore requests to keep the effective and permitted
+		  * capability sets when the user id becomes non-zero.
+		  */
+		break;
+	case LINUX_PR_SET_NAME:
+		/*
+		 * To be on the safe side we need to make sure not to
+		 * overflow the size a linux program expects. We already
+		 * do this here in the copyin, so that we don't need to
+		 * check on copyout.
+		 */
+		max_size = MIN(sizeof(comm), sizeof(p->p_comm));
+		error = copyinstr((void *)SCARG(uap, arg2), comm,
+		    max_size, NULL);
+
+		/* Linux silently truncates the name if it is too long. */
+		if (error == ENAMETOOLONG) {
+			/*
+			 * XXX: copyinstr() isn't documented to populate the
+			 * array completely, so do a copyin() to be on the
+			 * safe side. This should be changed in case copyinstr()
+			 * is changed to guarantee this.
+			 */
+			error = copyin((void *)SCARG(uap, arg2), comm,
+			    max_size - 1);
+			comm[max_size - 1] = '\0';
+		}
+		if (error)
+			return (error);
+		strlcpy(p->p_comm, comm, sizeof(p->p_comm));
+		break;
+	case LINUX_PR_GET_NAME:
+		strlcpy(comm, p->p_comm, sizeof(comm));
+		error = copyout(comm, (void *)SCARG(uap, arg2),
+		    strlen(comm) + 1);
+		break;
+	default:
+		printf("linux_sys_prctl: unsupported option %d\n",
+		    SCARG(uap, option));
+		error = EINVAL;
+		break;
+	}
+
+	return (error);
+}