2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 * Copyright (C) 1994 - 2000 Ralf Baechle
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 * Copyright (C) 2014, Imagination Technologies Ltd.
11 #include <linux/cache.h>
12 #include <linux/context_tracking.h>
13 #include <linux/irqflags.h>
14 #include <linux/sched.h>
16 #include <linux/personality.h>
17 #include <linux/smp.h>
18 #include <linux/kernel.h>
19 #include <linux/signal.h>
20 #include <linux/errno.h>
21 #include <linux/wait.h>
22 #include <linux/ptrace.h>
23 #include <linux/unistd.h>
24 #include <linux/compiler.h>
25 #include <linux/syscalls.h>
26 #include <linux/uaccess.h>
27 #include <linux/tracehook.h>
31 #include <linux/bitops.h>
32 #include <asm/cacheflush.h>
35 #include <asm/ucontext.h>
36 #include <asm/cpu-features.h>
42 #include "signal-common.h"
44 static int (*save_fp_context
)(struct sigcontext __user
*sc
);
45 static int (*restore_fp_context
)(struct sigcontext __user
*sc
);
47 extern asmlinkage
int _save_fp_context(struct sigcontext __user
*sc
);
48 extern asmlinkage
int _restore_fp_context(struct sigcontext __user
*sc
);
51 u32 sf_ass
[4]; /* argument save space for o32 */
52 u32 sf_pad
[2]; /* Was: signal trampoline */
53 struct sigcontext sf_sc
;
58 u32 rs_ass
[4]; /* argument save space for o32 */
59 u32 rs_pad
[2]; /* Was: signal trampoline */
60 struct siginfo rs_info
;
61 struct ucontext rs_uc
;
65 * Thread saved context copy to/from a signal context presumed to be on the
66 * user stack, and therefore accessed with appropriate macros from uaccess.h.
68 static int copy_fp_to_sigcontext(struct sigcontext __user
*sc
)
73 for (i
= 0; i
< NUM_FPU_REGS
; i
++) {
75 __put_user(get_fpr64(¤t
->thread
.fpu
.fpr
[i
], 0),
78 err
|= __put_user(current
->thread
.fpu
.fcr31
, &sc
->sc_fpc_csr
);
83 static int copy_fp_from_sigcontext(struct sigcontext __user
*sc
)
89 for (i
= 0; i
< NUM_FPU_REGS
; i
++) {
90 err
|= __get_user(fpr_val
, &sc
->sc_fpregs
[i
]);
91 set_fpr64(¤t
->thread
.fpu
.fpr
[i
], 0, fpr_val
);
93 err
|= __get_user(current
->thread
.fpu
.fcr31
, &sc
->sc_fpc_csr
);
101 static int protected_save_fp_context(struct sigcontext __user
*sc
)
107 if (is_fpu_owner()) {
108 err
= save_fp_context(sc
);
112 err
= copy_fp_to_sigcontext(sc
);
116 /* touch the sigcontext and try again */
117 err
= __put_user(0, &sc
->sc_fpregs
[0]) |
118 __put_user(0, &sc
->sc_fpregs
[31]) |
119 __put_user(0, &sc
->sc_fpc_csr
);
121 break; /* really bad sigcontext */
125 * EVA does not have FPU EVA instructions so saving fpu context directly
129 err
= save_fp_context(sc
); /* this might fail */
134 static int protected_restore_fp_context(struct sigcontext __user
*sc
)
136 int err
, tmp __maybe_unused
;
140 if (is_fpu_owner()) {
141 err
= restore_fp_context(sc
);
145 err
= copy_fp_from_sigcontext(sc
);
149 /* touch the sigcontext and try again */
150 err
= __get_user(tmp
, &sc
->sc_fpregs
[0]) |
151 __get_user(tmp
, &sc
->sc_fpregs
[31]) |
152 __get_user(tmp
, &sc
->sc_fpc_csr
);
154 break; /* really bad sigcontext */
158 * EVA does not have FPU EVA instructions so restoring fpu context
159 * directly does not work.
