[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 <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 345 insertions, 0 deletions

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 <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/syscalls.h>
+
+#include <asm/spu.h>
+#include <asm/syscalls.h>
+#include <asm/unistd.h>
+
+/*
+ * 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);