diff options
author | Chris Zankel <chris@zankel.net> | 2007-06-01 00:49:32 (GMT) |
---|---|---|
committer | Chris Zankel <chris@zankel.net> | 2007-06-01 00:49:32 (GMT) |
commit | 29c4dfd92edc26c2cd2c0c64c9201d5b91d6418e (patch) | |
tree | 64b2884bb49a86f2895d9206b79bf9f64e384615 /arch | |
parent | adba09f01577ea441a761a85aacb1e43b58d35c4 (diff) | |
download | linux-29c4dfd92edc26c2cd2c0c64c9201d5b91d6418e.tar.xz |
[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')
-rw-r--r-- | arch/xtensa/kernel/asm-offsets.c | 1 | ||||
-rw-r--r-- | arch/xtensa/kernel/entry.S | 36 | ||||
-rw-r--r-- | arch/xtensa/kernel/signal.c | 795 |
3 files changed, 334 insertions, 498 deletions
diff --git a/arch/xtensa/kernel/asm-offsets.c b/arch/xtensa/kernel/asm-offsets.c index 698079b..d0323cd 100644 --- a/arch/xtensa/kernel/asm-offsets.c +++ b/arch/xtensa/kernel/asm-offsets.c @@ -39,6 +39,7 @@ int main(void) DEFINE(PT_LEND, offsetof (struct pt_regs, lend)); DEFINE(PT_LCOUNT, offsetof (struct pt_regs, lcount)); DEFINE(PT_SAR, offsetof (struct pt_regs, sar)); + DEFINE(PT_ICOUNTLEVEL, offsetof (struct pt_regs, icountlevel)); DEFINE(PT_SYSCALL, offsetof (struct pt_regs, syscall)); DEFINE(PT_AREG, offsetof (struct pt_regs, areg[0])); DEFINE(PT_AREG0, offsetof (struct pt_regs, areg[0])); diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 9e271ba..8dc7a2c 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -125,8 +125,9 @@ _user_exception: movi a2, 0 rsr a3, SAR - wsr a2, ICOUNTLEVEL + xsr a2, ICOUNTLEVEL s32i a3, a1, PT_SAR + s32i a2, a1, PT_ICOUNTLEVEL /* Rotate ws so that the current windowbase is at bit0. */ /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */ @@ -276,8 +277,9 @@ _kernel_exception: movi a2, 0 rsr a3, SAR - wsr a2, ICOUNTLEVEL + xsr a2, ICOUNTLEVEL s32i a3, a1, PT_SAR + s32i a2, a1, PT_ICOUNTLEVEL /* Rotate ws so that the current windowbase is at bit0. */ /* Assume ws = xxwww1yyyy. Rotate ws right, so that a2 = yyyyxxwww1 */ @@ -330,14 +332,16 @@ _kernel_exception: common_exception: - /* Save EXCVADDR, DEBUGCAUSE, and PC, and clear LCOUNT */ + /* Save some registers, disable loops and clear the syscall flag. */ rsr a2, DEBUGCAUSE rsr a3, EPC_1 s32i a2, a1, PT_DEBUGCAUSE s32i a3, a1, PT_PC + movi a2, -1 rsr a3, EXCVADDR + s32i a2, a1, PT_SYSCALL movi a2, 0 s32i a3, a1, PT_EXCVADDR xsr a2, LCOUNT @@ -450,27 +454,8 @@ common_exception_return: /* Restore the state of the task and return from the exception. */ - - /* If we are returning from a user exception, and the process - * to run next has PT_SINGLESTEP set, we want to setup - * ICOUNT and ICOUNTLEVEL to step one instruction. - * PT_SINGLESTEP is set by sys_ptrace (ptrace.c) - */ - 4: /* a2 holds GET_CURRENT(a2,a1) */ - l32i a3, a2, TI_TASK - l32i a3, a3, TASK_PTRACE - bbci.l a3, PT_SINGLESTEP_BIT, 1f # jump if single-step flag is not set - - movi a3, -2 # PT_SINGLESTEP flag is set, - movi a4, 1 # icountlevel of 1 means it won't - wsr a3, ICOUNT # start counting until after rfe - wsr a4, ICOUNTLEVEL # so setup icount & icountlevel. - isync - -1: - #if XCHAL_EXTRA_SA_SIZE /* For user exceptions, restore the extra state from the user's TCB. */ @@ -665,6 +650,13 @@ common_exception_exit: wsr a3, LEND wsr a2, LCOUNT + /* We control single stepping through the ICOUNTLEVEL register. */ + + l32i a2, a1, PT_ICOUNTLEVEL + movi a3, -2 + wsr a2, ICOUNTLEVEL + wsr a3, ICOUNT + /* Check if it was double exception. */ l32i a0, a1, PT_DEPC diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index 5810767..033aae0 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -1,397 +1,239 @@ -// TODO coprocessor stuff /* - * linux/arch/xtensa/kernel/signal.c + * arch/xtensa/kernel/signal.c * - * Copyright (C) 