xref: /openbmc/linux/arch/parisc/kernel/signal32.c (revision 2cf1c348)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*    Signal support for 32-bit kernel builds
3  *
4  *    Copyright (C) 2001 Matthew Wilcox <willy at parisc-linux.org>
5  *    Copyright (C) 2006 Kyle McMartin <kyle at parisc-linux.org>
6  *
7  *    Code was mostly borrowed from kernel/signal.c.
8  *    See kernel/signal.c for additional Copyrights.
9  */
10 
11 #include <linux/compat.h>
12 #include <linux/module.h>
13 #include <linux/unistd.h>
14 #include <linux/init.h>
15 #include <linux/sched.h>
16 #include <linux/syscalls.h>
17 #include <linux/types.h>
18 #include <linux/errno.h>
19 
20 #include <linux/uaccess.h>
21 
22 #include "signal32.h"
23 
24 #define DEBUG_COMPAT_SIG 0
25 #define DEBUG_COMPAT_SIG_LEVEL 2
26 
27 #if DEBUG_COMPAT_SIG
28 #define DBG(LEVEL, ...) \
29 	((DEBUG_COMPAT_SIG_LEVEL >= LEVEL) \
30 	? printk(__VA_ARGS__) : (void) 0)
31 #else
32 #define DBG(LEVEL, ...)
33 #endif
34 
35 long
36 restore_sigcontext32(struct compat_sigcontext __user *sc, struct compat_regfile __user * rf,
37 		struct pt_regs *regs)
38 {
39 	long err = 0;
40 	compat_uint_t compat_reg;
41 	compat_uint_t compat_regt;
42 	int regn;
43 
44 	/* When loading 32-bit values into 64-bit registers make
45 	   sure to clear the upper 32-bits */
46 	DBG(2,"restore_sigcontext32: PER_LINUX32 process\n");
47 	DBG(2,"restore_sigcontext32: sc = 0x%p, rf = 0x%p, regs = 0x%p\n", sc, rf, regs);
48 	DBG(2,"restore_sigcontext32: compat_sigcontext is %#lx bytes\n", sizeof(*sc));
49 	for(regn=0; regn < 32; regn++){
50 		err |= __get_user(compat_reg,&sc->sc_gr[regn]);
51 		regs->gr[regn] = compat_reg;
52 		/* Load upper half */
53 		err |= __get_user(compat_regt,&rf->rf_gr[regn]);
54 		regs->gr[regn] = ((u64)compat_regt << 32) | (u64)compat_reg;
55 		DBG(3,"restore_sigcontext32: gr%02d = %#lx (%#x / %#x)\n",
56 				regn, regs->gr[regn], compat_regt, compat_reg);
57 	}
58 	DBG(2,"restore_sigcontext32: sc->sc_fr = 0x%p (%#lx)\n",sc->sc_fr, sizeof(sc->sc_fr));
59 	/* XXX: BE WARNED FR's are 64-BIT! */
60 	err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
61 
62 	/* Better safe than sorry, pass __get_user two things of
63 	   the same size and let gcc do the upward conversion to
64 	   64-bits */
65 	err |= __get_user(compat_reg, &sc->sc_iaoq[0]);
66 	/* Load upper half */
67 	err |= __get_user(compat_regt, &rf->rf_iaoq[0]);
68 	regs->iaoq[0] = ((u64)compat_regt << 32) | (u64)compat_reg;
69 	DBG(2,"restore_sigcontext32: upper half of iaoq[0] = %#lx\n", compat_regt);
70 	DBG(2,"restore_sigcontext32: sc->sc_iaoq[0] = %p => %#x\n",
71 			&sc->sc_iaoq[0], compat_reg);
72 
73 	err |= __get_user(compat_reg, &sc->sc_iaoq[1]);
74 	/* Load upper half */
75 	err |= __get_user(compat_regt, &rf->rf_iaoq[1]);
76 	regs->iaoq[1] = ((u64)compat_regt << 32) | (u64)compat_reg;
77 	DBG(2,"restore_sigcontext32: upper half of iaoq[1] = %#lx\n", compat_regt);
78 	DBG(2,"restore_sigcontext32: sc->sc_iaoq[1] = %p => %#x\n",
79 			&sc->sc_iaoq[1],compat_reg);
80 	DBG(2,"restore_sigcontext32: iaoq is %#lx / %#lx\n",
81 			regs->iaoq[0],regs->iaoq[1]);
82 
83 	err |= __get_user(compat_reg, &sc->sc_iasq[0]);
84 	/* Load the upper half for iasq */
85 	err |= __get_user(compat_regt, &rf->rf_iasq[0]);
