xref: /linux/arch/mips/kernel/signal_n32.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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/smp_lock.h>
23 #include <linux/kernel.h>
24 #include <linux/signal.h>
25 #include <linux/errno.h>
26 #include <linux/wait.h>
27 #include <linux/ptrace.h>
28 #include <linux/unistd.h>
29 #include <linux/compat.h>
30 #include <linux/bitops.h>
31 
32 #include <asm/abi.h>
33 #include <asm/asm.h>
34 #include <asm/cacheflush.h>
35 #include <asm/compat-signal.h>
36 #include <asm/sim.h>
37 #include <asm/uaccess.h>
38 #include <asm/ucontext.h>
39 #include <asm/system.h>
40 #include <asm/fpu.h>
41 #include <asm/cpu-features.h>
42 #include <asm/war.h>
43 
44 #include "signal-common.h"
45 
46 /*
47  * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
48  */
49 #define __NR_N32_rt_sigreturn		6211
50 #define __NR_N32_restart_syscall	6214
51 
52 extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
53 extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
54 
55 
56 /* IRIX compatible stack_t  */
57 typedef struct sigaltstack32 {
58 	s32 ss_sp;
59 	compat_size_t ss_size;
60 	int ss_flags;
61 } stack32_t;
62 
63 struct ucontextn32 {
64 	u32                 uc_flags;
65 	s32                 uc_link;
66 	stack32_t           uc_stack;
67 	struct sigcontext   uc_mcontext;
68 	compat_sigset_t     uc_sigmask;   /* mask last for extensibility */
69 };
70 
71 #if ICACHE_REFILLS_WORKAROUND_WAR == 0
72 
73 struct rt_sigframe_n32 {
74 	u32 rs_ass[4];			/* argument save space for o32 */
75 	u32 rs_code[2];			/* signal trampoline */
76 	struct siginfo rs_info;
77 	struct ucontextn32 rs_uc;
78 };
79 
80 #else  /* ICACHE_REFILLS_WORKAROUND_WAR */
81 
82 struct rt_sigframe_n32 {
83 	u32 rs_ass[4];			/* argument save space for o32 */
84 	u32 rs_pad[2];
85 	struct siginfo rs_info;
86 	struct ucontextn32 rs_uc;
87 	u32 rs_code[8] ____cacheline_aligned;		/* signal trampoline */
88 };
89 
90 #endif	/* !ICACHE_REFILLS_WORKAROUND_WAR */
91 
92 extern void sigset_from_compat (sigset_t *set, compat_sigset_t *compat);
93 
94 asmlinkage int sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
95 {
96 	compat_sigset_t __user *unewset;
97 	compat_sigset_t uset;
98 	size_t sigsetsize;
99 	sigset_t newset;
100 
101 	/* XXX Don't preclude handling different sized sigset_t's.  */
102 	sigsetsize = regs.regs[5];
103 	if (sigsetsize != sizeof(sigset_t))
104 		return -EINVAL;
105 
106 	unewset = (compat_sigset_t __user *) regs.regs[4];
107 	if (copy_from_user(&uset, unewset, sizeof(uset)))
108 		return -EFAULT;
109 	sigset_from_compat (&newset, &uset);
110 	sigdelsetmask(&newset, ~_BLOCKABLE);
111 
112 	spin_lock_irq(&current->sighand->siglock);
113 	current->saved_sigmask = current->blocked;
114 	current->blocked = newset;
115 	recalc_sigpending();
116 	spin_unlock_irq(&current->sighand->siglock);
117 
118 	current->state = TASK_INTERRUPTIBLE;
119 	schedule();
120 	set_thread_flag(TIF_RESTORE_SIGMASK);
121 	return -ERESTARTNOHAND;
122 }
123 
124 asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
125 {
126 	struct rt_sigframe_n32 __user *frame;
127 	sigset_t set;
128 	stack_t st;
129 	s32 sp;
130 
131 	frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
132 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
133 		goto badframe;
134 	if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
135 		goto badframe;
136 
137 	sigdelsetmask(&set, ~_BLOCKABLE);
138 	spin_lock_irq(&current->sighand->siglock);
139 	current->blocked = set;
140 	recalc_sigpending();
141 	spin_unlock_irq(&current->sighand->siglock);
142 
143 	if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
144 		goto badframe;
145 
146 	/* The ucontext contains a stack32_t, so we must convert!  */
147 	if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
148 		goto badframe;
149 	st.ss_sp = (void __user *)(long) sp;
150 	if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
151 		goto badframe;
152 	if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
153 		goto badframe;
154 
155 	/* It is more difficult to avoid calling this function than to
156 	   call it and ignore errors.  */
157 	do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
158 
159 	/*
160 	 * Don't let your children do this ...
161 	 */
162 	__asm__ __volatile__(
163 		"move\t$29, %0\n\t"
164 		"j\tsyscall_exit"
165 		:/* no outputs */
166 		:"r" (&regs));
167 	/* Unreached */
168 
169 badframe:
170 	force_sig(SIGSEGV, current);
171 }
172 
173 static int setup_rt_frame_n32(struct k_sigaction * ka,
174 	struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
175 {
176 	struct rt_sigframe_n32 __user *frame;
177 	int err = 0;
178 	s32 sp;
179 
180 	frame = get_sigframe(ka, regs, sizeof(*frame));
181 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
182 		goto give_sigsegv;
183 
184 	install_sigtramp(frame->rs_code, __NR_N32_rt_sigreturn);
185 
186 	/* Create siginfo.  */
187 	err |= copy_siginfo_to_user(&frame->rs_info, info);
188 
189 	/* Create the ucontext.  */
190 	err |= __put_user(0, &frame->rs_uc.uc_flags);
191 	err |= __put_user(0, &frame->rs_uc.uc_link);
192 	sp = (int) (long) current->sas_ss_sp;
193 	err |= __put_user(sp,
194 	                  &frame->rs_uc.uc_stack.ss_sp);
195 	err |= __put_user(sas_ss_flags(regs->regs[29]),
196 	                  &frame->rs_uc.uc_stack.ss_flags);
197 	err |= __put_user(current->sas_ss_size,
198 	                  &frame->rs_uc.uc_stack.ss_size);
199 	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
200 	err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
201 
202 	if (err)
203 		goto give_sigsegv;
204 
205 	/*
206 	 * Arguments to signal handler:
207 	 *
208 	 *   a0 = signal number
209 	 *   a1 = 0 (should be cause)
210 	 *   a2 = pointer to ucontext
211 	 *
212 	 * $25 and c0_epc point to the signal handler, $29 points to
213 	 * the struct rt_sigframe.
214 	 */
215 	regs->regs[ 4] = signr;
216 	regs->regs[ 5] = (unsigned long) &frame->rs_info;
217 	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
218 	regs->regs[29] = (unsigned long) frame;
219 	regs->regs[31] = (unsigned long) frame->rs_code;
220 	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
221 
222 	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
223 	       current->comm, current->pid,
224 	       frame, regs->cp0_epc, regs->regs[31]);
225 
226 	return 0;
227 
228 give_sigsegv:
229 	force_sigsegv(signr, current);
230 	return -EFAULT;
231 }
232 
233 struct mips_abi mips_abi_n32 = {
234 	.setup_rt_frame	= setup_rt_frame_n32,
235 	.restart	= __NR_N32_restart_syscall
236 };
237