diff options
| -rw-r--r-- | arch/arm64/include/asm/sigcontext.h | 69 | ||||
| -rw-r--r-- | arch/arm64/include/asm/siginfo.h | 23 | ||||
| -rw-r--r-- | arch/arm64/include/asm/signal.h | 24 | ||||
| -rw-r--r-- | arch/arm64/include/asm/ucontext.h | 30 | ||||
| -rw-r--r-- | arch/arm64/kernel/signal.c | 437 |
5 files changed, 583 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/sigcontext.h b/arch/arm64/include/asm/sigcontext.h new file mode 100644 index 00000000000..573cec77881 --- /dev/null +++ b/arch/arm64/include/asm/sigcontext.h @@ -0,0 +1,69 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * + * 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. + * + * 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. 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_SIGCONTEXT_H +#define __ASM_SIGCONTEXT_H + +#include <linux/types.h> + +/* + * Signal context structure - contains all info to do with the state + * before the signal handler was invoked. + */ +struct sigcontext { + __u64 fault_address; + /* AArch64 registers */ + __u64 regs[31]; + __u64 sp; + __u64 pc; + __u64 pstate; + /* 4K reserved for FP/SIMD state and future expansion */ + __u8 __reserved[4096] __attribute__((__aligned__(16))); +}; + +/* + * Header to be used at the beginning of structures extending the user + * context. Such structures must be placed after the rt_sigframe on the stack + * and be 16-byte aligned. The last structure must be a dummy one with the + * magic and size set to 0. + */ +struct _aarch64_ctx { + __u32 magic; + __u32 size; +}; + +#define FPSIMD_MAGIC 0x46508001 + +struct fpsimd_context { + struct _aarch64_ctx head; + __u32 fpsr; + __u32 fpcr; + __uint128_t vregs[32]; +}; + +#ifdef __KERNEL__ +/* + * Auxiliary context saved in the sigcontext.__reserved array. Not exported to + * user space as it will change with the addition of new context. User space + * should check the magic/size information. + */ +struct aux_context { + struct fpsimd_context fpsimd; + /* additional context to be added before "end" */ + struct _aarch64_ctx end; +}; +#endif + +#endif diff --git a/arch/arm64/include/asm/siginfo.h b/arch/arm64/include/asm/siginfo.h new file mode 100644 index 00000000000..5a74a0853db --- /dev/null +++ b/arch/arm64/include/asm/siginfo.h @@ -0,0 +1,23 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * + * 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. + * + * 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. 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_SIGINFO_H +#define __ASM_SIGINFO_H + +#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int)) + +#include <asm-generic/siginfo.h> + +#endif diff --git a/arch/arm64/include/asm/signal.h b/arch/arm64/include/asm/signal.h new file mode 100644 index 00000000000..8d1e7236431 --- /dev/null +++ b/arch/arm64/include/asm/signal.h @@ -0,0 +1,24 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * + * 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. + * + * 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. 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_SIGNAL_H +#define __ASM_SIGNAL_H + +/* Required for AArch32 compatibility. */ +#define SA_RESTORER 0x04000000 + +#include <asm-generic/signal.h> + +#endif diff --git a/arch/arm64/include/asm/ucontext.h b/arch/arm64/include/asm/ucontext.h new file mode 100644 index 00000000000..bde96072089 --- /dev/null +++ b/arch/arm64/include/asm/ucontext.h @@ -0,0 +1,30 @@ +/* + * Copyright (C) 2012 ARM Ltd. + * + * 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. + * + * 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. 