From 2dd14934c9138c562d93c501e88c6d6f061eb8ba Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 23 Mar 2006 00:00:09 +0100 Subject: [PATCH] [PATCH] spufs: allow SPU code to do syscalls An SPU does not have a way to implement system calls itself, but it can create intercepts to the kernel. This patch uses the method defined by the JSRE interface for C99 host library calls from an SPU to implement Linux system calls. It uses the reserved SPU stop code 0x2104 for this, using the structure layout and syscall numbers for ppc64-linux. I'm still undecided wether it is better to have a list of allowed syscalls or a list of forbidden syscalls, since we can't allow an SPU to call all syscalls that are defined for ppc64-linux. This patch implements the easier choice of them, with a blacklist that only prevents an SPU from calling anything that interacts with its own execution, e.g fork, execve, clone, vfork, exit, spu_run and spu_create and everything that deals with signals. Signed-off-by: Arnd Bergmann Signed-off-by: Paul Mackerras --- arch/powerpc/platforms/cell/Makefile | 10 +- arch/powerpc/platforms/cell/spu_callbacks.c | 345 ++++++++++++++++++++ arch/powerpc/platforms/cell/spufs/run.c | 91 ++++++ include/asm-powerpc/spu.h | 9 +- 4 files changed, 452 insertions(+), 3 deletions(-) create mode 100644 arch/powerpc/platforms/cell/spu_callbacks.c diff --git a/arch/powerpc/platforms/cell/Makefile b/arch/powerpc/platforms/cell/Makefile index 3b998a393e3f..e570bad06394 100644 --- a/arch/powerpc/platforms/cell/Makefile +++ b/arch/powerpc/platforms/cell/Makefile @@ -6,5 +6,11 @@ obj-$(CONFIG_SPU_FS) += spu-base.o spufs/ spu-base-y += spu_base.o spu_priv1.o -builtin-spufs-$(CONFIG_SPU_FS) += spu_syscalls.o -obj-y += $(builtin-spufs-m) +# needed only when building loadable spufs.ko +spufs-modular-$(CONFIG_SPU_FS) += spu_syscalls.o +obj-y += $(spufs-modular-m) + +# always needed in kernel +spufs-builtin-$(CONFIG_SPU_FS) += spu_callbacks.o +obj-y += $(spufs-builtin-y) $(spufs-builtin-m) + diff --git a/arch/powerpc/platforms/cell/spu_callbacks.c b/arch/powerpc/platforms/cell/spu_callbacks.c new file mode 100644 index 000000000000..3a4245c926ad --- /dev/null +++ b/arch/powerpc/platforms/cell/spu_callbacks.c @@ -0,0 +1,345 @@ +/* + * System call callback functions for SPUs + */ + +#define DEBUG + +#include +#include +#include + +#include +#include +#include + +/* + * This table defines the system calls that an SPU can call. + * It is currently a subset of the 64 bit powerpc system calls, + * with the exact semantics. + * + * The reasons for disabling some of the system calls are: + * 1. They interact with the way SPU syscalls are handled + * and we can't let them execute ever: + * restart_syscall, exit, for, execve, ptrace, ... + * 2. They are deprecated and replaced by other means: + * uselib, pciconfig_*, sysfs, ... + * 3. They are somewhat interacting with the system in a way + * we don't want an SPU to: + * reboot, init_module, mount, kexec_load + * 4. They are optional and we can't rely on them being + * linked into the kernel. Unfortunately, the