1 // SPDX-License-Identifier: GPL-2.0-or-later
2
3 #include <linux/compat.h>
4 #include <linux/context_tracking.h>
5 #include <linux/entry-common.h>
6
7 #include <asm/interrupt.h>
8 #include <asm/kup.h>
9 #include <asm/syscall.h>
10 #include <asm/time.h>
11 #include <asm/tm.h>
12 #include <asm/unistd.h>
13
14
15 /* Has to run notrace because it is entered not completely "reconciled" */
system_call_exception(struct pt_regs * regs,unsigned long r0)16 notrace long system_call_exception(struct pt_regs *regs, unsigned long r0)
17 {
18 long ret;
19 syscall_fn f;
20
21 if (unlikely(!syscall_enter_from_user_mode_randomize_stack(regs, &r0))) {
22 clear_thread_flag(TIF_SYSCALL_RET);
23 return syscall_get_error(current, regs);
24 }
25
26 if (unlikely(test_and_clear_thread_flag(TIF_SYSCALL_RET)))
27 return syscall_get_error(current, regs);
28
29 if (unlikely(r0 >= NR_syscalls)) {
30 if (unlikely(trap_is_unsupported_scv(regs))) {
31 /* Unsupported scv vector */
32 _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
33 return regs->gpr[3];
34 }
35 return -ENOSYS;
36 }
37
38 /* May be faster to do array_index_nospec? */
39 barrier_nospec();
40
41 #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
42 // No COMPAT if we have SYSCALL_WRAPPER, see Kconfig
43 f = (void *)sys_call_table[r0];
44 ret = f(regs);
45 #else
46 if (unlikely(is_compat_task())) {
47 unsigned long r3, r4, r5, r6, r7, r8;
48
49 f = (void *)compat_sys_call_table[r0];
50
51 r3 = regs->gpr[3] & 0x00000000ffffffffULL;
52 r4 = regs->gpr[4] & 0x00000000ffffffffULL;
53 r5 = regs->gpr[5] & 0x00000000ffffffffULL;
54 r6 = regs->gpr[6] & 0x00000000ffffffffULL;
55 r7 = regs->gpr[7] & 0x00000000ffffffffULL;
56 r8 = regs->gpr[8] & 0x00000000ffffffffULL;
57
58 ret = f(r3, r4, r5, r6, r7, r8);
59 } else {
60 f = (void *)sys_call_table[r0];
61
62 ret = f(regs->gpr[3], regs->gpr[4], regs->gpr[5],
63 regs->gpr[6], regs->gpr[7], regs->gpr[8]);
64 }
65 #endif
66
67 return ret;
68 }
69