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_UCONTEXT_H +#define __ASM_UCONTEXT_H + +struct ucontext { + unsigned long uc_flags; + struct ucontext *uc_link; + stack_t uc_stack; + sigset_t uc_sigmask; + /* glibc uses a 1024-bit sigset_t */ + __u8 __unused[(1024 - sizeof(sigset_t)) / 8]; + /* last for future expansion */ + struct sigcontext uc_mcontext; +}; + +#endif /* __ASM_UCONTEXT_H */ diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c new file mode 100644 index 00000000000..8807ba2cf26 --- /dev/null +++ b/arch/arm64/kernel/signal.c @@ -0,0 +1,437 @@ +/* + * Based on arch/arm/kernel/signal.c + * + * Copyright (C) 1995-2009 Russell King + * Copyright (C) 2012 ARM Ltd. + * + * 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. + * + * 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. 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/>. + */ + +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/personality.h> +#include <linux/freezer.h> +#include <linux/uaccess.h> +#include <linux/tracehook.h> +#include <linux/ratelimit.h> + +#include <asm/compat.h> +#include <asm/debug-monitors.h> +#include <asm/elf.h> +#include <asm/cacheflush.h> +#include <asm/ucontext.h> +#include <asm/unistd.h> +#include <asm/fpsimd.h> +#include <asm/signal32.h> +#include <asm/vdso.h> + +/* + * Do a signal return; undo the signal stack. These are aligned to 128-bit. + */ +struct rt_sigframe { + struct siginfo info; + struct ucontext uc; +}; + +static int preserve_fpsimd_context(struct fpsimd_context __user *ctx) +{ + struct fpsimd_state *fpsimd = ¤t->thread.fpsimd_state; + int err; + + /* dump the hardware registers to the fpsimd_state structure */ + fpsimd_save_state(fpsimd); + + /* copy the FP and status/control registers */ + err = __copy_to_user(ctx->vregs, fpsimd->vregs, sizeof(fpsimd->vregs)); + __put_user_error(fpsimd->fpsr, &ctx->fpsr, err); + __put_user_error(fpsimd->fpcr, &ctx->fpcr, err); + + /* copy the magic/size information */ + __put_user_error(FPSIMD_MAGIC, &ctx->head.magic, err); + __put_user_error(sizeof(struct fpsimd_context), &ctx->head.size, err); + + return err ? -EFAULT : 0; +} + +static int restore_fpsimd_context(struct fpsimd_context __user *ctx) +{ + struct fpsimd_state fpsimd; + __u32 magic, size; + int err = 0; + + /* check the magic/size information */ + __get_user_error(magic, &ctx->head.magic, err); + __get_user_error(size, &ctx->head.size, err); + if (err) + return -EFAULT; + if (magic != FPSIMD_MAGIC || size != sizeof(struct fpsimd_context)) + return -EINVAL; + + /* copy the FP and status/control registers */ + err = __copy_from_user(fpsimd.vregs, ctx->vregs, + sizeof(fpsimd.vregs)); + __get_user_error(fpsimd.fpsr, &ctx->fpsr, err); + __get_user_error(fpsimd.fpcr, &ctx->fpcr, err); + + /* load the hardware registers from the fpsimd_state structure */ + if (!err) { + preempt_disable(); + fpsimd_load_state(&fpsimd); + preempt_enable(); + } + + return err ? -EFAULT : 0; +} + +static int restore_sigframe(struct pt_regs *regs, + struct rt_sigframe __user *sf) +{ + sigset_t set; + int i, err; + struct aux_context __user *aux = + (struct aux_context __user *)sf->uc.uc_mcontext.__reserved; + + err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); + if (err == 0) + set_current_blocked(&set); + + for (i = 0; i < 31; i++) + __get_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i], + err); + __get_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err); + __get_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err); + __get_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err); + + /* + * Avoid sys_rt_sigreturn() restarting. + */ + regs->syscallno = ~0UL; + + err |= !valid_user_regs(®s->user_regs); + + if (err == 0) + err |= restore_fpsimd_context(&aux->fpsimd); + + return