diff options
Diffstat (limited to '')
| -rw-r--r-- | arch/nds32/kernel/signal.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/arch/nds32/kernel/signal.c b/arch/nds32/kernel/signal.c new file mode 100644 index 000000000..7e3ca430a --- /dev/null +++ b/arch/nds32/kernel/signal.c @@ -0,0 +1,384 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2005-2017 Andes Technology Corporation + +#include <linux/errno.h> +#include <linux/signal.h> +#include <linux/ptrace.h> +#include <linux/personality.h> +#include <linux/freezer.h> +#include <linux/tracehook.h> +#include <linux/uaccess.h> + +#include <asm/cacheflush.h> +#include <asm/ucontext.h> +#include <asm/unistd.h> +#include <asm/fpu.h> + +#include <asm/ptrace.h> +#include <asm/vdso.h> + +struct rt_sigframe { + struct siginfo info; + struct ucontext uc; +}; +#if IS_ENABLED(CONFIG_FPU) +static inline int restore_sigcontext_fpu(struct pt_regs *regs, + struct sigcontext __user *sc) +{ + struct task_struct *tsk = current; + unsigned long used_math_flag; + int ret = 0; + + clear_used_math(); + __get_user_error(used_math_flag, &sc->used_math_flag, ret); + + if (!used_math_flag) + return 0; + set_used_math(); + +#if IS_ENABLED(CONFIG_LAZY_FPU) + preempt_disable(); + if (current == last_task_used_math) { + last_task_used_math = NULL; + disable_ptreg_fpu(regs); + } + preempt_enable(); +#else + clear_fpu(regs); +#endif + + return __copy_from_user(&tsk->thread.fpu, &sc->fpu, + sizeof(struct fpu_struct)); +} + +static inline int setup_sigcontext_fpu(struct pt_regs *regs, + struct sigcontext __user *sc) +{ + struct task_struct *tsk = current; + int ret = 0; + + __put_user_error(used_math(), &sc->used_math_flag, ret); + + if (!used_math()) + return ret; + + preempt_disable(); +#if IS_ENABLED(CONFIG_LAZY_FPU) + if (last_task_used_math == tsk) + save_fpu(last_task_used_math); +#else + unlazy_fpu(tsk); +#endif + ret = __copy_to_user(&sc->fpu, &tsk->thread.fpu, + sizeof(struct fpu_struct)); + preempt_enable(); + return ret; +} +#endif + +static int restore_sigframe(struct pt_regs *regs, + struct rt_sigframe __user * sf) +{ + sigset_t set; + int err; + + err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); + if (err == 0) { + set_current_blocked(&set); + } + + __get_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err); + __get_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err); + __get_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err); + __get_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err); + __get_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err); + __get_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err); + __get_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err); + __get_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err); + __get_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err); + __get_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err); + __get_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err); + __get_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err); + __get_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err); + __get_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err); + __get_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err); + __get_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err); + __get_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err); + __get_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err); + __get_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err); + __get_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err); + __get_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err); + __get_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err); + __get_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err); + __get_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err); + __get_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err); + __get_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err); + + __get_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err); + __get_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err); + __get_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err); + __get_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err); + __get_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err); +#if defined(CONFIG_HWZOL) + __get_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err); + __get_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err); + __get_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err); +#endif +#if IS_ENABLED(CONFIG_FPU) + err |= restore_sigcontext_fpu(regs, &sf->uc.uc_mcontext); +#endif + /* + * Avoid sys_rt_sigreturn() restarting. + */ + forget_syscall(regs); + 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->restart_block.fn = do_no_restart_syscall; + + /* + * Since we stacked the signal on a 64-bit boundary, + * then 'sp' should be two-word aligned here. If it's + * not, then the user is trying to mess with us. + */ + if (regs->sp & 7) + goto badframe; + + frame = (struct rt_sigframe __user *)regs->sp; + + if (!access_ok(frame, sizeof(*frame))) + goto badframe; + + if (restore_sigframe(regs, frame)) + goto badframe; + + if (restore_altstack(&frame->uc.uc_stack)) + goto badframe; + + return regs->uregs[0]; + +badframe: + force_sig(SIGSEGV); + return 0; +} + +static int +setup_sigframe(struct rt_sigframe __user * sf, struct pt_regs *regs, + sigset_t * set) +{ + int err = 