162 err
= restore_fp_context(sc
); /* this might fail */
167 int setup_sigcontext(struct pt_regs
*regs
, struct sigcontext __user
*sc
)
171 unsigned int used_math
;
173 err
|= __put_user(regs
->cp0_epc
, &sc
->sc_pc
);
175 err
|= __put_user(0, &sc
->sc_regs
[0]);
176 for (i
= 1; i
< 32; i
++)
177 err
|= __put_user(regs
->regs
[i
], &sc
->sc_regs
[i
]);
179 #ifdef CONFIG_CPU_HAS_SMARTMIPS
180 err
|= __put_user(regs
->acx
, &sc
->sc_acx
);
182 err
|= __put_user(regs
->hi
, &sc
->sc_mdhi
);
183 err
|= __put_user(regs
->lo
, &sc
->sc_mdlo
);
185 err
|= __put_user(mfhi1(), &sc
->sc_hi1
);
186 err
|= __put_user(mflo1(), &sc
->sc_lo1
);
187 err
|= __put_user(mfhi2(), &sc
->sc_hi2
);
188 err
|= __put_user(mflo2(), &sc
->sc_lo2
);
189 err
|= __put_user(mfhi3(), &sc
->sc_hi3
);
190 err
|= __put_user(mflo3(), &sc
->sc_lo3
);
191 err
|= __put_user(rddsp(DSP_MASK
), &sc
->sc_dsp
);
194 used_math
= !!used_math();
195 err
|= __put_user(used_math
, &sc
->sc_used_math
);
199 * Save FPU state to signal context. Signal handler
200 * will "inherit" current FPU state.
202 err
|= protected_save_fp_context(sc
);
207 int fpcsr_pending(unsigned int __user
*fpcsr
)
210 unsigned int csr
, enabled
;
212 err
= __get_user(csr
, fpcsr
);
213 enabled
= FPU_CSR_UNI_X
| ((csr
& FPU_CSR_ALL_E
) << 5);
215 * If the signal handler set some FPU exceptions, clear it and
220 err
|= __put_user(csr
, fpcsr
);
227 check_and_restore_fp_context(struct sigcontext __user
*sc
)
231 err
= sig
= fpcsr_pending(&sc
->sc_fpc_csr
);
234 err
|= protected_restore_fp_context(sc
);
238 int restore_sigcontext(struct pt_regs
*regs
, struct sigcontext __user
*sc
)
240 unsigned int used_math
;
245 /* Always make any pending restarted system calls return -EINTR */
246 current_thread_info()->restart_block
.fn
= do_no_restart_syscall
;
248 err
|= __get_user(regs
->cp0_epc
, &sc
->sc_pc
);
250 #ifdef CONFIG_CPU_HAS_SMARTMIPS
251 err
|= __get_user(regs
->acx
, &sc
->sc_acx
);
253 err
|= __get_user(regs
->hi
, &sc
->sc_mdhi
);
254 err
|= __get_user(regs
->lo
, &sc
->sc_mdlo
);
256 err
|= __get_user(treg
, &sc
->sc_hi1
); mthi1(treg
);
257 err
|= __get_user(treg
, &sc
->sc_lo1
); mtlo1(treg
);
258 err
|= __get_user(treg
, &sc
->sc_hi2
); mthi2(treg
);
259 err
|= __get_user(treg
, &sc
->sc_lo2
); mtlo2(treg
);
260 err
|= __get_user(treg
, &sc
->sc_hi3
); mthi3(treg
);
261 err
|= __get_user(treg
, &sc
->sc_lo3
); mtlo3(treg
);
262 err
|= __get_user(treg
, &sc
->sc_dsp
); wrdsp(treg
, DSP_MASK
);
265 for (i
= 1; i
< 32; i
++)
266 err
|= __get_user(regs
->regs
[i
], &sc
->sc_regs
[i
]);
268 err
|= __get_user(used_math
, &sc
->sc_used_math
);
269 conditional_used_math(used_math
);
272 /* restore fpu context if we have used it before */
274 err
= check_and_restore_fp_context(sc
);
276 /* signal handler may have used FPU. Give it up. */
283 void __user
*get_sigframe(struct k_sigaction
*ka
, struct pt_regs
*regs
,
288 /* Default to using normal stack */
292 * FPU emulator may have it's own trampoline active just
293 * above the user stack, 16-bytes before the next lowest
294 * 16 byte boundary. Try to avoid trashing it.