err; +} + +asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) +{ + struct rt_sigframe __user *frame; + + /* Always make any pending restarted system calls return -EINTR */ + current_thread_info()->restart_block.fn = do_no_restart_syscall; + + /* + * Since we stacked the signal on a 128-bit boundary, then 'sp' should + * be word aligned here. + */ + if (regs->sp & 15) + goto badframe; + + frame = (struct rt_sigframe __user *)regs->sp; + + if (!access_ok(VERIFY_READ, frame, sizeof (*frame))) + goto badframe; + + if (restore_sigframe(regs, frame)) + goto badframe; + + if (do_sigaltstack(&frame->uc.uc_stack, + NULL, regs->sp) == -EFAULT) + goto badframe; + + return regs->regs[0]; + +badframe: + if (show_unhandled_signals) + pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n", + current->comm, task_pid_nr(current), __func__, + regs->pc, regs->sp); + force_sig(SIGSEGV, current); + return 0; +} + +asmlinkage long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, + unsigned long sp) +{ + return do_sigaltstack(uss, uoss, sp); +} + +static int setup_sigframe(struct rt_sigframe __user *sf, + struct pt_regs *regs, sigset_t *set) +{ + int i, err = 0; + struct aux_context __user *aux = + (struct aux_context __user *)sf->uc.uc_mcontext.__reserved; + + for (i = 0; i < 31; i++) + __put_user_error(regs->regs[i], &sf->uc.uc_mcontext.regs[i], + err); + __put_user_error(regs->sp, &sf->uc.uc_mcontext.sp, err); + __put_user_error(regs->pc, &sf->uc.uc_mcontext.pc, err); + __put_user_error(regs->pstate, &sf->uc.uc_mcontext.pstate, err); + + __put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err); + + err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); + + if (err == 0) + err |= preserve_fpsimd_context(&aux->fpsimd); + + /* set the "end" magic */ + __put_user_error(0, &aux->end.magic, err); + __put_user_error(0, &aux->end.size, err); + + return err; +} + +static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, + int framesize) +{ + unsigned long sp, sp_top; + void __user *frame; + + sp = sp_top = regs->sp; + + /* + * This is the X/Open sanctioned signal stack switching. + */ + if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp)) + sp = sp_top = current->sas_ss_sp + current->sas_ss_size; + + /* room for stack frame (FP, LR) */ + sp -= 16; + + sp = (sp - framesize) & ~15; + frame = (void __user *)sp; + + /* + * Check that we can actually write to the signal frame. + */ + if (!access_ok(VERIFY_WRITE, frame, sp_top - sp)) + frame = NULL; + + return frame; +} + +static int setup_return(struct pt_regs *regs, struct k_sigaction *ka, + void __user *frame, int usig) +{ + int err = 0; + __sigrestore_t sigtramp; + unsigned long __user *sp = (unsigned long __user *)regs->sp; + + /* set up the stack frame */ + __put_user_error(regs->regs[29], sp - 2, err); + __put_user_error(regs->regs[30], sp - 1, err); + + regs->regs[0] = usig; + regs->regs[29] = regs->sp - 16; + regs->sp = (unsigned long)frame; + regs->pc = (unsigned long)ka->sa.sa_handler; + + if (ka->sa.sa_flags & SA_RESTORER) + sigtramp = ka->sa.sa_restorer; + else + sigtramp = VDSO_SYMBOL(current->mm->context.vdso, sigtramp); + + regs->regs[30] = (unsigned long)sigtramp; + + return err; +} + +static int setup_rt_frame(int usig, struct k_sigaction *ka, siginfo_t *info, + sigset_t *set, struct pt_regs *regs) +{ + struct rt_sigframe __user *frame; + stack_t stack; + int err = 0; + + frame = get_sigframe(ka, regs, sizeof(*frame)); + if (!frame) + return 1; + + __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->sp); + stack.ss_size = current->sas_ss_size; + err |= __copy_to_user(&frame->uc.uc_stack, &stack, sizeof(stack)); + + err |= setup_sigframe(frame, regs, set); + if (err == 