This patch adds support for signal handling. Signed-off-by: Ley Foon Tan <lftan@xxxxxxxxxx> --- arch/nios2/include/asm/signal.h | 22 ++ arch/nios2/include/asm/ucontext.h | 34 +++ arch/nios2/include/uapi/asm/sigcontext.h | 30 +++ arch/nios2/include/uapi/asm/signal.h | 23 ++ arch/nios2/kernel/signal.c | 364 +++++++++++++++++++++++++++++++ 5 files changed, 473 insertions(+) create mode 100644 arch/nios2/include/asm/signal.h create mode 100644 arch/nios2/include/asm/ucontext.h create mode 100644 arch/nios2/include/uapi/asm/sigcontext.h create mode 100644 arch/nios2/include/uapi/asm/signal.h create mode 100644 arch/nios2/kernel/signal.c diff --git a/arch/nios2/include/asm/signal.h b/arch/nios2/include/asm/signal.h new file mode 100644 index 0000000..bbcf11eecb0194b7c7b0f9352b0154d67b2dc06a --- /dev/null +++ b/arch/nios2/include/asm/signal.h @@ -0,0 +1,22 @@ +/* + * Copyright Altera Corporation (C) 2013. All rights reserved + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + * + */ +#ifndef _NIOS2_SIGNAL_H +#define _NIOS2_SIGNAL_H + +#include <uapi/asm/signal.h> + +#endif /* _NIOS2_SIGNAL_H */ diff --git a/arch/nios2/include/asm/ucontext.h b/arch/nios2/include/asm/ucontext.h new file mode 100644 index 0000000..5870ef4e92fbaec9137142534ce3c5b23705d43e --- /dev/null +++ b/arch/nios2/include/asm/ucontext.h @@ -0,0 +1,34 @@ +/* + * Copyright (C) 2010 Tobias Klauser <tklauser@xxxxxxxxxx> + * Copyright (C) 2004 Microtronix Datacom Ltd + * + * derived from m68knommu + * + * 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. + */ + +#ifndef _ASM_NIOS2_UCONTEXT_H +#define _ASM_NIOS2_UCONTEXT_H + +typedef int greg_t; +#define NGREG 32 +typedef greg_t gregset_t[NGREG]; + +struct mcontext { + int version; + gregset_t gregs; +}; + +#define MCONTEXT_VERSION 2 + +struct ucontext { + unsigned long uc_flags; + struct ucontext *uc_link; + stack_t uc_stack; + struct mcontext uc_mcontext; + sigset_t uc_sigmask; /* mask last for extensibility */ +}; + +#endif diff --git a/arch/nios2/include/uapi/asm/sigcontext.h b/arch/nios2/include/uapi/asm/sigcontext.h new file mode 100644 index 0000000..6bfd8807597a7d6abc0ae32f030e44cb4f77809f --- /dev/null +++ b/arch/nios2/include/uapi/asm/sigcontext.h @@ -0,0 +1,30 @@ +/* + * Taken from the m68knommu. + * + * Copyright (C) 2004, Microtronix Datacom Ltd. + * + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more + * details. + */ + +#ifndef _ASM_NIOS2_SIGCONTEXT_H +#define _ASM_NIOS2_SIGCONTEXT_H + +#include <asm/ptrace.h> + +struct sigcontext { + struct pt_regs regs; + unsigned long sc_mask; /* old sigmask */ +}; + +#endif diff --git a/arch/nios2/include/uapi/asm/signal.h b/arch/nios2/include/uapi/asm/signal.h new file mode 100644 index 0000000..f29ee63144817e9798965c0b8279c08844c44e6a --- /dev/null +++ b/arch/nios2/include/uapi/asm/signal.h @@ -0,0 +1,23 @@ +/* + * Copyright Altera Corporation (C) 2013. All rights reserved + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + * + */ +#ifndef _ASM_NIOS2_SIGNAL_H +#define _ASM_NIOS2_SIGNAL_H + +#define SA_RESTORER 0x04000000 +#include <asm-generic/signal.h> + +#endif /* _ASM_NIOS2_SIGNAL_H */ diff --git a/arch/nios2/kernel/signal.c b/arch/nios2/kernel/signal.c new file mode 100644 index 