298 /* This is the X/Open sanctioned signal stack switching. */
299 if ((ka
->sa
.sa_flags
& SA_ONSTACK
) && (sas_ss_flags (sp
) == 0))
300 sp
= current
->sas_ss_sp
+ current
->sas_ss_size
;
302 return (void __user
*)((sp
- frame_size
) & (ICACHE_REFILLS_WORKAROUND_WAR
? ~(cpu_icache_line_size()-1) : ALMASK
));
306 * Atomically swap in the new signal mask, and wait for a signal.
309 #ifdef CONFIG_TRAD_SIGNALS
310 SYSCALL_DEFINE1(sigsuspend
, sigset_t __user
*, uset
)
312 return sys_rt_sigsuspend(uset
, sizeof(sigset_t
));
316 #ifdef CONFIG_TRAD_SIGNALS
317 SYSCALL_DEFINE3(sigaction
, int, sig
, const struct sigaction __user
*, act
,
318 struct sigaction __user
*, oact
)
320 struct k_sigaction new_ka
, old_ka
;
327 if (!access_ok(VERIFY_READ
, act
, sizeof(*act
)))
329 err
|= __get_user(new_ka
.sa
.sa_handler
, &act
->sa_handler
);
330 err
|= __get_user(new_ka
.sa
.sa_flags
, &act
->sa_flags
);
331 err
|= __get_user(mask
, &act
->sa_mask
.sig
[0]);
335 siginitset(&new_ka
.sa
.sa_mask
, mask
);
338 ret
= do_sigaction(sig
, act
? &new_ka
: NULL
, oact
? &old_ka
: NULL
);
341 if (!access_ok(VERIFY_WRITE
, oact
, sizeof(*oact
)))
343 err
|= __put_user(old_ka
.sa
.sa_flags
, &oact
->sa_flags
);
344 err
|= __put_user(old_ka
.sa
.sa_handler
, &oact
->sa_handler
);
345 err
|= __put_user(old_ka
.sa
.sa_mask
.sig
[0], oact
->sa_mask
.sig
);
346 err
|= __put_user(0, &oact
->sa_mask
.sig
[1]);
347 err
|= __put_user(0, &oact
->sa_mask
.sig
[2]);
348 err
|= __put_user(0, &oact
->sa_mask
.sig
[3]);
357 #ifdef CONFIG_TRAD_SIGNALS
358 asmlinkage
void sys_sigreturn(nabi_no_regargs
struct pt_regs regs
)
360 struct sigframe __user
*frame
;
364 frame
= (struct sigframe __user
*) regs
.regs
[29];
365 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
367 if (__copy_from_user(&blocked
, &frame
->sf_mask
, sizeof(blocked
)))
370 set_current_blocked(&blocked
);
372 sig
= restore_sigcontext(®s
, &frame
->sf_sc
);
376 force_sig(sig
, current
);
379 * Don't let your children do this ...
381 __asm__
__volatile__(
389 force_sig(SIGSEGV
, current
);
391 #endif /* CONFIG_TRAD_SIGNALS */
393 asmlinkage
void sys_rt_sigreturn(nabi_no_regargs
struct pt_regs regs
)
395 struct rt_sigframe __user
*frame
;
399 frame
= (struct rt_sigframe __user
*) regs
.regs
[29];
400 if (!access_ok(VERIFY_READ
, frame
, sizeof(*frame
)))
402 if (__copy_from_user(&set
, &frame
->rs_uc
.uc_sigmask
, sizeof(set
)))
405 set_current_blocked(&set
);
407 sig
= restore_sigcontext(®s
, &frame
->rs_uc
.uc_mcontext
);
411 force_sig(sig
, current
);
413 if (restore_altstack(&frame
->rs_uc
.uc_stack
))
417 * Don't let your children do this ...
