Give MEXTADD() another argument to make both void pointers to the

free function controlable, instead of passing the KVA of the buffer
storage as the first argument.

Fix all conventional users of the API to pass the KVA of the buffer
as the first argument, to make this a no-op commit.

Likely break the only non-convetional user of the API, after informing
the relevant committer.

Update the mbuf(9) manual page, which was already out of sync on
this point.

Bump __FreeBSD_version to 800016 as there is no way to tell how
many arguments a CPP macro needs any other way.

This paves the way for giving sendfile(9) a way to wait for the
passed storage to have been accessed before returning.

This does not affect the memory layout or size of mbufs.

Parental oversight by:	sam and rwatson.

No MFC is anticipated.

19 files changed, 45 insertions, 36 deletions

diff --git a/sys/compat/ndis/kern_ndis.c b/sys/compat/ndis/kern_ndis.c
index ba84c4f..0720dda 100644
--- a/sys/compat/ndis/kern_ndis.c
+++ b/sys/compat/ndis/kern_ndis.c
@@ -734,7 +734,7 @@ ndis_ptom(m0, p)
 		m->m_len = MmGetMdlByteCount(buf);
 		m->m_data = MmGetMdlVirtualAddress(buf);
 		MEXTADD(m, m->m_data, m->m_len, ndis_return_packet,
-		    p, 0, EXT_NDIS);
+		    m->m_data, p, 0, EXT_NDIS);
 		p->np_refcnt++;
 
 		totlen += m->m_len;
diff --git a/sys/dev/cxgb/cxgb_sge.c b/sys/dev/cxgb/cxgb_sge.c
index f643e38..78b2651 100644
--- a/sys/dev/cxgb/cxgb_sge.c
+++ b/sys/dev/cxgb/cxgb_sge.c
@@ -2452,7 +2452,8 @@ init_cluster_mbuf(caddr_t cl, int flags, int type, uma_zone_t zone)
 	m->m_ext.ref_cnt = (uint32_t *)(cl + header_size - sizeof(uint32_t));
 	m->m_ext.ext_size = m_getsizefromtype(type);
 	m->m_ext.ext_free = ext_free_handler;
-	m->m_ext.ext_args = (void *)(uintptr_t)type;
+	m->m_ext.ext_arg1 = cl;
+	m->m_ext.ext_arg2 = (void *)(uintptr_t)type;
 	m->m_ext.ext_type = EXT_EXTREF;
 	*(m->m_ext.ref_cnt) = 1;
 	DPRINTF("data=%p ref_cnt=%p\n", m->m_data, m->m_ext.ref_cnt); 
diff --git a/sys/dev/cxgb/ulp/tom/cxgb_cpl_socket.c b/sys/dev/cxgb/ulp/tom/cxgb_cpl_socket.c
index 7860f4b..a3dd692 100644
--- a/sys/dev/cxgb/ulp/tom/cxgb_cpl_socket.c
+++ b/sys/dev/cxgb/ulp/tom/cxgb_cpl_socket.c
@@ -224,7 +224,8 @@ cxgb_vm_page_to_miov(struct toepcb *toep, struct uio *uio, struct mbuf **m)
 	m0->m_flags = (M_EXT|M_NOFREE);
 	m0->m_ext.ext_type = EXT_EXTREF;
 	m0->m_ext.ext_free = cxgb_zero_copy_free;
-	m0->m_ext.ext_args = NULL;
+	m0->m_ext.ext_arg1 = NULL;	/* XXX: probably wrong /phk */
+	m0->m_ext.ext_arg2 = NULL;
     
