xref: /linux/arch/mips/kernel/signal_n32.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
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/sched.h>
21 #include <linux/mm.h>
22 #include <linux/smp.h>
23 #include <linux/smp_lock.h>
24 #include <linux/kernel.h>
25 #include <linux/signal.h>
26 #include <linux/errno.h>
27 #include <linux/wait.h>
28 #include <linux/ptrace.h>
29 #include <linux/unistd.h>
30 #include <linux/compat.h>
31 #include <linux/bitops.h>
32 
33 #include <asm/asm.h>
34 #include <asm/cacheflush.h>
35 #include <asm/sim.h>
36 #include <asm/uaccess.h>
37 #include <asm/ucontext.h>
38 #include <asm/system.h>
39 #include <asm/fpu.h>
40 #include <asm/cpu-features.h>
41 #include <asm/war.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_rt_sigreturn		6211
49 #define __NR_N32_restart_syscall	6214
50 
51 #define DEBUG_SIG 0
52 
53 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
54 
55 /* IRIX compatible stack_t  */
56 typedef struct sigaltstack32 {
57 	s32 ss_sp;
58 	compat_size_t ss_size;
59 	int ss_flags;
60 } stack32_t;
61 
62 struct ucontextn32 {
63 	u32                 uc_flags;
64 	s32                 uc_link;
65 	stack32_t           uc_stack;
66 	struct sigcontext   uc_mcontext;
67 	sigset_t            uc_sigmask;   /* mask last for extensibility */
68 };
69 
70 struct rt_sigframe_n32 {
71 	u32 rs_ass[4];			/* argument save space for o32 */
72 #if ICACHE_REFILLS_WORKAROUND_WAR
73 	u32 rs_pad[2];
74 #else
75 	u32 rs_code[2];			/* signal trampoline */
76 #endif
77 	struct siginfo rs_info;
78 	struct ucontextn32 rs_uc;
79 #if ICACHE_REFILLS_WORKAROUND_WAR
80 	u32 rs_code[8] ____cacheline_aligned;		/* signal trampoline */
81 #endif
82 };
83 
84 extern void sigset_from_compat (sigset_t *set, compat_sigset_t *compat);
85 
86 save_static_function(sysn32_rt_sigsuspend);
87 __attribute_used__ noinline static int
88 _sysn32_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
89 {
90 	compat_sigset_t __user *unewset;
91 	compat_sigset_t uset;
92 	size_t sigsetsize;
93 	sigset_t newset;
94 
95 	/* XXX Don't preclude handling different sized sigset_t's.  */
96 	sigsetsize = regs.regs[5];
97 	if (sigsetsize != sizeof(sigset_t))
98 		return -EINVAL;
99 
100 	unewset = (compat_sigset_t __user *) regs.regs[4];
101 	if (copy_from_user(&uset, unewset, sizeof(uset)))
102 		return -EFAULT;
103 	sigset_from_compat (&newset, &uset);
104 	sigdelsetmask(&newset, ~_BLOCKABLE);
105 
106 	spin_lock_irq(&current->sighand->siglock);
107 	current->saved_sigmask = current->blocked;
108 	current->blocked = newset;
109         recalc_sigpending();
110 	spin_unlock_irq(&current->sighand->siglock);
111 
112 	current->state = TASK_INTERRUPTIBLE;
113 	schedule();
114 	set_thread_flag(TIF_RESTORE_SIGMASK);
115 	return -ERESTARTNOHAND;
116 }
117 
118 save_static_function(sysn32_rt_sigreturn);
119 __attribute_used__ noinline static void
120 _sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
121 {
122 	struct rt_sigframe_n32 __user *frame;
123 	sigset_t set;
124 	stack_t st;
125 	s32 sp;
126 
127 	frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
128 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
129 		goto badframe;
130 	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
131 		goto badframe;
132 
133 	sigdelsetmask(&set, ~_BLOCKABLE);
134 	spin_lock_irq(&current->sighand->siglock);
135 	current->blocked = set;
136 	recalc_sigpending();
137 	spin_unlock_irq(&current->sighand->siglock);
138 
139 	if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
140 		goto badframe;
141 
142 	/* The ucontext contains a stack32_t, so we must convert!  */
143 	if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
144 		goto badframe;
145 	st.ss_sp = (void __user *)(long) sp;
146 	if (__get_user(st.ss_size, &frame->rs_uc.uc_stack.ss_size))
147 		goto badframe;
148 	if (__get_user(st.ss_flags, &frame->rs_uc.uc_stack.ss_flags))
149 		goto badframe;
150 
151 	/* It is more difficult to avoid calling this function than to
152 	   call it and ignore errors.  */
153 	do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
154 
155 	/*
156 	 * Don't let your children do this ...
157 	 */
158 	__asm__ __volatile__(
159 		"move\t$29, %0\n\t"
160 		"j\tsyscall_exit"
161 		:/* no outputs */
162 		:"r" (&regs));
163 	/* Unreached */
164 
165 badframe:
166 	force_sig(SIGSEGV, current);
167 }
168 
169 int setup_rt_frame_n32(struct k_sigaction * ka,
170 	struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info)
171 {
172 	struct rt_sigframe_n32 __user *frame;
173 	int err = 0;
174 	s32 sp;
175 
176 	frame = get_sigframe(ka, regs, sizeof(*frame));
177 	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
178 		goto give_sigsegv;
179 
180 	install_sigtramp(frame->rs_code, __NR_N32_rt_sigreturn);
181 
182 	/* Create siginfo.  */
183 	err |= copy_siginfo_to_user(&frame->rs_info, info);
184 
185 	/* Create the ucontext.  */
186 	err |= __put_user(0, &frame->rs_uc.uc_flags);
187 	err |= __put_user(0, &frame->rs_uc.uc_link);
188         sp = (int) (long) current->sas_ss_sp;
189 	err |= __put_user(sp,
190 	                  &frame->rs_uc.uc_stack.ss_sp);
191 	err |= __put_user(sas_ss_flags(regs->regs[29]),
192 	                  &frame->rs_uc.uc_stack.ss_flags);
193 	err |= __put_user(current->sas_ss_size,
194 	                  &frame->rs_uc.uc_stack.ss_size);
195 	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
196 	err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
197 
198 	if (err)
199 		goto give_sigsegv;
200 
201 	/*
202 	 * Arguments to signal handler:
203 	 *
204 	 *   a0 = signal number
205 	 *   a1 = 0 (should be cause)
206 	 *   a2 = pointer to ucontext
207 	 *
208 	 * $25 and c0_epc point to the signal handler, $29 points to
209 	 * the struct rt_sigframe.
210 	 */
211 	regs->regs[ 4] = signr;
212 	regs->regs[ 5] = (unsigned long) &frame->rs_info;
213 	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
214 	regs->regs[29] = (unsigned long) frame;
215 	regs->regs[31] = (unsigned long) frame->rs_code;
216 	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
217 
218 #if DEBUG_SIG
219 	printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
220 	       current->comm, current->pid,
221 	       frame, regs->cp0_epc, regs->regs[31]);
222 #endif
223 	return 0;
224 
225 give_sigsegv:
226 	force_sigsegv(signr, current);
227 	return -EFAULT;
228 }
229