diff options
| -rw-r--r-- | arch/openrisc/kernel/entry.S | 59 | ||||
| -rw-r--r-- | arch/openrisc/kernel/signal.c | 198 |
2 files changed, 139 insertions, 118 deletions
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S index d8a455ede5a7..fec8bf97d806 100644 --- a/arch/openrisc/kernel/entry.S +++ b/arch/openrisc/kernel/entry.S @@ -853,37 +853,44 @@ UNHANDLED_EXCEPTION(_vector_0x1f00,0x1f00) /* ========================================================[ return ] === */ +_resume_userspace: + DISABLE_INTERRUPTS(r3,r4) + l.lwz r4,TI_FLAGS(r10) + l.andi r13,r4,_TIF_WORK_MASK + l.sfeqi r13,0 + l.bf _restore_all + l.nop + _work_pending: - /* - * if (current_thread_info->flags & _TIF_NEED_RESCHED) - * schedule(); - */ - l.lwz r5,TI_FLAGS(r10) - l.andi r3,r5,_TIF_NEED_RESCHED - l.sfnei r3,0 - l.bnf _work_notifysig + l.lwz r5,PT_ORIG_GPR11(r1) + l.sfltsi r5,0 + l.bnf 1f l.nop - l.jal schedule + l.andi r5,r5,0 +1: + l.jal do_work_pending + l.ori r3,r1,0 /* pt_regs */ + + l.sfeqi r11,0 + l.bf _restore_all l.nop - l.j _resume_userspace + l.sfltsi r11,0 + l.bnf 1f l.nop - -/* Handle pending signals and notify-resume requests. - * do_notify_resume must be passed the latest pushed pt_regs, not - * necessarily the "userspace" ones. Also, pt_regs->syscallno - * must be set so that the syscall restart functionality works. - */ -_work_notifysig: - l.jal do_notify_resume - l.ori r3,r1,0 /* pt_regs */ - -_resume_userspace: - DISABLE_INTERRUPTS(r3,r4) - l.lwz r3,TI_FLAGS(r10) - l.andi r3,r3,_TIF_WORK_MASK - l.sfnei r3,0 - l.bf _work_pending + l.and r11,r11,r0 + l.ori r11,r11,__NR_restart_syscall + l.j _syscall_check_trace_enter l.nop +1: + l.lwz r11,PT_ORIG_GPR11(r1) + /* Restore arg registers */ + l.lwz r3,PT_GPR3(r1) + l.lwz r4,PT_GPR4(r1) + l.lwz r5,PT_GPR5(r1) + l.lwz r6,PT_GPR6(r1) + l.lwz r7,PT_GPR7(r1) + l.j _syscall_check_trace_enter + l.lwz r8,PT_GPR8(r1) _restore_all: RESTORE_ALL diff --git a/arch/openrisc/kernel/signal.c b/arch/openrisc/kernel/signal.c index ae167f7e081a..c277ec82783d 100644 --- a/arch/openrisc/kernel/signal.c +++ b/arch/openrisc/kernel/signal.c @@ -28,24 +28,24 @@ #include <linux/tracehook.h> #include <asm/processor.h> +#include <asm/syscall.h> #include <asm/ucontext.h> #include <asm/uaccess.h> #define DEBUG_SIG 0 struct rt_sigframe { - struct siginfo *pinfo; - void *puc; struct siginfo info; struct ucontext uc; unsigned char retcode[16]; /* trampoline code */ }; -static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc) +static int restore_sigcontext(struct pt_regs *regs, + struct sigcontext __user *sc) { - unsigned int err = 0; + int err = 0; - /* Alwys make any pending restarted system call return -EINTR */ + /* Always make any pending restarted system calls return -EINTR */ current_thread_info()->restart_block.fn = do_no_restart_syscall; /* @@ -53,25 +53,21 @@ static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc) * (sc is already checked for VERIFY_READ since the sigframe was * checked in sys_sigreturn previously) */ - if (__copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long))) - goto badframe; - if (__copy_from_user(®s->pc, &sc->regs.pc, sizeof(unsigned long))) - goto badframe; - if (__copy_from_user(®s->sr, &sc->regs.sr, sizeof(unsigned long))) - goto badframe; + err |= __copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long)); + err |= __copy_from_user(®s->pc, &sc->regs.pc, sizeof(unsigned long)); + err |= __copy_from_user(®s->sr, &sc->regs.sr, sizeof(unsigned long)); /* make sure the SM-bit is cleared so user-mode cannot fool us */ regs->sr &= ~SPR_SR_SM; + regs->orig_gpr11 = -1; /* Avoid syscall restart checks */ + /* TODO: the other ports use regs->orig_XX to disable syscall checks * after this completes, but we don't use that mechanism. maybe we can * use it now ? */ return err; - -badframe: - return 1; } asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs) @@ -111,21 +107,18 @@ badframe: * Set up a signal frame. */ -static int setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs, - unsigned long mask) +static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { int err = 0; /* copy the regs */ - + /* There should be no need to save callee-saved registers here... + * ...but we save them anyway. Revisit this + */ err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long)); err |= __copy_to_user(&sc->regs.pc, ®s->pc, sizeof(unsigned long)); err |= __copy_to_user(&sc->regs.sr, ®s->sr, sizeof(unsigned long)); - /* then some other stuff */ - - err |= __put_user(mask, &sc->oldmask); - return err; } @@ -181,24 +174,18 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, int err = 0; frame = get_sigframe(ka, regs, sizeof(*frame)); - if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) goto give_sigsegv; - err |= __put_user(&frame->info, &frame->pinfo); - err |= __put_user(&frame->uc, &frame->puc); - + /* Create siginfo. */ if (ka->sa.sa_flags & SA_SIGINFO) err |= copy_siginfo_to_user(&frame->info, info); - if (err) - goto give_sigsegv; - /* Clear all the bits of the ucontext we don't use. */ - err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext)); + /* 