 	mv = mtomv(m0);
 	mv->mv_count = seg_count;
diff --git a/sys/dev/hatm/if_hatm_intr.c b/sys/dev/hatm/if_hatm_intr.c
index b20af45..35bbd57 100644
--- a/sys/dev/hatm/if_hatm_intr.c
+++ b/sys/dev/hatm/if_hatm_intr.c
@@ -458,7 +458,7 @@ hatm_rx_buffer(struct hatm_softc *sc, u_int group, u_int handle)
 		if (m != NULL) {
 			m->m_ext.ref_cnt = &c0->hdr.ref_cnt;
 			MEXTADD(m, (void *)c0, MBUF0_SIZE,
-			    hatm_mbuf0_free, sc, M_PKTHDR, EXT_EXTREF);
+			    hatm_mbuf0_free, c0, sc, M_PKTHDR, EXT_EXTREF);
 			m->m_data += MBUF0_OFFSET;
 		} else
 			hatm_mbuf0_free(c0, sc);
@@ -482,7 +482,7 @@ hatm_rx_buffer(struct hatm_softc *sc, u_int group, u_int handle)
 		if (m != NULL) {
 			m->m_ext.ref_cnt = &c1->hdr.ref_cnt;
 			MEXTADD(m, (void *)c1, MBUF1_SIZE,
-			    hatm_mbuf1_free, sc, M_PKTHDR, EXT_EXTREF);
+			    hatm_mbuf1_free, c1, sc, M_PKTHDR, EXT_EXTREF);
 			m->m_data += MBUF1_OFFSET;
 		} else
 			hatm_mbuf1_free(c1, sc);
diff --git a/sys/dev/iscsi/initiator/isc_soc.c b/sys/dev/iscsi/initiator/isc_soc.c
index f5a8344..0826ff6 100644
--- a/sys/dev/iscsi/initiator/isc_soc.c
+++ b/sys/dev/iscsi/initiator/isc_soc.c
@@ -164,7 +164,7 @@ isc_sendPDU(isc_session_t *sp, pduq_t *pq)
 		md->m_ext.ref_cnt = &nil_refcnt;
                 l = min(MCLBYTES, len);
                 MEXTADD(md, pp->ds + off, l, nil_fn,
-                        NULL, 0, EXT_EXTREF);
+                        pp->ds + off, NULL, 0, EXT_EXTREF);
                 md->m_len = l;
                 md->m_next = NULL;
                 mh->m_pkthdr.len += l;
diff --git a/sys/dev/lge/if_lge.c b/sys/dev/lge/if_lge.c
index 0f3dc2d..1313990 100644
--- a/sys/dev/lge/if_lge.c
+++ b/sys/dev/lge/if_lge.c
@@ -719,7 +719,7 @@ lge_newbuf(sc, c, m)
 		m_new->m_data = (void *)buf;
 		m_new->m_len = m_new->m_pkthdr.len = LGE_JUMBO_FRAMELEN;
 		MEXTADD(m_new, buf, LGE_JUMBO_FRAMELEN, lge_jfree,
-		    (struct lge_softc *)sc, 0, EXT_NET_DRV);
+		    buf, (struct lge_softc *)sc, 0, EXT_NET_DRV);
 	} else {
 		m_new = m;
 		m_new->m_len = m_new->m_pkthdr.len = LGE_JUMBO_FRAMELEN;
diff --git a/sys/dev/msk/if_msk.c b/sys/dev/msk/if_msk.c
index 669fcd0..2613b81 100644
--- a/sys/dev/msk/if_msk.c
+++ b/sys/dev/msk/if_msk.c
@@ -833,8 +833,8 @@ msk_jumbo_newbuf(struct msk_if_softc *sc_if, int idx)
 		return (ENOBUFS);
 	}
 	/* Attach the buffer to the mbuf. */
-	MEXTADD(m, buf, MSK_JLEN, msk_jfree, (struct msk_if_softc *)sc_if, 0,
-	    EXT_NET_DRV);
+	MEXTADD(m, buf, MSK_JLEN, msk_jfree, buf,
+	    (struct msk_if_softc *)sc_if, 0, EXT_NET_DRV);
 	if ((m->m_flags & M_EXT) == 0) {
 		m_freem(m);
 		return (ENOBUFS);
diff --git a/sys/dev/nfe/if_nfe.c b/sys/dev/nfe/if_nfe.c
index 9c4e71c..5cf1351 100644
--- a/sys/dev/nfe/if_nfe.c
+++ b/sys/dev/nfe/if_nfe.c
@@ -2094,7 +2094,7 @@ nfe_jnewbuf(struct nfe_softc *sc, int idx)
 		return (ENOBUFS);
 	}
 	/* Attach the buffer to the mbuf. */
-	MEXTADD(m, buf, NFE_JLEN, nfe_jfree, (struct nfe_softc *)sc, 0,
+	MEXTADD(m, buf, NFE_JLEN, nfe_jfree, buf, (struct nfe_softc *)sc, 0,
 	    EXT_NET_DRV);
 	if ((m->m_flags & M_EXT) == 0) {
 		m_freem(m);
diff --git a/sys/dev/patm/if_patm_rx.c b/sys/dev/patm/if_patm_rx.c
index b972e3c..024d8ef 100644
--- a/sys/dev/patm/if_patm_rx.c
+++ b/sys/dev/patm/if_patm_rx.c
@@ -406,11 +406,11 @@ patm_rcv_mbuf(struct patm_softc *sc, void *buf, u_int h, int hdr)
 
