diff options
| -rw-r--r-- | linux-user/syscall.c | 66 |
1 files changed, 63 insertions, 3 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 3b7b51f6c7..d7e4d9ff2f 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -112,8 +112,56 @@ int __clone2(int (*fn)(void *), void *child_stack_base, #include "qemu.h" -#define CLONE_NPTL_FLAGS2 (CLONE_SETTLS | \ - CLONE_PARENT_SETTID | CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID) +#ifndef CLONE_IO +#define CLONE_IO 0x80000000 /* Clone io context */ +#endif + +/* We can't directly call the host clone syscall, because this will + * badly confuse libc (breaking mutexes, for example). So we must + * divide clone flags into: + * * flag combinations that look like pthread_create() + * * flag combinations that look like fork() + * * flags we can implement within QEMU itself + * * flags we can't support and will return an error for + */ +/* For thread creation, all these flags must be present; for + * fork, none must be present. + */ +#define CLONE_THREAD_FLAGS \ + (CLONE_VM | CLONE_FS | CLONE_FILES | \ + CLONE_SIGHAND | CLONE_THREAD | CLONE_SYSVSEM) + +/* These flags are ignored: + * CLONE_DETACHED is now ignored by the kernel; + * CLONE_IO is just an optimisation hint to the I/O scheduler + */ +#define CLONE_IGNORED_FLAGS \ + (CLONE_DETACHED | CLONE_IO) + +/* Flags for fork which we can implement within QEMU itself */ +#define CLONE_OPTIONAL_FORK_FLAGS \ + (CLONE_SETTLS | CLONE_PARENT_SETTID | \ + CLONE_CHILD_CLEARTID | CLONE_CHILD_SETTID) + +/* Flags for thread creation which we can implement within QEMU itself */ +#define CLONE_OPTIONAL_THREAD_FLAGS \ + (CLONE_SETTLS | CLONE_PARENT_SETTID | \ + CLONE_CHILD_CLEARTID | CLONE_CHILD_SETTID | CLONE_PARENT) + +#define CLONE_INVALID_FORK_FLAGS \ + (~(CSIGNAL | CLONE_OPTIONAL_FORK_FLAGS | CLONE_IGNORED_FLAGS)) + +#define CLONE_INVALID_THREAD_FLAGS \ + (~(CSIGNAL | CLONE_THREAD_FLAGS | CLONE_OPTIONAL_THREAD_FLAGS | \ + CLONE_IGNORED_FLAGS)) + +/* CLONE_VFORK is special cased early in do_fork(). The other flag bits + * have almost all been allocated. We cannot support any of + * CLONE_NEWNS, CLONE_NEWCGROUP, CLONE_NEWUTS, CLONE_NEWIPC, + * CLONE_NEWUSER, CLONE_NEWPID, CLONE_NEWNET, CLONE_PTRACE, CLONE_UNTRACED. + * The checks against the invalid thread masks above will catch these. + * (The one remaining unallocated bit is 0x1000 which used to be CLONE_PID.) + */ //#define DEBUG /* Define DEBUG_ERESTARTSYS to force every syscall to be restarted @@ -6013,6 +6061,8 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp, CPUArchState *new_env; sigset_t sigmask; + flags &= ~CLONE_IGNORED_FLAGS; + /* Emulate vfork() with fork() */ if (flags & CLONE_VFORK) flags &= ~(CLONE_VFORK | CLONE_VM); @@ -6022,6 +6072,11 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp, new_thread_info info; pthread_attr_t attr; + if (((flags & CLONE_THREAD_FLAGS) != CLONE_THREAD_FLAGS) || + (flags & CLONE_INVALID_THREAD_FLAGS)) { + return -TARGET_EINVAL; + } + ts = g_new0(TaskState, 1); init_task_state(ts); /* we create a new CPU instance. */ @@ -6083,7 +6138,12 @@ static int do_fork(CPUArchState *env, unsigned int flags, abi_ulong newsp, pthread_mutex_unlock(&clone_lock); } else { /* if no CLONE_VM, we consider it is a fork */ - if ((flags & ~(CSIGNAL | CLONE_NPTL_FLAGS2)) != 0) { + if (flags & CLONE_INVALID_FORK_FLAGS) { + return -TARGET_EINVAL; + } + + /* We can't support custom termination signals */ + if ((flags & CSIGNAL) != TARGET_SIGCHLD) { return -TARGET_EINVAL; } |