~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/ia64/kernel/signal.c

Version: ~ [ linux-5.8-rc3 ] ~ [ linux-5.7.5 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.48 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.129 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.185 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.228 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.228 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * Architecture-specific signal handling support.
  4  *
  5  * Copyright (C) 1999-2004 Hewlett-Packard Co
  6  *      David Mosberger-Tang <davidm@hpl.hp.com>
  7  *
  8  * Derived from i386 and Alpha versions.
  9  */
 10 
 11 #include <linux/errno.h>
 12 #include <linux/kernel.h>
 13 #include <linux/mm.h>
 14 #include <linux/ptrace.h>
 15 #include <linux/tracehook.h>
 16 #include <linux/sched.h>
 17 #include <linux/signal.h>
 18 #include <linux/smp.h>
 19 #include <linux/stddef.h>
 20 #include <linux/tty.h>
 21 #include <linux/binfmts.h>
 22 #include <linux/unistd.h>
 23 #include <linux/wait.h>
 24 
 25 #include <asm/intrinsics.h>
 26 #include <linux/uaccess.h>
 27 #include <asm/rse.h>
 28 #include <asm/sigcontext.h>
 29 
 30 #include "sigframe.h"
 31 
 32 #define DEBUG_SIG       0
 33 #define STACK_ALIGN     16              /* minimal alignment for stack pointer */
 34 
 35 #if _NSIG_WORDS > 1
 36 # define PUT_SIGSET(k,u)        __copy_to_user((u)->sig, (k)->sig, sizeof(sigset_t))
 37 # define GET_SIGSET(k,u)        __copy_from_user((k)->sig, (u)->sig, sizeof(sigset_t))
 38 #else
 39 # define PUT_SIGSET(k,u)        __put_user((k)->sig[0], &(u)->sig[0])
 40 # define GET_SIGSET(k,u)        __get_user((k)->sig[0], &(u)->sig[0])
 41 #endif
 42 
 43 static long
 44 restore_sigcontext (struct sigcontext __user *sc, struct sigscratch *scr)
 45 {
 46         unsigned long ip, flags, nat, um, cfm, rsc;
 47         long err;
 48 
 49         /* Always make any pending restarted system calls return -EINTR */
 50         current->restart_block.fn = do_no_restart_syscall;
 51 
 52         /* restore scratch that always needs gets updated during signal delivery: */
 53         err  = __get_user(flags, &sc->sc_flags);
 54         err |= __get_user(nat, &sc->sc_nat);
 55         err |= __get_user(ip, &sc->sc_ip);                      /* instruction pointer */
 56         err |= __get_user(cfm, &sc->sc_cfm);
 57         err |= __get_user(um, &sc->sc_um);                      /* user mask */
 58         err |= __get_user(rsc, &sc->sc_ar_rsc);
 59         err |= __get_user(scr->pt.ar_unat, &sc->sc_ar_unat);
 60         err |= __get_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr);
 61         err |= __get_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
 62         err |= __get_user(scr->pt.pr, &sc->sc_pr);              /* predicates */
 63         err |= __get_user(scr->pt.b0, &sc->sc_br[0]);           /* b0 (rp) */
 64         err |= __get_user(scr->pt.b6, &sc->sc_br[6]);           /* b6 */
 65         err |= __copy_from_user(&scr->pt.r1, &sc->sc_gr[1], 8); /* r1 */
 66         err |= __copy_from_user(&scr->pt.r8, &sc->sc_gr[8], 4*8);       /* r8-r11 */
 67         err |= __copy_from_user(&scr->pt.r12, &sc->sc_gr[12], 2*8);     /* r12-r13 */
 68         err |= __copy_from_user(&scr->pt.r15, &sc->sc_gr[15], 8);       /* r15 */
 69 
 70         scr->pt.cr_ifs = cfm | (1UL << 63);
 71         scr->pt.ar_rsc = rsc | (3 << 2); /* force PL3 */
 72 
 73         /* establish new instruction pointer: */
 74         scr->pt.cr_iip = ip & ~0x3UL;
 75         ia64_psr(&scr->pt)->ri = ip & 0x3;