419 __asm__
__volatile__(
427 force_sig(SIGSEGV
, current
);
430 #ifdef CONFIG_TRAD_SIGNALS
431 static int setup_frame(void *sig_return
, struct k_sigaction
*ka
,
432 struct pt_regs
*regs
, int signr
, sigset_t
*set
)
434 struct sigframe __user
*frame
;
437 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
438 if (!access_ok(VERIFY_WRITE
, frame
, sizeof (*frame
)))
441 err
|= setup_sigcontext(regs
, &frame
->sf_sc
);
442 err
|= __copy_to_user(&frame
->sf_mask
, set
, sizeof(*set
));
447 * Arguments to signal handler:
450 * a1 = 0 (should be cause)
451 * a2 = pointer to struct sigcontext
453 * $25 and c0_epc point to the signal handler, $29 points to the
456 regs
->regs
[ 4] = signr
;
458 regs
->regs
[ 6] = (unsigned long) &frame
->sf_sc
;
459 regs
->regs
[29] = (unsigned long) frame
;
460 regs
->regs
[31] = (unsigned long) sig_return
;
461 regs
->cp0_epc
= regs
->regs
[25] = (unsigned long) ka
->sa
.sa_handler
;
463 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
464 current
->comm
, current
->pid
,
465 frame
, regs
->cp0_epc
, regs
->regs
[31]);
469 force_sigsegv(signr
, current
);
474 static int setup_rt_frame(void *sig_return
, struct k_sigaction
*ka
,
475 struct pt_regs
*regs
, int signr
, sigset_t
*set
,
478 struct rt_sigframe __user
*frame
;
481 frame
= get_sigframe(ka
, regs
, sizeof(*frame
));
482 if (!access_ok(VERIFY_WRITE
, frame
, sizeof (*frame
)))
485 /* Create siginfo. */
486 err
|= copy_siginfo_to_user(&frame
->rs_info
, info
);
488 /* Create the ucontext. */
489 err
|= __put_user(0, &frame
->rs_uc
.uc_flags
);
490 err
|= __put_user(NULL
, &frame
->rs_uc
.uc_link
);
491 err
|= __save_altstack(&frame
->rs_uc
.uc_stack
, regs
->regs
[29]);
492 err
|= setup_sigcontext(regs
, &frame
->rs_uc
.uc_mcontext
);
493 err
|= __copy_to_user(&frame
->rs_uc
.uc_sigmask
, set
, sizeof(*set
));
499 * Arguments to signal handler:
502 * a1 = 0 (should be cause)
503 * a2 = pointer to ucontext
505 * $25 and c0_epc point to the signal handler, $29 points to
506 * the struct rt_sigframe.
