xref: /linux/arch/mips/kernel/signal_n32.c (revision 2dbf708448c836754d25fe6108c5bfe1f5697c95)
1 /*
2  * Copyright (C) 2003 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
17  */
18 #include <linux/cache.h>
19 #include <linux/sched.h>
20 #include <linux/mm.h>
21 #include <linux/smp.h>
22 #include <linux/kernel.h>
23 #include <linux/signal.h>
24 #include <linux/errno.h>
25 #include <linux/wait.h>
26 #include <linux/ptrace.h>
27 #include <linux/unistd.h>
28 #include <linux/compat.h>
29 #include <linux/bitops.h>
30 
31 #include <asm/abi.h>
32 #include <asm/asm.h>
33 #include <asm/cacheflush.h>
34 #include <asm/compat-signal.h>
35 #include <asm/sim.h>
36 #include <asm/uaccess.h>
37 #include <asm/ucontext.h>
38 #include <asm/fpu.h>
39 #include <asm/cpu-features.h>
40 #include <asm/war.h>
41 #include <asm/vdso.h>
42 
43 #include "signal-common.h"
44 
45 /*
46  * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
47  */
48 #define __NR_N32_restart_syscall	6214
49 
50 extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
51 extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
52 
53 
54 /* IRIX compatible stack_t  */
55 typedef struct sigaltstack32 {
56 	s32 ss_sp;
57 	compat_size_t ss_size;
58 	int ss_flags;
59 } stack32_t;
60 
61 struct ucontextn32 {
62 	u32                 uc_flags;
63 	s32                 uc_link;
64 	stack32_t           uc_stack;
65 	struct sigcontext   uc_mcontext;
66 	compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
67 };
68 
69 struct rt_sigframe_n32 {
70 	u32 rs_ass[4];			/* argument save space for o32 */
71 	u32 rs_pad[2];			/* Was: signal trampoline */
72 	struct compat_siginfo rs_info;
73 	struct ucontextn32 rs_uc;
74 };
75 
76 extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
77 
78 asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
79 {
80 	compat_sigset_t __user *unewset;
81 	compat_sigset_t uset;
82 	size_t sigsetsize;
83 	sigset_t newset;
84 
85 	/* XXX Don't preclude handling different sized sigset_t's.  */
86 	sigsetsize = regs.regs[5];
87 	if (sigsetsize != sizeof(sigset_t))
88 		return -EINVAL;
89 
90 	unewset = (compat_sigset_t __user *) regs.regs[4];
91 	if (copy_from_user(&uset, unewset, sizeof(uset)))
92 		return -EFAULT;
93 	sigset_from_compat(&newset, &uset);
94 	sigdelsetmask(&newset, ~_BLOCKABLE);
95 
96 	spin_lock_irq(&current->sighand->siglock);
97 	current->saved_sigmask = current->blocked;
98 	current->blocked = newset;
99 	recalc_sigpending();
100 	spin_unlock_irq(&current->sighand->siglock);
101 
102 	current->state = TASK_INTERRUPTIBLE;
103 	schedule();
104 	set_thread_flag(TIF_RESTORE_SIGMASK);
105 	return -ERESTARTNOHAND;
106 }
107 
108 asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
109 {
110 	struct rt_sigframe_n32 __user *frame;
111 	mm_segment_t old_fs;
112 	sigset_t set;
113 	stack_t st;
114 	s32 sp;
115 	int sig;
116 
117 	frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
118 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
119 		goto badframe;
120 	if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
121 		goto badframe;
122 
123 	sigdelsetmask(&set, ~_BLOCKABLE);
124 	spin_lock_irq(&current->sighand->siglock);
125 	current->blocked = set;
126 	recalc_sigpending();
127 	spin_unlock_irq(&current->sighand->siglock);
128 
129 	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
130 	if (sig < 0)
131 		goto badframe;
132 	else if (sig)
133 		force_sig(sig, current);
134 
135 	/* The ucontext contains a stack32_t, so we must convert!  */
136 	if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
137 		goto badframe;
138 	st.ss_sp = (void __user *)(long) sp;
139 	if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
140 		goto badframe;
141 	if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
142 		goto badframe;
143 
144 	/* It is more difficult to avoid calling this function than to
145 	   call it and ignore errors.  */
146 	old_fs = get_fs();
147 	set_fs(KERNEL_DS);
148 	do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
149 	set_fs(old_fs);
150 
151 
152 	/*
153 	 * Don't let your children do this ...
154 	 */
155 	__asm__ __volatile__(
156 		"move\t$29, %0\n\t"
157 		"j\tsyscall_exit"
158 		:/* no outputs */
159 		:"r" (&regs));
160 	/* Unreached */
161 
162 badframe:
163 	force_sig(SIGSEGV, current);
164 }
165 
166 static int setup_rt_frame_n32(void *sig_return, struct k_sigaction *ka,
167 	struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
168 {
169 	struct rt_sigframe_n32 __user *frame;
170 	int err = 0;
171 	s32 sp;
172 
173 	frame = get_sigframe(ka, regs, sizeof(*frame));
174 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
175 		goto give_sigsegv;
176 
177 	/* Create siginfo.  */
178 	err |= copy_siginfo_to_user32(&frame->rs_info, info);
179 
180 	/* Create the ucontext.  */
181 	err |= __put_user(0, &frame->rs_uc.uc_flags);
182 	err |= __put_user(0, &frame->rs_uc.uc_link);
183 	sp = (int) (long) current->sas_ss_sp;
184 	err |= __put_user(sp,
185 	                  &frame->rs_uc.uc_stack.ss_sp);
186 	err |= __put_user(sas_ss_flags(regs->regs[29]),
187 	                  &frame->rs_uc.uc_stack.ss_flags);
188 	err |= __put_user(current->sas_ss_size,
189 	                  &frame->rs_uc.uc_stack.ss_size);
190 	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
191 	err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
192 
193 	if (err)
194 		goto give_sigsegv;
195 
196 	/*
197 	 * Arguments to signal handler:
198 	 *
199 	 *   a0 = signal number
200 	 *   a1 = 0 (should be cause)
201 	 *   a2 = pointer to ucontext
202 	 *
203 	 * $25 and c0_epc point to the signal handler, $29 points to
204 	 * the struct rt_sigframe.
205 	 */
206 	regs->regs[ 4] = signr;
207 	regs->regs[ 5] = (unsigned long) &frame->rs_info;
208 	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
209 	regs->regs[29] = (unsigned long) frame;
210 	regs->regs[31] = (unsigned long) sig_return;
211 	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
212 
213 	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
214 	       current->comm, current->pid,
215 	       frame, regs->cp0_epc, regs->regs[31]);
216 
217 	return 0;
218 
219 give_sigsegv:
220 	force_sigsegv(signr, current);
221 	return -EFAULT;
222 }
223 
224 struct mips_abi mips_abi_n32 = {
225 	.setup_rt_frame	= setup_rt_frame_n32,
226 	.rt_signal_return_offset =
227 		offsetof(struct mips_vdso, n32_rt_signal_trampoline),
228 	.restart	= __NR_N32_restart_syscall
229 };
230