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-rw-r--r--pkg/abi/linux/sem.go2
-rw-r--r--pkg/sentry/kernel/semaphore/semaphore.go28
-rw-r--r--pkg/sentry/syscalls/linux/linux64.go4
-rw-r--r--pkg/sentry/syscalls/linux/sys_sem.go35
-rw-r--r--test/syscalls/linux/semaphore.cc182
5 files changed, 214 insertions, 37 deletions
diff --git a/pkg/abi/linux/sem.go b/pkg/abi/linux/sem.go
index 0adff8dff..2424884c1 100644
--- a/pkg/abi/linux/sem.go
+++ b/pkg/abi/linux/sem.go
@@ -43,10 +43,10 @@ const (
SEMVMX = 32767
SEMAEM = SEMVMX
- // followings are unused in kernel
SEMUME = SEMOPM
SEMMNU = SEMMNS
SEMMAP = SEMMNS
+ SEMUSZ = 20
)
const SEM_UNDO = 0x1000
diff --git a/pkg/sentry/kernel/semaphore/semaphore.go b/pkg/sentry/kernel/semaphore/semaphore.go
index 3dd3953b3..db01e4a97 100644
--- a/pkg/sentry/kernel/semaphore/semaphore.go
+++ b/pkg/sentry/kernel/semaphore/semaphore.go
@@ -193,12 +193,26 @@ func (r *Registry) IPCInfo() *linux.SemInfo {
SemMsl: linux.SEMMSL,
SemOpm: linux.SEMOPM,
SemUme: linux.SEMUME,
- SemUsz: 0, // SemUsz not supported.
+ SemUsz: linux.SEMUSZ,
SemVmx: linux.SEMVMX,
SemAem: linux.SEMAEM,
}
}
+// SemInfo returns a seminfo structure containing the same information as
+// for IPC_INFO, except that SemUsz field returns the number of existing
+// semaphore sets, and SemAem field returns the number of existing semaphores.
+func (r *Registry) SemInfo() *linux.SemInfo {
+ r.mu.Lock()
+ defer r.mu.Unlock()
+
+ info := r.IPCInfo()
+ info.SemUsz = uint32(len(r.semaphores))
+ info.SemAem = uint32(r.totalSems())
+
+ return info
+}
+
// HighestIndex returns the index of the highest used entry in
// the kernel's array.
func (r *Registry) HighestIndex() int32 {
@@ -289,6 +303,18 @@ func (r *Registry) FindByID(id int32) *Set {
return r.semaphores[id]
}
+// FindByIndex looks up a set given an index.
+func (r *Registry) FindByIndex(index int32) *Set {
+ r.mu.Lock()
+ defer r.mu.Unlock()
+
+ id, present := r.indexes[index]
+ if !present {
+ return nil
+ }
+ return r.semaphores[id]
+}
+
func (r *Registry) findByKey(key int32) *Set {
for _, v := range r.semaphores {
if v.key == key {
diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index cff442846..b815e498f 100644
--- a/pkg/sentry/syscalls/linux/linux64.go
+++ b/pkg/sentry/syscalls/linux/linux64.go
@@ -118,7 +118,7 @@ var AMD64 = &kernel.SyscallTable{
63: syscalls.Supported("uname", Uname),
64: syscalls.Supported("semget", Semget),
65: syscalls.PartiallySupported("semop", Semop, "Option SEM_UNDO not supported.", nil),
- 66: syscalls.PartiallySupported("semctl", Semctl, "Options SEM_INFO, SEM_STAT, SEM_STAT_ANY not supported.", nil),
+ 66: syscalls.PartiallySupported("semctl", Semctl, "Options SEM_STAT_ANY not supported.", nil),
67: syscalls.Supported("shmdt", Shmdt),
68: syscalls.ErrorWithEvent("msgget", syserror.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
69: syscalls.ErrorWithEvent("msgsnd", syserror.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
@@ -619,7 +619,7 @@ var ARM64 = &kernel.SyscallTable{
188: syscalls.ErrorWithEvent("msgrcv", syserror.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
189: syscalls.ErrorWithEvent("msgsnd", syserror.ENOSYS, "", []string{"gvisor.dev/issue/135"}), // TODO(b/29354921)
190: syscalls.Supported("semget", Semget),
- 191: syscalls.PartiallySupported("semctl", Semctl, "Options SEM_INFO, SEM_STAT, SEM_STAT_ANY not supported.", nil),
+ 191: syscalls.PartiallySupported("semctl", Semctl, "Options SEM_STAT_ANY not supported.", nil),
192: syscalls.ErrorWithEvent("semtimedop", syserror.ENOSYS, "", []string{"gvisor.dev/issue/137"}),
193: syscalls.PartiallySupported("semop", Semop, "Option SEM_UNDO not supported.", nil),
194: syscalls.PartiallySupported("shmget", Shmget, "Option SHM_HUGETLB is not supported.", nil),
diff --git a/pkg/sentry/syscalls/linux/sys_sem.go b/pkg/sentry/syscalls/linux/sys_sem.go
index a62a6b3b5..1166cd7bb 100644
--- a/pkg/sentry/syscalls/linux/sys_sem.go
+++ b/pkg/sentry/syscalls/linux/sys_sem.go
@@ -155,10 +155,28 @@ func Semctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
}
return uintptr(r.HighestIndex()), nil, nil
- case linux.SEM_INFO,
- linux.SEM_STAT,
- linux.SEM_STAT_ANY:
+ case linux.SEM_INFO:
+ buf := args[3].Pointer()
+ r := t.IPCNamespace().SemaphoreRegistry()
+ info := r.SemInfo()
+ if _, err := info.CopyOut(t, buf); err != nil {
+ return 0, nil, err
+ }
+ return uintptr(r.HighestIndex()), nil, nil
+ case linux.SEM_STAT:
+ arg := args[3].Pointer()
+ // id is an index in SEM_STAT.
