1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Copyright (C) 2003 Broadcom Corporation |
4 | */ |
5 | #include <linux/cache.h> |
6 | #include <linux/sched.h> |
7 | #include <linux/mm.h> |
8 | #include <linux/smp.h> |
9 | #include <linux/kernel.h> |
10 | #include <linux/signal.h> |
11 | #include <linux/errno.h> |
12 | #include <linux/wait.h> |
13 | #include <linux/ptrace.h> |
14 | #include <linux/unistd.h> |
15 | #include <linux/compat.h> |
16 | #include <linux/bitops.h> |
17 | |
18 | #include <asm/abi.h> |
19 | #include <asm/asm.h> |
20 | #include <asm/cacheflush.h> |
21 | #include <asm/compat-signal.h> |
22 | #include <asm/sim.h> |
23 | #include <linux/uaccess.h> |
24 | #include <asm/ucontext.h> |
25 | #include <asm/fpu.h> |
26 | #include <asm/cpu-features.h> |
27 | #include <asm/syscalls.h> |
28 | |
29 | #include "signal-common.h" |
30 | |
31 | /* |
32 | * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... |
33 | */ |
34 | #define __NR_N32_restart_syscall 6214 |
35 | |
36 | struct ucontextn32 { |
37 | u32 uc_flags; |
38 | s32 uc_link; |
39 | compat_stack_t uc_stack; |
40 | struct sigcontext uc_mcontext; |
41 | compat_sigset_t uc_sigmask; /* mask last for extensibility */ |
42 | }; |
43 | |
44 | struct rt_sigframe_n32 { |
45 | u32 rs_ass[4]; /* argument save space for o32 */ |
46 | u32 rs_pad[2]; /* Was: signal trampoline */ |
47 | struct compat_siginfo rs_info; |
48 | struct ucontextn32 rs_uc; |
49 | }; |
50 | |
51 | asmlinkage void sysn32_rt_sigreturn(void) |
52 | { |
53 | struct rt_sigframe_n32 __user *frame; |
54 | struct pt_regs *regs; |
55 | sigset_t set; |
56 | int sig; |
57 | |
58 | regs = current_pt_regs(); |
59 | frame = (struct rt_sigframe_n32 __user *)regs->regs[29]; |
60 | if (!access_ok(frame, sizeof(*frame))) |
61 | goto badframe; |
62 | if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask)) |
63 | goto badframe; |
64 | |
65 | set_current_blocked(&set); |
66 | |
67 | sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext); |
68 | if (sig < 0) |
69 | goto badframe; |
70 | else if (sig) |
71 | force_sig(sig); |
72 | |
73 | if (compat_restore_altstack(uss: &frame->rs_uc.uc_stack)) |
74 | goto badframe; |
75 | |
76 | /* |
77 | * Don't let your children do this ... |
78 | */ |
79 | __asm__ __volatile__( |
80 | "move\t$29, %0\n\t" |
81 | "j\tsyscall_exit" |
82 | : /* no outputs */ |
83 | : "r" (regs)); |
84 | /* Unreached */ |
85 | |
86 | badframe: |
87 | force_sig(SIGSEGV); |
88 | } |
89 | |
90 | static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig, |
91 | struct pt_regs *regs, sigset_t *set) |
92 | { |
93 | struct rt_sigframe_n32 __user *frame; |
94 | int err = 0; |
95 | |
96 | frame = get_sigframe(ksig, regs, frame_size: sizeof(*frame)); |
97 | if (!access_ok(frame, sizeof (*frame))) |
98 | return -EFAULT; |
99 | |
100 | /* Create siginfo. */ |
101 | err |= copy_siginfo_to_user32(to: &frame->rs_info, from: &ksig->info); |
102 | |
103 | /* Create the ucontext. */ |
104 | err |= __put_user(0, &frame->rs_uc.uc_flags); |
105 | err |= __put_user(0, &frame->rs_uc.uc_link); |
106 | err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); |
107 | err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); |
108 | err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set); |
109 | |
110 | if (err) |
111 | return -EFAULT; |
112 | |
113 | /* |
114 | * Arguments to signal handler: |
115 | * |
116 | * a0 = signal number |
117 | * a1 = 0 (should be cause) |
118 | * a2 = pointer to ucontext |
119 | * |
120 | * $25 and c0_epc point to the signal handler, $29 points to |
121 | * the struct rt_sigframe. |
122 | */ |
123 | regs->regs[ 4] = ksig->sig; |
124 | regs->regs[ 5] = (unsigned long) &frame->rs_info; |
125 | regs->regs[ 6] = (unsigned long) &frame->rs_uc; |
126 | regs->regs[29] = (unsigned long) frame; |
127 | regs->regs[31] = (unsigned long) sig_return; |
128 | regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; |
129 | |
130 | DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n" , |
131 | current->comm, current->pid, |
132 | frame, regs->cp0_epc, regs->regs[31]); |
133 | |
134 | return 0; |
135 | } |
136 | |
137 | struct mips_abi mips_abi_n32 = { |
138 | .setup_rt_frame = setup_rt_frame_n32, |
139 | .restart = __NR_N32_restart_syscall, |
140 | |
141 | .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs), |
142 | .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr), |
143 | .off_sc_used_math = offsetof(struct sigcontext, sc_used_math), |
144 | |
145 | .vdso = &vdso_image_n32, |
146 | }; |
147 | |