From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/microblaze/kernel/signal.c | 325 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 325 insertions(+) create mode 100644 arch/microblaze/kernel/signal.c (limited to 'arch/microblaze/kernel/signal.c') diff --git a/arch/microblaze/kernel/signal.c b/arch/microblaze/kernel/signal.c new file mode 100644 index 000000000..97001524c --- /dev/null +++ b/arch/microblaze/kernel/signal.c @@ -0,0 +1,325 @@ +/* + * Signal handling + * + * Copyright (C) 2008-2009 Michal Simek + * Copyright (C) 2008-2009 PetaLogix + * Copyright (C) 2003,2004 John Williams + * Copyright (C) 2001 NEC Corporation + * Copyright (C) 2001 Miles Bader + * 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 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * 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(VERIFY_READ, 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, current); + 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; +#ifdef CONFIG_MMU + pmd_t *pmdp; + pte_t *ptep; +#endif + + frame = get_sigframe(ksig, regs, sizeof(*frame)); + + if (!access_ok(VERIFY_WRITE, 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); +#ifdef CONFIG_MMU + pmdp = pmd_offset(pud_offset( + pgd_offset(current->mm, address), + address), 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(); +#else + flush_icache_range(address, address + 8); + flush_dcache_range(address, address + 8); +#endif + 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, current_thread_info()->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)) + do_signal(regs, in_syscall); + + if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) + tracehook_notify_resume(regs); +} -- cgit v1.2.3-54-g00ecf