 	if ((h & ~MBUF_HMASK) == MBUF_VHANDLE) {
 		MEXTADD(m, (caddr_t)buf, VMBUF_SIZE, mbp_ext_free,
-		    sc->vbuf_pool, M_PKTHDR, EXT_NET_DRV);
+		    buf, sc->vbuf_pool, M_PKTHDR, EXT_NET_DRV);
 		m->m_data += VMBUF_OFFSET;
 	} else {
 		MEXTADD(m, (caddr_t)buf, SMBUF_SIZE, mbp_ext_free,
-		    sc->sbuf_pool, M_PKTHDR, EXT_NET_DRV);
+		    buf, sc->sbuf_pool, M_PKTHDR, EXT_NET_DRV);
 		m->m_data += SMBUF_OFFSET;
 	}
 
diff --git a/sys/dev/sk/if_sk.c b/sys/dev/sk/if_sk.c
index 217d3a6..c51b4d1 100644
--- a/sys/dev/sk/if_sk.c
+++ b/sys/dev/sk/if_sk.c
@@ -1055,7 +1055,7 @@ sk_jumbo_newbuf(sc_if, idx)
 		return (ENOBUFS);
 	}
 	/* Attach the buffer to the mbuf */
-	MEXTADD(m, buf, SK_JLEN, sk_jfree, (struct sk_if_softc *)sc_if, 0,
+	MEXTADD(m, buf, SK_JLEN, sk_jfree, (struct sk_if_softc *)sc_if, buf, 0,
 	    EXT_NET_DRV);
 	if ((m->m_flags & M_EXT) == 0) {
 		m_freem(m);
diff --git a/sys/dev/ti/if_ti.c b/sys/dev/ti/if_ti.c
index 343dee5..80a2064 100644
--- a/sys/dev/ti/if_ti.c
+++ b/sys/dev/ti/if_ti.c
@@ -1503,7 +1503,8 @@ ti_newbuf_jumbo(sc, idx, m_old)
 			m[i]->m_data = (void *)sf_buf_kva(sf[i]);
 			m[i]->m_len = PAGE_SIZE;
 			MEXTADD(m[i], sf_buf_kva(sf[i]), PAGE_SIZE,
-			    sf_buf_mext, sf[i], 0, EXT_DISPOSABLE);
+			    sf_buf_mext, (void*)sf_buf_kva(sf[i]), sf[i],
+			    0, EXT_DISPOSABLE);
 			m[i]->m_next = m[i+1];
 		}
 		/* link the buffers to the header */
diff --git a/sys/dev/wpi/if_wpi.c b/sys/dev/wpi/if_wpi.c
index cc56c8a..315a5c3 100644
--- a/sys/dev/wpi/if_wpi.c
+++ b/sys/dev/wpi/if_wpi.c
@@ -1060,7 +1060,7 @@ wpi_alloc_rx_ring(struct wpi_softc *sc, struct wpi_rx_ring *ring)
 
 		/* attach RxBuffer to mbuf */
 		MEXTADD(data->m, rbuf->vaddr, WPI_RBUF_SIZE,wpi_free_rbuf,
-		    rbuf,0,EXT_NET_DRV);
+		    rbuf->vaddr, rbuf, 0, EXT_NET_DRV);
 
 		if ((data->m->m_flags & M_EXT) == 0) {
 			m_freem(data->m);
@@ -1631,8 +1631,8 @@ wpi_rx_intr(struct wpi_softc *sc, struct wpi_rx_desc *desc,
 		}
 
 		/* attach Rx buffer to mbuf */
-		MEXTADD(mnew,rbuf->vaddr,WPI_RBUF_SIZE, wpi_free_rbuf, rbuf, 0,
-		    EXT_NET_DRV);
+		MEXTADD(mnew, rbuf->vaddr, WPI_RBUF_SIZE, wpi_free_rbuf,
+		    rbuf->vaddr, rbuf, 0, EXT_NET_DRV);
 		SLIST_REMOVE_HEAD(&sc->rxq.freelist, next);
 		data->m = mnew;
 
diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c
index 1dd8a16..275b92d 100644
--- a/sys/kern/kern_mbuf.c
+++ b/sys/kern/kern_mbuf.c
@@ -463,7 +463,8 @@ mb_dtor_pack(void *mem, int size, void *arg)
 	KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
 	KASSERT(m->m_ext.ext_buf != NULL, ("%s: ext_buf == NULL", __func__));
 	KASSERT(m->m_ext.ext_free == NULL, ("%s: ext_free != NULL", __func__));
-	KASSERT(m->m_ext.ext_args == NULL, ("%s: ext_args != NULL", __func__));
+	KASSERT(m->m_ext.ext_arg1 == NULL, ("%s: ext_arg1 != NULL", __func__));
+	KASSERT(m->m_ext.ext_arg2 == NULL, ("%s: ext_arg2 != NULL", __func__));
 	KASSERT(m->m_ext.ext_size == MCLBYTES, ("%s: ext_size != MCLBYTES", __func__));
 	KASSERT(m->m_ext.ext_type == EXT_PACKET, ("%s: ext_type != EXT_PACKET", __func__));
 	KASSERT(*m->m_ext.ref_cnt == 1, ("%s: ref_cnt != 1", __func__));
@@ -533,7 +534,8 @@ mb_ctor_clust(void *mem, int size, void *arg, int how)
 		m->m_data = m->m_ext.ext_buf;
 		m->m_flags |= M_EXT;
 		m->m_ext.ext_free = NULL;
-		m->m_ext.ext_args = NULL;
+		m->m_ext.ext_arg1 = NULL;
+		m->m_ext.ext_arg2 = NULL;
 		m->m_ext.ext_size = size;
 		m->m_ext.ext_type = type;
 		m->m_ext.ref_cnt = refcnt;
diff --git a/sys/kern/uipc_cow.c b/sys/kern/uipc_cow.c
index b4773d1..2e29ee3 100644
--- a/sys/kern/uipc_cow.c
+++ b/sys/kern/uipc_cow.c
@@ -160,8 +160,8 @@ socow_setup(struct mbuf *m0, struct uio *uio)
 	/* 
 	 * attach to mbuf
 	 */
-	MEXTADD(m0, sf_buf_kva(sf), PAGE_SIZE, socow_iodone, sf, M_RDONLY,
-	    EXT_SFBUF);
+	MEXTADD(m0, sf_buf_kva(sf), PAGE_SIZE, socow_iodone,
+	    (void*)sf_buf_kva(sf), sf, M_RDONLY, EXT_SFBUF);
 	m0->m_len = PAGE_SIZE - offset;
 	m0->m_data = (caddr_t)sf_buf_kva(sf) + offset;
 	socow_stats.success++;
diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index a7fa18c..9015ec7 100644
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -186,7 +186,7 @@ m_freem(struct mbuf *mb)
  */
 void
 m_extadd(struct mbuf *mb, caddr_t buf, u_int size,
-    void (*freef)(void *, void *), void *args, int flags, int type)
+    void (*freef)(void *, void *), void *arg1, void *arg2, int flags, int type)
 {
 	KASSERT(type != EXT_CLUSTER, ("%s: EXT_CLUSTER not allowed", __func__));
 
@@ -199,7 +199,8 @@ m_extadd(struct mbuf *mb, caddr_t buf, u_int size,
 		mb->m_data = mb->m_ext.ext_buf;
 		mb->m_ext.ext_size = size;
 		mb->m_ext.ext_free = freef;
-		mb->m_ext.ext_args = args;
+		mb->m_ext.ext_arg1 = arg1;
+		mb->m_ext.ext_arg2 = arg2;
 		mb->m_ext.ext_type = type;
         }
 }
@@ -254,8 +255,8 @@ mb_free_ext(struct mbuf *m)
 		case EXT_EXTREF:
 			KASSERT(m->m_ext.ext_free != NULL,
 				("%s: ext_free not set", __func__));
-			(*(m->m_ext.ext_free))(m->m_ext.ext_buf,
-			    m->m_ext.ext_args);
+			(*(m->m_ext.ext_free))(m->m_ext.ext_arg1,
+			    m->m_ext.ext_arg2);
 			break;
 		default:
 			KASSERT(m->m_ext.ext_type == 0,
@@ -271,7 +272,8 @@ mb_free_ext(struct mbuf *m)
 	 */
 	m->m_ext.ext_buf = NULL;
 	m->m_ext.ext_free = NULL;
-	m->m_ext.ext_args = NULL;
+	m->m_ext.ext_arg1 = NULL;
+	m->m_ext.ext_arg2 = NULL;
 	m->m_ext.ref_cnt = NULL;
 	m->m_ext.ext_size = 0;
 	m->m_ext.ext_type = 0;
@@ -296,7 +298,8 @@ mb_dupcl(struct mbuf *n, struct mbuf *m)
 		atomic_add_int(m->m_ext.ref_cnt, 1);
 	n->m_ext.ext_buf = m->m_ext.ext_buf;
 	n->m_ext.ext_free = m->m_ext.ext_free;
-	n->m_ext.ext_args = m->m_ext.ext_args;
+	n->m_ext.ext_arg1 = m->m_ext.ext_arg1;
+	n->m_ext.ext_arg2 = m->m_ext.ext_arg2;
 	n->m_ext.ext_size = m->m_ext.ext_size;
 	n->m_ext.ref_cnt = m->m_ext.ref_cnt;
 	n->m_ext.ext_type = m->m_ext.ext_type;
diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index d0daa82..beca062 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -2099,7 +2099,7 @@ retry_space:
 				break;
 			}
 			MEXTADD(m0, sf_buf_kva(sf), PAGE_SIZE, sf_buf_mext,
-			    sf, M_RDONLY, EXT_SFBUF);
+			    (void*)sf_buf_kva(sf), sf, M_RDONLY, EXT_SFBUF);
 			m0->m_data = (char *)sf_buf_kva(sf) + pgoff;
 			m0->m_len = xfsize;
 
