summaryrefslogtreecommitdiffstats
path: root/arch/mips/kernel/signal_n32.c
blob: 8f65aaf9206d1ba88ab0f68e580eb176aacd173e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
/*
 * Copyright (C) 2003 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
#include <linux/cache.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/compat.h>
#include <linux/bitops.h>

#include <asm/abi.h>
#include <asm/asm.h>
#include <asm/cacheflush.h>
#include <asm/compat-signal.h>
#include <asm/sim.h>
#include <linux/uaccess.h>
#include <asm/ucontext.h>
#include <asm/fpu.h>
#include <asm/cpu-features.h>
#include <asm/war.h>

#include "signal-common.h"

/*
 * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
 */
#define __NR_N32_restart_syscall	6214

extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);

struct ucontextn32 {
	u32		    uc_flags;
	s32		    uc_link;
	compat_stack_t      uc_stack;
	struct sigcontext   uc_mcontext;
	compat_sigset_t	    uc_sigmask;	  /* mask last for extensibility */
};

struct rt_sigframe_n32 {
	u32 rs_ass[4];			/* argument save space for o32 */
	u32 rs_pad[2];			/* Was: signal trampoline */
	struct compat_siginfo rs_info;
	struct ucontextn32 rs_uc;
};

asmlinkage void sysn32_rt_sigreturn(void)
{
	struct rt_sigframe_n32 __user *frame;
	struct pt_regs *regs;
	sigset_t set;
	int sig;

	regs = current_pt_regs();
	frame = (struct rt_sigframe_n32 __user *)regs->regs[29];
	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
		goto badframe;

	set_current_blocked(&set);

	sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
	if (sig < 0)
		goto badframe;
	else if (sig)
		force_sig(sig, current);

	if (compat_restore_altstack(&frame->rs_uc.uc_stack))
		goto badframe;

	/*
	 * Don't let your children do this ...
	 */
	__asm__ __volatile__(
		"move\t$29, %0\n\t"
		"j\tsyscall_exit"
		: /* no outputs */
		: "r" (regs));
	/* Unreached */

badframe:
	force_sig(SIGSEGV, current);
}

static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig,
			      struct pt_regs *regs, sigset_t *set)
{
	struct rt_sigframe_n32 __user *frame;
	int err = 0;

	frame = get_sigframe(ksig, regs, sizeof(*frame));
	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
		return -EFAULT;

	/* Create siginfo.  */
	err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info);

	/* Create the ucontext.	 */
	err |= __put_user(0, &frame->rs_uc.uc_flags);
	err |= __put_user(0, &frame->rs_uc.uc_link);
	err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
	err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);

	if (err)
		return -EFAULT;

	/*
	 * Arguments to signal handler:
	 *
	 *   a0 = signal number
	 *   a1 = 0 (should be cause)
	 *   a2 = pointer to ucontext
	 *
	 * $25 and c0_epc point to the signal handler, $29 points to
	 * the struct rt_sigframe.
	 */
	regs->regs[ 4] = ksig->sig;
	regs->regs[ 5] = (unsigned long) &frame->rs_info;
	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
	regs->regs[29] = (unsigned long) frame;
	regs->regs[31] = (unsigned long) sig_return;
	regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;

	DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
	       current->comm, current->pid,
	       frame, regs->cp0_epc, regs->regs[31]);

	return 0;
}

struct mips_abi mips_abi_n32 = {
	.setup_rt_frame = setup_rt_frame_n32,
	.restart	= __NR_N32_restart_syscall,

	.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
	.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
	.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),

	.vdso		= &vdso_image_n32,
};