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authorChris Zankel <chris@zankel.net>2007-05-31 20:49:32 -0400
committerChris Zankel <chris@zankel.net>2007-05-31 20:49:32 -0400
commit29c4dfd92edc26c2cd2c0c64c9201d5b91d6418e (patch)
tree64b2884bb49a86f2895d9206b79bf9f64e384615 /arch/xtensa
parentadba09f01577ea441a761a85aacb1e43b58d35c4 (diff)
[XTENSA] Remove non-rt signal handling
The non-rt signal handling was never really used, so we don't break anything. This patch also cleans up the signal stack-frame to make it independent from the processor configuration. It also improves the method used for controlling single-stepping. We now save and restore the 'icountlevel' register that controls single stepping and set or clear the saved state to enable or disable it. Signed-off-by: Chris Zankel <chris@zankel.net>
Diffstat (limited to 'arch/xtensa')
-rw-r--r--arch/xtensa/kernel/asm-offsets.c1
-rw-r--r--arch/xtensa/kernel/entry.S36
-rw-r--r--arch/xtensa/kernel/signal.c795
3 files changed, 334 insertions, 498 deletions
diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c
index 698079b3a336..d0323cd6a2ea 100644
--- a/arch/xtensa/kernel/asm-offsets.c
+++ b/arch/xtensa/kernel/asm-offsets.c
@@ -39,6 +39,7 @@ int main(void)
39 DEFINE(PT_LEND, offsetof (struct pt_regs, lend)); 39 DEFINE(PT_LEND, offsetof (struct pt_regs, lend));
40 DEFINE(PT_LCOUNT, offsetof (struct pt_regs, lcount)); 40 DEFINE(PT_LCOUNT, offsetof (struct pt_regs, lcount));
41 DEFINE(PT_SAR, offsetof (struct pt_regs, sar)); 41 DEFINE(PT_SAR, offsetof (struct pt_regs, sar));
42 DEFINE(PT_ICOUNTLEVEL, offsetof (struct pt_regs, icountlevel));
42 DEFINE(PT_SYSCALL, offsetof (struct pt_regs, syscall)); 43 DEFINE(PT_SYSCALL, offsetof (struct pt_regs, syscall));
43 DEFINE(PT_AREG, offsetof (struct pt_regs, areg[0])); 44 DEFINE(PT_AREG, offsetof (struct pt_regs, areg[0]));
44 DEFINE(PT_AREG0, offsetof (struct pt_regs, areg[0])); 45 DEFINE(PT_AREG0, offsetof (struct pt_regs, areg[0]));
diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 9e271ba009bf..8dc7a2c26ff9 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -125,8 +125,9 @@ _user_exception:
125 125
126 movi a2, 0 126 movi a2, 0
127 rsr a3, SAR 127 rsr a3, SAR
128 wsr a2, ICOUNTLEVEL 128 xsr a2, ICOUNTLEVEL
129 s32i a3, a1, PT_SAR 129 s32i a3, a1, PT_SAR
130 s32i a2, a1, PT_ICOUNTLEVEL
130 131
131 /* Rotate ws so that the current windowbase is at bit0. */ 132 /* Rotate ws so that the current windowbase is at bit0. */
132 /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */ 133 /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */
@@ -276,8 +277,9 @@ _kernel_exception:
276 277
277 movi a2, 0 278 movi a2, 0
278 rsr a3, SAR 279 rsr a3, SAR
279 wsr a2, ICOUNTLEVEL 280 xsr a2, ICOUNTLEVEL
280 s32i a3, a1, PT_SAR 281 s32i a3, a1, PT_SAR
282 s32i a2, a1, PT_ICOUNTLEVEL
281 283
282 /* Rotate ws so that the current windowbase is at bit0. */ 284 /* Rotate ws so that the current windowbase is at bit0. */
283 /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */ 285 /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */
@@ -330,14 +332,16 @@ _kernel_exception:
330 332
331common_exception: 333common_exception:
332 334
333 /* Save EXCVADDR, DEBUGCAUSE, and PC, and clear LCOUNT */ 335 /* Save some registers, disable loops and clear the syscall flag. */
334 336
335 rsr a2, DEBUGCAUSE 337 rsr a2, DEBUGCAUSE
336 rsr a3, EPC_1 338 rsr a3, EPC_1
337 s32i a2, a1, PT_DEBUGCAUSE 339 s32i a2, a1, PT_DEBUGCAUSE
338 s32i a3, a1, PT_PC 340 s32i a3, a1, PT_PC
339 341
342 movi a2, -1
340 rsr a3, EXCVADDR 343 rsr a3, EXCVADDR
344 s32i a2, a1, PT_SYSCALL
341 movi a2, 0 345 movi a2, 0
342 s32i a3, a1, PT_EXCVADDR 346 s32i a3, a1, PT_EXCVADDR
343 xsr a2, LCOUNT 347 xsr a2, LCOUNT
@@ -450,27 +454,8 @@ common_exception_return:
450 454
451 /* Restore the state of the task and return from the exception. */ 455 /* Restore the state of the task and return from the exception. */
452 456
453
454 /* If we are returning from a user exception, and the process
455 * to run next has PT_SINGLESTEP set, we want to setup
456 * ICOUNT and ICOUNTLEVEL to step one instruction.