+ semid, ds, err := semStat(t, id)
+ if err != nil {
+ return 0, nil, err
+ }
+ if _, err := ds.CopyOut(t, arg); err != nil {
+ return 0, nil, err
+ }
+ return uintptr(semid), nil, err
+
+ case linux.SEM_STAT_ANY:
t.Kernel().EmitUnimplementedEvent(t)
fallthrough
@@ -203,6 +221,17 @@ func ipcStat(t *kernel.Task, id int32) (*linux.SemidDS, error) {
return set.GetStat(creds)
}
+func semStat(t *kernel.Task, index int32) (int32, *linux.SemidDS, error) {
+ r := t.IPCNamespace().SemaphoreRegistry()
+ set := r.FindByIndex(index)
+ if set == nil {
+ return 0, nil, syserror.EINVAL
+ }
+ creds := auth.CredentialsFromContext(t)
+ ds, err := set.GetStat(creds)
+ return set.ID, ds, err
+}
+
func setVal(t *kernel.Task, id int32, num int32, val int16) error {
r := t.IPCNamespace().SemaphoreRegistry()
set := r.FindByID(id)
diff --git a/test/syscalls/linux/semaphore.cc b/test/syscalls/linux/semaphore.cc
index fb4695e72..c2f080917 100644
--- a/test/syscalls/linux/semaphore.cc
+++ b/test/syscalls/linux/semaphore.cc
@@ -20,7 +20,7 @@
#include <atomic>
#include <cerrno>
#include <ctime>
-#include <stack>
+#include <set>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
@@ -32,10 +32,23 @@
#include "test/util/test_util.h"
#include "test/util/thread_util.h"
+using ::testing::Contains;
+
namespace gvisor {
namespace testing {
namespace {
+constexpr int kSemMap = 1024000000;
+constexpr int kSemMni = 32000;
+constexpr int kSemMns = 1024000000;
+constexpr int kSemMnu = 1024000000;
+constexpr int kSemMsl = 32000;
+constexpr int kSemOpm = 500;
+constexpr int kSemUme = 500;
+constexpr int kSemUsz = 20;
+constexpr int kSemVmx = 32767;
+constexpr int kSemAem = 32767;
+
class AutoSem {
public:
explicit AutoSem(int id) : id_(id) {}
@@ -775,42 +788,151 @@ TEST(SemaphoreTest, SemopGetncntOnSignal_NoRandomSave) {
}
TEST(SemaphoreTest, IpcInfo) {
- std::stack<int> sem_ids;
- std::stack<int> max_used_indexes;
+ constexpr int kLoops = 5;
+ std::set<int> sem_ids;
struct seminfo info;
- for (int i = 0; i < 3; i++) {
- int sem_id = 0;
- ASSERT_THAT(sem_id = semget(IPC_PRIVATE, 1, 0600 | IPC_CREAT),
- SyscallSucceeds());
- sem_ids.push(sem_id);
- int max_used_index = 0;
- EXPECT_THAT(max_used_index = semctl(0, 0, IPC_INFO, &info),
- SyscallSucceeds());
- if (!max_used_indexes.empty()) {
- EXPECT_GT(max_used_index, max_used_indexes.top());
+ // Drop CAP_IPC_OWNER which allows us to bypass semaphore permissions.