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->sp); - err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]); + err |= setup_sigcontext(regs, &frame->uc.uc_mcontext); err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); @@ -207,9 +194,12 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, /* trampoline - the desired return ip is the retcode itself */ return_ip = (unsigned long)&frame->retcode; - /* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */ - err |= __put_user(0xa960, (short *)(frame->retcode + 0)); - err |= __put_user(__NR_rt_sigreturn, (short *)(frame->retcode + 2)); + /* This is: + l.ori r11,r0,__NR_sigreturn + l.sys 1 + */ + err |= __put_user(0xa960, (short *)(frame->retcode + 0)); + err |= __put_user(__NR_rt_sigreturn, (short *)(frame->retcode + 2)); err |= __put_user(0x20000001, (unsigned long *)(frame->retcode + 4)); err |= __put_user(0x15000000, (unsigned long *)(frame->retcode + 8)); @@ -262,82 +252,106 @@ handle_signal(unsigned long sig, * mode below. */ -void do_signal(struct pt_regs *regs) +int do_signal(struct pt_regs *regs, int syscall) { siginfo_t info; int signr; struct k_sigaction ka; - - /* - * We want the common case to go fast, which - * is why we may in certain cases get here from - * kernel mode. Just return without doing anything - * if so. - */ - if (!user_mode(regs)) - return; - - signr = get_signal_to_deliver(&info, &ka, regs, NULL); - - /* If we are coming out of a syscall then we need - * to check if the syscall was interrupted and wants to be - * restarted after handling the signal. If so, the original - * syscall number is put back into r11 and the PC rewound to - * point at the l.sys instruction that resulted in the - * original syscall. Syscall results other than the four - * below mean that the syscall executed to completion and no - * restart is necessary. - */ - if (regs->orig_gpr11) { - int restart = 0; - - switch (regs->gpr[11]) { + unsigned long continue_addr = 0; + unsigned long restart_addr = 0; + unsigned long retval = 0; + int restart = 0; + + if (syscall) { + continue_addr = regs->pc; + restart_addr = continue_addr - 4; + retval = regs->gpr[11]; + + /* + * Setup syscall restart here so that a debugger will + * see the already changed PC. + */ + switch (retval) { case -ERESTART_RESTARTBLOCK: + restart = -2; + /* Fall through */ case -ERESTARTNOHAND: - /* Restart if there is no signal handler */ - restart = (signr <= 0); - break; case -ERESTARTSYS: - /* Restart if there no signal handler or - * SA_RESTART flag is set */ - restart = (signr <= 0 || (ka.sa.sa_flags & SA_RESTART)); - break; case -ERESTARTNOINTR: - /* Always restart */ - restart = 1; + restart++; + regs->gpr[11] = regs->orig_gpr11; + regs->pc = restart_addr; break; } + } - if (restart) { - if (regs->gpr[11] == -ERESTART_RESTARTBLOCK) - regs->gpr[11] = __NR_restart_syscall; - else - regs->gpr[11] = regs->orig_gpr11; - regs->pc -= 4; - } else { - regs->gpr[11] = -EINTR; + /* + * Get the signal to deliver. When running under ptrace, at this + * point the debugger may change all our registers ... + */ + signr = get_signal_to_deliver(&info, &ka, regs, NULL); + /* + * Depending on the signal settings we may need to revert the + * decision to restart the system call. But skip this if a + * debugger has chosen to restart at a different PC. + */ + if (signr > 0) { + if (unlikely(restart) && regs->pc == restart_addr) { + if (retval == -ERESTARTNOHAND || + retval == -ERESTART_RESTARTBLOCK + || (retval == -ERESTARTSYS + && !(ka.sa.sa_flags & SA_RESTART))) { + /* No automatic restart */ + regs->gpr[11] = -EINTR; + regs->pc = continue_addr; + } } - } - if (signr <= 0) { - /* no signal to deliver so we just put the saved sigmask - * back */ - restore_saved_sigmask(); - } else { /* signr > 0 */ - /* Whee! Actually deliver the signal. */ handle_signal(signr, &info, &ka, regs); + } else { + /* no handler */ + restore_saved_sigmask(); + /* + * Restore pt_regs PC as syscall restart will be handled by + * kernel without return to userspace + */ + if (unlikely(restart) && regs->pc == restart_addr) { + regs->pc = continue_addr; + return restart; + } } - return; + return 0; } -asmlinkage void do_notify_resume(struct pt_regs *regs) +asmlinkage int +do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall) { - if (current_thread_info()->flags & _TIF_SIGPENDING) - do_signal(regs); - - if (current_thread_info()->flags & _TIF_NOTIFY_RESUME) { - clear_thread_flag(TIF_NOTIFY_RESUME); - tracehook_notify_resume(regs); - } + do { + if (likely(thread_flags & _TIF_NEED_RESCHED)) { + schedule(); + } else { + if (unlikely(!user_mode(regs))) + return 0; + local_irq_enable(); + if (thread_flags & _TIF_SIGPENDING) { + int restart = do_signal(regs, syscall); + if (unlikely(restart)) { + /* + * Restart without handlers. + * Deal with it without leaving + * the kernel space. + */ + return restart; + } + syscall = 0; + } else { + clear_thread_flag(TIF_NOTIFY_RESUME); + tracehook_notify_resume(regs); + } + } + local_irq_disable(); + thread_flags = current_thread_info()->flags; + } while (thread_flags & _TIF_WORK_MASK); + return 0; } |