457 * PT_SINGLESTEP is set by sys_ptrace (ptrace.c)
458 */
459
4604: /* a2 holds GET_CURRENT(a2,a1) */ 4574: /* a2 holds GET_CURRENT(a2,a1) */
461 458
462 l32i a3, a2, TI_TASK
463 l32i a3, a3, TASK_PTRACE
464 bbci.l a3, PT_SINGLESTEP_BIT, 1f # jump if single-step flag is not set
465
466 movi a3, -2 # PT_SINGLESTEP flag is set,
467 movi a4, 1 # icountlevel of 1 means it won't
468 wsr a3, ICOUNT # start counting until after rfe
469 wsr a4, ICOUNTLEVEL # so setup icount & icountlevel.
470 isync
471
4721:
473
474#if XCHAL_EXTRA_SA_SIZE 459#if XCHAL_EXTRA_SA_SIZE
475 460
476 /* For user exceptions, restore the extra state from the user's TCB. */ 461 /* For user exceptions, restore the extra state from the user's TCB. */
@@ -665,6 +650,13 @@ common_exception_exit:
665 wsr a3, LEND 650 wsr a3, LEND
666 wsr a2, LCOUNT 651 wsr a2, LCOUNT
667 652
653 /* We control single stepping through the ICOUNTLEVEL register. */
654
655 l32i a2, a1, PT_ICOUNTLEVEL
656 movi a3, -2
657 wsr a2, ICOUNTLEVEL
658 wsr a3, ICOUNT
659
668 /* Check if it was double exception. */ 660 /* Check if it was double exception. */
669 661
670 l32i a0, a1, PT_DEPC 662 l32i a0, a1, PT_DEPC
diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c
index 58107672a619..033aae0336d2 100644
--- a/arch/xtensa/kernel/signal.c
+++ b/arch/xtensa/kernel/signal.c
@@ -1,397 +1,239 @@
1// TODO coprocessor stuff
2/* 1/*
3 * linux/arch/xtensa/kernel/signal.c 2 * arch/xtensa/kernel/signal.c
4 * 3 *
5 * Copyright (C) 1991, 1992 Linus Torvalds 4 * Default platform functions.
6 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
7 *
8 * Joe Taylor <joe@tensilica.com>
9 * Chris Zankel <chris@zankel.net>
10 * 5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
11 * 9 *
10 * Copyright (C) 2005, 2006 Tensilica Inc.
11 * Copyright (C) 1991, 1992 Linus Torvalds
12 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
12 * 13 *
14 * Chris Zankel <chris@zankel.net>
15 * Joe Taylor <joe@tensilica.com>
13 */ 16 */
14 17
15#include <asm/variant/core.h>
16#include <asm/coprocessor.h>
17#include <linux/sched.h>
18#include <linux/mm.h>
19#include <linux/smp.h>
20#include <linux/kernel.h>
21#include <linux/signal.h> 18#include <linux/signal.h>
22#include <linux/errno.h> 19#include <linux/errno.h>
23#include <linux/wait.h>
24#include <linux/ptrace.h> 20#include <linux/ptrace.h>
25#include <linux/unistd.h>
26#include <linux/stddef.h>
27#include <linux/personality.h> 21#include <linux/personality.h>
22#include <linux/freezer.h>
23
28#include <asm/ucontext.h> 24#include <asm/ucontext.h>
29#include <asm/uaccess.h> 25#include <asm/uaccess.h>
30#include <asm/pgtable.h>
31#include <asm/cacheflush.h> 26#include <asm/cacheflush.h>
27#include <asm/coprocessor.h>
28#include <asm/unistd.h>
32 29
33#define DEBUG_SIG 0 30#define DEBUG_SIG 0
34 31
35#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) 32#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
36 33
37asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options,
38 struct rusage * ru);
39asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); 34asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
40 35
41extern struct task_struct *coproc_owners[]; 36extern struct task_struct *coproc_owners[];
42 37
38extern void release_all_cp (struct task_struct *);
43 39
44/* 40struct rt_sigframe
45 * Atomically swap in the new signal mask, and wait for a signal. 41{
42 struct siginfo info;
43 struct ucontext uc;
44 cp_state_t cpstate;
45 unsigned char retcode[6];
46 unsigned int window[4];
47};
48
49/*
50 * Flush register windows stored in pt_regs to stack.
51 * Returns 1 for errors.
52 *
53 * Note that windowbase, windowstart, and wmask are not updated!