0; + + __put_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err); + __put_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err); + __put_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err); + __put_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err); + __put_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err); + __put_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err); + __put_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err); + __put_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err); + __put_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err); + __put_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err); + __put_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err); + __put_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err); + __put_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err); + __put_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err); + __put_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err); + __put_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err); + __put_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err); + __put_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err); + __put_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err); + __put_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err); + __put_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err); + + __put_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err); + __put_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err); + __put_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err); + __put_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err); + __put_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err); + __put_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err); + __put_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err); + __put_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err); + __put_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err); + __put_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err); +#if defined(CONFIG_HWZOL) + __put_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err); + __put_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err); + __put_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err); +#endif +#if IS_ENABLED(CONFIG_FPU) + err |= setup_sigcontext_fpu(regs, &sf->uc.uc_mcontext); +#endif + + __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)); + + return err; +} + +static inline void __user *get_sigframe(struct ksignal *ksig, + struct pt_regs *regs, int framesize) +{ + unsigned long sp; + + /* Default to using normal stack */ + sp = regs->sp; + + /* + * If we are on the alternate signal stack and would overflow it, don't. + * Return an always-bogus address instead so we will die with SIGSEGV. + */ + if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize))) + return (void __user __force *)(-1UL); + + /* This is the X/Open sanctioned signal stack switching. */ + sp = (sigsp(sp, ksig) - framesize); + + /* + * nds32 mandates 8-byte alignment + */ + sp &= ~0x7UL; + + return (void __user *)sp; +} + +static int +setup_return(struct pt_regs *regs, struct ksignal *ksig, void __user * frame) +{ + unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler; + unsigned long retcode; + + retcode = VDSO_SYMBOL(current->mm->context.vdso, rt_sigtramp); + regs->uregs[0] = ksig->sig; + regs->sp = (unsigned long)frame; + regs->lp = retcode; + regs->ipc = handler; + + return 0; +} + +static int +setup_rt_frame(struct ksignal *ksig, sigset_t * set, struct pt_regs *regs) +{ + struct rt_sigframe __user *frame = + get_sigframe(ksig, regs, sizeof(*frame)); + int err = 0; + + if (!access_ok(frame, sizeof(*frame))) + return -EFAULT; + + __put_user_error(0, &frame->uc.uc_flags, err); + __put_user_error(NULL, &frame->uc.uc_link, err); + + err |= __save_altstack(&frame->uc.uc_stack, regs->sp); + err |= setup_sigframe(frame, regs, set); + if (err == 0) { + setup_return(regs, ksig, frame); + if (ksig->ka.sa.sa_flags & SA_SIGINFO) { + err |= copy_siginfo_to_user(&frame->info, &ksig->info); + regs->uregs[1] = (unsigned long)&frame->info; + regs->uregs[2] = (unsigned long)&frame->uc; + } + } + return err; +} + +/* + * OK, we're invoking a handler + */ +static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) +{ + int ret; + sigset_t *oldset = sigmask_to_save(); + + if (in_syscall(regs)) { + /* Avoid additional syscall restarting via ret_slow_syscall. */ + forget_syscall(regs); + + switch (regs->uregs[0]) { + case -ERESTART_RESTARTBLOCK: + case -ERESTARTNOHAND: + regs->uregs[0] = -EINTR; + break; + case -ERESTARTSYS: + if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { + regs->uregs[0] = -EINTR; + break; + } + fallthrough; + case -ERESTARTNOINTR: + regs->uregs[0] = regs->orig_r0; + regs->ipc -= 4; + break; + } + } + /* + * Set up the stack frame + */ + ret = setup_rt_frame(ksig, oldset, regs); + + signal_setup_done(ret, ksig, 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) +{ + struct ksignal ksig; + + if (get_signal(&ksig)) { + handle_signal(&ksig, regs); + return; + } + + /* + * If we were from a system call, check for system call restarting... + */ + if (in_syscall(regs)) { + /* Restart the system call - no handlers present */ + + /* Avoid additional syscall restarting via ret_slow_syscall. */ + forget_syscall(regs); + + switch (regs->uregs[0]) { + case -ERESTART_RESTARTBLOCK: + regs->uregs[15] = __NR_restart_syscall; + fallthrough; + case -ERESTARTNOHAND: + case -ERESTARTSYS: + case -ERESTARTNOINTR: + regs->uregs[0] = regs->orig_r0; + regs->ipc -= 0x4; + break; + } + } + restore_saved_sigmask(); +} + +asmlinkage void +do_notify_resume(struct pt_regs *regs, unsigned int thread_flags) +{ + if (thread_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) + do_signal(regs); + + if (thread_flags & _TIF_NOTIFY_RESUME) + tracehook_notify_resume(regs); +} |