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 | |
28 | #include "signal-common.h" |
29 | |
30 | /* |
31 | * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... |
32 | */ |
33 | #define __NR_N32_restart_syscall 6214 |
34 | |
35 | extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *); |
36 | extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *); |
37 | |
38 | struct ucontextn32 { |
39 | u32 uc_flags; |
40 | s32 uc_link; |
41 | compat_stack_t uc_stack; |
42 | struct sigcontext uc_mcontext; |
43 | compat_sigset_t uc_sigmask; /* mask last for extensibility */ |
44 | }; |
45 | |
46 | struct rt_sigframe_n32 { |
47 | u32 rs_ass[4]; /* argument save space for o32 */ |
48 | u32 rs_pad[2]; /* Was: signal trampoline */ |
49 | struct compat_siginfo rs_info; |
50 | struct ucontextn32 rs_uc; |
51 | }; |
52 | |
53 | asmlinkage void sysn32_rt_sigreturn(void) |
54 | { |
55 | struct rt_sigframe_n32 __user *frame; |
56 | struct pt_regs *regs; |
57 | sigset_t set; |
58 | int sig; |
59 | |
60 | regs = current_pt_regs(); |
61 | frame = (struct rt_sigframe_n32 __user *)regs->regs[29]; |
62 | if (!access_ok(frame, sizeof(*frame))) |
63 | goto badframe; |
64 | if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask)) |
65 | goto badframe; |
66 | |
67 | set_current_blocked(&set); |
68 | |
69 | sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext); |
70 | if (sig < 0) |
71 | goto badframe; |
72 | else if (sig) |
73 | force_sig(sig); |
74 | |
75 | if (compat_restore_altstack(uss: &frame->rs_uc.uc_stack)) |
76 | goto badframe; |
77 | |
78 | /* |
79 | * Don't let your children do this ... |
80 | */ |
81 | __asm__ __volatile__( |
82 | "move\t$29, %0\n\t" |
83 | "j\tsyscall_exit" |
84 | : /* no outputs */ |
85 | : "r" (regs)); |
86 | /* Unreached */ |
87 | |
88 | badframe: |
89 | force_sig(SIGSEGV); |
90 | } |
91 | |
92 | static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig, |
93 | struct pt_regs *regs, sigset_t *set) |
94 | { |
95 | struct rt_sigframe_n32 __user *frame; |
96 | int err = 0; |
97 | |
98 | frame = get_sigframe(ksig, regs, frame_size: sizeof(*frame)); |
99 | if (!access_ok(frame, sizeof (*frame))) |
100 | return -EFAULT; |
101 | |
102 | /* Create siginfo. */ |
103 | err |= copy_siginfo_to_user32(to: &frame->rs_info, from: &ksig->info); |
104 | |
105 | /* Create the ucontext. */ |
106 | err |= __put_user(0, &frame->rs_uc.uc_flags); |
107 | err |= __put_user(0, &frame->rs_uc.uc_link); |
108 | err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]); |
109 | err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext); |
110 | err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set); |
111 | |
112 | if (err) |
113 | return -EFAULT; |
114 | |
115 | /* |
116 | * Arguments to signal handler: |
117 | * |
118 | * a0 = signal number |
119 | * a1 = 0 (should be cause) |
120 | * a2 = pointer to ucontext |
121 | * |
122 | * $25 and c0_epc point to the signal handler, $29 points to |
123 | * the struct rt_sigframe. |
124 | */ |
125 | regs->regs[ 4] = ksig->sig; |
126 | regs->regs[ 5] = (unsigned long) &frame->rs_info; |
127 | regs->regs[ 6] = (unsigned long) &frame->rs_uc; |
128 | regs->regs[29] = (unsigned long) frame; |
129 | regs->regs[31] = (unsigned long) sig_return; |
130 | regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler; |
131 | |
132 | DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n" , |
133 | current->comm, current->pid, |
134 | frame, regs->cp0_epc, regs->regs[31]); |
135 | |
136 | return 0; |
137 | } |
138 | |
139 | struct mips_abi mips_abi_n32 = { |
140 | .setup_rt_frame = setup_rt_frame_n32, |
141 | .restart = __NR_N32_restart_syscall, |
142 | |
143 | .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs), |
144 | .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr), |
145 | .off_sc_used_math = offsetof(struct sigcontext, sc_used_math), |
146 | |
147 | .vdso = &vdso_image_n32, |
148 | }; |
149 | |