| // 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) |
| do_signal(regs); |
| |
| if (thread_flags & _TIF_NOTIFY_RESUME) { |
| clear_thread_flag(TIF_NOTIFY_RESUME); |
| tracehook_notify_resume(regs); |
| } |
| } |