diff options
Diffstat (limited to 'arch/arm/kernel/signal.c')
| -rw-r--r-- | arch/arm/kernel/signal.c | 802 |
1 files changed, 340 insertions, 462 deletions
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c index a94d75fef59..bd198343720 100644 --- a/arch/arm/kernel/signal.c +++ b/arch/arm/kernel/signal.c @@ -1,300 +1,186 @@ /* * linux/arch/arm/kernel/signal.c * - * Copyright (C) 1995-2002 Russell King + * Copyright (C) 1995-2009 Russell King * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ -#include <linux/config.h> #include <linux/errno.h> +#include <linux/random.h> #include <linux/signal.h> -#include <linux/ptrace.h> #include <linux/personality.h> +#include <linux/uaccess.h> +#include <linux/tracehook.h> +#include <linux/uprobes.h> +#include <asm/elf.h> #include <asm/cacheflush.h> +#include <asm/traps.h> #include <asm/ucontext.h> -#include <asm/uaccess.h> #include <asm/unistd.h> +#include <asm/vfp.h> -#include "ptrace.h" -#include "signal.h" +extern const unsigned long sigreturn_codes[7]; -#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) +static unsigned long signal_return_offset; -/* - * For ARM syscalls, we encode the syscall number into the instruction. - */ -#define SWI_SYS_SIGRETURN (0xef000000|(__NR_sigreturn)) -#define SWI_SYS_RT_SIGRETURN (0xef000000|(__NR_rt_sigreturn)) - -/* - * For Thumb syscalls, we pass the syscall number via r7. We therefore - * need two 16-bit instructions. - */ -#define SWI_THUMB_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE)) -#define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE)) - -const unsigned long sigreturn_codes[4] = { - SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN, - SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN -}; - -static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall); - -/* - * atomically swap in the new signal mask, and wait for a signal. - */ -asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs) +#ifdef CONFIG_CRUNCH +static int preserve_crunch_context(struct crunch_sigframe __user *frame) { - sigset_t saveset; - - mask &= _BLOCKABLE; - spin_lock_irq(¤t->sighand->siglock); - saveset = current->blocked; - siginitset(¤t->blocked, mask); - recalc_sigpending(); - spin_unlock_irq(¤t->sighand->siglock); - regs->ARM_r0 = -EINTR; - - while (1) { - current->state = TASK_INTERRUPTIBLE; - schedule(); - if (do_signal(&saveset, regs, 0)) - return regs->ARM_r0; - } + char kbuf[sizeof(*frame) + 8]; + struct crunch_sigframe *kframe; + + /* the crunch context must be 64 bit aligned */ + kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7); + kframe->magic = CRUNCH_MAGIC; + kframe->size = CRUNCH_STORAGE_SIZE; + crunch_task_copy(current_thread_info(), &kframe->storage); + return __copy_to_user(frame, kframe, sizeof(*frame)); } -asmlinkage int -sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs) +static int restore_crunch_context(struct crunch_sigframe __user *frame) { - 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->ARM_r0 = -EINTR; - - while (1) { - current->state = TASK_INTERRUPTIBLE; - schedule(); - if (do_signal(&saveset, regs, 0)) - return regs->ARM_r0; - } -} - -asmlinkage int -sys_sigaction(int sig, const struct old_sigaction __user *act, - struct old_sigaction __user *oact) -{ - struct k_sigaction new_ka, old_ka; - int ret; - - 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); - } - - ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); - - 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); - } - - return ret; + char kbuf[sizeof(*frame) + 8]; + struct crunch_sigframe *kframe; + + /* the crunch context must be 64 bit aligned */ + kframe = (struct crunch_sigframe *)((unsigned long)(kbuf + 8) & ~7); + if (__copy_from_user(kframe, frame, sizeof(*frame))) + return -1; + if (kframe->magic != CRUNCH_MAGIC || + kframe->size != CRUNCH_STORAGE_SIZE) + return -1; + crunch_task_restore(current_thread_info(), &kframe->storage); + return 0; } +#endif #ifdef CONFIG_IWMMXT -/* iwmmxt_area is 0x98 bytes long, preceeded by 8 bytes of signature */ -#define IWMMXT_STORAGE_SIZE (0x98 + 8) -#define IWMMXT_MAGIC0 0x12ef842a -#define IWMMXT_MAGIC1 0x1c07ca71 - -struct iwmmxt_sigframe { - unsigned long magic0; - unsigned long magic1; - unsigned long storage[0x98/4]; -}; - -static int page_present(struct mm_struct *mm, void __user *uptr, int wr) +static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame) { - unsigned long addr = (unsigned long)uptr; - pgd_t *pgd = pgd_offset(mm, addr); - if (pgd_present(*pgd)) { - pmd_t *pmd = pmd_offset(pgd, addr); - if (pmd_present(*pmd)) { - pte_t *pte = pte_offset_map(pmd, addr); - return (pte_present(*pte) && (!wr || pte_write(*pte))); - } - } - return 0; + char kbuf[sizeof(*frame) + 8]; + struct iwmmxt_sigframe *kframe; + + /* the iWMMXt context must be 64 bit aligned */ + kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); + kframe->magic = IWMMXT_MAGIC; + kframe->size = IWMMXT_STORAGE_SIZE; + iwmmxt_task_copy(current_thread_info(), &kframe->storage); + return __copy_to_user(frame, kframe, sizeof(*frame)); } -static int copy_locked(void __user *uptr, void *kptr, size_t size, int write, - void (*copyfn)(void *, void __user *)) +static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) { - unsigned char v, __user *userptr = uptr; - int err = 0; - - do { - struct mm_struct *mm; + char kbuf[sizeof(*frame) + 8]; + struct iwmmxt_sigframe *kframe; - if (write) { - __put_user_error(0, userptr, err); - __put_user_error(0, userptr + size - 1, err); - } else { - __get_user_error(v, userptr, err); - __get_user_error(v, userptr + size - 1, err); - } - - if (err) - break; + /* the iWMMXt context must be 64 bit aligned */ + kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7); + if (__copy_from_user(kframe, frame, sizeof(*frame))) + return -1; + if (kframe->magic != IWMMXT_MAGIC || + kframe->size != IWMMXT_STORAGE_SIZE) + return -1; + iwmmxt_task_restore(current_thread_info(), &kframe->storage); + return 0; +} - mm = current->mm; - spin_lock(&mm->page_table_lock); - if (page_present(mm, userptr, write) && - page_present(mm, userptr + size - 1, write)) { - copyfn(kptr, uptr); - } else - err = 1; - spin_unlock(&mm->page_table_lock); - } while (err); +#endif - return err; -} +#ifdef CONFIG_VFP -static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame) +static int preserve_vfp_context(struct vfp_sigframe __user *frame) { + const unsigned long magic = VFP_MAGIC; + const unsigned long size = VFP_STORAGE_SIZE; int err = 0; - /* the iWMMXt context must be 64 bit aligned */ - WARN_ON((unsigned long)frame & 7); + __put_user_error(magic, &frame->magic, err); + __put_user_error(size, &frame->size, err); - __put_user_error(IWMMXT_MAGIC0, &frame->magic0, err); - __put_user_error(IWMMXT_MAGIC1, &frame->magic1, err); + if (err) + return -EFAULT; - /* - * iwmmxt_task_copy() doesn't check user permissions. - * Let's do a dummy write on the upper boundary to ensure - * access to user mem is OK all way up. - */ - err |= copy_locked(&frame->storage, current_thread_info(), - sizeof(frame->storage), 1, iwmmxt_task_copy); - return err; + return vfp_preserve_user_clear_hwstate(&frame->ufp, &frame->ufp_exc); } -static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame) +static int restore_vfp_context(struct vfp_sigframe __user *frame) { - unsigned long magic0, magic1; + unsigned long magic; + unsigned long size; int err = 