| /* |
| * Port on Texas Instruments TMS320C6x architecture |
| * |
| * Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated |
| * Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com) |
| * |
| * Updated for 2.6.34: Mark Salter <msalter@redhat.com> |
| * |
| * 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/kernel.h> |
| #include <linux/uaccess.h> |
| #include <linux/syscalls.h> |
| #include <linux/tracehook.h> |
| |
| #include <asm/ucontext.h> |
| #include <asm/cacheflush.h> |
| |
| |
| #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
| |
| /* |
| * Do a signal return, undo the signal stack. |
| */ |
| |
| #define RETCODE_SIZE (9 << 2) /* 9 instructions = 36 bytes */ |
| |
| struct rt_sigframe { |
| struct siginfo __user *pinfo; |
| void __user *puc; |
| struct siginfo info; |
| struct ucontext uc; |
| unsigned long retcode[RETCODE_SIZE >> 2]; |
| }; |
| |
| static int restore_sigcontext(struct pt_regs *regs, |
| struct sigcontext __user *sc) |
| { |
| int err = 0; |
| |
| /* The access_ok check was done by caller, so use __get_user here */ |
| #define COPY(x) (err |= __get_user(regs->x, &sc->sc_##x)) |
| |
| COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8); |
| COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9); |
| COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9); |
| |
| COPY(a16); COPY(a17); COPY(a18); COPY(a19); |
| COPY(a20); COPY(a21); COPY(a22); COPY(a23); |
| COPY(a24); COPY(a25); COPY(a26); COPY(a27); |
| COPY(a28); COPY(a29); COPY(a30); COPY(a31); |
| COPY(b16); COPY(b17); COPY(b18); COPY(b19); |
| COPY(b20); COPY(b21); COPY(b22); COPY(b23); |
| COPY(b24); COPY(b25); COPY(b26); COPY(b27); |
| COPY(b28); COPY(b29); COPY(b30); COPY(b31); |
| |
| COPY(csr); COPY(pc); |
| |
| #undef COPY |
| |
| return err; |
| } |
| |
| asmlinkage int do_rt_sigreturn(struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| sigset_t set; |
| |
| /* |
| * Since we stacked the signal on a dword boundary, |
| * 'sp' should be dword 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 *) ((unsigned long) regs->sp + 8); |
| |
| 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); |
| set_current_blocked(&set); |
| |
| if (restore_sigcontext(regs, &frame->uc.uc_mcontext)) |
| goto badframe; |
| |
| return regs->a4; |
| |
| badframe: |
| force_sig(SIGSEGV, current); |
| return 0; |
| } |
| |
| static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, |
| unsigned long mask) |
| { |
| int err = 0; |
| |
| err |= __put_user(mask, &sc->sc_mask); |
| |
| /* The access_ok check was done by caller, so use __put_user here */ |
| #define COPY(x) (err |= __put_user(regs->x, &sc->sc_##x)) |
| |
| COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8); |
| COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9); |
| COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9); |
| |
| COPY(a16); COPY(a17); COPY(a18); COPY(a19); |
| COPY(a20); COPY(a21); COPY(a22); COPY(a23); |
| COPY(a24); COPY(a25); COPY(a26); COPY(a27); |
| COPY(a28); COPY(a29); COPY(a30); COPY(a31); |
| COPY(b16); COPY(b17); COPY(b18); COPY(b19); |
| COPY(b20); COPY(b21); COPY(b22); COPY(b23); |
| COPY(b24); COPY(b25); COPY(b26); COPY(b27); |
| COPY(b28); COPY(b29); COPY(b30); COPY(b31); |
| |
| COPY(csr); COPY(pc); |
| |
| #undef COPY |
| |
| return err; |
| } |
| |
| static inline void __user *get_sigframe(struct k_sigaction *ka, |
| struct pt_regs *regs, |
| unsigned long framesize) |
| { |
| unsigned long sp = regs->sp; |
| |
| /* |
| * This is the X/Open sanctioned signal stack switching. |
| */ |
| if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags(sp) == 0) |
| sp = current->sas_ss_sp + current->sas_ss_size; |
| |
| /* |
| * No matter what happens, 'sp' must be dword |
| * aligned. Otherwise, nasty things will happen |
| */ |
| return (void __user *)((sp - framesize) & ~7); |
| } |
| |
| static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info, |
| sigset_t *set, struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| unsigned long __user *retcode; |
| int err = 0; |
| |
| frame = get_sigframe(ka, regs, sizeof(*frame)); |
| |
| if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| goto segv_and_exit; |
| |
| err |= __put_user(&frame->info, &frame->pinfo); |
| err |= __put_user(&frame->uc, &frame->puc); |
| err |= copy_siginfo_to_user(&frame->info, info); |
| |
| /* Clear all the bits of the ucontext we don't use. */ |
| err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext)); |
| |
| err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]); |
| err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
| |
| /* Set up to return from userspace */ |
| retcode = (unsigned long __user *) &frame->retcode; |
| |
| /* The access_ok check was done above, so use __put_user here */ |
| #define COPY(x) (err |= __put_user(x, retcode++)) |
| |
