| /* |
| * Signal handling |
| * |
| * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> |
| * Copyright (C) 2008-2009 PetaLogix |
| * Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au> |
| * Copyright (C) 2001 NEC Corporation |
| * Copyright (C) 2001 Miles Bader <miles@gnu.org> |
| * Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima |
| * Copyright (C) 1991,1992 Linus Torvalds |
| * |
| * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson |
| * |
| * This file was derived from the sh version, arch/sh/kernel/signal.c |
| * |
| * 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/sched.h> |
| #include <linux/mm.h> |
| #include <linux/smp.h> |
| #include <linux/kernel.h> |
| #include <linux/signal.h> |
| #include <linux/errno.h> |
| #include <linux/wait.h> |
| #include <linux/ptrace.h> |
| #include <linux/unistd.h> |
| #include <linux/stddef.h> |
| #include <linux/personality.h> |
| #include <linux/percpu.h> |
| #include <linux/linkage.h> |
| #include <linux/resume_user_mode.h> |
| #include <asm/entry.h> |
| #include <asm/ucontext.h> |
| #include <linux/uaccess.h> |
| #include <linux/syscalls.h> |
| #include <asm/cacheflush.h> |
| #include <asm/syscalls.h> |
| |
| /* |
| * Do a signal return; undo the signal stack. |
| */ |
| struct sigframe { |
| struct sigcontext sc; |
| unsigned long extramask[_NSIG_WORDS-1]; |
| unsigned long tramp[2]; /* signal trampoline */ |
| }; |
| |
| struct rt_sigframe { |
| struct siginfo info; |
| struct ucontext uc; |
| unsigned long tramp[2]; /* signal trampoline */ |
| }; |
| |
| static int restore_sigcontext(struct pt_regs *regs, |
| struct sigcontext __user *sc, int *rval_p) |
| { |
| unsigned int err = 0; |
| |
| #define COPY(x) {err |= __get_user(regs->x, &sc->regs.x); } |
| COPY(r0); |
| COPY(r1); |
| COPY(r2); COPY(r3); COPY(r4); COPY(r5); |
| COPY(r6); COPY(r7); COPY(r8); COPY(r9); |
| COPY(r10); COPY(r11); COPY(r12); COPY(r13); |
| COPY(r14); COPY(r15); COPY(r16); COPY(r17); |
| COPY(r18); COPY(r19); COPY(r20); COPY(r21); |
| COPY(r22); COPY(r23); COPY(r24); COPY(r25); |
| COPY(r26); COPY(r27); COPY(r28); COPY(r29); |
| COPY(r30); COPY(r31); |
| COPY(pc); COPY(ear); COPY(esr); COPY(fsr); |
| #undef COPY |
| |
| *rval_p = regs->r3; |
| |
| return err; |
| } |
| |
| asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame = |
| (struct rt_sigframe __user *)(regs->r1); |
| |
| sigset_t set; |
| int rval; |
| |
| /* Always make any pending restarted system calls return -EINTR */ |
| current->restart_block.fn = do_no_restart_syscall; |
| |
| if (!access_ok(frame, sizeof(*frame))) |
| goto badframe; |
| |
| if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) |
| goto badframe; |
| |
| set_current_blocked(&set); |
| |
| if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval)) |
| goto badframe; |
| |
| if (restore_altstack(&frame->uc.uc_stack)) |
| goto badframe; |
| |
| return rval; |
| |
| badframe: |
| force_sig(SIGSEGV); |
| return 0; |
| } |
| |
| /* |
| * Set up a signal frame. |
| */ |
| |
| static int |
| setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, |
| unsigned long mask) |
| { |
| int err = 0; |
| |
| #define COPY(x) {err |= __put_user(regs->x, &sc->regs.x); } |
| COPY(r0); |
| COPY(r1); |
| COPY(r2); COPY(r3); COPY(r4); COPY(r5); |
| COPY(r6); COPY(r7); COPY(r8); COPY(r9); |
| COPY(r10); COPY(r11); COPY(r12); COPY(r13); |
| COPY(r14); COPY(r15); COPY(r16); COPY(r17); |
| COPY(r18); COPY(r19); COPY(r20); COPY(r21); |
| COPY(r22); COPY(r23); COPY(r24); COPY(r25); |
| COPY(r26); COPY(r27); COPY(r28); COPY(r29); |
| COPY(r30); COPY(r31); |
| COPY(pc); COPY(ear); COPY(esr); COPY(fsr); |
| #undef COPY |
| |
| err |= __put_user(mask, &sc->oldmask); |
| |
| return err; |
| } |
| |
| /* |
| * Determine which stack to use.. |
| */ |
| static inline void __user * |
| get_sigframe(struct ksignal *ksig, struct pt_regs *regs, size_t frame_size) |
| { |
| /* Default to using normal stack */ |
| unsigned long sp = sigsp(regs->r1, ksig); |
| |
| return (void __user *)((sp - frame_size) & -8UL); |
| } |
| |
| static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
| struct pt_regs *regs) |
| { |
