General cleanup of core-dumping code.

Submitted by: Sean Fagan,

7 files changed, 87 insertions, 88 deletions

diff --git a/sys/kern/imgact_aout.c b/sys/kern/imgact_aout.c
index 0b3cbf5..90f22dd 100644
--- a/sys/kern/imgact_aout.c
+++ b/sys/kern/imgact_aout.c
@@ -75,7 +75,7 @@ struct sysentvec aout_sysvec = {
 	aout_coredump
 };
 
-static int
+int
 exec_aout_imgact(imgp)
 	struct image_params *imgp;
 {
@@ -244,44 +244,19 @@ exec_aout_imgact(imgp)
  * expand_name(), unless the process was setuid/setgid.
  */
 int
-aout_coredump(p)
+aout_coredump(p, vp, limit)
 	register struct proc *p;
-{
 	register struct vnode *vp;
+	off_t limit;
+{
 	register struct ucred *cred = p->p_cred->pc_ucred;
 	register struct vmspace *vm = p->p_vmspace;
-	struct nameidata nd;
-	struct vattr vattr;
-	int error, error1;
-	char *name;			/* name of corefile */
+	int error = 0;
 
-	STOPEVENT(p, S_CORE, 0);
-	if (sugid_coredump == 0 && p->p_flag & P_SUGID)
-		return (EFAULT);
 	if (ctob(UPAGES + vm->vm_dsize + vm->vm_ssize) >=
-	    p->p_rlimit[RLIMIT_CORE].rlim_cur)
+	    limit)
 		return (EFAULT);
-	name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
-	if (name == NULL)
-		return (EFAULT);	/* XXX -- not the best error */
-	NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p);
-	error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
-	free(name, M_TEMP);
-	if (error)
-		return (error);
-	vp = nd.ni_vp;
 
-	/* Don't dump to non-regular files or files with links. */
-	if (vp->v_type != VREG ||
-	    VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) {
-		error = EFAULT;
-		goto out;
-	}
-	VATTR_NULL(&vattr);
-	vattr.va_size = 0;
-	VOP_LEASE(vp, p, cred, LEASE_WRITE);
-	VOP_SETATTR(vp, &vattr, cred, p);
-	p->p_acflag |= ACORE;
 	bcopy(p, &p->p_addr->u_kproc.kp_proc, sizeof(struct proc));
 	fill_eproc(p, &p->p_addr->u_kproc.kp_eproc);
 	error = cpu_coredump(p, vp, cred);
@@ -295,12 +270,7 @@ aout_coredump(p)
 		    round_page(ctob(vm->vm_ssize)),
 		    (off_t)ctob(UPAGES) + ctob(vm->vm_dsize), UIO_USERSPACE,
 		    IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, p);
-out:
-	VOP_UNLOCK(vp, 0, p);
-	error1 = vn_close(vp, FWRITE, cred, p);
-	if (error == 0)
-		error = error1;
-	return (error);
+	return error;
 }
 
 /*
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index d58d274..e31d90b 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -683,24 +683,17 @@ static void elf_putnote __P((void *, size_t *, const char *, int,
 extern int osreldate;
 
 int
-elf_coredump(p)
+elf_coredump(p, vp, limit)
 	register struct proc *p;
-{
 	register struct vnode *vp;
+	off_t limit;
+{
 	register struct ucred *cred = p->p_cred->pc_ucred;
-	struct nameidata nd;
-	struct vattr vattr;
-	int error, error1;
-	char *name;			/* name of corefile */
+	int error = 0;
 	struct sseg_closure seginfo;
 	void *hdr;
 	size_t hdrsize;
 
-	STOPEVENT(p, S_CORE, 0);
-
-	if (sugid_coredump == 0 && p->p_flag & P_SUGID)
-		return (EFAULT);
-
 	/* Size the program segments. */
 	seginfo.count = 0;
 	seginfo.size = 0;
@@ -716,31 +709,8 @@ elf_coredump(p)
 	    (const prstatus_t *)NULL, (const prfpregset_t *)NULL,
 	    (const prpsinfo_t *)NULL, seginfo.count);
 