0; - /* the iWMMXt context is 64 bit aligned */ - WARN_ON((unsigned long)frame & 7); + __get_user_error(magic, &frame->magic, err); + __get_user_error(size, &frame->size, err); - /* - * Validate iWMMXt context signature. - * Also, iwmmxt_task_restore() doesn't check user permissions. - * Let's do a dummy write on the upper boundary to ensure - * access to user mem is OK all way up. - */ - __get_user_error(magic0, &frame->magic0, err); - __get_user_error(magic1, &frame->magic1, err); - if (!err && magic0 == IWMMXT_MAGIC0 && magic1 == IWMMXT_MAGIC1) - err = copy_locked(&frame->storage, current_thread_info(), - sizeof(frame->storage), 0, iwmmxt_task_restore); - return err; + if (err) + return -EFAULT; + if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE) + return -EINVAL; + + return vfp_restore_user_hwstate(&frame->ufp, &frame->ufp_exc); } #endif /* - * Auxiliary signal frame. This saves stuff like FP state. - * The layout of this structure is not part of the user ABI. - */ -struct aux_sigframe { -#ifdef CONFIG_IWMMXT - struct iwmmxt_sigframe iwmmxt; -#endif -#ifdef CONFIG_VFP - union vfp_state vfp; -#endif -}; - -/* * Do a signal return; undo the signal stack. These are aligned to 64-bit. */ struct sigframe { - struct sigcontext sc; - unsigned long extramask[_NSIG_WORDS-1]; - unsigned long retcode; - struct aux_sigframe aux __attribute__((aligned(8))); + struct ucontext uc; + unsigned long retcode[2]; }; struct rt_sigframe { - struct siginfo __user *pinfo; - void __user *puc; struct siginfo info; - struct ucontext uc; - unsigned long retcode; - struct aux_sigframe aux __attribute__((aligned(8))); + struct sigframe sig; }; -static int -restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, - struct aux_sigframe __user *aux) +static int restore_sigframe(struct pt_regs *regs, struct sigframe __user *sf) { - int err = 0; + struct aux_sigframe __user *aux; + sigset_t set; + int err; - __get_user_error(regs->ARM_r0, &sc->arm_r0, err); - __get_user_error(regs->ARM_r1, &sc->arm_r1, err); - __get_user_error(regs->ARM_r2, &sc->arm_r2, err); - __get_user_error(regs->ARM_r3, &sc->arm_r3, err); - __get_user_error(regs->ARM_r4, &sc->arm_r4, err); - __get_user_error(regs->ARM_r5, &sc->arm_r5, err); - __get_user_error(regs->ARM_r6, &sc->arm_r6, err); - __get_user_error(regs->ARM_r7, &sc->arm_r7, err); - __get_user_error(regs->ARM_r8, &sc->arm_r8, err); - __get_user_error(regs->ARM_r9, &sc->arm_r9, err); - __get_user_error(regs->ARM_r10, &sc->arm_r10, err); - __get_user_error(regs->ARM_fp, &sc->arm_fp, err); - __get_user_error(regs->ARM_ip, &sc->arm_ip, err); - __get_user_error(regs->ARM_sp, &sc->arm_sp, err); - __get_user_error(regs->ARM_lr, &sc->arm_lr, err); - __get_user_error(regs->ARM_pc, &sc->arm_pc, err); - __get_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err); + err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); + if (err == 0) + set_current_blocked(&set); + + __get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); + __get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); + __get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err); + __get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err); + __get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err); + __get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err); + __get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err); + __get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err); + __get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err); + __get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err); + __get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err); + __get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err); + __get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err); + __get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err); + __get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err); + __get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err); + __get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err); err |= !valid_user_regs(regs); + aux = (struct aux_sigframe __user *) sf->uc.uc_regspace; +#ifdef CONFIG_CRUNCH + if (err == 0) + err |= restore_crunch_context(&aux->crunch); +#endif #ifdef CONFIG_IWMMXT if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) err |= restore_iwmmxt_context(&aux->iwmmxt); #endif #ifdef CONFIG_VFP -// if (err == 0) -// err |= vfp_restore_state(&aux->vfp); + if (err == 0) + err |= restore_vfp_context(&aux->vfp); #endif return err; @@ -303,7 +189,6 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, asmlinkage int sys_sigreturn(struct pt_regs *regs) { struct sigframe __user *frame; - sigset_t set; /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; @@ -320,27 +205,10 @@ asmlinkage int sys_sigreturn(struct pt_regs *regs) 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, &frame->aux)) + if (restore_sigframe(regs, frame)) goto badframe; - /* Send SIGTRAP if we're single-stepping */ - if (current->ptrace & PT_SINGLESTEP) { - ptrace_cancel_bpt(current); - send_sig(SIGTRAP, current, 1); - } - return regs->ARM_r0; badframe: @@ -351,7 +219,6 @@ badframe: asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) { struct rt_sigframe __user *frame; - sigset_t set; /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; @@ -368,27 +235,13 @@ asmlinkage int sys_rt_sigreturn(struct pt_regs *regs) if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) goto badframe; - if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) - 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->uc.uc_mcontext, &frame->aux)) + if (restore_sigframe(regs, &frame->sig)) goto badframe; - if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT) + if (restore_altstack(&frame->sig.uc.uc_stack)) goto badframe; - /* Send SIGTRAP if we're single-stepping */ - if (current->ptrace & PT_SINGLESTEP) { - ptrace_cancel_bpt(current); - send_sig(SIGTRAP, current, 1); - } - return regs->ARM_r0; badframe: @@ -397,59 +250,61 @@ badframe: } static int -setup_sigcontext(struct sigcontext __user *sc, struct aux_sigframe __user *aux, - struct pt_regs *regs, unsigned long mask) +setup_sigframe(struct sigframe __user *sf, struct pt_regs *regs, sigset_t *set) { + struct aux_sigframe __user *aux; int err = 0; - __put_user_error(regs->ARM_r0, &sc->arm_r0, err); - __put_user_error(regs->ARM_r1, &sc->arm_r1, err); - __put_user_error(regs->ARM_r2, &sc->arm_r2, err); - __put_user_error(regs->ARM_r3, &sc->arm_r3, err); - __put_user_error(regs->ARM_r4, &sc->arm_r4, err); - __put_user_error(regs->ARM_r5, &sc->arm_r5, err); - __put_user_error(regs->ARM_r6, &sc->arm_r6, err); - __put_user_error(regs->ARM_r7, &sc->arm_r7, err); - __put_user_error(regs->ARM_r8, &sc->arm_r8, err); - __put_user_error(regs->ARM_r9, &sc->arm_r9, err); - __put_user_error(regs->ARM_r10, &sc->arm_r10, err); - __put_user_error(regs->ARM_fp, &sc->arm_fp, err); - __put_user_error(regs->ARM_ip, &sc->arm_ip, err); - __put_user_error(regs->ARM_sp, &sc->arm_sp, err); - __put_user_error(regs->ARM_lr, &sc->arm_lr, err); - __put_user_error(regs->ARM_pc, &sc->arm_pc, err); - __put_user_error(regs->ARM_cpsr, &sc->arm_cpsr, err); - - __put_user_error(current->thread.trap_no, &sc->trap_no, err); - __put_user_error(current->thread.error_code, &sc->error_code, err); - __put_user_error(current->thread.address, &sc->fault_address, err); - __put_user_error(mask, &sc->oldmask