86 	regs->iasq[0] = ((u64)compat_regt << 32) | (u64)compat_reg;
87 	DBG(2,"restore_sigcontext32: upper half of iasq[0] = %#lx\n", compat_regt);
88 
89 	err |= __get_user(compat_reg, &sc->sc_iasq[1]);
90 	/* Load the upper half for iasq */
91 	err |= __get_user(compat_regt, &rf->rf_iasq[1]);
92 	regs->iasq[1] = ((u64)compat_regt << 32) | (u64)compat_reg;
93 	DBG(2,"restore_sigcontext32: upper half of iasq[1] = %#lx\n", compat_regt);
94 	DBG(2,"restore_sigcontext32: iasq is %#lx / %#lx\n",
95 		regs->iasq[0],regs->iasq[1]);
96 
97 	err |= __get_user(compat_reg, &sc->sc_sar);
98 	/* Load the upper half for sar */
99 	err |= __get_user(compat_regt, &rf->rf_sar);
100 	regs->sar = ((u64)compat_regt << 32) | (u64)compat_reg;
101 	DBG(2,"restore_sigcontext32: upper_half & sar = %#lx\n", compat_regt);
102 	DBG(2,"restore_sigcontext32: sar is %#lx\n", regs->sar);
103 	DBG(2,"restore_sigcontext32: r28 is %ld\n", regs->gr[28]);
104 
105 	return err;
106 }
107 
108 /*
109  * Set up the sigcontext structure for this process.
110  * This is not an easy task if the kernel is 64-bit, it will require
111  * that we examine the process personality to determine if we need to
112  * truncate for a 32-bit userspace.
113  */
114 long
115 setup_sigcontext32(struct compat_sigcontext __user *sc, struct compat_regfile __user * rf,
116 		struct pt_regs *regs, int in_syscall)
117 {
118 	compat_int_t flags = 0;
119 	long err = 0;
120 	compat_uint_t compat_reg;
121 	compat_uint_t compat_regb;
122 	int regn;
123 
124 	if (on_sig_stack((unsigned long) sc))
125 		flags |= PARISC_SC_FLAG_ONSTACK;
126 
127 	if (in_syscall) {
128 
129 		DBG(1,"setup_sigcontext32: in_syscall\n");
130 
131 		flags |= PARISC_SC_FLAG_IN_SYSCALL;
132 		/* Truncate gr31 */
133 		compat_reg = (compat_uint_t)(regs->gr[31]);
134 		/* regs->iaoq is undefined in the syscall return path */
135 		err |= __put_user(compat_reg, &sc->sc_iaoq[0]);
136 		DBG(2,"setup_sigcontext32: sc->sc_iaoq[0] = %p <= %#x\n",
137 				&sc->sc_iaoq[0], compat_reg);
138 
139 		/* Store upper half */
140 		compat_reg = (compat_uint_t)(regs->gr[31] >> 32);
141 		err |= __put_user(compat_reg, &rf->rf_iaoq[0]);
142 		DBG(2,"setup_sigcontext32: upper half iaoq[0] = %#x\n", compat_reg);
143 
144 
145 		compat_reg = (compat_uint_t)(regs->gr[31]+4);
146 		err |= __put_user(compat_reg, &sc->sc_iaoq[1]);
147 		DBG(2,"setup_sigcontext32: sc->sc_iaoq[1] = %p <= %#x\n",
148 				&sc->sc_iaoq[1], compat_reg);
149 		/* Store upper half */
150 		compat_reg = (compat_uint_t)((regs->gr[31]+4) >> 32);
151 		err |= __put_user(compat_reg, &rf->rf_iaoq[1]);
152 		DBG(2,"setup_sigcontext32: upper half iaoq[1] = %#x\n", compat_reg);
153 
154 		/* Truncate sr3 */
155 		compat_reg = (compat_uint_t)(regs->sr[3]);
156 		err |= __put_user(compat_reg, &sc->sc_iasq[0]);
157 		err |= __put_user(compat_reg, &sc->sc_iasq[1]);
158 
159 		/* Store upper half */
160 		compat_reg = (compat_uint_t)(regs->sr[3] >> 32);
161 		err |= __put_user(compat_reg, &rf->rf_iasq[0]);
162 		err |= __put_user(compat_reg, &rf->rf_iasq[1]);
163 
164 		DBG(2,"setup_sigcontext32: upper half iasq[0] = %#x\n", compat_reg);
165 		DBG(2,"setup_sigcontext32: upper half iasq[1] = %#x\n", compat_reg);
166 		DBG(1,"setup_sigcontext32: iaoq %#lx / %#lx\n",
167 			regs->gr[31], regs->gr[31]+4);
168 
