diff options
| author | Fabricio Voznika <fvoznika@google.com> | 2021-06-10 13:28:06 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2021-06-10 13:36:03 -0700 |
| commit | 21169357ca913de9cef50da6f235a482b7a3cfab (patch) | |
| tree | 9b78610d4f10ffa7c97bc89cb2fc83b2c7bd56ba | |
| parent | 8d426b73818cf07aeee3db88478a00b80ad9aafe (diff) | |
Add /proc/sys/vm/max_map_count
Set it to int32 max because gVisor doesn't have a limit.
Fixes #2337
PiperOrigin-RevId: 378722230
| -rw-r--r-- | pkg/sentry/fs/proc/sys.go | 22 | ||||
| -rw-r--r-- | pkg/sentry/fsimpl/proc/tasks_sys.go | 1 | ||||
| -rw-r--r-- | test/syscalls/linux/proc.cc | 9 |
3 files changed, 32 insertions, 0 deletions
diff --git a/pkg/sentry/fs/proc/sys.go b/pkg/sentry/fs/proc/sys.go index b998fb75d..085aa6d61 100644 --- a/pkg/sentry/fs/proc/sys.go +++ b/pkg/sentry/fs/proc/sys.go @@ -77,6 +77,27 @@ func (*overcommitMemory) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandl }, 0 } +// +stateify savable +type maxMapCount struct{} + +// NeedsUpdate implements seqfile.SeqSource. +func (*maxMapCount) NeedsUpdate(int64) bool { + return true +} + +// ReadSeqFileData implements seqfile.SeqSource. +func (*maxMapCount) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) { + if h != nil { + return nil, 0 + } + return []seqfile.SeqData{ + { + Buf: []byte("2147483647\n"), + Handle: (*maxMapCount)(nil), + }, + }, 0 +} + func (p *proc) newKernelDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode { h := hostname{ SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC), @@ -96,6 +117,7 @@ func (p *proc) newKernelDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode func (p *proc) newVMDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode { children := map[string]*fs.Inode{ + "max_map_count": seqfile.NewSeqFileInode(ctx, &maxMapCount{}, msrc), "mmap_min_addr": seqfile.NewSeqFileInode(ctx, &mmapMinAddrData{p.k}, msrc), "overcommit_memory": seqfile.NewSeqFileInode(ctx, &overcommitMemory{}, msrc), } diff --git a/pkg/sentry/fsimpl/proc/tasks_sys.go b/pkg/sentry/fsimpl/proc/tasks_sys.go index 88ab49048..2bc98a94f 100644 --- a/pkg/sentry/fsimpl/proc/tasks_sys.go +++ b/pkg/sentry/fsimpl/proc/tasks_sys.go @@ -55,6 +55,7 @@ func (fs *filesystem) newSysDir(ctx context.Context, root *auth.Credentials, k * }), }), "vm": fs.newStaticDir(ctx, root, map[string]kernfs.Inode{ + "max_map_count": fs.newInode(ctx, root, 0444, newStaticFile("2147483647\n")), "mmap_min_addr": fs.newInode(ctx, root, 0444, &mmapMinAddrData{k: k}), "overcommit_memory": fs.newInode(ctx, root, 0444, newStaticFile("0\n")), }), diff --git a/test/syscalls/linux/proc.cc b/test/syscalls/linux/proc.cc index 24928d876..78aa73edc 100644 --- a/test/syscalls/linux/proc.cc +++ b/test/syscalls/linux/proc.cc @@ -2364,6 +2364,15 @@ TEST(ProcSysKernelHostname, MatchesUname) { EXPECT_EQ(procfs_hostname, hostname); } +TEST(ProcSysVmMaxmapCount, HasNumericValue) { + const std::string val_str = + ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/sys/vm/max_map_count")); + int32_t val; + EXPECT_TRUE(absl::SimpleAtoi(val_str, &val)) + << "/proc/sys/vm/max_map_count does not contain a numeric value: " + << val_str; +} + TEST(ProcSysVmMmapMinAddr, HasNumericValue) { const std::string mmap_min_addr_str = ASSERT_NO_ERRNO_AND_VALUE(GetContents("/proc/sys/vm/mmap_min_addr")); |