-	if (hdrsize + seginfo.size >= p->p_rlimit[RLIMIT_CORE].rlim_cur)
+	if (hdrsize + seginfo.size >= limit)
 		return (EFAULT);
-	name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
-	if (name == NULL)
-		return (EFAULT);	/* XXX -- not the best error */
-	
-	NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p);
-	error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
-	free(name, M_TEMP);
-	if (error)
-		return (error);
-	vp = nd.ni_vp;
-
-	/* Don't dump to non-regular files or files with links. */
-	if (vp->v_type != VREG ||
-	    VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) {
-		error = EFAULT;
-		goto out;
-	}
-	VATTR_NULL(&vattr);
-	vattr.va_size = 0;
-	VOP_LEASE(vp, p, cred, LEASE_WRITE);
-	VOP_SETATTR(vp, &vattr, cred, p);
-	p->p_acflag |= ACORE;
-
 
 	/*
 	 * Allocate memory for building the header, fill it up,
@@ -748,8 +718,7 @@ elf_coredump(p)
 	 */
 	hdr = malloc(hdrsize, M_TEMP, M_WAITOK);
 	if (hdr == NULL) {
-		error = EINVAL;
-		goto out;
+		return EINVAL;
 	}
 	error = elf_corehdr(p, vp, cred, seginfo.count, hdr, hdrsize);
 
@@ -772,13 +741,8 @@ elf_coredump(p)
 		}
 	}
 	free(hdr, M_TEMP);
-
-out:
-	VOP_UNLOCK(vp, 0, p);
-	error1 = vn_close(vp, FWRITE, cred, p);
-	if (error == 0)
-		error = error1;
-	return (error);
+	
+	return error;
 }
 
 /*
diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 49465fc..4921a39 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -71,6 +71,8 @@
 static int killpg1	__P((struct proc *cp, int signum, int pgid, int all));
 static void setsigvec	__P((struct proc *p, int signum, struct sigaction *sa));
 static void stop	__P((struct proc *));
+static char *expand_name	__P((const char *, uid_t, int));
+static int coredump	__P((struct proc *));
 
 static int	kern_logsigexit = 1;
 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 
@@ -1255,8 +1257,7 @@ sigexit(p, signum)
 		 * these messages.)
 		 * XXX : Todo, as well as euid, write out ruid too
 		 */
-		if (p->p_sysent->sv_coredump != NULL &&
-		    (*p->p_sysent->sv_coredump)(p) == 0)
+		if (coredump(p) == 0)
 			signum |= WCOREFLAG;
 		if (kern_logsigexit)
 			log(LOG_INFO,
@@ -1286,7 +1287,7 @@ SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename,
  * This is controlled by the sysctl variable kern.corefile (see above).
  */
 
-char *
+static char *
 expand_name(name, uid, pid)
 const char *name; uid_t uid; pid_t pid; {
 	char *temp;
@@ -1353,6 +1354,71 @@ const char *name; uid_t uid; pid_t pid; {
 }
 