 76         scr->pt.cr_ipsr = (scr->pt.cr_ipsr & ~IA64_PSR_UM) | (um & IA64_PSR_UM);
 77 
 78         scr->scratch_unat = ia64_put_scratch_nat_bits(&scr->pt, nat);
 79 
 80         if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) {
 81                 /* Restore most scratch-state only when not in syscall. */
 82                 err |= __get_user(scr->pt.ar_ccv, &sc->sc_ar_ccv);              /* ar.ccv */
 83                 err |= __get_user(scr->pt.b7, &sc->sc_br[7]);                   /* b7 */
 84                 err |= __get_user(scr->pt.r14, &sc->sc_gr[14]);                 /* r14 */
 85                 err |= __copy_from_user(&scr->pt.ar_csd, &sc->sc_ar25, 2*8); /* ar.csd & ar.ssd */
 86                 err |= __copy_from_user(&scr->pt.r2, &sc->sc_gr[2], 2*8);       /* r2-r3 */
 87                 err |= __copy_from_user(&scr->pt.r16, &sc->sc_gr[16], 16*8);    /* r16-r31 */
 88         }
 89 
 90         if ((flags & IA64_SC_FLAG_FPH_VALID) != 0) {
 91                 struct ia64_psr *psr = ia64_psr(&scr->pt);
 92 
 93                 err |= __copy_from_user(current->thread.fph, &sc->sc_fr[32], 96*16);
 94                 psr->mfh = 0;   /* drop signal handler's fph contents... */
 95                 preempt_disable();
 96                 if (psr->dfh)
 97                         ia64_drop_fpu(current);
 98                 else {
 99                         /* We already own the local fph, otherwise psr->dfh wouldn't be 0.  */
100                         __ia64_load_fpu(current->thread.fph);
101                         ia64_set_local_fpu_owner(current);
102                 }
103                 preempt_enable();
104         }
105         return err;
106 }
107 
108 long
109 ia64_rt_sigreturn (struct sigscratch *scr)
110 {
111         extern char ia64_strace_leave_kernel, ia64_leave_kernel;
112         struct sigcontext __user *sc;
113         sigset_t set;
114         long retval;
115 
116         sc = &((struct sigframe __user *) (scr->pt.r12 + 16))->sc;
117 
118         /*
119          * When we return to the previously executing context, r8 and r10 have already
120          * been setup the way we want them.  Indeed, if the signal wasn't delivered while
121          * in a system call, we must not touch r8 or r10 as otherwise user-level state
122          * could be corrupted.
123          */
124         retval = (long) &ia64_leave_kernel;
125         if (test_thread_flag(TIF_SYSCALL_TRACE)
126             || test_thread_flag(TIF_SYSCALL_AUDIT))
127                 /*
128                  * strace expects to be notified after sigreturn returns even though the
129                  * context to which we return may not be in the middle of a syscall.
130                  * Thus, the return-value that strace displays for sigreturn is
131                  * meaningless.
132                  */
133                 retval = (long) &ia64_strace_leave_kernel;
134 
135         if (!access_ok(sc, sizeof(*sc)))
136                 goto give_sigsegv;
137 
138         if (GET_SIGSET(&set, &sc->sc_mask))
139                 goto give_sigsegv;
140 
141         set_current_blocked(&set);
142 
143         if (restore_sigcontext(sc, scr))
144                 goto give_sigsegv;
145 
146 #if DEBUG_SIG
147         printk("SIG return (%s:%d): sp=%lx ip=%lx\n",
148                current->comm, current->pid, scr->pt.r12, scr->pt.cr_iip);
149 #endif
150         if (restore_altstack(&sc->sc_stack))
151                 goto give_sigsegv;
152         return retval;
153 
154   give_sigsegv:
155         force_sig(SIGSEGV);
156         return retval;
157 }
158 
159 /*
160  * This does just the minimum required setup of sigcontext.