169 	} else {
170 
171 		compat_reg = (compat_uint_t)(regs->iaoq[0]);
172 		err |= __put_user(compat_reg, &sc->sc_iaoq[0]);
173 		DBG(2,"setup_sigcontext32: sc->sc_iaoq[0] = %p <= %#x\n",
174 				&sc->sc_iaoq[0], compat_reg);
175 		/* Store upper half */
176 		compat_reg = (compat_uint_t)(regs->iaoq[0] >> 32);
177 		err |= __put_user(compat_reg, &rf->rf_iaoq[0]);
178 		DBG(2,"setup_sigcontext32: upper half iaoq[0] = %#x\n", compat_reg);
179 
180 		compat_reg = (compat_uint_t)(regs->iaoq[1]);
181 		err |= __put_user(compat_reg, &sc->sc_iaoq[1]);
182 		DBG(2,"setup_sigcontext32: sc->sc_iaoq[1] = %p <= %#x\n",
183 				&sc->sc_iaoq[1], compat_reg);
184 		/* Store upper half */
185 		compat_reg = (compat_uint_t)(regs->iaoq[1] >> 32);
186 		err |= __put_user(compat_reg, &rf->rf_iaoq[1]);
187 		DBG(2,"setup_sigcontext32: upper half iaoq[1] = %#x\n", compat_reg);
188 
189 
190 		compat_reg = (compat_uint_t)(regs->iasq[0]);
191 		err |= __put_user(compat_reg, &sc->sc_iasq[0]);
192 		DBG(2,"setup_sigcontext32: sc->sc_iasq[0] = %p <= %#x\n",
193 				&sc->sc_iasq[0], compat_reg);
194 		/* Store upper half */
195 		compat_reg = (compat_uint_t)(regs->iasq[0] >> 32);
196 		err |= __put_user(compat_reg, &rf->rf_iasq[0]);
197 		DBG(2,"setup_sigcontext32: upper half iasq[0] = %#x\n", compat_reg);
198 
199 
200 		compat_reg = (compat_uint_t)(regs->iasq[1]);
201 		err |= __put_user(compat_reg, &sc->sc_iasq[1]);
202 		DBG(2,"setup_sigcontext32: sc->sc_iasq[1] = %p <= %#x\n",
203 				&sc->sc_iasq[1], compat_reg);
204 		/* Store upper half */
205 		compat_reg = (compat_uint_t)(regs->iasq[1] >> 32);
206 		err |= __put_user(compat_reg, &rf->rf_iasq[1]);
207 		DBG(2,"setup_sigcontext32: upper half iasq[1] = %#x\n", compat_reg);
208 
209 		/* Print out the IAOQ for debugging */
210 		DBG(1,"setup_sigcontext32: ia0q %#lx / %#lx\n",
211 			regs->iaoq[0], regs->iaoq[1]);
212 	}
213 
214 	err |= __put_user(flags, &sc->sc_flags);
215 
216 	DBG(1,"setup_sigcontext32: Truncating general registers.\n");
217 
218 	for(regn=0; regn < 32; regn++){
219 		/* Truncate a general register */
220 		compat_reg = (compat_uint_t)(regs->gr[regn]);
221 		err |= __put_user(compat_reg, &sc->sc_gr[regn]);
222 		/* Store upper half */
223 		compat_regb = (compat_uint_t)(regs->gr[regn] >> 32);
224 		err |= __put_user(compat_regb, &rf->rf_gr[regn]);
225 
226 		/* DEBUG: Write out the "upper / lower" register data */
227 		DBG(2,"setup_sigcontext32: gr%02d = %#x / %#x\n", regn,
228 				compat_regb, compat_reg);
229 	}
230 
231 	/* Copy the floating point registers (same size)
232 	   XXX: BE WARNED FR's are 64-BIT! */
233 	DBG(1,"setup_sigcontext32: Copying from regs to sc, "
234 	      "sc->sc_fr size = %#lx, regs->fr size = %#lx\n",
235 		sizeof(regs->fr), sizeof(sc->sc_fr));
236 	err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
237 
238 	compat_reg = (compat_uint_t)(regs->sar);
239 	err |= __put_user(compat_reg, &sc->sc_sar);
240 	DBG(2,"setup_sigcontext32: sar is %#x\n", compat_reg);
241 	/* Store upper half */
242 	compat_reg = (compat_uint_t)(regs->sar >> 32);
243 	err |= __put_user(compat_reg, &rf->rf_sar);
244 	DBG(2,"setup_sigcontext32: upper half sar = %#x\n", compat_reg);
245 	DBG(1,"setup_sigcontext32: r28 is %ld\n", regs->gr[28]);
246 
247 	return err;
248 }
249