VM: 64-bit mmap()

Some (backwards-compatible) changes in mmap() call message fields
that allow for a 64-bit offset. minix_mmap() takes an off_t and
minix_mmap64() takes a u64_t. Some mmap() work in VM goes into a
separate function, using the new fields, so that that can be re-used
when files are to be mapped (future commit).

Change-Id: Ifb77a90b593dd3c33cf81b396068e4da1ec5fb1c

include/minix/com.h

@@ -942,8 +942,9 @@
 #	define VMM_PROT			m5_s1
 #	define VMM_FLAGS		m5_s2
 #	define VMM_FD			m5_i1
-#	define VMM_OFFSET		m5_i2
+#	define VMM_OFFSET_LO		m5_i2
 #	define VMM_FORWHOM		m5_l3
+#	define VMM_OFFSET_HI		m5_l3
 #	define VMM_RETADDR		m5_l1	/* result */
 #define VM_UMAP			(VM_RQ_BASE+11)
 #	define VMU_SEG			m1_i1

lib/libc/sys-minix/mmap.c

@@ -2,6 +2,8 @@
 #include <sys/cdefs.h>
 #include "namespace.h"
 #include <lib.h>
+#include <minix/u64.h>
+#include <minix/vm.h>
 
 /* INCLUDES HERE */
 
@@ -21,7 +23,7 @@ __weak_alias(minix_munmap, _minix_munmap)
 #include <errno.h>
 
 void *minix_mmap_for(endpoint_t forwhom,
-	void *addr, size_t len, int prot, int flags, int fd, off_t offset)
+	void *addr, size_t len, int prot, int flags, int fd, u64_t offset)
 {
 	message m;
 	int r;
@@ -31,11 +33,13 @@ void *minix_mmap_for(endpoint_t forwhom,
 	m.VMM_PROT = prot;
 	m.VMM_FLAGS = flags;
 	m.VMM_FD = fd;
-	m.VMM_OFFSET = offset;
-	m.VMM_FORWHOM = forwhom;
+	m.VMM_OFFSET_LO = ex64lo(offset);
 
 	if(forwhom != SELF) {
 		m.VMM_FLAGS |= MAP_THIRDPARTY;
+		m.VMM_FORWHOM = forwhom;
+	} else {
+		m.VMM_OFFSET_HI = ex64hi(offset);
 	}
 
 	r = _syscall(VM_PROC_NR, VM_MMAP, &m);

servers/vm/mmap.c

@@ -32,6 +32,58 @@
 #include "util.h"
 #include "region.h"
 
+
+static struct vir_region *mmap_region(struct vmproc *vmp, vir_bytes addr,
+	u32_t vmm_flags, size_t len, u32_t vrflags,
+	mem_type_t *mt, int execpriv)
+{
+	u32_t mfflags = 0;
+	struct vir_region *vr = NULL;
+
+	if(vmm_flags & MAP_LOWER16M) vrflags |= VR_LOWER16MB;
+	if(vmm_flags & MAP_LOWER1M)  vrflags |= VR_LOWER1MB;
+	if(vmm_flags & MAP_ALIGN64K) vrflags |= VR_PHYS64K;
+	if(vmm_flags & MAP_PREALLOC) mfflags |= MF_PREALLOC;
+	if(vmm_flags & MAP_UNINITIALIZED) {
+		if(!execpriv) return NULL;
+		vrflags |= VR_UNINITIALIZED;
+	}
+
+	if(len <= 0) {
+		return NULL;
+	}
+
+	if(len % VM_PAGE_SIZE)
+		len += VM_PAGE_SIZE - (len % VM_PAGE_SIZE);
+
+#if 0
+	/* MAP_FIXED is restored in a later commit */
+	if (addr && (vmm_flags & MAP_FIXED)) {
+		int r = map_unmap_range(vmp, addr, len);
+		if(r != OK) {
+			printf("mmap_region: map_unmap_range failed (%d)\n", r);
+			return NULL;
+		}
+	}
+#endif
+
+	if (addr || (vmm_flags & MAP_FIXED)) {
+		/* An address is given, first try at that address. */
+		vr = map_page_region(vmp, addr, 0, len,
+			vrflags, mfflags, mt);
+		if(!vr && (vmm_flags & MAP_FIXED))
+			return NULL;
+	}
+
+	if (!vr) {
+		/* No address given or address already in use. */
+		vr = map_page_region(vmp, VM_PAGE_SIZE, VM_DATATOP, len,
+			vrflags, mfflags, mt);
+	}
+
+	return vr;
+}
+
 /*===========================================================================*
  *				do_mmap			     		     *
  *===========================================================================*/
@@ -39,10 +91,10 @@ int do_mmap(message *m)
 {
 	int r, n;
 	struct vmproc *vmp;
-	int mfflags = 0;
-	vir_bytes addr;
+	vir_bytes addr = m->VMM_ADDR;
 	struct vir_region *vr = NULL;
 	int execpriv = 0;
+	size_t len = (vir_bytes) m->VMM_LEN;
 
 	/* RS and VFS can do slightly more special mmap() things */
 	if(m->m_source == VFS_PROC_NR || m->m_source == RS_PROC_NR)
@@ -63,11 +115,11 @@ int do_mmap(message *m)
 	vmp = &vmproc[n];
 
 	if(m->VMM_FD == -1 || (m->VMM_FLAGS & MAP_ANON)) {
-		mem_type_t *mt;
-		u32_t vrflags = VR_ANON | VR_WRITABLE;
-		size_t len = (vir_bytes) m->VMM_LEN;
+		/* actual memory in some form */
+		mem_type_t *mt = NULL;
 
 		if(m->VMM_FD != -1 || len <= 0) {
+			printf("VM: mmap: fd %d, len 0x%x\n", m->VMM_FD, len);
 			return EINVAL;
 		}
 
@@ -76,48 +128,21 @@ int do_mmap(message *m)
 			return EINVAL;
 		}
 
-		if(m->VMM_FLAGS & MAP_PREALLOC) mfflags |= MF_PREALLOC;
-		if(m->VMM_FLAGS & MAP_LOWER16M) vrflags |= VR_LOWER16MB;
-		if(m->VMM_FLAGS & MAP_LOWER1M)  vrflags |= VR_LOWER1MB;
-		if(m->VMM_FLAGS & MAP_ALIGN64K) vrflags |= VR_PHYS64K;
-		if(m->VMM_FLAGS & MAP_UNINITIALIZED) {
-			if(!execpriv) return EPERM;
-			vrflags |= VR_UNINITIALIZED;
-		}
 		if(m->VMM_FLAGS & MAP_CONTIG) {
-			vrflags |= VR_CONTIG;
 			mt = &mem_type_anon_contig;
 		} else	mt = &mem_type_anon;
 
-		if(len % VM_PAGE_SIZE)
-			len += VM_PAGE_SIZE - (len % VM_PAGE_SIZE);
-
-		vr = NULL;
-		if (m->VMM_ADDR || (m->VMM_FLAGS & MAP_FIXED)) {
-			/* An address is given, first try at that address. */
-			addr = m->VMM_ADDR;
-			vr = map_page_region(vmp, addr, 0, len,
-				vrflags, mfflags, mt);
-			if(!vr && (m->VMM_FLAGS & MAP_FIXED))
-				return ENOMEM;
-		}
-		if (!vr) {
-			/* No address given or address already in use. */
-			vr = map_page_region(vmp, 0, VM_DATATOP, len,
-				vrflags, mfflags, mt);
-		}
-		if (!vr) {
+		if(!(vr = mmap_region(vmp, addr, m->VMM_FLAGS, len,
+			VR_WRITABLE | VR_ANON, mt, execpriv))) {
 			return ENOMEM;
 		}
 	} else {
-		return ENOSYS;
+		return ENXIO;
 	}
 
 	/* Return mapping, as seen from process. */
-	assert(vr);
 	m->VMM_RETADDR = vr->vaddr;
 
-
 	return OK;
 }
 

sys/sys/mman.h

@@ -106,7 +106,8 @@ void *	mmap(void *, size_t, int, int, int, off_t);
 int	munmap(void *, size_t);
 #else
 void *	minix_mmap(void *, size_t, int, int, int, off_t);
-void *	minix_mmap_for(endpoint_t, void *, size_t, int, int, int, off_t);
+void *	minix_mmap64(void *, size_t, int, int, int, u64_t);
+void *	minix_mmap_for(endpoint_t, void *, size_t, int, int, int, u64_t);
 int	minix_munmap(void *, size_t);
 void *		vm_remap(endpoint_t d, endpoint_t s, void *da, void *sa, size_t si);
 void *		vm_remap_ro(endpoint_t d, endpoint_t s, void *da, void *sa, size_t si);