cond_syscall + * helper does not work here as it does not add the necessary + * opd symbols: + * mbind, mq_open, ipc, ... + */ + +void *spu_syscall_table[] = { + [__NR_restart_syscall] sys_ni_syscall, /* sys_restart_syscall */ + [__NR_exit] sys_ni_syscall, /* sys_exit */ + [__NR_fork] sys_ni_syscall, /* ppc_fork */ + [__NR_read] sys_read, + [__NR_write] sys_write, + [__NR_open] sys_open, + [__NR_close] sys_close, + [__NR_waitpid] sys_waitpid, + [__NR_creat] sys_creat, + [__NR_link] sys_link, + [__NR_unlink] sys_unlink, + [__NR_execve] sys_ni_syscall, /* sys_execve */ + [__NR_chdir] sys_chdir, + [__NR_time] sys_time, + [__NR_mknod] sys_mknod, + [__NR_chmod] sys_chmod, + [__NR_lchown] sys_lchown, + [__NR_break] sys_ni_syscall, + [__NR_oldstat] sys_ni_syscall, + [__NR_lseek] sys_lseek, + [__NR_getpid] sys_getpid, + [__NR_mount] sys_ni_syscall, /* sys_mount */ + [__NR_umount] sys_ni_syscall, + [__NR_setuid] sys_setuid, + [__NR_getuid] sys_getuid, + [__NR_stime] sys_stime, + [__NR_ptrace] sys_ni_syscall, /* sys_ptrace */ + [__NR_alarm] sys_alarm, + [__NR_oldfstat] sys_ni_syscall, + [__NR_pause] sys_ni_syscall, /* sys_pause */ + [__NR_utime] sys_ni_syscall, /* sys_utime */ + [__NR_stty] sys_ni_syscall, + [__NR_gtty] sys_ni_syscall, + [__NR_access] sys_access, + [__NR_nice] sys_nice, + [__NR_ftime] sys_ni_syscall, + [__NR_sync] sys_sync, + [__NR_kill] sys_kill, + [__NR_rename] sys_rename, + [__NR_mkdir] sys_mkdir, + [__NR_rmdir] sys_rmdir, + [__NR_dup] sys_dup, + [__NR_pipe] sys_pipe, + [__NR_times] sys_times, + [__NR_prof] sys_ni_syscall, + [__NR_brk] sys_brk, + [__NR_setgid] sys_setgid, + [__NR_getgid] sys_getgid, + [__NR_signal] sys_ni_syscall, /* sys_signal */ + [__NR_geteuid] sys_geteuid, + [__NR_getegid] sys_getegid, + [__NR_acct] sys_ni_syscall, /* sys_acct */ + [__NR_umount2] sys_ni_syscall, /* sys_umount */ + [__NR_lock] sys_ni_syscall, + [__NR_ioctl] sys_ioctl, + [__NR_fcntl] sys_fcntl, + [__NR_mpx] sys_ni_syscall, + [__NR_setpgid] sys_setpgid, + [__NR_ulimit] sys_ni_syscall, + [__NR_oldolduname] sys_ni_syscall, + [__NR_umask] sys_umask, + [__NR_chroot] sys_chroot, + [__NR_ustat] sys_ni_syscall, /* sys_ustat */ + [__NR_dup2] sys_dup2, + [__NR_getppid] sys_getppid, + [__NR_getpgrp] sys_getpgrp, + [__NR_setsid] sys_setsid, + [__NR_sigaction] sys_ni_syscall, + [__NR_sgetmask] sys_sgetmask, + [__NR_ssetmask] sys_ssetmask, + [__NR_setreuid] sys_setreuid, + [__NR_setregid] sys_setregid, + [__NR_sigsuspend] sys_ni_syscall, + [__NR_sigpending] sys_ni_syscall, + [__NR_sethostname] sys_sethostname, + [__NR_setrlimit] sys_setrlimit, + [__NR_getrlimit] sys_ni_syscall, + [__NR_getrusage] sys_getrusage, + [__NR_gettimeofday] sys_gettimeofday, + [__NR_settimeofday] sys_settimeofday, + [__NR_getgroups] sys_getgroups, + [__NR_setgroups] sys_setgroups, + [__NR_select] sys_ni_syscall, + [__NR_symlink] sys_symlink, + [__NR_oldlstat] sys_ni_syscall, + [__NR_readlink] sys_readlink, + [__NR_uselib] sys_ni_syscall, /* sys_uselib */ + [__NR_swapon] sys_ni_syscall, /* sys_swapon */ + [__NR_reboot] sys_ni_syscall, /* sys_reboot */ + [__NR_readdir] sys_ni_syscall, + [__NR_mmap] sys_mmap, + [__NR_munmap] sys_munmap, + [__NR_truncate] sys_truncate, + [__NR_ftruncate] sys_ftruncate, + [__NR_fchmod] sys_fchmod, + [__NR_fchown] sys_fchown, + [__NR_getpriority] sys_getpriority, + [__NR_setpriority] sys_setpriority, + [__NR_profil] sys_ni_syscall, + [__NR_statfs] sys_ni_syscall, /* sys_statfs */ + [__NR_fstatfs] sys_ni_syscall, /* sys_fstatfs */ + [__NR_ioperm] sys_ni_syscall, + [__NR_socketcall] sys_socketcall, + [__NR_syslog] sys_syslog, + [__NR_setitimer] sys_setitimer, + [__NR_getitimer] sys_getitimer, + [__NR_stat] sys_newstat, + [__NR_lstat] sys_newlstat, + [__NR_fstat] sys_newfstat, + [__NR_olduname] sys_ni_syscall, + [__NR_iopl] sys_ni_syscall, + [__NR_vhangup] sys_vhangup, + [__NR_idle] sys_ni_syscall, + [__NR_vm86] sys_ni_syscall, + [__NR_wait4] sys_wait4, + [__NR_swapoff] sys_ni_syscall, /* sys_swapoff */ + [__NR_sysinfo] sys_sysinfo, + [__NR_ipc] sys_ni_syscall, /* sys_ipc */ + [__NR_fsync] sys_fsync, + [__NR_sigreturn] sys_ni_syscall, + [__NR_clone] sys_ni_syscall, /* ppc_clone */ + [__NR_setdomainname] sys_setdomainname, + [__NR_uname] ppc_newuname, + [__NR_modify_ldt] sys_ni_syscall, + [__NR_adjtimex] sys_adjtimex, + [__NR_mprotect] sys_mprotect, + [__NR_sigprocmask] sys_ni_syscall, + [__NR_create_module] sys_ni_syscall, + [__NR_init_module] sys_ni_syscall, /* sys_init_module */ + [__NR_delete_module] sys_ni_syscall, /* sys_delete_module */ + [__NR_get_kernel_syms] sys_ni_syscall, + [__NR_quotactl] sys_ni_syscall, /* sys_quotactl */ + [__NR_getpgid] sys_getpgid, + [__NR_fchdir] sys_fchdir, + [__NR_bdflush] sys_bdflush, + [__NR_sysfs] sys_ni_syscall, /* sys_sysfs */ + [__NR_personality] ppc64_personality, + [__NR_afs_syscall] sys_ni_syscall, + [__NR_setfsuid] sys_setfsuid, + [__NR_setfsgid] sys_setfsgid, + [__NR__llseek] sys_llseek, + [__NR_getdents] sys_getdents, + [__NR__newselect] sys_select, + [__NR_flock] sys_flock, + [__NR_msync] sys_msync, + [__NR_readv] sys_readv, + [__NR_writev] sys_writev, + [__NR_getsid] sys_getsid, + [__NR_fdatasync] sys_fdatasync, + [__NR__sysctl] sys_ni_syscall, /* sys_sysctl */ + [__NR_mlock] sys_mlock, + [__NR_munlock] sys_munlock, + [__NR_mlockall] sys_mlockall, + [__NR_munlockall] sys_munlockall, + [__NR_sched_setparam] sys_sched_setparam, + [__NR_sched_getparam] sys_sched_getparam, + [__NR_sched_setscheduler] sys_sched_setscheduler, + [__NR_sched_getscheduler] sys_sched_getscheduler, + [__NR_sched_yield] sys_sched_yield, + [__NR_sched_get_priority_max] sys_sched_get_priority_max, + [__NR_sched_get_priority_min] sys_sched_get_priority_min, + [__NR_sched_rr_get_interval] sys_sched_rr_get_interval, + [__NR_nanosleep] sys_nanosleep, + [__NR_mremap] sys_mremap, + [__NR_setresuid] sys_setresuid, + [__NR_getresuid] sys_getresuid, + [__NR_query_module] sys_ni_syscall, + [__NR_poll] sys_poll, + [__NR_nfsservctl] sys_ni_syscall, /* sys_nfsservctl */ + [__NR_setresgid] sys_setresgid, + [__NR_getresgid] sys_getresgid, + [__NR_prctl] sys_prctl, + [__NR_rt_sigreturn] sys_ni_syscall, /* ppc64_rt_sigreturn */ + [__NR_rt_sigaction] sys_ni_syscall, /* sys_rt_sigaction */ + [__NR_rt_sigprocmask] sys_ni_syscall, /* sys_rt_sigprocmask */ + [__NR_rt_sigpending] sys_ni_syscall, /* sys_rt_sigpending */ + [__NR_rt_sigtimedwait] sys_ni_syscall, /* sys_rt_sigtimedwait */ + [__NR_rt_sigqueueinfo] sys_ni_syscall, /* sys_rt_sigqueueinfo */ + [__NR_rt_sigsuspend] sys_ni_syscall, /* sys_rt_sigsuspend */ + [__NR_pread64] sys_pread64, + [__NR_pwrite64] sys_pwrite64, + [__NR_chown] sys_chown, + [__NR_getcwd] sys_getcwd, + [__NR_capget] sys_capget, + [__NR_capset] sys_capset, + [__NR_sigaltstack] sys_ni_syscall, /* sys_sigaltstack */ + [__NR_sendfile] sys_sendfile64, + [__NR_getpmsg] sys_ni_syscall, + [__NR_putpmsg] sys_ni_syscall, + [__NR_vfork] sys_ni_syscall, /* ppc_vfork */ + [__NR_ugetrlimit] sys_getrlimit, + [__NR_readahead] sys_readahead, + [192] sys_ni_syscall, + [193] sys_ni_syscall, + [194] sys_ni_syscall, + [195] sys_ni_syscall, + [196] sys_ni_syscall, + [197] sys_ni_syscall, + [__NR_pciconfig_read] sys_ni_syscall, /* sys_pciconfig_read */ + [__NR_pciconfig_write] sys_ni_syscall, /* sys_pciconfig_write */ + [__NR_pciconfig_iobase] sys_ni_syscall, /* sys_pciconfig_iobase */ + [__NR_multiplexer] sys_ni_syscall, + [__NR_getdents64] sys_getdents64, + [__NR_pivot_root] sys_pivot_root, + [204] sys_ni_syscall, + [__NR_madvise] sys_madvise, + [__NR_mincore] sys_mincore, + [__NR_gettid] sys_gettid, + [__NR_tkill] sys_tkill, + [__NR_setxattr] sys_setxattr, + [__NR_lsetxattr] sys_lsetxattr, + [__NR_fsetxattr] sys_fsetxattr, + [__NR_getxattr] sys_getxattr, + [__NR_lgetxattr] sys_lgetxattr, + [__NR_fgetxattr] sys_fgetxattr, + [__NR_listxattr] sys_listxattr, + [__NR_llistxattr] sys_llistxattr, + [__NR_flistxattr] sys_flistxattr, + [__NR_removexattr] sys_removexattr, + [__NR_lremovexattr] sys_lremovexattr, + [__NR_fremovexattr] sys_fremovexattr, + [__NR_futex] sys_futex, + [__NR_sched_setaffinity] sys_sched_setaffinity, + [__NR_sched_getaffinity] sys_sched_getaffinity, + [__NR_tuxcall] sys_ni_syscall, + [226] sys_ni_syscall, + [__NR_io_setup] sys_io_setup, + [__NR_io_destroy] sys_io_destroy, + [__NR_io_getevents] sys_io_getevents, + [__NR_io_submit] sys_io_submit, + [__NR_io_cancel] sys_io_cancel, + [__NR_set_tid_address] sys_ni_syscall, /* sys_set_tid_address */ + [__NR_fadvise64] sys_fadvise64, + [__NR_exit_group] sys_ni_syscall, /* sys_exit_group */ + [__NR_lookup_dcookie] sys_ni_syscall, /* sys_lookup_dcookie */ + [__NR_epoll_create] sys_epoll_create, + [__NR_epoll_ctl] sys_epoll_ctl, + [__NR_epoll_wait] sys_epoll_wait, + [__NR_remap_file_pages] sys_remap_file_pages, + [__NR_timer_create] sys_timer_create, + [__NR_timer_settime] sys_timer_settime, + [__NR_timer_gettime] sys_timer_gettime, + [__NR_timer_getoverrun] sys_timer_getoverrun, + [__NR_timer_delete] sys_timer_delete, + [__NR_clock_settime] sys_clock_settime, + [__NR_clock_gettime] sys_clock_gettime, + [__NR_clock_getres] sys_clock_getres, + [__NR_clock_nanosleep] sys_clock_nanosleep, + [__NR_swapcontext] sys_ni_syscall, /* ppc64_swapcontext */ + [__NR_tgkill] sys_tgkill, + [__NR_utimes] sys_utimes, + [__NR_statfs64] sys_statfs64, + [__NR_fstatfs64] sys_fstatfs64, + [254] sys_ni_syscall, + [__NR_rtas] ppc_rtas, + [256] sys_ni_syscall, + [257] sys_ni_syscall, + [258] sys_ni_syscall, + [__NR_mbind] sys_ni_syscall, /* sys_mbind */ + [__NR_get_mempolicy] sys_ni_syscall, /* sys_get_mempolicy */ + [__NR_set_mempolicy] sys_ni_syscall, /* sys_set_mempolicy */ + [__NR_mq_open] sys_ni_syscall, /* sys_mq_open */ + [__NR_mq_unlink] sys_ni_syscall, /* sys_mq_unlink */ + [__NR_mq_timedsend] sys_ni_syscall, /* sys_mq_timedsend */ + [__NR_mq_timedreceive] sys_ni_syscall, /* sys_mq_timedreceive */ + [__NR_mq_notify] sys_ni_syscall, /* sys_mq_notify */ + [__NR_mq_getsetattr] sys_ni_syscall, /* sys_mq_getsetattr */ + [__NR_kexec_load] sys_ni_syscall, /* sys_kexec_load */ + [__NR_add_key] sys_ni_syscall, /* sys_add_key */ + [__NR_request_key] sys_ni_syscall, /* sys_request_key */ + [__NR_keyctl] sys_ni_syscall, /* sys_keyctl */ + [__NR_waitid] sys_ni_syscall, /* sys_waitid */ + [__NR_ioprio_set] sys_ni_syscall, /* sys_ioprio_set */ + [__NR_ioprio_get] sys_ni_syscall, /* sys_ioprio_get */ + [__NR_inotify_init] sys_ni_syscall, /* sys_inotify_init */ + [__NR_inotify_add_watch] sys_ni_syscall, /* sys_inotify_add_watch */ + [__NR_inotify_rm_watch] sys_ni_syscall, /* sys_inotify_rm_watch */ + [__NR_spu_run] sys_ni_syscall, /* sys_spu_run */ + [__NR_spu_create] sys_ni_syscall, /* sys_spu_create */ + [__NR_pselect6] sys_ni_syscall, /* sys_pselect */ + [__NR_ppoll] sys_ni_syscall, /* sys_ppoll */ + [__NR_unshare] sys_unshare, +}; + +long spu_sys_callback(struct spu_syscall_block *s) +{ + long (*syscall)(u64 a1, u64 a2, u64 a3, u64 a4, u64 a5, u64 a6); + + BUILD_BUG_ON(ARRAY_SIZE(spu_syscall_table) != __NR_syscalls); + + syscall = spu_syscall_table[s->nr_ret]; + + if (s->nr_ret >= __NR_syscalls) { + pr_debug("%s: invalid syscall #%ld", __FUNCTION__, s->nr_ret); + return -ENOSYS; + } + +#ifdef DEBUG + print_symbol(KERN_DEBUG "SPU-syscall %s:", (unsigned long)syscall); + printk("syscall%ld(%lx, %lx, %lx, %lx, %lx, %lx)\n", + s->nr_ret, + s->parm[0], s->parm[1], s->parm[2], + s->parm[3], s->parm[4], s->parm[5]); +#endif + + return syscall(s->parm[0], s->parm[1], s->parm[2], + s->parm[3], s->parm[4], s->parm[5]); +} +EXPORT_SYMBOL_GPL(spu_sys_callback); diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c index 18ea8866c61a..c04e078c0fe5 100644 --- a/arch/powerpc/platforms/cell/spufs/run.c +++ b/arch/powerpc/platforms/cell/spufs/run.c @@ -76,6 +76,90 @@ static inline int spu_reacquire_runnable(struct spu_context *ctx, u32 *npc, return 0; } +/* + * SPU syscall restarting is tricky because we violate the basic + * assumption that the signal handler is running on the interrupted + * thread. Here instead, the handler runs on PowerPC user space code, + * while the syscall was called from the SPU. + * This means we can only do a very rough approximation of POSIX + * signal semantics. + */ +int spu_handle_restartsys(struct spu_context *ctx, long *spu_ret, + unsigned int *npc) +{ + int ret; + + switch (*spu_ret) { + case -ERESTARTSYS: + case -ERESTARTNOINTR: + /* + * Enter the regular syscall restarting for + * sys_spu_run, then restart the SPU syscall + * callback. + */ + *npc -= 8; + ret = -ERESTARTSYS; + break; + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + /* + * Restart block is too hard for now, just return -EINTR + * to the SPU. + * ERESTARTNOHAND comes from sys_pause, we also return + * -EINTR from there. + * Assume that we need to be restarted ourselves though. + */ + *spu_ret = -EINTR; + ret = -ERESTARTSYS; + break; + default: + printk(KERN_WARNING "%s: unexpected return code %ld\n", + __FUNCTION__, *spu_ret); + ret = 0; + } + return ret; +} + +int spu_process_callback(struct spu_context *ctx) +{ + struct spu_syscall_block s; + u32 ls_pointer, npc; + char *ls; + long spu_ret; + int ret; + + /* get syscall block from local store */ + npc = ctx->ops->npc_read(ctx); + ls = ctx->ops->get_ls(ctx); + ls_pointer = *(u32*)(ls + npc); + if (ls_pointer > (LS_SIZE - sizeof(s))) + return -EFAULT; + memcpy(&s, ls + ls_pointer, sizeof (s)); + + /* do actual syscall without pinning the spu */ + ret = 0; + spu_ret = -ENOSYS; + npc += 4; + + if (s.nr_ret < __NR_syscalls) { + spu_release(ctx); + /* do actual system call from here */ + spu_ret = spu_sys_callback(&s); + if (spu_ret <= -ERESTARTSYS) { + ret = spu_handle_restartsys(ctx, &spu_ret, &npc); + } + spu_acquire(ctx); + if (ret == -ERESTARTSYS) + return ret; + } + + /* write result, jump over indirect pointer */ + memcpy(ls + ls_pointer, &spu_ret, sizeof (spu_ret)); + ctx->ops->npc_write(ctx, npc); + ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE); + return ret; +} + static inline int spu_process_events(struct spu_context *ctx) { struct spu *spu = ctx->spu; @@ -107,6 +191,13 @@ long spufs_run_spu(struct file *file, struct spu_context *ctx, ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, status)); if (unlikely(ret)) break; + if ((*status & SPU_STATUS_STOPPED_BY_STOP) && + (*status >> SPU_STOP_STATUS_SHIFT == 0x2104)) { + ret = spu_process_callback(ctx); + if (ret) + break; + *status &= ~SPU_STATUS_STOPPED_BY_STOP; + } if (unlikely(ctx->state != SPU_STATE_RUNNABLE)) { ret = spu_reacquire_runnable(ctx, npc, status); if (ret) diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h index 38bacf2f6e0c..b5c90d6fdceb 100644 --- a/include/asm-powerpc/spu.h +++ b/include/asm-powerpc/spu.h @@ -149,6 +149,14 @@ int spu_irq_class_0_bottom(struct spu *spu); int spu_irq_class_1_bottom(struct spu *spu); void spu_irq_setaffinity(struct spu *spu, int cpu); +/* system callbacks from the SPU */ +struct spu_syscall_block { + u64 nr_ret; + u64 parm[6]; +}; +extern long spu_sys_callback(struct spu_syscall_block *s); + +/* syscalls implemented in spufs */ extern struct spufs_calls { asmlinkage long (*create_thread)(const char __user *name, unsigned int flags, mode_t mode); @@ -399,7 +407,6 @@ struct spu_priv1 { #define SPU_GET_REVISION_BITS(vr) (vr & SPU_REVISION_BITS) u8 pad_0x28_0x100[0x100 - 0x28]; /* 0x28 */ - /* Interrupt Area */ u64 int_mask_RW[3]; /* 0x100 */ #define CLASS0_ENABLE_DMA_ALIGNMENT_INTR 0x1L -- 2.20.1