161  * Specifically, it only installs data that is either not knowable at
162  * the user-level or that gets modified before execution in the
163  * trampoline starts.  Everything else is done at the user-level.
164  */
165 static long
166 setup_sigcontext (struct sigcontext __user *sc, sigset_t *mask, struct sigscratch *scr)
167 {
168         unsigned long flags = 0, ifs, cfm, nat;
169         long err = 0;
170 
171         ifs = scr->pt.cr_ifs;
172 
173         if (on_sig_stack((unsigned long) sc))
174                 flags |= IA64_SC_FLAG_ONSTACK;
175         if ((ifs & (1UL << 63)) == 0)
176                 /* if cr_ifs doesn't have the valid bit set, we got here through a syscall */
177                 flags |= IA64_SC_FLAG_IN_SYSCALL;
178         cfm = ifs & ((1UL << 38) - 1);
179         ia64_flush_fph(current);
180         if ((current->thread.flags & IA64_THREAD_FPH_VALID)) {
181                 flags |= IA64_SC_FLAG_FPH_VALID;
182                 err = __copy_to_user(&sc->sc_fr[32], current->thread.fph, 96*16);
183         }
184 
185         nat = ia64_get_scratch_nat_bits(&scr->pt, scr->scratch_unat);
186 
187         err |= __put_user(flags, &sc->sc_flags);
188         err |= __put_user(nat, &sc->sc_nat);
189         err |= PUT_SIGSET(mask, &sc->sc_mask);
190         err |= __put_user(cfm, &sc->sc_cfm);
191         err |= __put_user(scr->pt.cr_ipsr & IA64_PSR_UM, &sc->sc_um);
192         err |= __put_user(scr->pt.ar_rsc, &sc->sc_ar_rsc);
193         err |= __put_user(scr->pt.ar_unat, &sc->sc_ar_unat);            /* ar.unat */
194         err |= __put_user(scr->pt.ar_fpsr, &sc->sc_ar_fpsr);            /* ar.fpsr */
195         err |= __put_user(scr->pt.ar_pfs, &sc->sc_ar_pfs);
196         err |= __put_user(scr->pt.pr, &sc->sc_pr);                      /* predicates */
197         err |= __put_user(scr->pt.b0, &sc->sc_br[0]);                   /* b0 (rp) */
198         err |= __put_user(scr->pt.b6, &sc->sc_br[6]);                   /* b6 */
199         err |= __copy_to_user(&sc->sc_gr[1], &scr->pt.r1, 8);           /* r1 */
200         err |= __copy_to_user(&sc->sc_gr[8], &scr->pt.r8, 4*8);         /* r8-r11 */
201         err |= __copy_to_user(&sc->sc_gr[12], &scr->pt.r12, 2*8);       /* r12-r13 */
202         err |= __copy_to_user(&sc->sc_gr[15], &scr->pt.r15, 8);         /* r15 */
203         err |= __put_user(scr->pt.cr_iip + ia64_psr(&scr->pt)->ri, &sc->sc_ip);
204 
205         if (!(flags & IA64_SC_FLAG_IN_SYSCALL)) {
206                 /* Copy scratch regs to sigcontext if the signal didn't interrupt a syscall. */
207                 err |= __put_user(scr->pt.ar_ccv, &sc->sc_ar_ccv);              /* ar.ccv */
208                 err |= __put_user(scr->pt.b7, &sc->sc_br[7]);                   /* b7 */
209                 err |= __put_user(scr->pt.r14, &sc->sc_gr[14]);                 /* r14 */
210                 err |= __copy_to_user(&sc->sc_ar25, &scr->pt.ar_csd, 2*8); /* ar.csd & ar.ssd */
211                 err |= __copy_to_user(&sc->sc_gr[2], &scr->pt.r2, 2*8);         /* r2-r3 */
212                 err |= __copy_to_user(&sc->sc_gr[16], &scr->pt.r16, 16*8);      /* r16-r31 */
213         }
214         return err;
215 }
216 
217 /*
218  * Check whether the register-backing store is already on the signal stack.