| COPY(0x0000002AUL | (__NR_rt_sigreturn << 7)); |
| /* MVK __NR_rt_sigreturn,B0 */ |
| COPY(0x10000000UL); /* SWE */ |
| COPY(0x00006000UL); /* NOP 4 */ |
| COPY(0x00006000UL); /* NOP 4 */ |
| COPY(0x00006000UL); /* NOP 4 */ |
| COPY(0x00006000UL); /* NOP 4 */ |
| COPY(0x00006000UL); /* NOP 4 */ |
| COPY(0x00006000UL); /* NOP 4 */ |
| COPY(0x00006000UL); /* NOP 4 */ |
| |
| #undef COPY |
| |
| if (err) |
| goto segv_and_exit; |
| |
| flush_icache_range((unsigned long) &frame->retcode, |
| (unsigned long) &frame->retcode + RETCODE_SIZE); |
| |
| retcode = (unsigned long __user *) &frame->retcode; |
| |
| /* Change user context to branch to signal handler */ |
| regs->sp = (unsigned long) frame - 8; |
| regs->b3 = (unsigned long) retcode; |
| regs->pc = (unsigned long) ka->sa.sa_handler; |
| |
| /* Give the signal number to the handler */ |
| regs->a4 = signr; |
| |
| /* |
| * For realtime signals we must also set the second and third |
| * arguments for the signal handler. |
| * -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06 |
| */ |
| regs->b4 = (unsigned long)&frame->info; |
| regs->a6 = (unsigned long)&frame->uc; |
| |
| return 0; |
| |
| segv_and_exit: |
| force_sigsegv(signr, current); |
| return -EFAULT; |
| } |
| |
| static inline void |
| handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) |
| { |
| switch (regs->a4) { |
| case -ERESTARTNOHAND: |
| if (!has_handler) |
| goto do_restart; |
| regs->a4 = -EINTR; |
| break; |
| |
| case -ERESTARTSYS: |
| if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { |
| regs->a4 = -EINTR; |
| break; |
| } |
| /* fallthrough */ |
| case -ERESTARTNOINTR: |
| do_restart: |
| regs->a4 = regs->orig_a4; |
| regs->pc -= 4; |
| break; |
| } |
| } |
| |
| /* |
| * handle the actual delivery of a signal to userspace |
| */ |
| static int handle_signal(int sig, |
| siginfo_t *info, struct k_sigaction *ka, |
| sigset_t *oldset, struct pt_regs *regs, |
| int syscall) |
| { |
| int ret; |
| |
| /* Are we from a system call? */ |
| if (syscall) { |
| /* If so, check system call restarting.. */ |
| switch (regs->a4) { |
| case -ERESTART_RESTARTBLOCK: |
| case -ERESTARTNOHAND: |
| regs->a4 = -EINTR; |
| break; |
| |
| case -ERESTARTSYS: |
| if (!(ka->sa.sa_flags & SA_RESTART)) { |
| regs->a4 = -EINTR; |
| break; |
| } |
| |
| /* fallthrough */ |
| case -ERESTARTNOINTR: |
| regs->a4 = regs->orig_a4; |
| regs->pc -= 4; |
| } |
| } |
| |
| /* Set up the stack frame */ |
| ret = setup_rt_frame(sig, ka, info, oldset, regs); |
| if (ret == 0) |
| block_sigmask(ka, sig); |
| |
| return ret; |
| } |
| |
| /* |
| * handle a potential signal |
| */ |
| static void do_signal(struct pt_regs *regs, int syscall) |
| { |
| struct k_sigaction ka; |
| siginfo_t info; |
| sigset_t *oldset; |
| int signr; |
| |
| /* we want the common case to go fast, which is why we may in certain |
| * cases get here from kernel mode */ |
| if (!user_mode(regs)) |
| return; |
| |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| oldset = ¤t->saved_sigmask; |
| else |
| oldset = ¤t->blocked; |
| |
| signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
| if (signr > 0) { |
| if (handle_signal(signr, &info, &ka, oldset, |
| regs, syscall) == 0) { |
| /* a signal was successfully delivered; the saved |
| * sigmask will have been stored in the signal frame, |
| * and will be restored by sigreturn, so we can simply |
| * clear the TIF_RESTORE_SIGMASK flag */ |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| |
| tracehook_signal_handler(signr, &info, &ka, regs, 0); |
| } |
| |
| return; |
| } |
| |
| /* did we come from a system call? */ |
| if (syscall) { |
| /* restart the system call - no handlers present */ |
| switch (regs->a4) { |
| case -ERESTARTNOHAND: |
| case -ERESTARTSYS: |
| case -ERESTARTNOINTR: |
| regs->a4 = regs->orig_a4; |
| regs->pc -= 4; |
| break; |
| |
| case -ERESTART_RESTARTBLOCK: |
| regs->a4 = regs->orig_a4; |
| regs->b0 = __NR_restart_syscall; |
| regs->pc -= 4; |
| break; |
| } |
| } |
| |
| /* if there's no signal to deliver, we just put the saved sigmask |
| * back */ |
| if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
| clear_thread_flag(TIF_RESTORE_SIGMASK); |
| sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
| } |
| } |
| |
| /* |
| * notification of userspace execution resumption |
| * - triggered by current->work.notify_resume |
| */ |
| asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags, |
| int syscall) |
| { |
| /* deal with pending signal delivery */ |
| if (thread_info_flags & ((1 << TIF_SIGPENDING) | |
| (1 << TIF_RESTORE_SIGMASK))) |
| do_signal(regs, syscall); |
| |
| if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) { |
| clear_thread_flag(TIF_NOTIFY_RESUME); |
| tracehook_notify_resume(regs); |
| if (current->replacement_session_keyring) |
| key_replace_session_keyring(); |
| } |
| } |