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-rw-r--r--pkg/sentry/fsimpl/host/connected_endpoint_refs.go2
-rw-r--r--pkg/sentry/fsimpl/host/inode_refs.go2
-rw-r--r--pkg/sentry/fsimpl/sys/kcov.go116
-rw-r--r--pkg/sentry/fsimpl/sys/sys.go18
-rw-r--r--pkg/sentry/fsimpl/tmpfs/inode_refs.go2
5 files changed, 136 insertions, 4 deletions
diff --git a/pkg/sentry/fsimpl/host/connected_endpoint_refs.go b/pkg/sentry/fsimpl/host/connected_endpoint_refs.go
index 1f13a2608..3b7bf599e 100644
--- a/pkg/sentry/fsimpl/host/connected_endpoint_refs.go
+++ b/pkg/sentry/fsimpl/host/connected_endpoint_refs.go
@@ -1,11 +1,11 @@
package host
import (
+ "runtime"
"sync/atomic"
"gvisor.dev/gvisor/pkg/log"
refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
- "runtime"
)
// ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/host/inode_refs.go b/pkg/sentry/fsimpl/host/inode_refs.go
index 2c67758a0..55c0fb3a9 100644
--- a/pkg/sentry/fsimpl/host/inode_refs.go
+++ b/pkg/sentry/fsimpl/host/inode_refs.go
@@ -1,11 +1,11 @@
package host
import (
+ "runtime"
"sync/atomic"
"gvisor.dev/gvisor/pkg/log"
refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
- "runtime"
)
// ownerType is used to customize logging. Note that we use a pointer to T so
diff --git a/pkg/sentry/fsimpl/sys/kcov.go b/pkg/sentry/fsimpl/sys/kcov.go
new file mode 100644
index 000000000..92710d877
--- /dev/null
+++ b/pkg/sentry/fsimpl/sys/kcov.go
@@ -0,0 +1,116 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sys
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/memmap"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+func (fs *filesystem) newKcovFile(ctx context.Context, creds *auth.Credentials) *kernfs.Dentry {
+ k := &kcovInode{}
+ k.InodeAttrs.Init(creds, 0, 0, fs.NextIno(), linux.S_IFREG|0600)
+ d := &kernfs.Dentry{}
+ d.Init(k)
+ return d
+}
+
+// kcovInode implements kernfs.Inode.
+type kcovInode struct {
+ kernfs.InodeAttrs
+ kernfs.InodeNoopRefCount
+ kernfs.InodeNotSymlink
+ kernfs.InodeNotDirectory
+}
+
+func (i *kcovInode) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
+ k := kernel.KernelFromContext(ctx)
+ if k == nil {
+ panic("KernelFromContext returned nil")
+ }
+ fd := &kcovFD{
+ inode: i,
+ kcov: k.NewKcov(),
+ }
+
+ if err := fd.vfsfd.Init(fd, opts.Flags, rp.Mount(), vfsd, &vfs.FileDescriptionOptions{
+ DenyPRead: true,
+ DenyPWrite: true,
+ }); err != nil {
+ return nil, err
+ }
+ return &fd.vfsfd, nil
+}
+
+type kcovFD struct {
+ vfs.FileDescriptionDefaultImpl
+ vfs.NoLockFD
+
+ vfsfd vfs.FileDescription
+ inode *kcovInode
+ kcov *kernel.Kcov
+}
+
+// Ioctl implements vfs.FileDescriptionImpl.Ioctl.
+func (fd *kcovFD) Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArguments) (uintptr, error) {
+ cmd := uint32(args[1].Int())
+ arg := args[2].Uint64()
+ switch uint32(cmd) {
+ case linux.KCOV_INIT_TRACE:
+ return 0, fd.kcov.InitTrace(arg)
+ case linux.KCOV_ENABLE:
+ return 0, fd.kcov.EnableTrace(ctx, uint8(arg))
+ case linux.KCOV_DISABLE:
+ if arg != 0 {
+ // This arg is unused; it should be 0.