1991, 1992 Linus Torvalds - * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson - * - * Joe Taylor <joe@tensilica.com> - * Chris Zankel <chris@zankel.net> + * Default platform functions. * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. * + * Copyright (C) 2005, 2006 Tensilica Inc. + * Copyright (C) 1991, 1992 Linus Torvalds + * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson * + * Chris Zankel <chris@zankel.net> + * Joe Taylor <joe@tensilica.com> */ -#include <asm/variant/core.h> -#include <asm/coprocessor.h> -#include <linux/sched.h> -#include <linux/mm.h> -#include <linux/smp.h> -#include <linux/kernel.h> #include <linux/signal.h> #include <linux/errno.h> -#include <linux/wait.h> #include <linux/ptrace.h> -#include <linux/unistd.h> -#include <linux/stddef.h> #include <linux/personality.h> +#include <linux/freezer.h> + #include <asm/ucontext.h> #include <asm/uaccess.h> -#include <asm/pgtable.h> #include <asm/cacheflush.h> +#include <asm/coprocessor.h> +#include <asm/unistd.h> #define DEBUG_SIG 0 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) -asmlinkage long sys_wait4(pid_t pid,unsigned int * stat_addr, int options, - struct rusage * ru); asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset); extern struct task_struct *coproc_owners[]; +extern void release_all_cp (struct task_struct *); -/* - * Atomically swap in the new signal mask, and wait for a signal. +struct rt_sigframe +{ + struct siginfo info; + struct ucontext uc; + cp_state_t cpstate; + unsigned char retcode[6]; + unsigned int window[4]; +}; + +/* + * Flush register windows stored in pt_regs to stack. + * Returns 1 for errors. + * + * Note that windowbase, windowstart, and wmask are not updated! */ -int xtensa_sigsuspend(struct pt_regs *regs) +int +flush_window_regs_user(struct pt_regs *regs) { - old_sigset_t mask = (old_sigset_t) regs->areg[3]; - sigset_t saveset; + const unsigned long ws = regs->windowstart; + const unsigned long wb = regs->windowbase; + unsigned long sp = 0; + unsigned long wm; + int err = 1; + int base; - mask &= _BLOCKABLE; - spin_lock_irq(¤t->sighand->siglock); - saveset = current->blocked; - siginitset(¤t->blocked, mask); - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); + /* Return if no other frames. */ - regs->areg[2] = -EINTR; - while (1) { - current->state = TASK_INTERRUPTIBLE; - schedule(); - if (do_signal(regs, &saveset)) - return -EINTR; - } -} + if (regs->wmask == 1) + return 0; -asmlinkage int -xtensa_rt_sigsuspend(struct pt_regs *regs) -{ - sigset_t *unewset = (sigset_t *) regs->areg[4]; - size_t sigsetsize = (size_t) regs->areg[3]; - sigset_t saveset, newset; - /* XXX: Don't preclude handling different sized sigset_t's. */ - if (sigsetsize != sizeof(sigset_t)) - return -EINVAL; + /* Rotate windowmask and skip empty frames. */ - if (copy_from_user(&newset, unewset, sizeof(newset))) - return -EFAULT; - sigdelsetmask(&newset, ~_BLOCKABLE); - spin_lock_irq(¤t->sighand->siglock); - saveset = current->blocked; - current->blocked = newset; - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); + wm = (ws >> wb) | (ws << (XCHAL_NUM_AREGS / 4 - wb)); + base = (XCHAL_NUM_AREGS / 4) - (regs->wmask >> 4); + + /* For call8 or call12 frames, we need the previous stack pointer. */ - regs->areg[2] = -EINTR; - while (1) { - current->state = TASK_INTERRUPTIBLE; - schedule(); - if (do_signal(regs, &saveset)) - return -EINTR; - } -} + if ((regs->wmask & 2) == 0) + if (__get_user(sp, (int*)(regs->areg[base * 4 + 1] - 12))) + goto errout; -asmlinkage int -xtensa_sigaction(int sig, const struct old_sigaction *act, - struct old_sigaction *oact) -{ - struct k_sigaction new_ka, old_ka; - int ret; + /* Spill frames to stack. */ - if (act) { - old_sigset_t mask; - if (!access_ok(VERIFY_READ, act, sizeof(*act)) || - __get_user(new_ka.sa.sa_handler, &act->sa_handler) || - __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) - return -EFAULT; - __get_user(new_ka.sa.sa_flags, &act->sa_flags); - __get_user(mask, &act->sa_mask); - siginitset(&new_ka.sa.sa_mask, mask); - } + while (base < XCHAL_NUM_AREGS / 4) { - ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); + int m = (wm >> base); + int inc = 0; - if (!ret && oact) { - if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || - __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || - __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) - return -EFAULT; - __put_user(old_ka.sa.sa_flags, &oact->sa_flags); - __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); - } + /* Save registers a4..a7 (call8) or a4...a11 (call12) */ - return ret; -} + if (m & 2) { /* call4 */ + inc = 1; -asmlinkage int -xtensa_sigaltstack(struct pt_regs *regs) -{ - const stack_t *uss = (stack_t *) regs->areg[4]; - stack_t *uoss = (stack_t *) regs->areg[3]; + } else if (m & 4) { /* call8 */ + if (copy_to_user((void*)(sp - 32), + ®s->areg[(base + 1) * 4], 16)) + goto errout; + inc = 2; - if (regs->depc > 64) - panic ("Double exception sys_sigreturn\n"); + } else if (m & 8) { /* call12 */ + if (copy_to_user((void*)(sp - 48), + ®s->areg[(base + 1) * 4], 32)) + goto errout; + inc = 3; + } + /* Save current frame a0..a3 under next SP */ - return do_sigaltstack(uss, uoss, regs->areg[1]); -} + sp = regs->areg[((base + inc) * 4 + 1) % XCHAL_NUM_AREGS]; + if (copy_to_user((void*)(sp - 16), ®s->areg[base * 4], 16)) + goto errout; + + /* Get current stack pointer for next loop iteration. */ + + sp = regs->areg[base * 4 + 1]; + base += inc; + } + + return 0; +errout: + return err; +} /* - * Do a signal return; undo the signal stack. + * Note: We don't copy double exception 'regs', 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... */ -struct sigframe -{ - struct sigcontext sc; - struct _cpstate cpstate; - unsigned long extramask[_NSIG_WORDS-1]; - unsigned char retcode[6]; - unsigned int reserved[4]; /* Reserved area for chaining */ - unsigned int window[4]; /* Window of 4 registers for initial context */ -}; - -struct rt_sigframe +static int +setup_sigcontext(struct sigcontext __user *sc, cp_state_t *cpstate, + struct pt_regs *regs, unsigned long mask) { - struct siginfo info; - struct ucontext uc; - struct _cpstate cpstate; - unsigned char retcode[6]; - unsigned int reserved[4]; /* Reserved area for chaining */ - unsigned int window[4]; /* Window of 4 registers for initial context */ -}; + int err = 0; -extern void release_all_cp (struct task_struct *); +#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x) + COPY(pc); + COPY(ps); + COPY(lbeg); + COPY(lend); + COPY(lcount); + COPY(sar); +#undef COPY + err |= flush_window_regs_user(regs); + err |= __copy_to_user (sc->sc_a, regs->areg, 16 * 4); -// FIXME restore_cpextra -static inline int -restore_cpextra (struct _cpstate *buf) -{ -#if 0 - /* The signal handler may have used coprocessors in which - * case they are still enabled. We disable them to force a - * reloading of the original task's CP state by the lazy - * context-switching mechanisms of CP exception handling. - * Also, we essentially discard any coprocessor state that the - * signal handler created. */ + // err |= __copy_to_user (sc->sc_a, regs->areg, XCHAL_NUM_AREGS * 4) - struct task_struct *tsk = current; - release_all_cp(tsk); - return __copy_from_user(tsk->thread.cpextra, buf, XTENSA_CP_EXTRA_SIZE); +#if XCHAL_HAVE_CP +# error Coprocessors unsupported + err |= save_cpextra(cpstate); + err |= __put_user(err ? NULL : cpstate, &sc->sc_cpstate); #endif - return 0; -} - -/* 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... - */ + /* non-iBCS2 extensions.. */ + err |= __put_user(mask, &sc->oldmask); + return err; +} static int -restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc) +restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { - struct thread_struct *thread; unsigned int err = 0; unsigned long ps; - struct _cpstate *buf; #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) COPY(pc); - COPY(depc); - COPY(wmask); COPY(lbeg); COPY(lend); COPY(lcount); COPY(sar); - COPY(windowbase); - COPY(windowstart); #undef COPY + /* All registers were flushed to stack. Start with a prestine frame. */ + + regs->wmask = 1; + regs->windowbase = 0; + regs->windowstart = 1; + /* For PS, restore only PS.CALLINC. * Assume that all other bits are either the same as for the signal * handler, or the user mode value doesn't matter (e.g. PS.OWB). */ err |= __get_user(ps, &sc->sc_ps); - regs->ps = (regs->ps & ~PS_CALLINC_MASK) - | (ps & PS_CALLINC_MASK); + regs->ps = (regs->ps & ~PS_CALLINC_MASK) | (ps & PS_CALLINC_MASK); /* Additional corruption checks */ - if ((regs->windowbase >= (XCHAL_NUM_AREGS/4)) - || ((regs->windowstart & ~((1<<(XCHAL_NUM_AREGS/4)) - 1)) != 0) ) - err = 1; if ((regs->lcount > 0) - && ((regs->lbeg > TASK_SIZE) || (regs->lend > TASK_SIZE)) ) + && ((regs->lbeg > TASK_SIZE) || (regs->lend > TASK_SIZE)) ) err = 1; - /* Restore extended register state. - * See struct thread_struct in processor.h. - */ - thread = ¤t->thread; - - err |= __copy_from_user (regs->areg, sc->sc_areg, XCHAL_NUM_AREGS*4); - err |= __get_user(buf, &sc->sc_cpstate); - if (buf) { - if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) - goto badframe; - err |= restore_cpextra(buf); - } - - regs->syscall = -1; /* disable syscall checks */ - return err; - -badframe: - return 1; -} - -static inline void -flush_my_cpstate(struct task_struct *tsk) -{ - unsigned long flags; - local_irq_save(flags); - -#if 0 // FIXME - for (i = 0; i < XCHAL_CP_NUM; i++) { - if (tsk == coproc_owners[i]) { - xthal_validate_cp(i); - xthal_save_cpregs(tsk->thread.cpregs_ptr[i], i); + err |= __copy_from_user(regs->areg, sc->sc_a, 16 * 4); - /* Invalidate and "disown" the cp to allow - * callers the chance to reset cp state in the - * task_struct. */ +#if XCHAL_HAVE_CP +# error Coprocessors unsupported + /* The signal handler may have used coprocessors in which + * case they are still enabled. We disable them to force a + * reloading of the original task's CP state by the lazy + * context-switching mechanisms of CP exception handling. + * Also, we essentially discard any coprocessor state that the + * signal handler created. */ - xthal_invalidate_cp(i); - coproc_owners[i] = 0; - } + if (!err) { + struct task_struct *tsk = current; + release_all_cp(tsk); + err |= __copy_from_user(tsk->thread.cpextra, sc->sc_cpstate, + XTENSA_CP_EXTRA_SIZE); } #endif - local_irq_restore(flags); -} - -/* Return codes: - 0: nothing saved - 1: stuff to save, successful - -1: stuff to save, error happened -*/ -static int -save_cpextra (struct _cpstate *buf) -{ -#if XCHAL_CP_NUM == 0 - return 0; -#else - - /* FIXME: If a task has never used a coprocessor, there is - * no need to save and restore anything. Tracking this - * information would allow us to optimize this section. - * Perhaps we can use current->used_math or (current->flags & - * PF_USEDFPU) or define a new field in the thread - * structure. */ - - /* We flush any live, task-owned cp state to the task_struct, - * then copy it all to the sigframe. Then we clear all - * cp/extra state in the task_struct, effectively - * clearing/resetting all cp/extra state for the signal - * handler (cp-exception handling will load these new values - * into the cp/extra registers.) This step is important for - * things like a floating-point cp, where the OS must reset - * the FCR to the default rounding mode. */ - - int err = 0; - struct task_struct *tsk = current; - - flush_my_cpstate(tsk); - /* Note that we just copy everything: 'extra' and 'cp' state together.