, err); - + __put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err); + __put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err); + __put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err); + __put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err); + __put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err); + __put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err); + __put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err); + __put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err); + __put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err); + __put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err); + __put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err); + __put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err); + __put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err); + __put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err); + __put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err); + __put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err); + __put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err); + + __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err); + __put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err); + __put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err); + __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err); + + err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); + + aux = (struct aux_sigframe __user *) sf->uc.uc_regspace; +#ifdef CONFIG_CRUNCH + if (err == 0) + err |= preserve_crunch_context(&aux->crunch); +#endif #ifdef CONFIG_IWMMXT if (err == 0 && test_thread_flag(TIF_USING_IWMMXT)) err |= preserve_iwmmxt_context(&aux->iwmmxt); #endif #ifdef CONFIG_VFP -// if (err == 0) -// err |= vfp_save_state(&aux->vfp); + if (err == 0) + err |= preserve_vfp_context(&aux->vfp); #endif + __put_user_error(0, &aux->end_magic, err); return err; } static inline void __user * -get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) +get_sigframe(struct ksignal *ksig, struct pt_regs *regs, int framesize) { - unsigned long sp = regs->ARM_sp; + unsigned long sp = sigsp(regs->ARM_sp, ksig); void __user *frame; /* - * This is the X/Open sanctioned signal stack switching. - */ - if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) - sp = current->sas_ss_sp + current->sas_ss_size; - - /* * ATPCS B01 mandates 8-byte alignment */ frame = (void __user *)((sp - framesize) & ~7); @@ -463,19 +318,32 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize) return frame; } +/* + * translate the signal + */ +static inline int map_sig(int sig) +{ + struct thread_info *thread = current_thread_info(); + if (sig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) + sig = thread->exec_domain->signal_invmap[sig]; + return sig; +} + static int -setup_return(struct pt_regs *regs, struct k_sigaction *ka, - unsigned long __user *rc, void __user *frame, int usig) +setup_return(struct pt_regs *regs, struct ksignal *ksig, + unsigned long __user *rc, void __user *frame) { - unsigned long handler = (unsigned long)ka->sa.sa_handler; + unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler; unsigned long retcode; int thumb = 0; - unsigned long cpsr = regs->ARM_cpsr & ~PSR_f; + unsigned long cpsr = regs->ARM_cpsr & ~(PSR_f | PSR_E_BIT); + + cpsr |= PSR_ENDSTATE; /* * Maybe we need to deliver a 32-bit signal to a 26-bit task. */ - if (ka->sa.sa_flags & SA_THIRTYTWO) + if (ksig->ka.sa.sa_flags & SA_THIRTYTWO) cpsr = (cpsr & ~MODE_MASK) | USR_MODE; #ifdef CONFIG_ARM_THUMB @@ -486,43 +354,65 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka, */ thumb = handler & 1; - if (thumb) +#if __LINUX_ARM_ARCH__ >= 7 + /* + * Clear the If-Then Thumb-2 execution state + * ARM spec requires this to be all 000s in ARM mode + * Snapdragon S4/Krait misbehaves on a Thumb=>ARM + * signal transition without this. + */ + cpsr &= ~PSR_IT_MASK; +#endif + + if (thumb) { cpsr |= PSR_T_BIT; - else + } else cpsr &= ~PSR_T_BIT; } #endif - if (ka->sa.sa_flags & SA_RESTORER) { - retcode = (unsigned long)ka->sa.sa_restorer; + if (ksig->ka.sa.sa_flags & SA_RESTORER) { + retcode = (unsigned long)ksig->ka.sa.sa_restorer; } else { - unsigned int idx = thumb; + unsigned int idx = thumb << 1; - if (ka->sa.sa_flags & SA_SIGINFO) - idx += 2; + if (ksig->ka.sa.sa_flags & SA_SIGINFO) + idx += 3; - if (__put_user(sigreturn_codes[idx], rc)) + /* + * Put the sigreturn code on the stack no matter which return + * mechanism we use in order to remain ABI compliant + */ + if (__put_user(sigreturn_codes[idx], rc) || + __put_user(sigreturn_codes[idx+1], rc+1)) return 1; +#ifdef CONFIG_MMU if (cpsr & MODE32_BIT) { + struct mm_struct *mm = current->mm; + /* - * 32-bit code can use the new high-page - * signal return code support. + * 32-bit code can use the signal return page + * except when the MPU has protected the vectors + * page from PL0 */ - retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb; - } else { + retcode = mm->context.sigpage + signal_return_offset + + (idx << 2) + thumb; + } else +#endif + { /* * Ensure that the instruction cache sees * the return code written onto the stack. */ flush_icache_range((unsigned long)rc, - (unsigned long)(rc + 1)); + (unsigned long)(rc + 2)); retcode = ((unsigned long)rc) + thumb; } } - regs->ARM_r0 = usig; + regs->ARM_r0 = map_sig(ksig->sig); regs->ARM_sp = (unsigned long)frame; regs->ARM_lr = retcode; regs->ARM_pc = handler; @@ -532,57 +422,44 @@ setup_return(struct pt_regs *regs, struct k_sigaction *ka, } static int -setup_frame(int usig, struct k_sigaction *ka, sigset_t *set, struct pt_regs *regs) +setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { - struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); + struct sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame)); int err = 0; if (!frame) return 1; - err |= setup_sigcontext(&frame->sc, &frame->aux, regs, set->sig[0]); - - if (_NSIG_WORDS > 1) { - err |= __copy_to_user(frame->extramask, &set->sig[1], - sizeof(frame->extramask)); - } + /* + * Set uc.uc_flags to a value which sc.trap_no would never have. + */ + __put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err); + err |= setup_sigframe(frame, regs, set); if (err == 0) - err = setup_return(regs, ka, &frame->retcode, frame, usig); + err = setup_return(regs, ksig, frame->retcode, frame); return err; } static int -setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, - sigset_t *set, struct pt_regs *regs) +setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) { - struct rt_sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame)); - stack_t stack; + struct rt_sigframe __user *frame = get_sigframe(ksig, regs, sizeof(*frame)); int err = 0; if (!frame) return 1; - __put_user_error(&frame->info, &frame->pinfo, err); - __put_user_error(&frame->uc, &frame->puc, err); - err |= copy_siginfo_to_user(&frame->info, info); + err |= copy_siginfo_to_user(&frame->info, &ksig->info); - __put_user_error(0, &frame->uc.uc_flags, err); - __put_user_error(NULL, &frame->uc.uc_link, err); - - memset(&stack, 0, sizeof(stack)); - stack.ss_sp = (void __user *)current->sas_ss_sp; - stack.ss_flags = sas_ss_flags(regs->ARM_sp); - stack.ss_size = current->sas_ss_size; - err |= __copy_to_user(&frame->uc.uc_stack, &stack, sizeof(stack)); - - err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->aux, - regs, set->sig[0]); - err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + __put_user_error(0, &frame->sig.uc.uc_flags, err); + __put_user_error(NULL, &frame->sig.uc.uc_link, err); + err |= __save_altstack(&frame->sig.uc.uc_stack, regs->ARM_sp); + err |= setup_sigframe(&frame->sig, regs, set); if (err == 0) - err = setup_return(regs, ka, &frame->retcode, frame, usig); + err = setup_return(regs, ksig, frame->sig.retcode, frame); if (err == 0) { /* @@ -591,87 +468,34 @@ setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06 */ regs->ARM_r1 = (unsigned long)&frame->info; - regs->ARM_r2 = (unsigned long)&frame->uc; + regs->ARM_r2 = (unsigned long)&frame->sig.uc; } return err; } -static inline void restart_syscall(struct pt_regs *regs) -{ - regs->ARM_r0 = regs->ARM_ORIG_r0; - regs->ARM_pc -= thumb_mode(regs) ? 2 : 4; -} - /* * OK, we're invoking a handler */ -static void -handle_signal(unsigned long sig, struct k_sigaction *ka, - siginfo_t *info, sigset_t *oldset, - struct pt_regs * regs, int syscall) +static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) { - struct thread_info *thread = current_thread_info(); - struct task_struct *tsk = current; - int usig = sig; + sigset_t *oldset = sigmask_to_save(); int ret; /* - * If we were from a system call, check for system call restarting... - */ - if (syscall) { - switch (regs->ARM_r0) { - case -ERESTART_RESTARTBLOCK: - case -ERESTARTNOHAND: - regs->ARM_r0 = -EINTR; - break; - case -ERESTARTSYS: - if (!(ka->sa.sa_flags & SA_RESTART)) { - regs->ARM_r0 = -EINTR; - break; - } - /* fallthrough */ - case -ERESTARTNOINTR: - restart_syscall(regs); - } - } - - /* - * translate the signal - */ - if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap) - usig = thread->exec_domain->signal_invmap[usig]; - - /* * Set up the stack frame */ - if (ka->sa.sa_flags & SA_SIGINFO) - ret = setup_rt_frame(usig, ka, info, oldset, regs); + if (ksig->ka.sa.sa_flags & SA_SIGINFO) + ret = setup_rt_frame(ksig, oldset, regs); else - ret = setup_frame(usig, ka, oldset, regs); + ret = setup_frame(ksig, oldset, regs); /* * Check that the resulting registers are actually sane. */ ret |= !valid_user_regs(regs); - /* - * Block the signal if we were unsuccessful. - */ - if (ret != 0) { - spin_lock_irq(&tsk->sighand->siglock); - sigorsets(&tsk->blocked, &tsk->blocked, - &ka->sa.sa_mask); - if (!(ka->sa.sa_flags & SA_NODEFER)) - sigaddset(&tsk->blocked, sig); - recalc_sigpending(); - spin_unlock_irq(&tsk->sighand->siglock); - } - - if (ret == 0) - return; - - force_sigsegv(sig, tsk); + signal_setup_done(ret, ksig, 0); } /* @@ -683,76 +507,130 @@ handle_signal(unsigned long sig, struct k_sigaction *ka, * the kernel can handle, and then we build all the user-level signal handling * stack-frames in one go after that. */ -static int do_signal(sigset_t *oldset, struct pt_regs *regs, int syscall) +static int do_signal(struct pt_regs *regs, int syscall) { - struct k_sigaction ka; - siginfo_t info; - int signr; + unsigned int retval = 0, continue_addr = 0, restart_addr = 0; + struct ksignal ksig; + int restart = 0; /* - * We want the common case to go fast, which - * is why we may in certain cases get here from - * kernel mode. Just return without doing anything - * if so. + * If we were from a system call, check for system call restarting... */ - if (!user_mode(regs)) - return 0; - - if (try_to_freeze()) - goto no_signal; - - if (current->ptrace & PT_SINGLESTEP) - ptrace_cancel_bpt(current); + if (syscall) { + continue_addr = regs->ARM_pc; + restart_addr = continue_addr - (thumb_mode(regs) ? 