+ ASSERT_NO_ERRNO(SetCapability(CAP_IPC_OWNER, false));
+ ASSERT_THAT(semctl(0, 0, IPC_INFO, &info), SyscallSucceedsWithValue(0));
+ for (int i = 0; i < kLoops; i++) {
+ AutoSem sem(semget(IPC_PRIVATE, 1, 0600 | IPC_CREAT));
+ ASSERT_THAT(sem.get(), SyscallSucceeds());
+ sem_ids.insert(sem.release());
+ }
+ ASSERT_EQ(sem_ids.size(), kLoops);
+
+ int max_used_index = 0;
+ EXPECT_THAT(max_used_index = semctl(0, 0, IPC_INFO, &info),
+ SyscallSucceeds());
+
+ int index_count = 0;
+ for (int i = 0; i <= max_used_index; i++) {
+ struct semid_ds ds = {};
+ int sem_id = semctl(i, 0, SEM_STAT, &ds);
+ // Only if index i is used within the registry.
+ if (sem_id != -1) {
+ ASSERT_THAT(sem_ids, Contains(sem_id));
+ struct semid_ds ipc_stat_ds;
+ ASSERT_THAT(semctl(sem_id, 0, IPC_STAT, &ipc_stat_ds), SyscallSucceeds());
+ EXPECT_EQ(ds.sem_perm.__key, ipc_stat_ds.sem_perm.__key);
+ EXPECT_EQ(ds.sem_perm.uid, ipc_stat_ds.sem_perm.uid);
+ EXPECT_EQ(ds.sem_perm.gid, ipc_stat_ds.sem_perm.gid);
+ EXPECT_EQ(ds.sem_perm.cuid, ipc_stat_ds.sem_perm.cuid);
+ EXPECT_EQ(ds.sem_perm.cgid, ipc_stat_ds.sem_perm.cgid);
+ EXPECT_EQ(ds.sem_perm.mode, ipc_stat_ds.sem_perm.mode);
+ EXPECT_EQ(ds.sem_otime, ipc_stat_ds.sem_otime);
+ EXPECT_EQ(ds.sem_ctime, ipc_stat_ds.sem_ctime);
+ EXPECT_EQ(ds.sem_nsems, ipc_stat_ds.sem_nsems);
+
+ // Remove the semaphore set's read permission.
+ struct semid_ds ipc_set_ds;
+ ipc_set_ds.sem_perm.uid = getuid();
+ ipc_set_ds.sem_perm.gid = getgid();
+ // Keep the semaphore set's write permission so that it could be removed.
+ ipc_set_ds.sem_perm.mode = 0200;
+ ASSERT_THAT(semctl(sem_id, 0, IPC_SET, &ipc_set_ds), SyscallSucceeds());
+ ASSERT_THAT(semctl(i, 0, SEM_STAT, &ds), SyscallFailsWithErrno(EACCES));
+
+ index_count += 1;
}
- max_used_indexes.push(max_used_index);
}
- while (!sem_ids.empty()) {
- int sem_id = sem_ids.top();
- sem_ids.pop();
+ EXPECT_EQ(index_count, kLoops);
+ ASSERT_THAT(semctl(0, 0, IPC_INFO, &info),
+ SyscallSucceedsWithValue(max_used_index));
+ for (const int sem_id : sem_ids) {
ASSERT_THAT(semctl(sem_id, 0, IPC_RMID), SyscallSucceeds());
- int max_index = max_used_indexes.top();
- EXPECT_THAT(max_index = semctl(0, 0, IPC_INFO, &info), SyscallSucceeds());
- EXPECT_GE(max_used_indexes.top(), max_index);
- max_used_indexes.pop();
}
+
+ ASSERT_THAT(semctl(0, 0, IPC_INFO, &info), SyscallSucceedsWithValue(0));
+ EXPECT_EQ(info.semmap, kSemMap);
+ EXPECT_EQ(info.semmni, kSemMni);
+ EXPECT_EQ(info.semmns, kSemMns);
+ EXPECT_EQ(info.semmnu, kSemMnu);
+ EXPECT_EQ(info.semmsl, kSemMsl);
+ EXPECT_EQ(info.semopm, kSemOpm);
+ EXPECT_EQ(info.semume, kSemUme);
+ EXPECT_EQ(info.semusz, kSemUsz);
+ EXPECT_EQ(info.semvmx, kSemVmx);
+ EXPECT_EQ(info.semaem, kSemAem);
+}
+
+TEST(SemaphoreTest, SemInfo) {
+ constexpr int kLoops = 5;
+ constexpr int kSemSetSize = 3;
+ std::set<int> sem_ids;
+ struct seminfo info;
+ // Drop CAP_IPC_OWNER which allows us to bypass semaphore permissions.