| struct rt_sigframe __user *frame; |
| int err = 0, sig = ksig->sig; |
| unsigned long address = 0; |
| pmd_t *pmdp; |
| pte_t *ptep; |
| |
| frame = get_sigframe(ksig, regs, sizeof(*frame)); |
| |
| if (!access_ok(frame, sizeof(*frame))) |
| return -EFAULT; |
| |
| if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
| err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
| |
| /* Create the ucontext. */ |
| err |= __put_user(0, &frame->uc.uc_flags); |
| err |= __put_user(NULL, &frame->uc.uc_link); |
| err |= __save_altstack(&frame->uc.uc_stack, regs->r1); |
| 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. If provided, use a stub |
| already in userspace. */ |
| /* minus 8 is offset to cater for "rtsd r15,8" */ |
| /* addi r12, r0, __NR_sigreturn */ |
| err |= __put_user(0x31800000 | __NR_rt_sigreturn , |
| frame->tramp + 0); |
| /* brki r14, 0x8 */ |
| err |= __put_user(0xb9cc0008, frame->tramp + 1); |
| |
| /* Return from sighandler will jump to the tramp. |
| Negative 8 offset because return is rtsd r15, 8 */ |
| regs->r15 = ((unsigned long)frame->tramp)-8; |
| |
| address = ((unsigned long)frame->tramp); |
| pmdp = pmd_off(current->mm, address); |
| |
| preempt_disable(); |
| ptep = pte_offset_map(pmdp, address); |
| if (pte_present(*ptep)) { |
| address = (unsigned long) page_address(pte_page(*ptep)); |
| /* MS: I need add offset in page */ |
| address += ((unsigned long)frame->tramp) & ~PAGE_MASK; |
| /* MS address is virtual */ |
| address = __virt_to_phys(address); |
| invalidate_icache_range(address, address + 8); |
| flush_dcache_range(address, address + 8); |
| } |
| pte_unmap(ptep); |
| preempt_enable(); |
| if (err) |
| return -EFAULT; |
| |
| /* Set up registers for signal handler */ |
| regs->r1 = (unsigned long) frame; |
| |
| /* Signal handler args: */ |
| regs->r5 = sig; /* arg 0: signum */ |
| regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */ |
| regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */ |
| /* Offset to handle microblaze rtid r14, 0 */ |
| regs->pc = (unsigned long)ksig->ka.sa.sa_handler; |
| |
| #ifdef DEBUG_SIG |
| pr_info("SIG deliver (%s:%d): sp=%p pc=%08lx\n", |
| current->comm, current->pid, frame, regs->pc); |
| #endif |
| |
| return 0; |
| } |
| |
| /* Handle restarting system calls */ |
| static inline void |
| handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler) |
| { |
| switch (regs->r3) { |
| case -ERESTART_RESTARTBLOCK: |
| case -ERESTARTNOHAND: |
| if (!has_handler) |
| goto do_restart; |
| regs->r3 = -EINTR; |
| break; |
| case -ERESTARTSYS: |
| if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) { |
| regs->r3 = -EINTR; |
| break; |
| } |
| fallthrough; |
| case -ERESTARTNOINTR: |
| do_restart: |
| /* offset of 4 bytes to re-execute trap (brki) instruction */ |
| regs->pc -= 4; |
| break; |
| } |
| } |
| |
| /* |
| * OK, we're invoking a handler |
| */ |
| |
| static void |
| handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
| { |
| sigset_t *oldset = sigmask_to_save(); |
| int ret; |
| |
| /* Set up the stack frame */ |
| ret = setup_rt_frame(ksig, oldset, regs); |
| |
| signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); |
| } |
| |
| /* |
| * 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, int in_syscall) |
| { |
| struct ksignal ksig; |
| |
| #ifdef DEBUG_SIG |
| pr_info("do signal: %p %d\n", regs, in_syscall); |
| pr_info("do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1, |
| regs->r12, read_thread_flags()); |
| #endif |
| |
| if (get_signal(&ksig)) { |
| /* Whee! Actually deliver the signal. */ |
| if (in_syscall) |
| handle_restart(regs, &ksig.ka, 1); |
| handle_signal(&ksig, regs); |
| return; |
| } |
| |
| if (in_syscall) |
| handle_restart(regs, NULL, 0); |
| |
| /* |
| * If there's no signal to deliver, we just put the saved sigmask |
| * back. |
| */ |
| restore_saved_sigmask(); |
| } |
| |
| asmlinkage void do_notify_resume(struct pt_regs *regs, int in_syscall) |
| { |
| if (test_thread_flag(TIF_SIGPENDING) || |
| test_thread_flag(TIF_NOTIFY_SIGNAL)) |
| do_signal(regs, in_syscall); |
| |
| if (test_thread_flag(TIF_NOTIFY_RESUME)) |
| resume_user_mode_work(regs); |
| } |