1
2
3#include <linux/signal.h>
4#include <linux/uaccess.h>
5#include <linux/syscalls.h>
6#include <linux/tracehook.h>
7
8#include <asm/traps.h>
9#include <asm/ucontext.h>
10#include <asm/vdso.h>
11
12#include <abi/regdef.h>
13
14#ifdef CONFIG_CPU_HAS_FPU
15#include <abi/fpu.h>
16static int restore_fpu_state(struct sigcontext __user *sc)
17{
18 int err = 0;
19 struct user_fp user_fp;
20
21 err = __copy_from_user(&user_fp, &sc->sc_user_fp, sizeof(user_fp));
22
23 restore_from_user_fp(&user_fp);
24
25 return err;
26}
27
28static int save_fpu_state(struct sigcontext __user *sc)
29{
30 struct user_fp user_fp;
31
32 save_to_user_fp(&user_fp);
33
34 return __copy_to_user(&sc->sc_user_fp, &user_fp, sizeof(user_fp));
35}
36#else
37#define restore_fpu_state(sigcontext) (0)
38#define save_fpu_state(sigcontext) (0)
39#endif
40
41struct rt_sigframe {
42
43
44
45
46 int pad[3];
47 struct siginfo info;
48 struct ucontext uc;
49};
50
51static long restore_sigcontext(struct pt_regs *regs,
52 struct sigcontext __user *sc)
53{
54 int err = 0;
55
56
57 err |= __copy_from_user(regs, &sc->sc_pt_regs, sizeof(struct pt_regs));
58
59
60 err |= restore_fpu_state(sc);
61
62 return err;
63}
64
65SYSCALL_DEFINE0(rt_sigreturn)
66{
67 struct pt_regs *regs = current_pt_regs();
68 struct rt_sigframe __user *frame;
69 sigset_t set;
70
71
72 current->restart_block.fn = do_no_restart_syscall;
73
74 frame = (struct rt_sigframe __user *)regs->usp;
75
76 if (!access_ok(frame, sizeof(*frame)))
77 goto badframe;
78
79 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
80 goto badframe;
81
82 set_current_blocked(&set);
83
84 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
85 goto badframe;
86
87 if (restore_altstack(&frame->uc.uc_stack))
88 goto badframe;
89
90 return regs->a0;
91
92badframe:
93 force_sig(SIGSEGV);
94 return 0;
95}
96
97static int setup_sigcontext(struct rt_sigframe __user *frame,
98 struct pt_regs *regs)
99{
100 struct sigcontext __user *sc = &frame->uc.uc_mcontext;
101 int err = 0;
102
103 err |= __copy_to_user(&sc->sc_pt_regs, regs, sizeof(struct pt_regs));
104 err |= save_fpu_state(sc);
105
106 return err;
107}
108
109static inline void __user *get_sigframe(struct ksignal *ksig,
110 struct pt_regs *regs, size_t framesize)
111{
112 unsigned long sp;
113
114 sp = regs->usp;
115
116
117
118
119
120 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
121 return (void __user __force *)(-1UL);
122
123
124 sp = sigsp(sp, ksig) - framesize;
125
126
127 sp &= -8UL;
128
129 return (void __user *)sp;
130}
131
132static int
133setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
134{
135 struct rt_sigframe *frame;
136 int err = 0;
137 struct csky_vdso *vdso = current->mm->context.vdso;
138
139 frame = get_sigframe(ksig, regs, sizeof(*frame));
140 if (!access_ok(frame, sizeof(*frame)))
141 return -EFAULT;
142
143 err |= copy_siginfo_to_user(&frame->info, &ksig->info);
144
145
146 err |= __put_user(0, &frame->uc.uc_flags);
147 err |= __put_user(NULL, &frame->uc.uc_link);
148 err |= __save_altstack(&frame->uc.uc_stack, regs->usp);
149 err |= setup_sigcontext(frame, regs);
150 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
151 if (err)
152 return -EFAULT;
153
154
155 regs->lr = (unsigned long)(vdso->rt_signal_retcode);
156
157
158
159
160
161
162
163
164 regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
165 regs->usp = (unsigned long)frame;
166 regs->a0 = ksig->sig;
167 regs->a1 = (unsigned long)(&(frame->info));
168 regs->a2 = (unsigned long)(&(frame->uc));
169
170 return 0;
171}
172
173static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
174{
175 sigset_t *oldset = sigmask_to_save();
176 int ret;
177
178 rseq_signal_deliver(ksig, regs);
179
180
181 if (in_syscall(regs)) {
182
183 forget_syscall(regs);
184
185
186 switch (regs->a0) {
187 case -ERESTART_RESTARTBLOCK:
188 case -ERESTARTNOHAND:
189 regs->a0 = -EINTR;
190 break;
191
192 case -ERESTARTSYS:
193 if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
194 regs->a0 = -EINTR;
195 break;
196 }
197 fallthrough;
198 case -ERESTARTNOINTR:
199 regs->a0 = regs->orig_a0;
200 regs->pc -= TRAP0_SIZE;
201 break;
202 }
203 }
204
205
206 ret = setup_rt_frame(ksig, oldset, regs);
207
208 signal_setup_done(ret, ksig, 0);
209}
210
211static void do_signal(struct pt_regs *regs)
212{
213 struct ksignal ksig;
214
215 if (get_signal(&ksig)) {
216
217 handle_signal(&ksig, regs);
218 return;
219 }
220
221
222 if (in_syscall(regs)) {
223
224 forget_syscall(regs);
225
226
227 switch (regs->a0) {
228 case -ERESTARTNOHAND:
229 case -ERESTARTSYS:
230 case -ERESTARTNOINTR:
231 regs->a0 = regs->orig_a0;
232 regs->pc -= TRAP0_SIZE;
233 break;
234 case -ERESTART_RESTARTBLOCK:
235 regs->a0 = regs->orig_a0;
236 regs_syscallid(regs) = __NR_restart_syscall;
237 regs->pc -= TRAP0_SIZE;
238 break;
239 }
240 }
241
242
243
244
245
246 restore_saved_sigmask();
247}
248
249
250
251
252
253asmlinkage void do_notify_resume(struct pt_regs *regs,
254 unsigned long thread_info_flags)
255{
256 if (thread_info_flags & _TIF_UPROBE)
257 uprobe_notify_resume(regs);
258
259
260 if (thread_info_flags & _TIF_SIGPENDING)
261 do_signal(regs);
262
263 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
264 clear_thread_flag(TIF_NOTIFY_RESUME);
265 tracehook_notify_resume(regs);
266 rseq_handle_notify_resume(NULL, regs);
267 }
268}
269