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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * System call callback functions for SPUs
4  */
5 
6 #undef DEBUG
7 
8 #include <linux/kallsyms.h>
9 #include <linux/export.h>
10 #include <linux/syscalls.h>
11 
12 #include <asm/spu.h>
13 #include <asm/syscalls.h>
14 #include <asm/unistd.h>
15 
16 /*
17  * This table defines the system calls that an SPU can call.
18  * It is currently a subset of the 64 bit powerpc system calls,
19  * with the exact semantics.
20  *
21  * The reasons for disabling some of the system calls are:
22  * 1. They interact with the way SPU syscalls are handled
23  *    and we can't let them execute ever:
24  *	restart_syscall, exit, for, execve, ptrace, ...
25  * 2. They are deprecated and replaced by other means:
26  *	uselib, pciconfig_*, sysfs, ...
27  * 3. They are somewhat interacting with the system in a way
28  *    we don't want an SPU to:
29  *	reboot, init_module, mount, kexec_load
30  * 4. They are optional and we can't rely on them being
31  *    linked into the kernel. Unfortunately, the cond_syscall
32  *    helper does not work here as it does not add the necessary
33  *    opd symbols:
34  *	mbind, mq_open, ipc, ...
35  */
36 
37 static void *spu_syscall_table[] = {
38 #define __SYSCALL_WITH_COMPAT(nr, entry, compat) __SYSCALL(nr, entry)
39 #define __SYSCALL(nr, entry) [nr] = entry,
40 #include <asm/syscall_table_spu.h>
41 };
42 
spu_sys_callback(struct spu_syscall_block * s)43 long spu_sys_callback(struct spu_syscall_block *s)
44 {
45 	long (*syscall)(u64 a1, u64 a2, u64 a3, u64 a4, u64 a5, u64 a6);
46 
47 	if (s->nr_ret >= ARRAY_SIZE(spu_syscall_table)) {
48 		pr_debug("%s: invalid syscall #%lld", __func__, s->nr_ret);
49 		return -ENOSYS;
50 	}
51 
52 	syscall = spu_syscall_table[s->nr_ret];
53 
54 	pr_debug("SPU-syscall "
55 		 "%pSR:syscall%lld(%llx, %llx, %llx, %llx, %llx, %llx)\n",
56 		 syscall,
57 		 s->nr_ret,
58 		 s->parm[0], s->parm[1], s->parm[2],
59 		 s->parm[3], s->parm[4], s->parm[5]);
60 
61 	return syscall(s->parm[0], s->parm[1], s->parm[2],
62 		       s->parm[3], s->parm[4], s->parm[5]);
63 }
64 EXPORT_SYMBOL_GPL(spu_sys_callback);
65