46 */ 54 */
47 55
48int xtensa_sigsuspend(struct pt_regs *regs) 56int
57flush_window_regs_user(struct pt_regs *regs)
49{ 58{
50 old_sigset_t mask = (old_sigset_t) regs->areg[3]; 59 const unsigned long ws = regs->windowstart;
51 sigset_t saveset; 60 const unsigned long wb = regs->windowbase;
61 unsigned long sp = 0;
62 unsigned long wm;
63 int err = 1;
64 int base;
52 65
53 mask &= _BLOCKABLE; 66 /* Return if no other frames. */
54 spin_lock_irq(&current->sighand->siglock);
55 saveset = current->blocked;
56 siginitset(&current->blocked, mask);
57 recalc_sigpending();
58 spin_unlock_irq(&current->sighand->siglock);
59 67
60 regs->areg[2] = -EINTR; 68 if (regs->wmask == 1)
61 while (1) { 69 return 0;
62 current->state = TASK_INTERRUPTIBLE;
63 schedule();
64 if (do_signal(regs, &saveset))
65 return -EINTR;
66 }
67}
68 70
69asmlinkage int 71 /* Rotate windowmask and skip empty frames. */
70xtensa_rt_sigsuspend(struct pt_regs *regs)
71{
72 sigset_t *unewset = (sigset_t *) regs->areg[4];
73 size_t sigsetsize = (size_t) regs->areg[3];
74 sigset_t saveset, newset;
75 /* XXX: Don't preclude handling different sized sigset_t's. */
76 if (sigsetsize != sizeof(sigset_t))
77 return -EINVAL;
78 72
79 if (copy_from_user(&newset, unewset, sizeof(newset))) 73 wm = (ws >> wb) | (ws << (XCHAL_NUM_AREGS / 4 - wb));
80 return -EFAULT; 74 base = (XCHAL_NUM_AREGS / 4) - (regs->wmask >> 4);
81 sigdelsetmask(&newset, ~_BLOCKABLE); 75
82 spin_lock_irq(&current->sighand->siglock); 76 /* For call8 or call12 frames, we need the previous stack pointer. */
83 saveset = current->blocked;
84 current->blocked = newset;
85 recalc_sigpending();
86 spin_unlock_irq(&current->sighand->siglock);
87 77
88 regs->areg[2] = -EINTR; 78 if ((regs->wmask & 2) == 0)
89 while (1) { 79 if (__get_user(sp, (int*)(regs->areg[base * 4 + 1] - 12)))
90 current->state = TASK_INTERRUPTIBLE; 80 goto errout;
91 schedule();
92 if (do_signal(regs, &saveset))
93 return -EINTR;
94 }
95}
96 81
97asmlinkage int 82 /* Spill frames to stack. */
98xtensa_sigaction(int sig, const struct old_sigaction *act,
99 struct old_sigaction *oact)
100{
101 struct k_sigaction new_ka, old_ka;
102 int ret;
103 83
104 if (act) { 84 while (base < XCHAL_NUM_AREGS / 4) {
105 old_sigset_t mask;
106 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
107 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
108 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
109 return -EFAULT;
110 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
111 __get_user(mask, &act->sa_mask);
112 siginitset(&new_ka.sa.sa_mask, mask);
113 }
114 85
115 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); 86 int m = (wm >> base);
87 int inc = 0;
116 88
117 if (!ret && oact) { 89 /* Save registers a4..a7 (call8) or a4...a11 (call12) */
118 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
119 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
120 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
121 return -EFAULT;
122 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
123 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
124 }
125 90
126 return ret; 91 if (m & 2) { /* call4 */
127} 92 inc = 1;
128 93
129asmlinkage int 94 } else if (m & 4) { /* call8 */
130xtensa_sigaltstack(struct pt_regs *regs) 95 if (copy_to_user((void*)(sp - 32),
131{ 96 &regs->areg[(base + 1) * 4], 16))
132 const stack_t *uss = (stack_t *) regs->areg[4]; 97 goto errout;
133 stack_t *uoss = (stack_t *) regs->areg[3]; 98 inc = 2;
134 99
135 if (regs->depc > 64) 100 } else if (m & 8) { /* call12 */
136 panic ("Double exception sys_sigreturn\n"); 101 if (copy_to_user((void*)(sp - 48),
102 &regs->areg[(base + 1) * 4], 32))
103 goto errout;
104 inc = 3;
105 }
137 106
107 /* Save current frame a0..a3 under next SP */
138 108
139 return do_sigaltstack(uss, uoss, regs->areg[1]); 109 sp = regs->areg[((base + inc) * 4 + 1) % XCHAL_NUM_AREGS];
140} 110 if (copy_to_user((void*)(sp - 16), &regs->areg[base * 4], 16))
111 goto errout;
112
113 /* Get current stack pointer for next loop iteration. */
114
115 sp = regs->areg[base * 4 + 1];
116 base += inc;
117 }
118
119 return 0;
141 120
121errout:
122 return err;
123}
142 124
143/* 125/*
144 * Do a signal return; undo the signal stack. 126 * Note: We don't copy double exception 'regs', we have to finish double exc.
127 * first before we return to signal handler! This dbl.exc.handler might cause
128 * another double exception, but I think we are fine as the situation is the
129 * same as if we had returned to the signal handerl and got an interrupt
130 * immediately...
145 */ 131 */
146 132
147struct sigframe 133static int
148{ 134setup_sigcontext(struct sigcontext __user *sc, cp_state_t *cpstate,
149 struct sigcontext sc; 135 struct pt_regs *regs, unsigned long mask)
150 struct _cpstate cpstate;
151 unsigned long extramask[_NSIG_WORDS-1];
152 unsigned char retcode[6];
153 unsigned int reserved[4]; /* Reserved area for chaining */
154 unsigned int window[4]; /* Window of 4 registers for initial context */
155};
156
157struct rt_sigframe
158{ 136{
159 struct siginfo info; 137 int err = 0;
160 struct ucontext uc;
161 struct _cpstate cpstate;
162 unsigned char retcode[6];
163 unsigned int reserved[4]; /* Reserved area for chaining */
164 unsigned int window[4]; /* Window of 4 registers for initial context */
165};
166 138
167extern void release_all_cp (struct task_struct *); 139#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
140 COPY(pc);
141 COPY(ps);
142 COPY(lbeg);
143 COPY(lend);
144 COPY(lcount);
145 COPY(sar);
146#undef COPY
168 147
148 err |= flush_window_regs_user(regs);
149 err |= __copy_to_user (sc->sc_a, regs->areg, 16 * 4);
169 150
170// FIXME restore_cpextra 151 // err |= __copy_to_user (sc->sc_a, regs->areg, XCHAL_NUM_AREGS * 4)
171static inline int
172restore_cpextra (struct _cpstate *buf)
173{
174#if 0
175 /* The signal handler may have used coprocessors in which
176 * case they are still enabled. We disable them to force a
177 * reloading of the original task's CP state by the lazy
178 * context-switching mechanisms of CP exception handling.