0000000..1c5cbe9c55dde1c3467d727ec66c36b96f3cb9cd --- /dev/null +++ b/arch/nios2/kernel/signal.c @@ -0,0 +1,364 @@ +/* + * Copyright (C) 2013 Altera Corporation + * Copyright (C) 2011-2012 Tobias Klauser <tklauser@xxxxxxxxxx> + * Copyright (C) 2004 Microtronix Datacom Ltd + * Copyright (C) 1991, 1992 Linus Torvalds + * + * This file is based on kernel/signal.c from m68knommu. + * + * 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. + */ + +#include <linux/signal.h> +#include <linux/errno.h> +#include <linux/ptrace.h> +#include <linux/uaccess.h> +#include <linux/unistd.h> +#include <linux/personality.h> +#include <linux/tracehook.h> + +#include <asm/ucontext.h> +#include <asm/cacheflush.h> + +#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) + +static int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall); + +/* + * Do a signal return; undo the signal stack. + * + * Keep the return code on the stack quadword aligned! + * That makes the cache flush below easier. + */ + +struct sigframe { + char retcode[12]; + unsigned long extramask[_NSIG_WORDS-1]; + struct sigcontext sc; +}; + +struct rt_sigframe { + char retcode[12]; + struct siginfo info; + struct ucontext uc; +}; + +static inline int rt_restore_ucontext(struct pt_regs *regs, + struct switch_stack *sw, + struct ucontext *uc, int *pr2) +{ + int temp; + greg_t *gregs = uc->uc_mcontext.gregs; + int err; + + err = __get_user(temp, &uc->uc_mcontext.version); + if (temp != MCONTEXT_VERSION) + goto badframe; + /* restore passed registers */ + err |= __get_user(regs->r1, &gregs[0]); + err |= __get_user(regs->r2, &gregs[1]); + err |= __get_user(regs->r3, &gregs[2]); + err |= __get_user(regs->r4, &gregs[3]); + err |= __get_user(regs->r5, &gregs[4]); + err |= __get_user(regs->r6, &gregs[5]); + err |= __get_user(regs->r7, &gregs[6]); + err |= __get_user(regs->r8, &gregs[7]); + err |= __get_user(regs->r9, &gregs[8]); + err |= __get_user(regs->r10, &gregs[9]); + err |= __get_user(regs->r11, &gregs[10]); + err |= __get_user(regs->r12, &gregs[11]); + err |= __get_user(regs->r13, &gregs[12]); + err |= __get_user(regs->r14, &gregs[13]); + err |= __get_user(regs->r15, &gregs[14]); + err |= __get_user(sw->r16, &gregs[15]); + err |= __get_user(sw->r17, &gregs[16]); + err |= __get_user(sw->r18, &gregs[17]); + err |= __get_user(sw->r19, &gregs[18]); + err |= __get_user(sw->r20, &gregs[19]); + err |= __get_user(sw->r21, &gregs[20]); + err |= __get_user(sw->r22, &gregs[21]); + err |= __get_user(sw->r23, &gregs[22]); + /* gregs[23] is handled below */ + err |= __get_user(sw->fp, &gregs[24]); /* Verify, should this be + settable */ + err |= __get_user(sw->gp, &gregs[25]); /* Verify, should this be + settable */ + + err |= __get_user(temp, &gregs[26]); /* Not really necessary no user + settable bits */ + err |= __get_user(regs->ea, &gregs[27]); + + err |= __get_user(regs->ra, &gregs[23]); + err |= __get_user(regs->sp, &gregs[28]); + + regs->estatus = (regs->estatus & 0xffffffff); + regs->orig_r2 = -1; /* disable syscall checks */ + + err |= restore_altstack(&uc->uc_stack); + if (err) + goto badframe; + + *pr2 = regs->r2; + return err; + +badframe: + return 1; +} + +asmlinkage int do_rt_sigreturn(struct switch_stack *sw) +{ + struct pt_regs *regs = (struct pt_regs *)(sw + 1); + /* Verify, can we follow the stack back */ + struct rt_sigframe *frame = (struct rt_sigframe *) regs->sp; + sigset_t set; + int rval; + + 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 (rt_restore_ucontext(regs, sw, &frame->uc, &rval)) + goto badframe; + + return rval; + +badframe: + force_sig(SIGSEGV, current); + return 0; +} + +static inline int rt_setup_ucontext(struct ucontext *uc, struct pt_regs *regs) +{ + struct switch_stack *sw = (struct switch_stack *)regs - 1; + greg_t *gregs = uc->uc_mcontext.gregs; + int err = 0; + + err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version); + err |= __put_user(regs->r1, &gregs[0]); + err |= __put_user(regs->r2, &gregs[1]); + err |= __put_user(regs->r3, &gregs[2]); + err |= __put_user(regs->r4, &gregs[3]); + err |= __put_user(regs->r5, &gregs[4]); + err |= __put_user(regs->r6, &gregs[5]); + err |= __put_user(regs->r7, &gregs[6]); + err |= __put_user(regs->r8, &gregs[7]); + err |= __put_user(regs->r9, &gregs[8]); + err |= __put_user(regs->r10, &gregs[9]); + err |= __put_user(regs->r11, &gregs[10]); + err |= __put_user(regs->r12, &gregs[11]); + err |= __put_user(regs->r13, &gregs[12]); + err |= __put_user(regs->r14, &gregs[13]); + err |= __put_user(regs->r15, &gregs[14]); + err |= __put_user(sw->r16, &gregs[15]); + err |= __put_user(sw->r17, &gregs[16]); + err |= __put_user(sw->r18, &gregs[17]); + err |= __put_user(sw->r19, &gregs[18]); + err |= __put_user(sw->r20, &gregs[19]); + err |= __put_user(sw->r21, &gregs[20]); + err |= __put_user(sw->r22, &gregs[21]); + err |= __put_user(sw->r23, &gregs[22]); + err |= __put_user(regs->ra, &gregs[23]); + err |= __put_user(sw->fp, &gregs[24]); + err |= __put_user(sw->gp, &gregs[25]); + err |= __put_user(regs->ea, &gregs[27]); + err |= __put_user(regs->sp, &gregs[28]); + return err; +} + +static inline void push_cache(unsigned long vaddr) +{ + flush_dcache_range(vaddr, vaddr + 12); + flush_icache_range(vaddr, vaddr + 12); +} + +static inline void *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, + size_t frame_size) +{ + unsigned long usp; + + /* Default to using normal stack. */ + usp = regs->sp; + + /* This is the X/Open sanctioned signal stack switching. */ + if ((ka->sa.sa_flags & SA_ONSTACK) && (current->sas_ss_sp != 0)) { + if (!on_sig_stack(usp)) + usp = current->sas_ss_sp + current->sas_ss_size; + } + + /* Verify, is it 32 or 64 bit aligned */ + return (void *)((usp - frame_size) & -8UL); +} + +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; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + + if (info) + err |= copy_siginfo_to_user(&frame->info, info); + + /* Create the ucontext. */ + err |= __put_user(0, &frame->uc.uc_flags); + err |= __put_user(0, &frame->uc.uc_link); + err |= __save_altstack(&frame->uc.uc_stack, regs->sp); + err |= rt_setup_ucontext(&frame->uc, regs); + err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); + + /* Set up to return from userspace. */ + regs->ra = (unsigned long) &frame->retcode[0]; + + /* movi r2,__NR_rt_sigreturn */ + err |= __put_user(0x00800004 + (__NR_rt_sigreturn << 6), + (long *)(frame->retcode)); + /* trap */ + err |= __put_user(0x003b683a, (long *)(frame->retcode + 4)); + + if (err) + goto give_sigsegv; + + push_cache((unsigned long) &frame->retcode); + + /* Set up registers for signal handler */ + regs->sp = (unsigned long) frame; + regs->r4 = (unsigned long) (current_thread_info()->exec_domain + && current_thread_info()->exec_domain->signal_invmap + && sig < 32 + ? current_thread_info()->exec_domain->signal_invmap[sig] + : sig); + regs->r5 = (unsigned long) &frame->info; + regs->r6 = (unsigned long) &frame->uc; + regs->ea = (unsigned long) ka->sa.sa_handler; + return; + +give_sigsegv: + force_sigsegv(sig, current); +} + +static inline void handle_restart(struct pt_regs *regs, struct k_sigaction *ka, + int has_handler) +{ + switch (regs->r2) { + case ERESTART_RESTARTBLOCK: + case ERESTARTNOHAND: + regs->r2 = EINTR; + regs->r7 = 1; + break; + case ERESTARTSYS: + if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { + regs->r2 = EINTR; + regs->r7 = 1; + break; + } + /* fallthrough */ + case ERESTARTNOINTR: + regs->r2 = regs->orig_r2; + regs->r7 = regs->orig_r7; + regs->ea -= 4; + break; + } +} + +/* + * OK, we're invoking a handler + */ +static void handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, + sigset_t *oldset, struct pt_regs *regs) +{ + /* set up the stack frame */ + if (ka->sa.sa_flags & SA_SIGINFO) + setup_rt_frame(sig, ka, info, oldset, regs); + else + setup_rt_frame(sig, ka, NULL, oldset, regs); + + if (!(ka->sa.sa_flags & SA_NODEFER)) { + spin_lock_irq(¤t->sighand->siglock); + sigorsets(¤t->blocked, ¤t->blocked, + &ka->sa.sa_mask); + sigaddset(¤t->blocked, sig); + recalc_sigpending(); + spin_unlock_irq(¤t->sighand->siglock); + } +} + +/* + * Note that 'init' is a special process: it doesn't get signals it doesn't + * want to handle. Thus you cannot kill init even with a SIGKILL even by + * mistake. + */ +static int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall) +{ + struct k_sigaction ka; + siginfo_t info; + int signr; + + current->thread.kregs = regs; + + if (!oldset) + oldset = ¤t->blocked; + + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + /* + * Are we from a system call? If so, check system call + * restarting. + */ + if (in_syscall) + handle_restart(regs, &ka, 1); + /* Whee! Actually deliver the signal. */ + handle_signal(signr, &ka, &info, oldset, regs); + return 1; + } + + /* + * No signal to deliver to the process - restart the syscall. + */ + if (in_syscall) { + /* Did the syscall return an error code */ + if (regs->r7 == 1) { + if (regs->r2 == ERESTARTNOHAND || + regs->r2 == ERESTARTSYS || + regs->r2 == ERESTARTNOINTR) { + regs->r2 = regs->orig_r2; + regs->r7 = regs->orig_r7; + regs->ea -= 4; + } else if (regs->r2 == ERESTART_RESTARTBLOCK) { + regs->r2 = __NR_restart_syscall; + regs->ea -= 4; + } + } + } + + return 0; +} + +asmlinkage void do_notify_resume(struct pt_regs *regs, sigset_t *oldset, + int in_syscall) +{ + pr_debug("--> ENTERING %s\n", __func__); + /* + * 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 (!user_mode(regs)) + return; + + if (test_thread_flag(TIF_SIGPENDING)) + do_signal(regs, oldset, in_syscall); + + if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) + tracehook_notify_resume(regs); +} -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