219  */
220 static inline int
221 rbs_on_sig_stack (unsigned long bsp)
222 {
223         return (bsp - current->sas_ss_sp < current->sas_ss_size);
224 }
225 
226 static long
227 setup_frame(struct ksignal *ksig, sigset_t *set, struct sigscratch *scr)
228 {
229         extern char __kernel_sigtramp[];
230         unsigned long tramp_addr, new_rbs = 0, new_sp;
231         struct sigframe __user *frame;
232         long err;
233 
234         new_sp = scr->pt.r12;
235         tramp_addr = (unsigned long) __kernel_sigtramp;
236         if (ksig->ka.sa.sa_flags & SA_ONSTACK) {
237                 int onstack = sas_ss_flags(new_sp);
238 
239                 if (onstack == 0) {
240                         new_sp = current->sas_ss_sp + current->sas_ss_size;
241                         /*
242                          * We need to check for the register stack being on the
243                          * signal stack separately, because it's switched
244                          * separately (memory stack is switched in the kernel,
245                          * register stack is switched in the signal trampoline).
246                          */
247                         if (!rbs_on_sig_stack(scr->pt.ar_bspstore))
248                                 new_rbs = ALIGN(current->sas_ss_sp,
249                                                 sizeof(long));
250                 } else if (onstack == SS_ONSTACK) {
251                         unsigned long check_sp;
252 
253                         /*
254                          * If we are on the alternate signal stack and would
255                          * overflow it, don't. Return an always-bogus address
256                          * instead so we will die with SIGSEGV.
257                          */
258                         check_sp = (new_sp - sizeof(*frame)) & -STACK_ALIGN;
259                         if (!likely(on_sig_stack(check_sp))) {
260                                 force_sigsegv(ksig->sig);
261                                 return 1;
262                         }
263                 }
264         }
265         frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN);
266 
267         if (!access_ok(frame, sizeof(*frame))) {
268                 force_sigsegv(ksig->sig);
269                 return 1;
270         }
271 
272         err  = __put_user(ksig->sig, &frame->arg0);
273         err |= __put_user(&frame->info, &frame->arg1);
274         err |= __put_user(&frame->sc, &frame->arg2);
275         err |= __put_user(new_rbs, &frame->sc.sc_rbs_base);
276         err |= __put_user(0, &frame->sc.sc_loadrs);     /* initialize to zero */
277         err |= __put_user(ksig->ka.sa.sa_handler, &frame->handler);
278 
279         err |= copy_siginfo_to_user(&frame->info, &ksig->info);
280 
281         err |= __save_altstack(&frame->sc.sc_stack, scr->pt.r12);
282         err |= setup_sigcontext(&frame->sc, set, scr);
283 
284         if (unlikely(err)) {
285                 force_sigsegv(ksig->sig);
286                 return 1;
287         }
288 
289         scr->pt.r12 = (unsigned long) frame - 16;       /* new stack pointer */
290         scr->pt.ar_fpsr = FPSR_DEFAULT;                 /* reset fpsr for signal handler */
291         scr->pt.cr_iip = tramp_addr;
292         ia64_psr(&scr->pt)->ri = 0;                     /* start executing in first slot */
293         ia64_psr(&scr->pt)->be = 0;                     /* force little-endian byte-order */
294         /*
295          * Force the interruption function mask to zero.  This has no effect when a
296          * system-call got interrupted by a signal (since, in that case, scr->pt_cr_ifs is
297          * ignored), but it has the desirable effect of making it possible to deliver a
298          * signal with an incomplete register frame (which happens when a mandatory RSE
299          * load faults).  Furthermore, it has no negative effect on the getting the user's
300          * dirty partition preserved, because that's governed by scr->pt.loadrs.
301          */
302         scr->pt.cr_ifs = (1UL << 63);
303 
304         /*
305          * Note: this affects only the NaT bits of the scratch regs (the ones saved in
306          * pt_regs), which is exactly what we want.