179 * Also, we essentially discard any coprocessor state that the
180 * signal handler created. */
181 152
182 struct task_struct *tsk = current; 153#if XCHAL_HAVE_CP
183 release_all_cp(tsk); 154# error Coprocessors unsupported
184 return __copy_from_user(tsk->thread.cpextra, buf, XTENSA_CP_EXTRA_SIZE); 155 err |= save_cpextra(cpstate);
156 err |= __put_user(err ? NULL : cpstate, &sc->sc_cpstate);
185#endif 157#endif
186 return 0; 158 /* non-iBCS2 extensions.. */
187} 159 err |= __put_user(mask, &sc->oldmask);
188
189/* Note: We don't copy double exception 'tregs', we have to finish double exc. first before we return to signal handler! This dbl.exc.handler might cause another double exception, but I think we are fine as the situation is the same as if we had returned to the signal handerl and got an interrupt immediately...
190 */
191 160
161 return err;
162}
192 163
193static int 164static int
194restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc) 165restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
195{ 166{
196 struct thread_struct *thread;
197 unsigned int err = 0; 167 unsigned int err = 0;
198 unsigned long ps; 168 unsigned long ps;
199 struct _cpstate *buf;
200 169
201#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) 170#define COPY(x) err |= __get_user(regs->x, &sc->sc_##x)
202 COPY(pc); 171 COPY(pc);
203 COPY(depc);
204 COPY(wmask);
205 COPY(lbeg); 172 COPY(lbeg);
206 COPY(lend); 173 COPY(lend);
207 COPY(lcount); 174 COPY(lcount);
208 COPY(sar); 175 COPY(sar);
209 COPY(windowbase);
210 COPY(windowstart);
211#undef COPY 176#undef COPY
212 177
178 /* All registers were flushed to stack. Start with a prestine frame. */
179
180 regs->wmask = 1;
181 regs->windowbase = 0;
182 regs->windowstart = 1;
183
213 /* For PS, restore only PS.CALLINC. 184 /* For PS, restore only PS.CALLINC.
214 * Assume that all other bits are either the same as for the signal 185 * Assume that all other bits are either the same as for the signal
215 * handler, or the user mode value doesn't matter (e.g. PS.OWB). 186 * handler, or the user mode value doesn't matter (e.g. PS.OWB).
216 */ 187 */
217 err |= __get_user(ps, &sc->sc_ps); 188 err |= __get_user(ps, &sc->sc_ps);
218 regs->ps = (regs->ps & ~PS_CALLINC_MASK) 189 regs->ps = (regs->ps & ~PS_CALLINC_MASK) | (ps & PS_CALLINC_MASK);
219 | (ps & PS_CALLINC_MASK);
220 190
221 /* Additional corruption checks */ 191 /* Additional corruption checks */
222 192
223 if ((regs->windowbase >= (XCHAL_NUM_AREGS/4))
224 || ((regs->windowstart & ~((1<<(XCHAL_NUM_AREGS/4)) - 1)) != 0) )
225 err = 1;
226 if ((regs->lcount > 0) 193 if ((regs->lcount > 0)
227 && ((regs->lbeg > TASK_SIZE) || (regs->lend > TASK_SIZE)) ) 194 && ((regs->lbeg > TASK_SIZE) || (regs->lend > TASK_SIZE)) )
228 err = 1; 195 err = 1;
229 196
230 /* Restore extended register state. 197 err |= __copy_from_user(regs->areg, sc->sc_a, 16 * 4);
231 * See struct thread_struct in processor.h.
232 */
233 thread = &current->thread;
234
235 err |= __copy_from_user (regs->areg, sc->sc_areg, XCHAL_NUM_AREGS*4);
236 err |= __get_user(buf, &sc->sc_cpstate);
237 if (buf) {
238 if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
239 goto badframe;
240 err |= restore_cpextra(buf);
241 }
242
243 regs->syscall = -1; /* disable syscall checks */
244 return err;
245
246badframe:
247 return 1;
248}
249
250static inline void
251flush_my_cpstate(struct task_struct *tsk)
252{
253 unsigned long flags;
254 local_irq_save(flags);
255
256#if 0 // FIXME
257 for (i = 0; i < XCHAL_CP_NUM; i++) {
258 if (tsk == coproc_owners[i]) {
259 xthal_validate_cp(i);
260 xthal_save_cpregs(tsk->thread.cpregs_ptr[i], i);
261 198
262 /* Invalidate and "disown" the cp to allow 199#if XCHAL_HAVE_CP
263 * callers the chance to reset cp state in the 200# error Coprocessors unsupported
264 * task_struct. */ 201 /* The signal handler may have used coprocessors in which
202 * case they are still enabled. We disable them to force a
203 * reloading of the original task's CP state by the lazy
204 * context-switching mechanisms of CP exception handling.
205 * Also, we essentially discard any coprocessor state that the
206 * signal handler created. */
265 207
266 xthal_invalidate_cp(i); 208 if (!err) {
267 coproc_owners[i] = 0; 209 struct task_struct *tsk = current;
268 } 210 release_all_cp(tsk);
211 err |= __copy_from_user(tsk->thread.cpextra, sc->sc_cpstate,
212 XTENSA_CP_EXTRA_SIZE);
269 } 213 }
270#endif 214#endif
271 local_irq_restore(flags);
272}
273
274/* Return codes:
275 0: nothing saved
276 1: stuff to save, successful
277 -1: stuff to save, error happened
278*/
279static int
280save_cpextra (struct _cpstate *buf)
281{
282#if XCHAL_CP_NUM == 0
283 return 0;
284#else
285
286 /* FIXME: If a task has never used a coprocessor, there is
287 * no need to save and restore anything. Tracking this
288 * information would allow us to optimize this section.