+ return 0, syserror.EINVAL
+ }
+ return 0, fd.kcov.DisableTrace(ctx)
+ default:
+ return 0, syserror.ENOTTY
+ }
+}
+
+// ConfigureMmap implements vfs.FileDescriptionImpl.ConfigureMmap.
+func (fd *kcovFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error {
+ return fd.kcov.ConfigureMMap(ctx, opts)
+}
+
+// Release implements vfs.FileDescriptionImpl.Release.
+func (fd *kcovFD) Release(ctx context.Context) {
+ // kcov instances have reference counts in Linux, but this seems sufficient
+ // for our purposes.
+ fd.kcov.Reset()
+}
+
+// SetStat implements vfs.FileDescriptionImpl.SetStat.
+func (fd *kcovFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
+ creds := auth.CredentialsFromContext(ctx)
+ fs := fd.vfsfd.VirtualDentry().Mount().Filesystem()
+ return fd.inode.SetStat(ctx, fs, creds, opts)
+}
+
+// Stat implements vfs.FileDescriptionImpl.Stat.
+func (fd *kcovFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
+ return fd.inode.Stat(ctx, fd.vfsfd.Mount().Filesystem(), opts)
+}
diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go
index 393feb802..1f042d9f7 100644
--- a/pkg/sentry/fsimpl/sys/sys.go
+++ b/pkg/sentry/fsimpl/sys/sys.go
@@ -21,6 +21,7 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/coverage"
"gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
"gvisor.dev/gvisor/pkg/sentry/kernel"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
@@ -73,7 +74,7 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt
}),
"firmware": fs.newDir(creds, defaultSysDirMode, nil),
"fs": fs.newDir(creds, defaultSysDirMode, nil),
- "kernel": fs.newDir(creds, defaultSysDirMode, nil),
+ "kernel": kernelDir(ctx, fs, creds),
"module": fs.newDir(creds, defaultSysDirMode, nil),
"power": fs.newDir(creds, defaultSysDirMode, nil),
})
@@ -94,6 +95,21 @@ func cpuDir(ctx context.Context, fs *filesystem, creds *auth.Credentials) *kernf
return fs.newDir(creds, defaultSysDirMode, children)
}
+func kernelDir(ctx context.Context, fs *filesystem, creds *auth.Credentials) *kernfs.Dentry {
+ // If kcov is available, set up /sys/kernel/debug/kcov. Technically, debugfs
+ // should be mounted at debug/, but for our purposes, it is sufficient to
+ // keep it in sys.
+ var children map[string]*kernfs.Dentry
+ if coverage.KcovAvailable() {
+ children = map[string]*kernfs.Dentry{
+ "debug": fs.newDir(creds, linux.FileMode(0700), map[string]*kernfs.Dentry{
+ "kcov": fs.newKcovFile(ctx, creds),
+ }),
+ }
+ }
+ return fs.newDir(creds, defaultSysDirMode, children)
+}
+
// Release implements vfs.FilesystemImpl.Release.
func (fs *filesystem) Release(ctx context.Context) {
fs.Filesystem.VFSFilesystem().VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor)
diff --git a/pkg/sentry/fsimpl/tmpfs/inode_refs.go b/pkg/sentry/fsimpl/tmpfs/inode_refs.go
index 3245ede1f..8b7ff185f 100644
--- a/pkg/sentry/fsimpl/tmpfs/inode_refs.go
+++ b/pkg/sentry/fsimpl/tmpfs/inode_refs.go
@@ -1,11 +1,11 @@
package tmpfs
import (
+ "runtime"
"sync/atomic"
"gvisor.dev/gvisor/pkg/log"
refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
- "runtime"
)
// ownerType is used to customize logging. Note that we use a pointer to T so
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-12 20:12:03 +0000