diff --git a/sys/pci/if_wb.c b/sys/pci/if_wb.c
index f42bc56..b652d6d 100644
--- a/sys/pci/if_wb.c
+++ b/sys/pci/if_wb.c
@@ -1036,8 +1036,8 @@ wb_newbuf(sc, c, m)
 			return(ENOBUFS);
 		m_new->m_data = c->wb_buf;
 		m_new->m_pkthdr.len = m_new->m_len = WB_BUFBYTES;
-		MEXTADD(m_new, c->wb_buf, WB_BUFBYTES, wb_bfree, NULL, 0,
-		    EXT_NET_DRV);
+		MEXTADD(m_new, c->wb_buf, WB_BUFBYTES, wb_bfree, c->wb_buf,
+		    NULL, 0, EXT_NET_DRV);
 	} else {
 		m_new = m;
 		m_new->m_len = m_new->m_pkthdr.len = WB_BUFBYTES;
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index 5a499e5..7096e89 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -131,7 +131,8 @@ struct m_ext {
 	caddr_t		 ext_buf;	/* start of buffer */
 	void		(*ext_free)	/* free routine if not the usual */
 			    (void *, void *);
-	void		*ext_args;	/* optional argument pointer */
+	void		*ext_arg1;	/* optional argument pointer */
+	void		*ext_arg2;	/* optional argument pointer */
 	u_int		 ext_size;	/* size of buffer, for ext_free */
 	volatile u_int	*ref_cnt;	/* pointer to ref count info */
 	int		 ext_type;	/* type of external storage */
@@ -586,7 +587,7 @@ m_cljset(struct mbuf *m, void *cl, int type)
 	}
 
 	m->m_data = m->m_ext.ext_buf = cl;
-	m->m_ext.ext_free = m->m_ext.ext_args = NULL;
+	m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
 	m->m_ext.ext_size = size;
 	m->m_ext.ext_type = type;
 	m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
@@ -618,8 +619,8 @@ m_last(struct mbuf *m)
 #define	MGET(m, how, type)	((m) = m_get((how), (type)))
 #define	MGETHDR(m, how, type)	((m) = m_gethdr((how), (type)))
 #define	MCLGET(m, how)		m_clget((m), (how))
-#define	MEXTADD(m, buf, size, free, args, flags, type) 			\
-    m_extadd((m), (caddr_t)(buf), (size), (free), (args), (flags), (type))
+#define	MEXTADD(m, buf, size, free, arg1, arg2, flags, type)		\
+    m_extadd((m), (caddr_t)(buf), (size), (free),(arg1),(arg2),(flags), (type))
 #define	m_getm(m, len, how, type)					\
     m_getm2((m), (len), (how), (type), M_PKTHDR)
 
@@ -745,7 +746,7 @@ int		 m_apply(struct mbuf *, int, int,
 int		 m_append(struct mbuf *, int, c_caddr_t);
 void		 m_cat(struct mbuf *, struct mbuf *);
 void		 m_extadd(struct mbuf *, caddr_t, u_int,
-		    void (*)(void *, void *), void *, int, int);
+		    void (*)(void *, void *), void *, void *, int, int);
 struct mbuf	*m_collapse(struct mbuf *, int, int);
 void		 m_copyback(struct mbuf *, int, int, c_caddr_t);
 void		 m_copydata(const struct mbuf *, int, int, caddr_t);
diff --git a/sys/sys/param.h b/sys/sys/param.h
index 385571a..be4ff02 100644
--- a/sys/sys/param.h
+++ b/sys/sys/param.h
@@ -57,7 +57,7 @@
  *		is created, otherwise 1.
  */
 #undef __FreeBSD_version
-#define __FreeBSD_version 800015	/* Master, propagated to newvers */
+#define __FreeBSD_version 800016	/* Master, propagated to newvers */
 
 #ifndef LOCORE
 #include <sys/types.h>