289 * Perhaps we can use current->used_math or (current->flags &
290 * PF_USEDFPU) or define a new field in the thread
291 * structure. */
292
293 /* We flush any live, task-owned cp state to the task_struct,
294 * then copy it all to the sigframe. Then we clear all
295 * cp/extra state in the task_struct, effectively
296 * clearing/resetting all cp/extra state for the signal
297 * handler (cp-exception handling will load these new values
298 * into the cp/extra registers.) This step is important for
299 * things like a floating-point cp, where the OS must reset
300 * the FCR to the default rounding mode. */
301
302 int err = 0;
303 struct task_struct *tsk = current;
304
305 flush_my_cpstate(tsk);
306 /* Note that we just copy everything: 'extra' and 'cp' state together.*/
307 err |= __copy_to_user(buf, tsk->thread.cp_save, XTENSA_CP_EXTRA_SIZE);
308 memset(tsk->thread.cp_save, 0, XTENSA_CP_EXTRA_SIZE);
309
310#if (XTENSA_CP_EXTRA_SIZE == 0)
311#error Sanity check on memset above, cpextra_size should not be zero.
312#endif
313
314 return err ? -1 : 1;
315#endif
316}
317
318static int
319setup_sigcontext(struct sigcontext *sc, struct _cpstate *cpstate,
320 struct pt_regs *regs, unsigned long mask)
321{
322 struct thread_struct *thread;
323 int err = 0;
324
325//printk("setup_sigcontext\n");
326#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x)
327 COPY(pc);
328 COPY(ps);
329 COPY(depc);
330 COPY(wmask);
331 COPY(lbeg);
332 COPY(lend);
333 COPY(lcount);
334 COPY(sar);
335 COPY(windowbase);
336 COPY(windowstart);
337#undef COPY
338
339 /* Save extended register state.
340 * See struct thread_struct in processor.h.
341 */
342 thread = &current->thread;
343 err |= __copy_to_user (sc->sc_areg, regs->areg, XCHAL_NUM_AREGS * 4);
344 err |= save_cpextra(cpstate);
345 err |= __put_user(err ? NULL : cpstate, &sc->sc_cpstate);
346 /* non-iBCS2 extensions.. */
347 err |= __put_user(mask, &sc->oldmask);
348 215
216 regs->syscall = -1; /* disable syscall checks */
349 return err; 217 return err;
350} 218}
351 219
352asmlinkage int xtensa_sigreturn(struct pt_regs *regs)
353{
354 struct sigframe *frame = (struct sigframe *)regs->areg[1];
355 sigset_t set;
356 if (regs->depc > 64)
357 panic ("Double exception sys_sigreturn\n");
358
359 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
360 goto badframe;
361
362 if (__get_user(set.sig[0], &frame->sc.oldmask)
363 || (_NSIG_WORDS > 1
364 && __copy_from_user(&set.sig[1], &frame->extramask,
365 sizeof(frame->extramask))))
366 goto badframe;
367
368 sigdelsetmask(&set, ~_BLOCKABLE);
369
370 spin_lock_irq(&current->sighand->siglock);
371 current->blocked = set;
372 recalc_sigpending();
373 spin_unlock_irq(&current->sighand->siglock);
374 220
375 if (restore_sigcontext(regs, &frame->sc))
376 goto badframe;
377 return regs->areg[2];
378 221
379badframe: 222/*
380 force_sig(SIGSEGV, current); 223 * Do a signal return; undo the signal stack.
381 return 0; 224 */
382}
383 225
384asmlinkage int xtensa_rt_sigreturn(struct pt_regs *regs) 226asmlinkage long xtensa_rt_sigreturn(long a0, long a1, long a2, long a3,
227 long a4, long a5, struct pt_regs *regs)
385{ 228{
386 struct rt_sigframe *frame = (struct rt_sigframe *)regs->areg[1]; 229 struct rt_sigframe __user *frame;
387 sigset_t set; 230 sigset_t set;
388 stack_t st;
389 int ret; 231 int ret;
232
390 if (regs->depc > 64) 233 if (regs->depc > 64)
391 { 234 panic("rt_sigreturn in double exception!\n");
392 printk("!!!!!!! DEPC !!!!!!!\n"); 235
393 return 0; 236 frame = (struct rt_sigframe __user *) regs->areg[1];
394 }
395 237
396 if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) 238 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
397 goto badframe; 239 goto badframe;
@@ -407,13 +249,11 @@ asmlinkage int xtensa_rt_sigreturn(struct pt_regs *regs)
407 249
408 if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) 250 if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
409 goto badframe; 251 goto badframe;
252
410 ret = regs->areg[2]; 253 ret = regs->areg[2];
411 254
412 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) 255 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->areg[1]) == -EFAULT)
413 goto badframe; 256 goto badframe;
414 /* It is more difficult to avoid calling this function than to
415 call it and ignore errors. */
416 do_sigaltstack(&st, NULL, regs->areg[1]);
417 257
418 return ret; 258 return ret;
419 259
@@ -422,77 +262,50 @@ badframe:
422 return 0; 262 return 0;
423} 263}
424 264
425/* 265
426 * Set up a signal frame.
427 */
428 266
429/* 267/*
430 * Determine which stack to use.. 268 * Set up a signal frame.