307          */
308         scr->scratch_unat = 0; /* ensure NaT bits of r12 is clear */
309 
310 #if DEBUG_SIG
311         printk("SIG deliver (%s:%d): sig=%d sp=%lx ip=%lx handler=%p\n",
312                current->comm, current->pid, ksig->sig, scr->pt.r12, frame->sc.sc_ip, frame->handler);
313 #endif
314         return 0;
315 }
316 
317 static long
318 handle_signal (struct ksignal *ksig, struct sigscratch *scr)
319 {
320         int ret = setup_frame(ksig, sigmask_to_save(), scr);
321 
322         if (!ret)
323                 signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
324 
325         return ret;
326 }
327 
328 /*
329  * Note that `init' is a special process: it doesn't get signals it doesn't want to
330  * handle.  Thus you cannot kill init even with a SIGKILL even by mistake.
331  */
332 void
333 ia64_do_signal (struct sigscratch *scr, long in_syscall)
334 {
335         long restart = in_syscall;
336         long errno = scr->pt.r8;
337         struct ksignal ksig;
338 
339         /*
340          * This only loops in the rare cases of handle_signal() failing, in which case we
341          * need to push through a forced SIGSEGV.
342          */
343         while (1) {
344                 get_signal(&ksig);
345 
346                 /*
347                  * get_signal() may have run a debugger (via notify_parent())
348                  * and the debugger may have modified the state (e.g., to arrange for an
349                  * inferior call), thus it's important to check for restarting _after_
350                  * get_signal().
351                  */
352                 if ((long) scr->pt.r10 != -1)
353                         /*
354                          * A system calls has to be restarted only if one of the error codes
355                          * ERESTARTNOHAND, ERESTARTSYS, or ERESTARTNOINTR is returned.  If r10
356                          * isn't -1 then r8 doesn't hold an error code and we don't need to
357                          * restart the syscall, so we can clear the "restart" flag here.
358                          */
359                         restart = 0;
360 
361                 if (ksig.sig <= 0)
362                         break;
363 
364                 if (unlikely(restart)) {
365                         switch (errno) {
366                               case ERESTART_RESTARTBLOCK:
367                               case ERESTARTNOHAND:
368                                 scr->pt.r8 = EINTR;
369                                 /* note: scr->pt.r10 is already -1 */
370                                 break;
371 
372                               case ERESTARTSYS:
373                                 if ((ksig.ka.sa.sa_flags & SA_RESTART) == 0) {
374                                         scr->pt.r8 = EINTR;
375                                         /* note: scr->pt.r10 is already -1 */
376                                         break;
377                                 }
378                               case ERESTARTNOINTR:
379                                 ia64_decrement_ip(&scr->pt);
380                                 restart = 0; /* don't restart twice if handle_signal() fails... */
381                         }
382                 }
383 
384                 /*
385                  * Whee!  Actually deliver the signal.  If the delivery failed, we need to
386                  * continue to iterate in this loop so we can deliver the SIGSEGV...
387                  */
388                 if (handle_signal(&ksig, scr))
389                         return;
390         }
391 
392         /* Did we come from a system call? */
393         if (restart) {
394                 /* Restart the system call - no handlers present */
395                 if (errno == ERESTARTNOHAND || errno == ERESTARTSYS || errno == ERESTARTNOINTR
396                     || errno == ERESTART_RESTARTBLOCK)
397                 {
398                         /*
399                          * Note: the syscall number is in r15 which is saved in
400                          * pt_regs so all we need to do here is adjust ip so that
401                          * the "break" instruction gets re-executed.
402                          */
403                         ia64_decrement_ip(&scr->pt);
404                         if (errno == ERESTART_RESTARTBLOCK)
405                                 scr->pt.r15 = __NR_restart_syscall;
406                 }
407         }
408 
409         /* if there's no signal to deliver, we just put the saved sigmask
410          * back */
411         restore_saved_sigmask();
412 }
413 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp