Move platform.File in memmap

The subsequent systrap changes will need to import memmap from
the platform package.

PiperOrigin-RevId: 323409486

6 files changed, 9 insertions, 69 deletions

diff --git a/pkg/sentry/platform/BUILD b/pkg/sentry/platform/BUILD
index 453241eca..209b28053 100644
--- a/pkg/sentry/platform/BUILD
+++ b/pkg/sentry/platform/BUILD
@@ -1,39 +1,21 @@
 load("//tools:defs.bzl", "go_library")
-load("//tools/go_generics:defs.bzl", "go_template_instance")
 
 package(licenses = ["notice"])
 
-go_template_instance(
-    name = "file_range",
-    out = "file_range.go",
-    package = "platform",
-    prefix = "File",
-    template = "//pkg/segment:generic_range",
-    types = {
-        "T": "uint64",
-    },
-)
-
 go_library(
     name = "platform",
     srcs = [
         "context.go",
-        "file_range.go",
         "mmap_min_addr.go",
         "platform.go",
     ],
     visibility = ["//pkg/sentry:internal"],
     deps = [
         "//pkg/abi/linux",
-        "//pkg/atomicbitops",
         "//pkg/context",
-        "//pkg/log",
-        "//pkg/safecopy",
-        "//pkg/safemem",
         "//pkg/seccomp",
         "//pkg/sentry/arch",
-        "//pkg/sentry/usage",
-        "//pkg/syserror",
+        "//pkg/sentry/memmap",
         "//pkg/usermem",
     ],
 )
diff --git a/pkg/sentry/platform/kvm/BUILD b/pkg/sentry/platform/kvm/BUILD
index 10a10bfe2..b5d27a72a 100644
--- a/pkg/sentry/platform/kvm/BUILD
+++ b/pkg/sentry/platform/kvm/BUILD
@@ -47,6 +47,7 @@ go_library(
         "//pkg/safecopy",
         "//pkg/seccomp",
         "//pkg/sentry/arch",
+        "//pkg/sentry/memmap",
         "//pkg/sentry/platform",
         "//pkg/sentry/platform/interrupt",
         "//pkg/sentry/platform/ring0",
diff --git a/pkg/sentry/platform/kvm/address_space.go b/pkg/sentry/platform/kvm/address_space.go
index faf1d5e1c..98a3e539d 100644
--- a/pkg/sentry/platform/kvm/address_space.go
+++ b/pkg/sentry/platform/kvm/address_space.go
@@ -18,6 +18,7 @@ import (
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/atomicbitops"
+	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sentry/platform/ring0/pagetables"
 	"gvisor.dev/gvisor/pkg/sync"
@@ -150,7 +151,7 @@ func (as *addressSpace) mapLocked(addr usermem.Addr, m hostMapEntry, at usermem.
 }
 
 // MapFile implements platform.AddressSpace.MapFile.
-func (as *addressSpace) MapFile(addr usermem.Addr, f platform.File, fr platform.FileRange, at usermem.AccessType, precommit bool) error {
+func (as *addressSpace) MapFile(addr usermem.Addr, f memmap.File, fr memmap.FileRange, at usermem.AccessType, precommit bool) error {
 	as.mu.Lock()
 	defer as.mu.Unlock()
 
diff --git a/pkg/sentry/platform/platform.go b/pkg/sentry/platform/platform.go
index 171513f3f..4b13eec30 100644
--- a/pkg/sentry/platform/platform.go
+++ b/pkg/sentry/platform/platform.go
@@ -22,9 +22,9 @@ import (
 	"os"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/safemem"
 	"gvisor.dev/gvisor/pkg/seccomp"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/usermem"
 )
 
@@ -207,7 +207,7 @@ type AddressSpace interface {
 	// Preconditions: addr and fr must be page-aligned. fr.Length() > 0.
 	// at.Any() == true. At least one reference must be held on all pages in
 	// fr, and must continue to be held as long as pages are mapped.
-	MapFile(addr usermem.Addr, f File, fr FileRange, at usermem.AccessType, precommit bool) error
+	MapFile(addr usermem.Addr, f memmap.File, fr memmap.FileRange, at usermem.AccessType, precommit bool) error
 