431 */ 269 */
432static inline void *
433get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
434{
435 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
436 sp = current->sas_ss_sp + current->sas_ss_size;
437
438 return (void *)((sp - frame_size) & -16ul);
439}
440
441#define USE_SIGRETURN 0
442#define USE_RT_SIGRETURN 1
443 270
444static int 271static int
445gen_return_code(unsigned char *codemem, unsigned int use_rt_sigreturn) 272gen_return_code(unsigned char *codemem)
446{ 273{
447 unsigned int retcall;
448 int err = 0; 274 int err = 0;
449 275
450#if 0 276 /*
451 /* Ignoring SA_RESTORER for now; it's supposed to be obsolete, 277 * The 12-bit immediate is really split up within the 24-bit MOVI
452 * and the xtensa glibc doesn't use it. 278 * instruction. As long as the above system call numbers fit within
279 * 8-bits, the following code works fine. See the Xtensa ISA for
280 * details.
453 */ 281 */
454 if (ka->sa.sa_flags & SA_RESTORER) {
455 regs->pr = (unsigned long) ka->sa.sa_restorer;
456 } else
457#endif /* 0 */
458 {
459
460#if (__NR_sigreturn > 255) || (__NR_rt_sigreturn > 255)
461
462/* The 12-bit immediate is really split up within the 24-bit MOVI
463 * instruction. As long as the above system call numbers fit within
464 * 8-bits, the following code works fine. See the Xtensa ISA for
465 * details.
466 */
467 282
468#error Generating the MOVI instruction below breaks! 283#if __NR_rt_sigreturn > 255
284# error Generating the MOVI instruction below breaks!
469#endif 285#endif
470 286
471 retcall = use_rt_sigreturn ? __NR_rt_sigreturn : __NR_sigreturn;
472
473#ifdef __XTENSA_EB__ /* Big Endian version */ 287#ifdef __XTENSA_EB__ /* Big Endian version */
474 /* Generate instruction: MOVI a2, retcall */ 288 /* Generate instruction: MOVI a2, __NR_rt_sigreturn */
475 err |= __put_user(0x22, &codemem[0]); 289 err |= __put_user(0x22, &codemem[0]);
476 err |= __put_user(0x0a, &codemem[1]); 290 err |= __put_user(0x0a, &codemem[1]);
477 err |= __put_user(retcall, &codemem[2]); 291 err |= __put_user(__NR_rt_sigreturn, &codemem[2]);
478 /* Generate instruction: SYSCALL */ 292 /* Generate instruction: SYSCALL */
479 err |= __put_user(0x00, &codemem[3]); 293 err |= __put_user(0x00, &codemem[3]);
480 err |= __put_user(0x05, &codemem[4]); 294 err |= __put_user(0x05, &codemem[4]);
481 err |= __put_user(0x00, &codemem[5]); 295 err |= __put_user(0x00, &codemem[5]);
482 296
483#elif defined __XTENSA_EL__ /* Little Endian version */ 297#elif defined __XTENSA_EL__ /* Little Endian version */
484 /* Generate instruction: MOVI a2, retcall */ 298 /* Generate instruction: MOVI a2, __NR_rt_sigreturn */
485 err |= __put_user(0x22, &codemem[0]); 299 err |= __put_user(0x22, &codemem[0]);
486 err |= __put_user(0xa0, &codemem[1]); 300 err |= __put_user(0xa0, &codemem[1]);
487 err |= __put_user(retcall, &codemem[2]); 301 err |= __put_user(__NR_rt_sigreturn, &codemem[2]);
488 /* Generate instruction: SYSCALL */ 302 /* Generate instruction: SYSCALL */
489 err |= __put_user(0x00, &codemem[3]); 303 err |= __put_user(0x00, &codemem[3]);
490 err |= __put_user(0x50, &codemem[4]); 304 err |= __put_user(0x50, &codemem[4]);
491 err |= __put_user(0x00, &codemem[5]); 305 err |= __put_user(0x00, &codemem[5]);
492#else 306#else
493#error Must use compiler for Xtensa processors. 307# error Must use compiler for Xtensa processors.
494#endif 308#endif
495 }
496 309
497 /* Flush generated code out of the data cache */ 310 /* Flush generated code out of the data cache */
498 311
@@ -504,97 +317,29 @@ gen_return_code(unsigned char *codemem, unsigned int use_rt_sigreturn)
504 return err; 317 return err;
505} 318}
506 319
507static void
508set_thread_state(struct pt_regs *regs, void *stack, unsigned char *retaddr,
509 void *handler, unsigned long arg1, void *arg2, void *arg3)
510{
511 /* Set up registers for signal handler */
512 start_thread(regs, (unsigned long) handler, (unsigned long) stack);
513
514 /* Set up a stack frame for a call4
515 * Note: PS.CALLINC is set to one by start_thread
516 */
517 regs->areg[4] = (((unsigned long) retaddr) & 0x3fffffff) | 0x40000000;
518 regs->areg[6] = arg1;
519 regs->areg[7] = (unsigned long) arg2;
520 regs->areg[8] = (unsigned long) arg3;
521}
522 320
523static void setup_frame(int sig, struct k_sigaction *ka, 321static void setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
524 sigset_t *set, struct pt_regs *regs) 322 sigset_t *set, struct pt_regs *regs)
525{ 323{
526 struct sigframe *frame; 324 struct rt_sigframe *frame;
527 int err = 0; 325 int err = 0;
528 int signal; 326 int signal;
327 unsigned long sp, ra;
529 328
530 frame = get_sigframe(ka, regs->areg[1], sizeof(*frame)); 329 sp = regs->areg[1];
531 if (regs->depc > 64)
532 {
533 printk("!!!!!!! DEPC !!!!!!!\n");
534 return;
535 }
536
537
538 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
539 goto give_sigsegv;
540
541 signal = current_thread_info()->exec_domain
542 && current_thread_info()->exec_domain->signal_invmap
543 && sig < 32
544 ? current_thread_info()->exec_domain->signal_invmap[sig]
545 : sig;
546
547 err |= setup_sigcontext(&frame->sc, &frame->cpstate, regs, set->sig[0]);
548 330
549 if (_NSIG_WORDS > 1) { 331 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) {
550 err |= __copy_to_user(frame->extramask, &set->sig[1], 332 sp = current->sas_ss_sp + current->sas_ss_size;
551 sizeof(frame->extramask));
552 } 333 }
553 334
554 /* Create sys_sigreturn syscall in stack frame */ 335 frame = (void *)((sp - sizeof(*frame)) & -16ul);
555 err |= gen_return_code(frame->retcode, USE_SIGRETURN);
556
557 if (err)
558 goto give_sigsegv;
559
560 /* Create signal handler execution context.
561 * Return context not modified until this point.
562 */
563 set_thread_state(regs, frame, frame->retcode,
564 ka->sa.sa_handler, signal, &frame->sc, NULL);
565
566 /* Set access mode to USER_DS. Nomenclature is outdated, but
567 * functionality is used in uaccess.h
568 */
569 set_fs(USER_DS);
570
571
572#if DEBUG_SIG
573 printk("SIG deliver (%s:%d): signal=%d sp=%p pc=%08x\n",
574 current->comm, current->pid, signal, frame, regs->pc);
575#endif
576
577 return;
578
579give_sigsegv:
580 if (sig == SIGSEGV)
581 ka->sa.sa_handler = SIG_DFL;
582 force_sig(SIGSEGV, current);
583}
584
585static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
586 sigset_t *set, struct pt_regs *regs)
587{
588 struct rt_sigframe *frame;
589 int err = 0;
590 int signal;
591 336
592 frame = get_sigframe(ka, regs->areg[1], sizeof(*frame));
593 if (regs->depc > 64) 337 if (regs->depc > 64)
594 panic ("Double exception sys_sigreturn\n"); 338 panic ("Double exception sys_sigreturn\n");
595 339
596 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 340 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) {
597 goto give_sigsegv; 341 goto give_sigsegv;
342 }
598 343
599 signal = current_thread_info()->exec_domain 344 signal = current_thread_info()->exec_domain
600 && current_thread_info()->exec_domain->signal_invmap 345 && current_thread_info()->exec_domain->signal_invmap
@@ -602,9 +347,12 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
602 ? current_thread_info()->exec_domain->signal_invmap[sig] 347 ? current_thread_info()->exec_domain->signal_invmap[sig]
603 : sig; 348 : sig;
604 349
605 err |= copy_siginfo_to_user(&frame->info, info); 350 if (ka->sa.sa_flags & SA_SIGINFO) {
351 err |= copy_siginfo_to_user(&frame->info, info);
352 }
353
354 /* Create the user context. */
606 355
607 /* Create the ucontext. */
608 err |= __put_user(0, &frame->uc.uc_flags); 356 err |= __put_user(0, &frame->uc.uc_flags);
609 err |= __put_user(0, &frame->uc.uc_link); 357 err |= __put_user(0, &frame->uc.uc_link);
610 err |= __put_user((void *)current->sas_ss_sp, 358 err |= __put_user((void *)current->sas_ss_sp,
@@ -617,16 +365,31 @@ static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
617 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); 365 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
618 366
619 /* Create sys_rt_sigreturn syscall in stack frame */ 367 /* Create sys_rt_sigreturn syscall in stack frame */
620 err |= gen_return_code(frame->retcode, USE_RT_SIGRETURN);
621 368
622 if (err) 369 err |= gen_return_code(frame->retcode);
370
371 if (err) {
623 goto give_sigsegv; 372 goto give_sigsegv;
373 }
374
624 375
625 /* Create signal handler execution context. 376 /*
377 * Create signal handler execution context.
626 * Return context not modified until this point. 378 * Return context not modified until this point.
627 */ 379 */
628 set_thread_state(regs, frame, frame->retcode, 380
629 ka->sa.sa_handler, signal, &frame->info, &frame->uc); 381 /* Set up registers for signal handler */
382 start_thread(regs, (unsigned long) ka->sa.sa_handler,
383 (unsigned long) frame);
384
385 /* Set up a stack frame for a call4
386 * Note: PS.CALLINC is set to one by start_thread
387 */
388 ra = (unsigned long) frame->retcode;
389 regs->areg[4] = (((unsigned long) ra) & 0x3fffffff) | 0x40000000;
390 regs->areg[6] = (unsigned long) signal;
391 regs->areg[7] = (unsigned long) &frame->info;
392 regs->areg[8] = (unsigned long) &frame->uc;
630 393
631 /* Set access mode to USER_DS. Nomenclature is outdated, but 394 /* Set access mode to USER_DS. Nomenclature is outdated, but
632 * functionality is used in uaccess.h 395 * functionality is used in uaccess.h
@@ -646,6 +409,48 @@ give_sigsegv:
646 force_sig(SIGSEGV, current); 409 force_sig(SIGSEGV, current);
647} 410}
648 411
412/*
413 * Atomically swap in the new signal mask, and wait for a signal.
