implement prctl() for COMPAT_LINUX

ok pirofti@

5 files changed, 104 insertions, 7 deletions

diff --git a/sys/compat/linux/linux_dummy.c b/sys/compat/linux/linux_dummy.c
index d77613043cd..983e76fceb2 100644
--- a/sys/compat/linux/linux_dummy.c
+++ b/sys/compat/linux/linux_dummy.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: linux_dummy.c,v 1.18 2011/11/25 10:10:05 robert Exp $ */
+/*	$OpenBSD: linux_dummy.c,v 1.19 2011/12/14 08:33:18 robert Exp $ */
 
 /*-
  * Copyright (c) 1994-1995 Søren Schmidt
@@ -99,7 +99,6 @@ DUMMY(sched_rr_get_interval);	/* #161 */
 DUMMY(vm86);			/* #166 */
 DUMMY(query_module);		/* #167 */
 DUMMY(nfsservctl);		/* #169 */
-DUMMY(prctl);			/* #172 */
 DUMMY(rt_sigtimedwait);		/* #177 */
 DUMMY(rt_queueinfo);		/* #178 */
 DUMMY(capget);			/* #184 */
diff --git a/sys/compat/linux/linux_emuldata.h b/sys/compat/linux/linux_emuldata.h
index 63b22d1e498..783327715cb 100644
--- a/sys/compat/linux/linux_emuldata.h
+++ b/sys/compat/linux/linux_emuldata.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: linux_emuldata.h,v 1.7 2011/09/18 02:23:18 pirofti Exp $	*/
+/*	$OpenBSD: linux_emuldata.h,v 1.8 2011/12/14 08:33:18 robert Exp $	*/
 /*	$NetBSD: linux_emuldata.h,v 1.4 2002/02/15 16:48:02 christos Exp $	*/
 /*-
  * Copyright (c) 1998,2002 The NetBSD Foundation, Inc.
@@ -51,5 +51,6 @@ struct linux_emuldata {
 
 	struct linux_robust_list_head *led_robust_head;
 
+	int pdeath_signal;	/* parent death signal */
 };
 #endif /* !_LINUX_EMULDATA_H_ */
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);
+}
diff --git a/sys/compat/linux/linux_misc.h b/sys/compat/linux/linux_misc.h
index a4fd5c17baa..a556cba3159 100644
--- a/sys/compat/linux/linux_misc.h
+++ b/sys/compat/linux/linux_misc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: linux_misc.h,v 1.5 2011/04/05 22:54:30 pirofti Exp $	*/
+/*	$OpenBSD: linux_misc.h,v 1.6 2011/12/14 08:33:18 robert Exp $	*/
 /*	$NetBSD: linux_misc.h,v 1.3 1999/05/13 00:31:57 thorpej Exp $	*/
 
 /*-
@@ -33,6 +33,19 @@
 #ifndef _LINUX_MISC_H_
 #define _LINUX_MISC_H_
 
+/* defined for prctl(2) */
+#define LINUX_PR_SET_PDEATHSIG	1	/* Second arg is signal. */
+#define LINUX_PR_GET_PDEATHSIG	2	/*
+					 * Second arg is a ptr to return the
+					 * signal.
+					 */
+#define LINUX_PR_GET_KEEPCAPS	7	/* Get drop capabilities on setuid */
+#define LINUX_PR_SET_KEEPCAPS	8	/* Set drop capabilities on setuid */
+#define LINUX_PR_SET_NAME	15	/* Set process name. */
+#define LINUX_PR_GET_NAME	16	/* Get process name. */
+
+#define LINUX_MAX_COMM_LEN	16	/* Maximum length of process name. */
+
 /* This looks very unportable to me, but this is how Linux defines it. */
 struct linux_sysinfo {
 	long uptime;
diff --git a/sys/compat/linux/syscalls.master b/sys/compat/linux/syscalls.master
index ed1132c5358..78c776f17c0 100644
--- a/sys/compat/linux/syscalls.master
+++ b/sys/compat/linux/syscalls.master
@@ -1,4 +1,4 @@
-	$OpenBSD: syscalls.master,v 1.65 2011/11/25 10:10:05 robert Exp $
+	$OpenBSD: syscalls.master,v 1.66 2011/12/14 08:33:18 robert Exp $
 ;	$NetBSD: syscalls.master,v 1.15 1995/12/18 14:35:10 fvdl Exp $
 
 ;	@(#)syscalls.master	8.1 (Berkeley) 7/19/93
@@ -286,7 +286,9 @@
 			    u_int16_t egid, u_int16_t sgid); }
 171	STD		{ int linux_sys_getresgid16(u_int16_t *rgid, \
 			    u_int16_t *egid, u_int16_t *sgid); }
-172	STD		{ int linux_sys_prctl(void); }
+172	STD		{ int linux_sys_prctl(int option, unsigned long arg2, \
+			    unsigned long arg3, unsigned long arg4, \
+			    unsigned long arg5); }
 173	STD     	{ int linux_sys_rt_sigreturn( \
 	                    struct linux_rt_sigframe *sfp); }
 174	STD		{ int linux_sys_rt_sigaction(int signum, \