signal.c

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restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc, int *peax)
{
	unsigned int err = 0;
        abi_ulong fpstate_addr;
        unsigned int tmpflags;

        cpu_x86_load_seg(env, R_GS, tswap16(sc->gs));
        cpu_x86_load_seg(env, R_FS, tswap16(sc->fs));
        cpu_x86_load_seg(env, R_ES, tswap16(sc->es));
        cpu_x86_load_seg(env, R_DS, tswap16(sc->ds));

        env->regs[R_EDI] = tswapl(sc->edi);
        env->regs[R_ESI] = tswapl(sc->esi);
        env->regs[R_EBP] = tswapl(sc->ebp);
        env->regs[R_ESP] = tswapl(sc->esp);
        env->regs[R_EBX] = tswapl(sc->ebx);
        env->regs[R_EDX] = tswapl(sc->edx);
        env->regs[R_ECX] = tswapl(sc->ecx);
        env->eip = tswapl(sc->eip);

        cpu_x86_load_seg(env, R_CS, lduw(&sc->cs) | 3);
        cpu_x86_load_seg(env, R_SS, lduw(&sc->ss) | 3);

        tmpflags = tswapl(sc->eflags);
        env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
        //		regs->orig_eax = -1;		/* disable syscall checks */

        fpstate_addr = tswapl(sc->fpstate);
	if (fpstate_addr != 0) {
                if (!access_ok(VERIFY_READ, fpstate_addr, 
                               sizeof(struct target_fpstate)))
                        goto badframe;
                cpu_x86_frstor(env, fpstate_addr, 1);
	}

        *peax = tswapl(sc->eax);
	return err;
badframe:
	return 1;
}

long do_sigreturn(CPUX86State *env)
{
    struct sigframe *frame;
    abi_ulong frame_addr = env->regs[R_ESP] - 8;
    target_sigset_t target_set;
    sigset_t set;
    int eax, i;

#if defined(DEBUG_SIGNAL)
    fprintf(stderr, "do_sigreturn\n");
#endif
    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
        goto badframe;
    /* set blocked signals */
    if (__get_user(target_set.sig[0], &frame->sc.oldmask))
        goto badframe;
    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
        if (__get_user(target_set.sig[i], &frame->extramask[i - 1]))
            goto badframe;
    }

    target_to_host_sigset_internal(&set, &target_set);
    sigprocmask(SIG_SETMASK, &set, NULL);

    /* restore registers */
    if (restore_sigcontext(env, &frame->sc, &eax))
        goto badframe;
    unlock_user_struct(frame, frame_addr, 0);
    return eax;

badframe:
    unlock_user_struct(frame, frame_addr, 0);
    force_sig(TARGET_SIGSEGV);
    return 0;
}

long do_rt_sigreturn(CPUX86State *env)
{
        abi_ulong frame_addr;
	struct rt_sigframe *frame;
        sigset_t set;
	int eax;

        frame_addr = env->regs[R_ESP] - 4;
        if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
                goto badframe;
        target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
        sigprocmask(SIG_SETMASK, &set, NULL);

	if (restore_sigcontext(env, &frame->uc.tuc_mcontext, &eax))
		goto badframe;

	if (do_sigaltstack(frame_addr + offsetof(struct rt_sigframe, uc.tuc_stack), 0, 
                           get_sp_from_cpustate(env)) == -EFAULT)
		goto badframe;

        unlock_user_struct(frame, frame_addr, 0);
	return eax;

badframe:
        unlock_user_struct(frame, frame_addr, 0);
        force_sig(TARGET_SIGSEGV);
	return 0;
}

#elif defined(TARGET_ARM)

struct target_sigcontext {
	abi_ulong trap_no;
	abi_ulong error_code;
	abi_ulong oldmask;
	abi_ulong arm_r0;
	abi_ulong arm_r1;
	abi_ulong arm_r2;
	abi_ulong arm_r3;
	abi_ulong arm_r4;
	abi_ulong arm_r5;
	abi_ulong arm_r6;
	abi_ulong arm_r7;
	abi_ulong arm_r8;
	abi_ulong arm_r9;
	abi_ulong arm_r10;
	abi_ulong arm_fp;
	abi_ulong arm_ip;
	abi_ulong arm_sp;
	abi_ulong arm_lr;
	abi_ulong arm_pc;
	abi_ulong arm_cpsr;
	abi_ulong fault_address;
};

struct target_ucontext_v1 {
    abi_ulong tuc_flags;
    abi_ulong tuc_link;
    target_stack_t tuc_stack;
    struct target_sigcontext tuc_mcontext;
    target_sigset_t  tuc_sigmask;	/* mask last for extensibility */
};

struct target_ucontext_v2 {
    abi_ulong tuc_flags;
    abi_ulong tuc_link;
    target_stack_t tuc_stack;
    struct target_sigcontext tuc_mcontext;
    target_sigset_t  tuc_sigmask;	/* mask last for extensibility */
    char __unused[128 - sizeof(sigset_t)];
    abi_ulong tuc_regspace[128] __attribute__((__aligned__(8)));
};

struct sigframe_v1
{
    struct target_sigcontext sc;
    abi_ulong extramask[TARGET_NSIG_WORDS-1];
    abi_ulong retcode;
};

struct sigframe_v2
{
    struct target_ucontext_v2 uc;
    abi_ulong retcode;
};

struct rt_sigframe_v1
{
    abi_ulong pinfo;
    abi_ulong puc;
    struct target_siginfo info;
    struct target_ucontext_v1 uc;
    abi_ulong retcode;
};

struct rt_sigframe_v2
{
    struct target_siginfo info;
    struct target_ucontext_v2 uc;
    abi_ulong retcode;
};