 	// Unmap unmaps the given range.
 	//
@@ -310,52 +310,6 @@ func (f SegmentationFault) Error() string {
 	return fmt.Sprintf("segmentation fault at %#x", f.Addr)
 }
 
-// File represents a host file that may be mapped into an AddressSpace.
-type File interface {
-	// All pages in a File are reference-counted.
-
-	// IncRef increments the reference count on all pages in fr.
-	//
-	// Preconditions: fr.Start and fr.End must be page-aligned. fr.Length() >
-	// 0. At least one reference must be held on all pages in fr. (The File
-	// interface does not provide a way to acquire an initial reference;
-	// implementors may define mechanisms for doing so.)
-	IncRef(fr FileRange)
-
-	// DecRef decrements the reference count on all pages in fr.
-	//
-	// Preconditions: fr.Start and fr.End must be page-aligned. fr.Length() >
-	// 0. At least one reference must be held on all pages in fr.
-	DecRef(fr FileRange)
-
-	// MapInternal returns a mapping of the given file offsets in the invoking
-	// process' address space for reading and writing.
-	//
-	// Note that fr.Start and fr.End need not be page-aligned.
-	//
-	// Preconditions: fr.Length() > 0. At least one reference must be held on
-	// all pages in fr.
-	//
-	// Postconditions: The returned mapping is valid as long as at least one
-	// reference is held on the mapped pages.
-	MapInternal(fr FileRange, at usermem.AccessType) (safemem.BlockSeq, error)
-
-	// FD returns the file descriptor represented by the File.
-	//
-	// The only permitted operation on the returned file descriptor is to map
-	// pages from it consistent with the requirements of AddressSpace.MapFile.
-	FD() int
-}
-
-// FileRange represents a range of uint64 offsets into a File.
-//
-// type FileRange <generated using go_generics>
-
-// String implements fmt.Stringer.String.
-func (fr FileRange) String() string {
-	return fmt.Sprintf("[%#x, %#x)", fr.Start, fr.End)
-}
-
 // Requirements is used to specify platform specific requirements.
 type Requirements struct {
 	// RequiresCurrentPIDNS indicates that the sandbox has to be started in the
diff --git a/pkg/sentry/platform/ptrace/BUILD b/pkg/sentry/platform/ptrace/BUILD
index 30402c2df..29fd23cc3 100644
--- a/pkg/sentry/platform/ptrace/BUILD
+++ b/pkg/sentry/platform/ptrace/BUILD
@@ -30,6 +30,7 @@ go_library(
         "//pkg/seccomp",
         "//pkg/sentry/arch",
         "//pkg/sentry/hostcpu",
+        "//pkg/sentry/memmap",
         "//pkg/sentry/platform",
         "//pkg/sentry/platform/interrupt",
         "//pkg/sync",
diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go
index 2389423b0..c990f3454 100644
--- a/pkg/sentry/platform/ptrace/subprocess.go
+++ b/pkg/sentry/platform/ptrace/subprocess.go
@@ -24,6 +24,7 @@ import (
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/procid"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/memmap"
 	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/usermem"
@@ -616,7 +617,7 @@ func (s *subprocess) syscall(sysno uintptr, args ...arch.SyscallArgument) (uintp
 }
 
 // MapFile implements platform.AddressSpace.MapFile.
-func (s *subprocess) MapFile(addr usermem.Addr, f platform.File, fr platform.FileRange, at usermem.AccessType, precommit bool) error {
+func (s *subprocess) MapFile(addr usermem.Addr, f memmap.File, fr memmap.FileRange, at usermem.AccessType, precommit bool) error {
 	var flags int
 	if precommit {
 		flags |= syscall.MAP_POPULATE