414 */
415
416asmlinkage long xtensa_rt_sigsuspend(sigset_t __user *unewset,
417 size_t sigsetsize,
418 long a2, long a3, long a4, long a5,
419 struct pt_regs *regs)
420{
421 sigset_t saveset, newset;
422
423 /* XXX: Don't preclude handling different sized sigset_t's. */
424 if (sigsetsize != sizeof(sigset_t))
425 return -EINVAL;
426
427 if (copy_from_user(&newset, unewset, sizeof(newset)))
428 return -EFAULT;
429
430 sigdelsetmask(&newset, ~_BLOCKABLE);
431 spin_lock_irq(&current->sighand->siglock);
432 saveset = current->blocked;
433 current->blocked = newset;
434 recalc_sigpending();
435 spin_unlock_irq(&current->sighand->siglock);
436
437 regs->areg[2] = -EINTR;
438 while (1) {
439 current->state = TASK_INTERRUPTIBLE;
440 schedule();
441 if (do_signal(regs, &saveset))
442 return -EINTR;
443 }
444}
445
446asmlinkage long xtensa_sigaltstack(const stack_t __user *uss,
447 stack_t __user *uoss,
448 long a2, long a3, long a4, long a5,
449 struct pt_regs *regs)
450{
451 return do_sigaltstack(uss, uoss, regs->areg[1]);
452}
453
649 454
650 455
651/* 456/*
@@ -663,51 +468,89 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset)
663 int signr; 468 int signr;
664 struct k_sigaction ka; 469 struct k_sigaction ka;
665 470
471 if (!user_mode(regs))
472 return 0;
473
474 if (try_to_freeze())
475 goto no_signal;
476
666 if (!oldset) 477 if (!oldset)
667 oldset = &current->blocked; 478 oldset = &current->blocked;
668 479
480 task_pt_regs(current)->icountlevel = 0;
481
669 signr = get_signal_to_deliver(&info, &ka, regs, NULL); 482 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
670 483
671 /* Are we from a system call? */ 484 if (signr > 0) {
672 if (regs->syscall >= 0) { 485
673 /* If so, check system call restarting.. */ 486 /* Are we from a system call? */
674 switch (regs->areg[2]) { 487
675 case ERESTARTNOHAND: 488 if ((signed)regs->syscall >= 0) {
676 case ERESTART_RESTARTBLOCK:
677 regs->areg[2] = -EINTR;
678 break;
679 489
680 case ERESTARTSYS: 490 /* If so, check system call restarting.. */
681 if (!(ka.sa.sa_flags & SA_RESTART)) { 491
492 switch (regs->areg[2]) {
493 case -ERESTARTNOHAND:
494 case -ERESTART_RESTARTBLOCK:
682 regs->areg[2] = -EINTR; 495 regs->areg[2] = -EINTR;
683 break; 496 break;
684 } 497
685 /* fallthrough */ 498 case -ERESTARTSYS:
686 case ERESTARTNOINTR: 499 if (!(ka.sa.sa_flags & SA_RESTART)) {
687 regs->areg[2] = regs->syscall; 500 regs->areg[2] = -EINTR;
688 regs->pc -= 3; 501 break;
502 }
503 /* fallthrough */
504 case -ERESTARTNOINTR:
505 regs->areg[2] = regs->syscall;
506 regs->pc -= 3;
507 break;
508
509 default:
510 /* nothing to do */
511 if (regs->areg[2] != 0)
512 break;
513 }
689 } 514 }
690 }
691 515
692 if (signr == 0) 516 /* Whee! Actually deliver the signal. */
693 return 0; /* no signals delivered */ 517 /* Set up the stack frame */
518 setup_frame(signr, &ka, &info, oldset, regs);
694 519
695 /* Whee! Actually deliver the signal. */ 520 if (ka.sa.sa_flags & SA_ONESHOT)
521 ka.sa.sa_handler = SIG_DFL;
696 522
697 /* Set up the stack frame */ 523 spin_lock_irq(&current->sighand->siglock);
698 if (ka.sa.sa_flags & SA_SIGINFO) 524 sigorsets(&current->blocked, &current->blocked, &ka.sa.sa_mask);
699 setup_rt_frame(signr, &ka, &info, oldset, regs); 525 if (!(ka.sa.sa_flags & SA_NODEFER))
700 else 526 sigaddset(&current->blocked, signr);
701 setup_frame(signr, &ka, oldset, regs); 527 recalc_sigpending();
528 spin_unlock_irq(&current->sighand->siglock);
529 if (current->ptrace & PT_SINGLESTEP)
530 task_pt_regs(current)->icountlevel = 1;
702 531
703 if (ka.sa.sa_flags & SA_ONESHOT) 532 return 1;
704 ka.sa.sa_handler = SIG_DFL; 533 }
705 534
706 spin_lock_irq(&current->sighand->siglock); 535no_signal:
707 sigorsets(&current->blocked, &current->blocked, &ka.sa.sa_mask); 536 /* Did we come from a system call? */
708 if (!(ka.sa.sa_flags & SA_NODEFER)) 537 if ((signed) regs->syscall >= 0) {
709 sigaddset(&current->blocked, signr); 538 /* Restart the system call - no handlers present */
710 recalc_sigpending(); 539 switch (regs->areg[2]) {
711 spin_unlock_irq(&current->sighand->siglock); 540 case -ERESTARTNOHAND:
712 return 1; 541 case -ERESTARTSYS:
542 case -ERESTARTNOINTR:
543 regs->areg[2] = regs->syscall;
544 regs->pc -= 3;
545 break;
546 case -ERESTART_RESTARTBLOCK:
547 regs->areg[2] = __NR_restart_syscall;
548 regs->pc -= 3;
549 break;
550 }
551 }
552 if (current->ptrace & PT_SINGLESTEP)
553 task_pt_regs(current)->icountlevel = 1;
554 return 0;
713} 555}
556
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-01 06:24:28 -0400