Linux Kernel  3.7.1
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spu_callbacks.c
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1 /*
2  * System call callback functions for SPUs
3  */
4 
5 #undef DEBUG
6 
7 #include <linux/kallsyms.h>
8 #include <linux/export.h>
9 #include <linux/syscalls.h>
10 
11 #include <asm/spu.h>
12 #include <asm/syscalls.h>
13 #include <asm/unistd.h>
14 
15 /*
16  * This table defines the system calls that an SPU can call.
17  * It is currently a subset of the 64 bit powerpc system calls,
18  * with the exact semantics.
19  *
20  * The reasons for disabling some of the system calls are:
21  * 1. They interact with the way SPU syscalls are handled
22  * and we can't let them execute ever:
23  * restart_syscall, exit, for, execve, ptrace, ...
24  * 2. They are deprecated and replaced by other means:
25  * uselib, pciconfig_*, sysfs, ...
26  * 3. They are somewhat interacting with the system in a way
27  * we don't want an SPU to:
28  * reboot, init_module, mount, kexec_load
29  * 4. They are optional and we can't rely on them being
30  * linked into the kernel. Unfortunately, the cond_syscall
31  * helper does not work here as it does not add the necessary
32  * opd symbols:
33  * mbind, mq_open, ipc, ...
34  */
35 
36 static void *spu_syscall_table[] = {
37 #define SYSCALL(func) sys_ni_syscall,
38 #define COMPAT_SYS(func) sys_ni_syscall,
39 #define PPC_SYS(func) sys_ni_syscall,
40 #define OLDSYS(func) sys_ni_syscall,
41 #define SYS32ONLY(func) sys_ni_syscall,
42 #define SYSX(f, f3264, f32) sys_ni_syscall,
43 
44 #define SYSCALL_SPU(func) sys_##func,
45 #define COMPAT_SYS_SPU(func) sys_##func,
46 #define PPC_SYS_SPU(func) ppc_##func,
47 #define SYSX_SPU(f, f3264, f32) f,
48 
49 #include <asm/systbl.h>
50 };
51 
52 long spu_sys_callback(struct spu_syscall_block *s)
53 {
54  long (*syscall)(u64 a1, u64 a2, u64 a3, u64 a4, u64 a5, u64 a6);
55 
56  if (s->nr_ret >= ARRAY_SIZE(spu_syscall_table)) {
57  pr_debug("%s: invalid syscall #%lld", __func__, s->nr_ret);
58  return -ENOSYS;
59  }
60 
61  syscall = spu_syscall_table[s->nr_ret];
62 
63 #ifdef DEBUG
64  print_symbol(KERN_DEBUG "SPU-syscall %s:", (unsigned long)syscall);
65  printk("syscall%ld(%lx, %lx, %lx, %lx, %lx, %lx)\n",
66  s->nr_ret,
67  s->parm[0], s->parm[1], s->parm[2],
68  s->parm[3], s->parm[4], s->parm[5]);
69 #endif
70 
71  return syscall(s->parm[0], s->parm[1], s->parm[2],
72  s->parm[3], s->parm[4], s->parm[5]);
73 }