508 regs
->regs
[ 4] = signr
;
509 regs
->regs
[ 5] = (unsigned long) &frame
->rs_info
;
510 regs
->regs
[ 6] = (unsigned long) &frame
->rs_uc
;
511 regs
->regs
[29] = (unsigned long) frame
;
512 regs
->regs
[31] = (unsigned long) sig_return
;
513 regs
->cp0_epc
= regs
->regs
[25] = (unsigned long) ka
->sa
.sa_handler
;
515 DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
516 current
->comm
, current
->pid
,
517 frame
, regs
->cp0_epc
, regs
->regs
[31]);
522 force_sigsegv(signr
, current
);
526 struct mips_abi mips_abi
= {
527 #ifdef CONFIG_TRAD_SIGNALS
528 .setup_frame
= setup_frame
,
529 .signal_return_offset
= offsetof(struct mips_vdso
, signal_trampoline
),
531 .setup_rt_frame
= setup_rt_frame
,
532 .rt_signal_return_offset
=
533 offsetof(struct mips_vdso
, rt_signal_trampoline
),
534 .restart
= __NR_restart_syscall
537 static void handle_signal(unsigned long sig
, siginfo_t
*info
,
538 struct k_sigaction
*ka
, struct pt_regs
*regs
)
540 sigset_t
*oldset
= sigmask_to_save();
542 struct mips_abi
*abi
= current
->thread
.abi
;
543 #ifdef CONFIG_CPU_MICROMIPS
545 unsigned int tmp
= (unsigned int)current
->mm
->context
.vdso
;
550 void *vdso
= current
->mm
->context
.vdso
;
554 switch(regs
->regs
[2]) {
555 case ERESTART_RESTARTBLOCK
:
557 regs
->regs
[2] = EINTR
;
560 if (!(ka
->sa
.sa_flags
& SA_RESTART
)) {
561 regs
->regs
[2] = EINTR
;
566 regs
->regs
[7] = regs
->regs
[26];
567 regs
->regs
[2] = regs
->regs
[0];
571 regs
->regs
[0] = 0; /* Don't deal with this again. */
574 if (sig_uses_siginfo(ka
))
575 ret
= abi
->setup_rt_frame(vdso
+ abi
->rt_signal_return_offset
,
576 ka
, regs
, sig
, oldset
, info
);
578 ret
= abi
->setup_frame(vdso
+ abi
->signal_return_offset
,
579 ka
, regs
, sig
, oldset
);
584 signal_delivered(sig
, info
, ka
, regs
, 0);
587 static void do_signal(struct pt_regs
*regs
)
589 struct k_sigaction ka
;
593 signr
= get_signal_to_deliver(&info
, &ka
, regs
, NULL
);
595 /* Whee! Actually deliver the signal. */
596 handle_signal(signr
, &info
, &ka
, regs
);
601 switch (regs
->regs
[2]) {
605 regs
->regs
[2] = regs
->regs
[0];
606 regs
->regs
[7] = regs
->regs
[26];
610 case ERESTART_RESTARTBLOCK
:
611 regs
->regs
[2] = current
->thread
.abi
->restart
;
612 regs
->regs
[7] = regs
->regs
[26];
616 regs
->regs
[0] = 0; /* Don't deal with this again. */
620 * If there's no signal to deliver, we just put the saved sigmask
623 restore_saved_sigmask();
627 * notification of userspace execution resumption
628 * - triggered by the TIF_WORK_MASK flags
630 asmlinkage
void do_notify_resume(struct pt_regs
*regs
, void *unused
,
631 __u32 thread_info_flags
)
637 /* deal with pending signal delivery */
638 if (thread_info_flags
& _TIF_SIGPENDING
)
641 if (thread_info_flags
& _TIF_NOTIFY_RESUME
) {
642 clear_thread_flag(TIF_NOTIFY_RESUME
);
643 tracehook_notify_resume(regs
);
651 static int smp_save_fp_context(struct sigcontext __user
*sc
)
653 return raw_cpu_has_fpu
654 ? _save_fp_context(sc
)
655 : copy_fp_to_sigcontext(sc
);
658 static int smp_restore_fp_context(struct sigcontext __user
*sc
)
660 return raw_cpu_has_fpu
661 ? _restore_fp_context(sc
)
662 : copy_fp_from_sigcontext(sc
);
664 #endif /* CONFIG_EVA */
667 static int signal_setup(void)
671 /* For now just do the cpu_has_fpu check when the functions are invoked */
672 save_fp_context
= smp_save_fp_context
;
673 restore_fp_context
= smp_restore_fp_context
;
676 save_fp_context
= _save_fp_context
;
677 restore_fp_context
= _restore_fp_context
;
679 save_fp_context
= copy_fp_from_sigcontext
;
680 restore_fp_context
= copy_fp_to_sigcontext
;
682 #endif /* CONFIG_SMP */
684 save_fp_context
= copy_fp_from_sigcontext
;;
685 restore_fp_context
= copy_fp_to_sigcontext
;
691 arch_initcall(signal_setup
);