*/ - err |= __copy_to_user(buf, tsk->thread.cp_save, XTENSA_CP_EXTRA_SIZE); - memset(tsk->thread.cp_save, 0, XTENSA_CP_EXTRA_SIZE); - -#if (XTENSA_CP_EXTRA_SIZE == 0) -#error Sanity check on memset above, cpextra_size should not be zero. -#endif - - return err ? -1 : 1; -#endif -} - -static int -setup_sigcontext(struct sigcontext *sc, struct _cpstate *cpstate, - struct pt_regs *regs, unsigned long mask) -{ - struct thread_struct *thread; - int err = 0; - -//printk("setup_sigcontext\n"); -#define COPY(x) err |= __put_user(regs->x, &sc->sc_##x) - COPY(pc); - COPY(ps); - COPY(depc); - COPY(wmask); - COPY(lbeg); - COPY(lend); - COPY(lcount); - COPY(sar); - COPY(windowbase); - COPY(windowstart); -#undef COPY - - /* Save extended register state. - * See struct thread_struct in processor.h. - */ - thread = ¤t->thread; - err |= __copy_to_user (sc->sc_areg, regs->areg, XCHAL_NUM_AREGS * 4); - err |= save_cpextra(cpstate); - err |= __put_user(err ? NULL : cpstate, &sc->sc_cpstate); - /* non-iBCS2 extensions.. */ - err |= __put_user(mask, &sc->oldmask); + regs->syscall = -1; /* disable syscall checks */ return err; } -asmlinkage int xtensa_sigreturn(struct pt_regs *regs) -{ - struct sigframe *frame = (struct sigframe *)regs->areg[1]; - sigset_t set; - if (regs->depc > 64) - panic ("Double exception sys_sigreturn\n"); - - if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) - goto badframe; - - if (__get_user(set.sig[0], &frame->sc.oldmask) - || (_NSIG_WORDS > 1 - && __copy_from_user(&set.sig[1], &frame->extramask, - sizeof(frame->extramask)))) - goto badframe; - - sigdelsetmask(&set, ~_BLOCKABLE); - - spin_lock_irq(¤t->sighand->siglock); - current->blocked = set; - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); - if (restore_sigcontext(regs, &frame->sc)) - goto badframe; - return regs->areg[2]; -badframe: - force_sig(SIGSEGV, current); - return 0; -} +/* + * Do a signal return; undo the signal stack. + */ -asmlinkage int xtensa_rt_sigreturn(struct pt_regs *regs) +asmlinkage long xtensa_rt_sigreturn(long a0, long a1, long a2, long a3, + long a4, long a5, struct pt_regs *regs) { - struct rt_sigframe *frame = (struct rt_sigframe *)regs->areg[1]; + struct rt_sigframe __user *frame; sigset_t set; - stack_t st; int ret; + if (regs->depc > 64) - { - printk("!!!!!!! DEPC !!!!!!!\n"); - return 0; - } + panic("rt_sigreturn in double exception!\n"); + + frame = (struct rt_sigframe __user *) regs->areg[1]; if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) goto badframe; @@ -407,13 +249,11 @@ asmlinkage int xtensa_rt_sigreturn(struct pt_regs *regs) if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) goto badframe; + ret = regs->areg[2]; - if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st))) + if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->areg[1]) == -EFAULT) goto badframe; - /* It is more difficult to avoid calling this function than to - call it and ignore errors. */ - do_sigaltstack(&st, NULL, regs->areg[1]); return ret; @@ -422,77 +262,50 @@ badframe: return 0; } -/* - * Set up a signal frame. - */ + /* - * Determine which stack to use.. + * Set up a signal frame. */ -static inline void * -get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) -{ - if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) - sp = current->sas_ss_sp + current->sas_ss_size; - - return (void *)((sp - frame_size) & -16ul); -} - -#define USE_SIGRETURN 0 -#define USE_RT_SIGRETURN 1 static int -gen_return_code(unsigned char *codemem, unsigned int use_rt_sigreturn) +gen_return_code(unsigned char *codemem) { - unsigned int retcall; int err = 0; -#if 0 - /* Ignoring SA_RESTORER for now; it's supposed to be obsolete, - * and the xtensa glibc doesn't use it. + /* + * The 12-bit immediate is really split up within the 24-bit MOVI + * instruction. As long as the above system call numbers fit within + * 8-bits, the following code works fine. See the Xtensa ISA for + * details. */ - if (ka->sa.sa_flags & SA_RESTORER) { - regs->pr = (unsigned long) ka->sa.sa_restorer; - } else -#endif /* 0 */ - { - -#if (__NR_sigreturn > 255) || (__NR_rt_sigreturn > 255) - -/* The 12-bit immediate is really split up within the 24-bit MOVI - * instruction. As long as the above system call numbers fit within - * 8-bits, the following code works fine. See the Xtensa ISA for - * details. - */ -#error Generating the MOVI instruction below breaks! +#if __NR_rt_sigreturn > 255 +# error Generating the MOVI instruction below breaks! #endif - retcall = use_rt_sigreturn ? __NR_rt_sigreturn : __NR_sigreturn; - #ifdef __XTENSA_EB__ /* Big Endian version */ - /* Generate instruction: MOVI a2, retcall */ - err |= __put_user(0x22, &codemem[0]); - err |= __put_user(0x0a, &codemem[1]); - err |= __put_user(retcall, &codemem[2]); - /* Generate instruction: SYSCALL */ - err |= __put_user(0x00, &codemem[3]); - err |= __put_user(0x05, &codemem[4]); - err |= __put_user(0x00, &codemem[5]); + /* Generate instruction: MOVI a2, __NR_rt_sigreturn */ + err |= __put_user(0x22, &codemem[0]); + err |= __put_user(0x0a, &codemem[1]); + err |= __put_user(__NR_rt_sigreturn, &codemem[2]); + /* Generate instruction: SYSCALL */ + err |= __put_user(0x00, &codemem[3]); + err |= __put_user(0x05, &codemem[4]); + err |= __put_user(0x00, &codemem[5]); #elif defined __XTENSA_EL__ /* Little Endian version */ - /* Generate instruction: MOVI a2, retcall */ - err |= __put_user(0x22, &codemem[0]); - err |= __put_user(0xa0, &codemem[1]); - err |= __put_user(retcall, &codemem[2]); - /* Generate instruction: SYSCALL */ - err |= __put_user(0x00, &codemem[3]); - err |= __put_user(0x50, &codemem[4]); - err |= __put_user(0x00, &codemem[5]); + /* Generate instruction: MOVI a2, __NR_rt_sigreturn */ + err |= __put_user(0x22, &codemem[0]); + err |= __put_user(0xa0, &codemem[1]); + err |= __put_user(__NR_rt_sigreturn, &codemem[2]); + /* Generate instruction: SYSCALL */ + err |= __put_user(0x00, &codemem[3]); + err |= __put_user(0x50, &codemem[4]); + err |= __put_user(0x00, &codemem[5]); #else -#error Must use compiler for Xtensa processors. +# error Must use compiler for Xtensa processors. #endif - } /* Flush generated code out of the data cache */ @@ -504,97 +317,29 @@ gen_return_code(unsigned char *codemem, unsigned int use_rt_sigreturn) return err; } -static void -set_thread_state(struct pt_regs *regs, void *stack, unsigned char *retaddr, - void *handler, unsigned long arg1, void *arg2, void *arg3) -{ - /* Set up registers for signal handler */ - start_thread(regs, (unsigned long) handler, (unsigned long) stack); - - /* Set up a stack frame for a call4 - * Note: PS.CALLINC is set to one by start_thread - */ - regs->areg[4] = (((unsigned long) retaddr) & 0x3fffffff) | 0x40000000; - regs->areg[6] = arg1; - regs->areg[7] = (unsigned long) arg2; - regs->areg[8] = (unsigned long) arg3; -} -static void setup_frame(int sig, struct k_sigaction *ka, +static void setup_frame(int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct pt_regs *regs) { - struct sigframe *frame; + struct rt_sigframe *frame; int err = 0; int signal; + unsigned long sp, ra; - frame = get_sigframe(ka, regs->areg[1], sizeof(*frame)); - if (regs->depc > 64) - { - printk("!!!!!!! DEPC !!!!!!!