0) + err = setup_return(regs, ka, frame, usig); + + if (err == 0 && ka->sa.sa_flags & SA_SIGINFO) { + err |= copy_siginfo_to_user(&frame->info, info); + regs->regs[1] = (unsigned long)&frame->info; + regs->regs[2] = (unsigned long)&frame->uc; + } + + return err; +} + +static void setup_restart_syscall(struct pt_regs *regs) +{ + if (is_compat_task()) + compat_setup_restart_syscall(regs); + else + regs->regs[8] = __NR_restart_syscall; +} + +/* + * OK, we're invoking a handler + */ +static void handle_signal(unsigned long sig, struct k_sigaction *ka, + siginfo_t *info, struct pt_regs *regs) +{ + struct thread_info *thread = current_thread_info(); + struct task_struct *tsk = current; + sigset_t *oldset = sigmask_to_save(); + int usig = sig; + int ret; + + /* + * 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 (is_compat_task()) { + if (ka->sa.sa_flags & SA_SIGINFO) + ret = compat_setup_rt_frame(usig, ka, info, oldset, + regs); + else + ret = compat_setup_frame(usig, ka, oldset, regs); + } else { + ret = setup_rt_frame(usig, ka, info, oldset, regs); + } + + /* + * Check that the resulting registers are actually sane. + */ + ret |= !valid_user_regs(®s->user_regs); + + if (ret != 0) { + force_sigsegv(sig, tsk); + return; + } + + /* + * Fast forward the stepping logic so we step into the signal + * handler. + */ + user_fastforward_single_step(tsk); + + signal_delivered(sig, info, ka, regs, 0); +} + +/* + * 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. + * + * Note that we go through the signals twice: once to check the signals that + * the kernel can handle, and then we build all the user-level signal handling + * stack-frames in one go after that. + */ +static void do_signal(struct pt_regs *regs) +{ + unsigned long continue_addr = 0, restart_addr = 0; + struct k_sigaction ka; + siginfo_t info; + int signr, retval = 0; + int syscall = (int)regs->syscallno; + + /* + * If we were from a system call, check for system call restarting... + */ + if (syscall >= 0) { + continue_addr = regs->pc; + restart_addr = continue_addr - (compat_thumb_mode(regs) ? 2 : 4); + retval = regs->regs[0]; + + /* + * Avoid additional syscall restarting via ret_to_user. + */ + regs->syscallno = ~0UL; + + /* + * Prepare for system call restart. We do this here so that a + * debugger will see the already changed PC. + */ + switch (retval) { + case -ERESTARTNOHAND: + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTART_RESTARTBLOCK: + regs->regs[0] = regs->orig_x0; + regs->pc = restart_addr; + break; + } + } + + /* + * Get the signal to deliver. When running under ptrace, at this point + * the debugger may change all of our registers. + */ + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + if (signr > 0) { + /* + * 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 (regs->pc == restart_addr && + (retval == -ERESTARTNOHAND || + retval == -ERESTART_RESTARTBLOCK || + (retval == -ERESTARTSYS && + !(ka.sa.sa_flags & SA_RESTART)))) { + regs->regs[0] = -EINTR; + regs->pc = continue_addr; + } + + handle_signal(signr, &ka, &info, regs); + return; + } + + /* + * Handle restarting a different system call. As above, if a debugger + * has chosen to restart at a different PC, ignore the restart. + */ + if (syscall >= 0 && regs->pc == restart_addr) { + if (retval == -ERESTART_RESTARTBLOCK) + setup_restart_syscall(regs); + user_rewind_single_step(current); + } + + restore_saved_sigmask(); +} + +asmlinkage void do_notify_resume(struct pt_regs *regs, + unsigned int thread_flags) +{ + if (thread_flags & _TIF_SIGPENDING) + do_signal(regs); + + if (thread_flags & _TIF_NOTIFY_RESUME) { + clear_thread_flag(TIF_NOTIFY_RESUME); + tracehook_notify_resume(regs); + } +} |