From 6dced977eab69401a114257e386addb9cb03a39d Mon Sep 17 00:00:00 2001 From: gVisor bot Date: Tue, 11 Feb 2020 17:38:04 -0800 Subject: Ensure fsimpl/gofer.dentryPlatformFile.hostFileMapper is initialized. Fixes #1812. (The more direct cause of the deadlock is panic unsafety because the historically high cost of defer means that we avoid it in hot paths, including much of MM; defer is much cheaper as of Go 1.14, but still a measurable overhead.) PiperOrigin-RevId: 294560316 --- pkg/sentry/fsimpl/gofer/regular_file.go | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'pkg/sentry/fsimpl') diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go index 8e11e06b3..54c1031a7 100644 --- a/pkg/sentry/fsimpl/gofer/regular_file.go +++ b/pkg/sentry/fsimpl/gofer/regular_file.go @@ -571,6 +571,8 @@ func (fd *regularFileFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpt default: panic(fmt.Sprintf("unknown InteropMode %v", d.fs.opts.interop)) } + // After this point, d may be used as a memmap.Mappable. + d.pf.hostFileMapperInitOnce.Do(d.pf.hostFileMapper.Init) return vfs.GenericConfigureMMap(&fd.vfsfd, d, opts) } @@ -799,6 +801,9 @@ type dentryPlatformFile struct { // If this dentry represents a regular file, and handle.fd >= 0, // hostFileMapper caches mappings of handle.fd. hostFileMapper fsutil.HostFileMapper + + // hostFileMapperInitOnce is used to lazily initialize hostFileMapper. + hostFileMapperInitOnce sync.Once } // IncRef implements platform.File.IncRef. -- cgit v1.2.3