2 : 4); + retval = regs->ARM_r0; - signr = get_signal_to_deliver(&info, &ka, regs, NULL); - if (signr > 0) { - handle_signal(signr, &ka, &info, oldset, regs, syscall); - if (current->ptrace & PT_SINGLESTEP) - ptrace_set_bpt(current); - return 1; + /* + * Prepare for system call restart. We do this here so that a + * debugger will see the already changed PSW. + */ + switch (retval) { + case -ERESTART_RESTARTBLOCK: + restart -= 2; + case -ERESTARTNOHAND: + case -ERESTARTSYS: + case -ERESTARTNOINTR: + restart++; + regs->ARM_r0 = regs->ARM_ORIG_r0; + regs->ARM_pc = restart_addr; + break; + } } - no_signal: /* - * No signal to deliver to the process - restart the syscall. + * Get the signal to deliver. When running under ptrace, at this + * point the debugger may change all our registers ... */ - if (syscall) { - if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) { - if (thumb_mode(regs)) { - regs->ARM_r7 = __NR_restart_syscall; - regs->ARM_pc -= 2; - } else { - u32 __user *usp; - - regs->ARM_sp -= 12; - usp = (u32 __user *)regs->ARM_sp; - - put_user(regs->ARM_pc, &usp[0]); - /* swi __NR_restart_syscall */ - put_user(0xef000000 | __NR_restart_syscall, &usp[1]); - /* ldr pc, [sp], #12 */ - put_user(0xe49df00c, &usp[2]); - - flush_icache_range((unsigned long)usp, - (unsigned long)(usp + 3)); - - regs->ARM_pc = regs->ARM_sp + 4; + /* + * Depending on the signal settings we may need to revert the + * decision to restart the system call. But skip this if a + * debugger has chosen to restart at a different PC. + */ + if (get_signal(&ksig)) { + /* handler */ + if (unlikely(restart) && regs->ARM_pc == restart_addr) { + if (retval == -ERESTARTNOHAND || + retval == -ERESTART_RESTARTBLOCK + || (retval == -ERESTARTSYS + && !(ksig.ka.sa.sa_flags & SA_RESTART))) { + regs->ARM_r0 = -EINTR; + regs->ARM_pc = continue_addr; } } - if (regs->ARM_r0 == -ERESTARTNOHAND || - regs->ARM_r0 == -ERESTARTSYS || - regs->ARM_r0 == -ERESTARTNOINTR) { - restart_syscall(regs); + handle_signal(&ksig, regs); + } else { + /* no handler */ + restore_saved_sigmask(); + if (unlikely(restart) && regs->ARM_pc == restart_addr) { + regs->ARM_pc = continue_addr; + return restart; } } - if (current->ptrace & PT_SINGLESTEP) - ptrace_set_bpt(current); return 0; } -asmlinkage void -do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall) +asmlinkage int +do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) +{ + do { + if (likely(thread_flags & _TIF_NEED_RESCHED)) { + schedule(); + } else { + if (unlikely(!user_mode(regs))) + return 0; + local_irq_enable(); + if (thread_flags & _TIF_SIGPENDING) { + int restart = do_signal(regs, syscall); + if (unlikely(restart)) { + /* + * Restart without handlers. + * Deal with it without leaving + * the kernel space. + */ + return restart; + } + syscall = 0; + } else if (thread_flags & _TIF_UPROBE) { + clear_thread_flag(TIF_UPROBE); + uprobe_notify_resume(regs); + } else { + clear_thread_flag(TIF_NOTIFY_RESUME); + tracehook_notify_resume(regs); + } + } + local_irq_disable(); + thread_flags = current_thread_info()->flags; + } while (thread_flags & _TIF_WORK_MASK); + return 0; +} + +struct page *get_signal_page(void) { - if (thread_flags & _TIF_SIGPENDING) - do_signal(¤t->blocked, regs, syscall); + unsigned long ptr; + unsigned offset; + struct page *page; + void *addr; + + page = alloc_pages(GFP_KERNEL, 0); + + if (!page) + return NULL; + + addr = page_address(page); + + /* Give the signal return code some randomness */ + offset = 0x200 + (get_random_int() & 0x7fc); + signal_return_offset = offset; + + /* + * Copy signal return handlers into the vector page, and + * set sigreturn to be a pointer to these. + */ + memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes)); + + ptr = (unsigned long)addr + offset; + flush_icache_range(ptr, ptr + sizeof(sigreturn_codes)); + + return page; } |
