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
50extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
51extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
52
53struct ucontextn32 {
54	u32		    uc_flags;
55	s32		    uc_link;
56	compat_stack_t      uc_stack;
57	struct sigcontext   uc_mcontext;
58	compat_sigset_t	    uc_sigmask;	  /* mask last for extensibility */
59};
60
61struct rt_sigframe_n32 {
62	u32 rs_ass[4];			/* argument save space for o32 */
63	u32 rs_pad[2];			/* Was: signal trampoline */
64	struct compat_siginfo rs_info;
65	struct ucontextn32 rs_uc;
66};
67
68asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
69{
70	struct rt_sigframe_n32 __user *frame;
71	sigset_t set;
72	int sig;
73
74	frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
75	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
76		goto badframe;
77	if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
78		goto badframe;
79
80	set_current_blocked(&set);
81
82	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
83	if (sig < 0)
84		goto badframe;
85	else if (sig)
86		force_sig(sig, current);
87
88	if (compat_restore_altstack(&frame->rs_uc.uc_stack))
89		goto badframe;
90
91	/*
92	 * Don't let your children do this ...
93	 */
94	__asm__ __volatile__(
95		"move\t$29, %0\n\t"
96		"j\tsyscall_exit"
97		:/* no outputs */
98		:"r" (&regs));
99	/* Unreached */
100
101badframe:
102	force_sig(SIGSEGV, current);
103}
104
105static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig,
106			      struct pt_regs *regs, sigset_t *set)
107{
108	struct rt_sigframe_n32 __user *frame;
109	int err = 0;
110
111	frame = get_sigframe(ksig, regs, sizeof(*frame));
112	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
113		return -EFAULT;
114
115	/* Create siginfo.  */
116	err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info);
117
118	/* Create the ucontext.	 */
119	err |= __put_user(0, &frame->rs_uc.uc_flags);
120	err |= __put_user(0, &frame->rs_uc.uc_link);
121	err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
122	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
123	err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
124
125	if (err)
126		return -EFAULT;
127
128	/*
129	 * Arguments to signal handler:
130	 *
131	 *   a0 = signal number
132	 *   a1 = 0 (should be cause)
133	 *   a2 = pointer to ucontext
134	 *
135	 * $25 and c0_epc point to the signal handler, $29 points to
136	 * the struct rt_sigframe.
137	 */
138	regs->regs[ 4] = ksig->sig;
139	regs->regs[ 5] = (unsigned long) &frame->rs_info;
140	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
141	regs->regs[29] = (unsigned long) frame;
142	regs->regs[31] = (unsigned long) sig_return;
143	regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
144
145	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
146	       current->comm, current->pid,
147	       frame, regs->cp0_epc, regs->regs[31]);
148
149	return 0;
150}
151
152struct mips_abi mips_abi_n32 = {
153	.setup_rt_frame = setup_rt_frame_n32,
154	.rt_signal_return_offset =
155		offsetof(struct mips_vdso, n32_rt_signal_trampoline),
156	.restart	= __NR_N32_restart_syscall
157};
158