\n"); - return; - } - - - if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) - goto give_sigsegv; - - signal = current_thread_info()->exec_domain - && current_thread_info()->exec_domain->signal_invmap - && sig < 32 - ? current_thread_info()->exec_domain->signal_invmap[sig] - : sig; - - err |= setup_sigcontext(&frame->sc, &frame->cpstate, regs, set->sig[0]); + sp = regs->areg[1]; - if (_NSIG_WORDS > 1) { - err |= __copy_to_user(frame->extramask, &set->sig[1], - sizeof(frame->extramask)); + if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) { + sp = current->sas_ss_sp + current->sas_ss_size; } - /* Create sys_sigreturn syscall in stack frame */ - err |= gen_return_code(frame->retcode, USE_SIGRETURN); - - if (err) - goto give_sigsegv; - - /* Create signal handler execution context. - * Return context not modified until this point. - */ - set_thread_state(regs, frame, frame->retcode, - ka->sa.sa_handler, signal, &frame->sc, NULL); - - /* Set access mode to USER_DS. Nomenclature is outdated, but - * functionality is used in uaccess.h - */ - set_fs(USER_DS); - - -#if DEBUG_SIG - printk("SIG deliver (%s:%d): signal=%d sp=%p pc=%08x\n", - current->comm, current->pid, signal, frame, regs->pc); -#endif - - return; - -give_sigsegv: - if (sig == SIGSEGV) - ka->sa.sa_handler = SIG_DFL; - force_sig(SIGSEGV, current); -} - -static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, - sigset_t *set, struct pt_regs *regs) -{ - struct rt_sigframe *frame; - int err = 0; - int signal; + frame = (void *)((sp - sizeof(*frame)) & -16ul); - frame = get_sigframe(ka, regs->areg[1], sizeof(*frame)); if (regs->depc > 64) panic ("Double exception sys_sigreturn\n"); - if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) + if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) { goto give_sigsegv; + } signal = current_thread_info()->exec_domain && 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, ? current_thread_info()->exec_domain->signal_invmap[sig] : sig; - err |= copy_siginfo_to_user(&frame->info, info); + if (ka->sa.sa_flags & SA_SIGINFO) { + err |= copy_siginfo_to_user(&frame->info, info); + } + + /* Create the user context. */ - /* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); 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, err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); /* Create sys_rt_sigreturn syscall in stack frame */ - err |= gen_return_code(frame->retcode, USE_RT_SIGRETURN); - if (err) + err |= gen_return_code(frame->retcode); + + if (err) { goto give_sigsegv; + } + - /* Create signal handler execution context. + /* + * Create signal handler execution context. * Return context not modified until this point. */ - set_thread_state(regs, frame, frame->retcode, - ka->sa.sa_handler, signal, &frame->info, &frame->uc); + + /* Set up registers for signal handler */ + start_thread(regs, (unsigned long) ka->sa.sa_handler, + (unsigned long) frame); + + /* Set up a stack frame for a call4 + * Note: PS.CALLINC is set to one by start_thread + */ + ra = (unsigned long) frame->retcode; + regs->areg[4] = (((unsigned long) ra) & 0x3fffffff) | 0x40000000; + regs->areg[6] = (unsigned long) signal; + regs->areg[7] = (unsigned long) &frame->info; + regs->areg[8] = (unsigned long) &frame->uc; /* Set access mode to USER_DS. Nomenclature is outdated, but * functionality is used in uaccess.h @@ -646,6 +409,48 @@ give_sigsegv: force_sig(SIGSEGV, current); } +/* + * Atomically swap in the new signal mask, and wait for a signal. + */ + +asmlinkage long xtensa_rt_sigsuspend(sigset_t __user *unewset, + size_t sigsetsize, + long a2, long a3, long a4, long a5, + struct pt_regs *regs) +{ + sigset_t saveset, newset; + + /* XXX: Don't preclude handling different sized sigset_t's. */ + if (sigsetsize != sizeof(sigset_t)) + return -EINVAL; + + if (copy_from_user(&newset, unewset, sizeof(newset))) + return -EFAULT; + + sigdelsetmask(&newset, ~_BLOCKABLE); + spin_lock_irq(¤t->sighand->siglock); + saveset = current->blocked; + current->blocked = newset; + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + + regs->areg[2] = -EINTR; + while (1) { + current->state = TASK_INTERRUPTIBLE; + schedule(); + if (do_signal(regs, &saveset)) + return -EINTR; + } +} + +asmlinkage long xtensa_sigaltstack(const stack_t __user *uss, + stack_t __user *uoss, + long a2, long a3, long a4, long a5, + struct pt_regs *regs) +{ + return do_sigaltstack(uss, uoss, regs->areg[1]); +} + /* @@ -663,51 +468,89 @@ int do_signal(struct pt_regs *regs, sigset_t *oldset) int signr; struct k_sigaction ka; + if (!user_mode(regs)) + return 0; + + if (try_to_freeze()) + goto no_signal; + if (!oldset) oldset = ¤t->blocked; + task_pt_regs(current)->icountlevel = 0; + signr = get_signal_to_deliver(&info, &ka, regs, NULL); - /* Are we from a system call? */ - if (regs->syscall >= 0) { - /* If so, check system call restarting.. */ - switch (regs->areg[2]) { - case ERESTARTNOHAND: - case ERESTART_RESTARTBLOCK: - regs->areg[2] = -EINTR; - break; + if (signr > 0) { + + /* Are we from a system call? */ + + if ((signed)regs->syscall >= 0) { - case ERESTARTSYS: - if (!(ka.sa.sa_flags & SA_RESTART)) { + /* If so, check system call restarting.. */ + + switch (regs->areg[2]) { + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: regs->areg[2] = -EINTR; break; - } - /* fallthrough */ - case ERESTARTNOINTR: - regs->areg[2] = regs->syscall; - regs->pc -= 3; + + case -ERESTARTSYS: + if (!(ka.sa.sa_flags & SA_RESTART)) { + regs->areg[2] = -EINTR; + break; + } + /* fallthrough */ + case -ERESTARTNOINTR: + regs->areg[2] = regs->syscall; + regs->pc -= 3; + break; + + default: + /* nothing to do */ + if (regs->areg[2] != 0) + break; + } } - } - if (signr == 0) - return 0; /* no signals delivered */ + /* Whee! Actually deliver the signal. */ + /* Set up the stack frame */ + setup_frame(signr, &ka, &info, oldset, regs); - /* Whee! Actually deliver the signal. */ + if (ka.sa.sa_flags & SA_ONESHOT) + ka.sa.sa_handler = SIG_DFL; - /* Set up the stack frame */ - if (ka.sa.sa_flags & SA_SIGINFO) - setup_rt_frame(signr, &ka, &info, oldset, regs); - else - setup_frame(signr, &ka, oldset, regs); + spin_lock_irq(¤t->sighand->siglock); + sigorsets(¤t->blocked, ¤t->blocked, &ka.sa.sa_mask); + if (!(ka.sa.sa_flags & SA_NODEFER)) + sigaddset(¤t->blocked, signr); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + if (current->ptrace & PT_SINGLESTEP) + task_pt_regs(current)->icountlevel = 1; - if (ka.sa.sa_flags & SA_ONESHOT) - ka.sa.sa_handler = SIG_DFL; + return 1; + } - spin_lock_irq(¤t->sighand->siglock); - sigorsets(¤t->blocked, ¤t->blocked, &ka.sa.sa_mask); - if (!(ka.sa.sa_flags & SA_NODEFER)) - sigaddset(¤t->blocked, signr); - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); - return 1; +no_signal: + /* Did we come from a system call? */ + if ((signed) regs->syscall >= 0) { + /* Restart the system call - no handlers present */ + switch (regs->areg[2]) { + case -ERESTARTNOHAND: + case -ERESTARTSYS: + case -ERESTARTNOINTR: + regs->areg[2] = regs->syscall; + regs->pc -= 3; + break; + case -ERESTART_RESTARTBLOCK: + regs->areg[2] = __NR_restart_syscall; + regs->pc -= 3; + break; + } + } + if (current->ptrace & PT_SINGLESTEP) + task_pt_regs(current)->icountlevel = 1; + return 0; } + |