+ ASSERT_NO_ERRNO(SetCapability(CAP_IPC_OWNER, false));
ASSERT_THAT(semctl(0, 0, IPC_INFO, &info), SyscallSucceedsWithValue(0));
+ for (int i = 0; i < kLoops; i++) {
+ AutoSem sem(semget(IPC_PRIVATE, kSemSetSize, 0600 | IPC_CREAT));
+ ASSERT_THAT(sem.get(), SyscallSucceeds());
+ sem_ids.insert(sem.release());
+ }
+ ASSERT_EQ(sem_ids.size(), kLoops);
+ int max_used_index = 0;
+ EXPECT_THAT(max_used_index = semctl(0, 0, SEM_INFO, &info),
+ SyscallSucceeds());
+ EXPECT_EQ(info.semmap, kSemMap);
+ EXPECT_EQ(info.semmni, kSemMni);
+ EXPECT_EQ(info.semmns, kSemMns);
+ EXPECT_EQ(info.semmnu, kSemMnu);
+ EXPECT_EQ(info.semmsl, kSemMsl);
+ EXPECT_EQ(info.semopm, kSemOpm);
+ EXPECT_EQ(info.semume, kSemUme);
+ EXPECT_EQ(info.semusz, sem_ids.size());
+ EXPECT_EQ(info.semvmx, kSemVmx);
+ EXPECT_EQ(info.semaem, sem_ids.size() * kSemSetSize);
+
+ int index_count = 0;
+ for (int i = 0; i <= max_used_index; i++) {
+ struct semid_ds ds = {};
+ int sem_id = semctl(i, 0, SEM_STAT, &ds);
+ // Only if index i is used within the registry.
+ if (sem_id != -1) {
+ ASSERT_THAT(sem_ids, Contains(sem_id));
+ struct semid_ds ipc_stat_ds;
+ ASSERT_THAT(semctl(sem_id, 0, IPC_STAT, &ipc_stat_ds), SyscallSucceeds());
+ EXPECT_EQ(ds.sem_perm.__key, ipc_stat_ds.sem_perm.__key);
+ EXPECT_EQ(ds.sem_perm.uid, ipc_stat_ds.sem_perm.uid);
+ EXPECT_EQ(ds.sem_perm.gid, ipc_stat_ds.sem_perm.gid);
+ EXPECT_EQ(ds.sem_perm.cuid, ipc_stat_ds.sem_perm.cuid);
+ EXPECT_EQ(ds.sem_perm.cgid, ipc_stat_ds.sem_perm.cgid);
+ EXPECT_EQ(ds.sem_perm.mode, ipc_stat_ds.sem_perm.mode);
+ EXPECT_EQ(ds.sem_otime, ipc_stat_ds.sem_otime);
+ EXPECT_EQ(ds.sem_ctime, ipc_stat_ds.sem_ctime);
+ EXPECT_EQ(ds.sem_nsems, ipc_stat_ds.sem_nsems);
+
+ // Remove the semaphore set's read permission.
+ struct semid_ds ipc_set_ds;
+ ipc_set_ds.sem_perm.uid = getuid();
+ ipc_set_ds.sem_perm.gid = getgid();
+ // Keep the semaphore set's write permission so that it could be removed.
+ ipc_set_ds.sem_perm.mode = 0200;
+ ASSERT_THAT(semctl(sem_id, 0, IPC_SET, &ipc_set_ds), SyscallSucceeds());
+ ASSERT_THAT(semctl(i, 0, SEM_STAT, &ds), SyscallFailsWithErrno(EACCES));
+
+ index_count += 1;
+ }
+ }
+ EXPECT_EQ(index_count, kLoops);
+ ASSERT_THAT(semctl(0, 0, SEM_INFO, &info),
+ SyscallSucceedsWithValue(max_used_index));
+ for (const int sem_id : sem_ids) {
+ ASSERT_THAT(semctl(sem_id, 0, IPC_RMID), SyscallSucceeds());
+ }
- EXPECT_EQ(info.semmap, 1024000000);
- EXPECT_EQ(info.semmni, 32000);
- EXPECT_EQ(info.semmns, 1024000000);
- EXPECT_EQ(info.semmnu, 1024000000);
- EXPECT_EQ(info.semmsl, 32000);
- EXPECT_EQ(info.semopm, 500);
- EXPECT_EQ(info.semume, 500);
- EXPECT_EQ(info.semvmx, 32767);
- EXPECT_EQ(info.semaem, 32767);
+ ASSERT_THAT(semctl(0, 0, SEM_INFO, &info), SyscallSucceedsWithValue(0));
+ EXPECT_EQ(info.semmap, kSemMap);
+ EXPECT_EQ(info.semmni, kSemMni);
+ EXPECT_EQ(info.semmns, kSemMns);
+ EXPECT_EQ(info.semmnu, kSemMnu);
+ EXPECT_EQ(info.semmsl, kSemMsl);
+ EXPECT_EQ(info.semopm, kSemOpm);
+ EXPECT_EQ(info.semume, kSemUme);
+ EXPECT_EQ(info.semusz, 0);
+ EXPECT_EQ(info.semvmx, kSemVmx);
+ EXPECT_EQ(info.semaem, 0);
}
} // namespace
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-16 16:53:49 +0000