Merge release-20200818.0-54-gcb573c8e0 (automated)

1 files changed, 17 insertions, 1 deletions

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)