 /*
+ * Dump a process' core.  The main routine does some
+ * policy checking, and creates the name of the coredump;
+ * then it passes on a vnode and a size limit to the process-specific
+ * coredump routine if there is one; if there _is not_ one, it returns
+ * ENOSYS; otherwise it returns the error from the process-specific routine.
+ */
+
+static int
+coredump(p)
+	register struct proc *p;
+{
+	register struct vnode *vp;
+	register struct ucred *cred = p->p_cred->pc_ucred;
+	struct nameidata nd;
+	struct vattr vattr;
+	int error, error1;
+	char *name;			/* name of corefile */
+	off_t limit;
+	
+	STOPEVENT(p, S_CORE, 0);
+
+	if ((sugid_coredump == 0) && p->p_flag & P_SUGID)
+		return (EFAULT);
+	
+	/*
+	 * Note that this layout means that limit checking is done
+	 * AFTER the corefile name is created.  This could happen
+	 * other ways as well, so I'm not too worried about it, but
+	 * it is potentially confusing.
+	 */
+	name = expand_name(p->p_comm, p->p_ucred->cr_uid, p->p_pid);
+	NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, p);
+	error = vn_open(&nd, O_CREAT | FWRITE | O_NOFOLLOW, S_IRUSR | S_IWUSR);
+	free(name, M_TEMP);
+	if (error)
+		return (error);
+	vp = nd.ni_vp;
+
+	/* Don't dump to non-regular files or files with links. */
+	if (vp->v_type != VREG ||
+	    VOP_GETATTR(vp, &vattr, cred, p) || vattr.va_nlink != 1) {
+		error = EFAULT;
+		goto out;
+	}
+	VATTR_NULL(&vattr);
+	vattr.va_size = 0;
+	VOP_LEASE(vp, p, cred, LEASE_WRITE);
+	VOP_SETATTR(vp, &vattr, cred, p);
+	p->p_acflag |= ACORE;
+
+	limit = p->p_rlimit[RLIMIT_CORE].rlim_cur;
+
+	error = p->p_sysent->sv_coredump ?
+	  p->p_sysent->sv_coredump(p, vp, limit) :
+	  ENOSYS;
+
+out:
+	VOP_UNLOCK(vp, 0, p);
+	error1 = vn_close(vp, FWRITE, cred, p);
+	if (error == 0)
+		error = error1;
+	return (error);
+}
+
+/*
  * Nonexistent system call-- signal process (may want to handle it).
  * Flag error in case process won't see signal immediately (blocked or ignored).
  */
diff --git a/sys/sys/imgact_aout.h b/sys/sys/imgact_aout.h
index 5b4b68f..873f1b2 100644
--- a/sys/sys/imgact_aout.h
+++ b/sys/sys/imgact_aout.h
@@ -151,7 +151,7 @@ struct exec {
 struct proc;
 
 __BEGIN_DECLS
-int aout_coredump __P((struct proc *));
+int aout_coredump __P((struct proc *, struct vnode *, off_t));
 __END_DECLS
 #endif /* KERNEL */
 
diff --git a/sys/sys/imgact_elf.h b/sys/sys/imgact_elf.h
index 596ecdb..3c6e7ec 100644
--- a/sys/sys/imgact_elf.h
+++ b/sys/sys/imgact_elf.h
@@ -103,7 +103,7 @@ int	elf_remove_brand_entry __P((Elf64_Brandinfo *entry));
 
 struct proc;
 
-int	elf_coredump __P((struct proc *));
+int	elf_coredump __P((struct proc *, struct vnode *, off_t));
 
 #endif /* KERNEL */
 
diff --git a/sys/sys/signalvar.h b/sys/sys/signalvar.h
index 058f0f1..b3da667 100644
--- a/sys/sys/signalvar.h
+++ b/sys/sys/signalvar.h
@@ -158,7 +158,6 @@ extern int sugid_coredump;	/* Sysctl variable kern.sugid_coredump */
  * Machine-independent functions:
  */
 void	execsigs __P((struct proc *p));
-char	*expand_name __P((const char*, uid_t, pid_t));
 void	gsignal __P((int pgid, int sig));
 int	issignal __P((struct proc *p));
 void	killproc __P((struct proc *p, char *why));
diff --git a/sys/sys/sysent.h b/sys/sys/sysent.h
index ab258c2..e593f38 100644
--- a/sys/sys/sysent.h
+++ b/sys/sys/sysent.h
@@ -69,7 +69,7 @@ struct sysentvec {
 	void		(*sv_prepsyscall) __P((struct trapframe *, int *,
 					       u_int *, caddr_t *));
 	char		*sv_name;	/* name of binary type */
-	int		(*sv_coredump) __P((struct proc *p));
+	int		(*sv_coredump) __P((struct proc *p, struct vnode *, off_t));
 					/* function to dump core, or NULL */
 };