#define TARGET_CONFIG_CPU_32 1

/*
 * For ARM syscalls, we encode the syscall number into the instruction.
 */
#define SWI_SYS_SIGRETURN	(0xef000000|(TARGET_NR_sigreturn + ARM_SYSCALL_BASE))
#define SWI_SYS_RT_SIGRETURN	(0xef000000|(TARGET_NR_rt_sigreturn + ARM_SYSCALL_BASE))

/*
 * For Thumb syscalls, we pass the syscall number via r7.  We therefore
 * need two 16-bit instructions.
 */
#define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_sigreturn))
#define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (TARGET_NR_rt_sigreturn))

static const abi_ulong retcodes[4] = {
	SWI_SYS_SIGRETURN,	SWI_THUMB_SIGRETURN,
	SWI_SYS_RT_SIGRETURN,	SWI_THUMB_RT_SIGRETURN
};


#define __get_user_error(x,p,e) __get_user(x, p)

static inline int valid_user_regs(CPUState *regs)
{
    return 1;
}

static void
setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
		 CPUState *env, abi_ulong mask)
{
	__put_user(env->regs[0], &sc->arm_r0);
	__put_user(env->regs[1], &sc->arm_r1);
	__put_user(env->regs[2], &sc->arm_r2);
	__put_user(env->regs[3], &sc->arm_r3);
	__put_user(env->regs[4], &sc->arm_r4);
	__put_user(env->regs[5], &sc->arm_r5);
	__put_user(env->regs[6], &sc->arm_r6);
	__put_user(env->regs[7], &sc->arm_r7);
	__put_user(env->regs[8], &sc->arm_r8);
	__put_user(env->regs[9], &sc->arm_r9);
	__put_user(env->regs[10], &sc->arm_r10);
	__put_user(env->regs[11], &sc->arm_fp);
	__put_user(env->regs[12], &sc->arm_ip);
	__put_user(env->regs[13], &sc->arm_sp);
	__put_user(env->regs[14], &sc->arm_lr);
	__put_user(env->regs[15], &sc->arm_pc);
#ifdef TARGET_CONFIG_CPU_32
	__put_user(cpsr_read(env), &sc->arm_cpsr);
#endif

	__put_user(/* current->thread.trap_no */ 0, &sc->trap_no);
	__put_user(/* current->thread.error_code */ 0, &sc->error_code);
	__put_user(/* current->thread.address */ 0, &sc->fault_address);
	__put_user(mask, &sc->oldmask);
}

static inline abi_ulong
get_sigframe(struct emulated_sigaction *ka, CPUState *regs, int framesize)
{
	unsigned long sp = regs->regs[13];

	/*
	 * This is the X/Open sanctioned signal stack switching.
	 */
	if ((ka->sa.sa_flags & TARGET_SA_ONSTACK) && !sas_ss_flags(sp))
            sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
	/*
	 * ATPCS B01 mandates 8-byte alignment
	 */
	return (sp - framesize) & ~7;
}

static int
setup_return(CPUState *env, struct emulated_sigaction *ka,
	     abi_ulong *rc, abi_ulong frame_addr, int usig, abi_ulong rc_addr)
{
	abi_ulong handler = ka->sa._sa_handler;
	abi_ulong retcode;
	int thumb = handler & 1;

	if (ka->sa.sa_flags & TARGET_SA_RESTORER) {
		retcode = ka->sa.sa_restorer;
	} else {
		unsigned int idx = thumb;

		if (ka->sa.sa_flags & TARGET_SA_SIGINFO)
			idx += 2;

		if (__put_user(retcodes[idx], rc))
			return 1;
#if 0
		flush_icache_range((abi_ulong)rc,
				   (abi_ulong)(rc + 1));
#endif
		retcode = rc_addr + thumb;
	}

	env->regs[0] = usig;
	env->regs[13] = frame_addr;
	env->regs[14] = retcode;
	env->regs[15] = handler & (thumb ? ~1 : ~3);
	env->thumb = thumb;

#if 0
#ifdef TARGET_CONFIG_CPU_32
	env->cpsr = cpsr;
#endif
#endif

	return 0;
}

static void setup_sigframe_v2(struct target_ucontext_v2 *uc,
                              target_sigset_t *set, CPUState *env)
{
    struct target_sigaltstack stack;
    int i;

    /* Clear all the bits of the ucontext we don't use.  */
    memset(uc, 0, offsetof(struct target_ucontext_v2, tuc_mcontext));

    memset(&stack, 0, sizeof(stack));
    __put_user(target_sigaltstack_used.ss_sp, &stack.ss_sp);
    __put_user(target_sigaltstack_used.ss_size, &stack.ss_size);
    __put_user(sas_ss_flags(get_sp_from_cpustate(env)), &stack.ss_flags);
    memcpy(&uc->tuc_stack, &stack, sizeof(stack));

    setup_sigcontext(&uc->tuc_mcontext, env, set->sig[0]);
    /* FIXME: Save coprocessor signal frame.  */
    for(i = 0; i < TARGET_NSIG_WORDS; i++) {
        __put_user(set->sig[i], &uc->tuc_sigmask.sig[i]);
    }
}

/* compare linux/arch/arm/kernel/signal.c:setup_frame() */
static void setup_frame_v1(int usig, struct emulated_sigaction *ka,
			   target_sigset_t *set, CPUState *regs)
{
	struct sigframe_v1 *frame;
	abi_ulong frame_addr = get_sigframe(ka, regs, sizeof(*frame));
	int i;

	if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
		return;

	setup_sigcontext(&frame->sc, regs, set->sig[0]);

        for(i = 1; i < TARGET_NSIG_WORDS; i++) {
            if (__put_user(set->sig[i], &frame->extramask[i - 1]))
                goto end;
	}

        setup_return(regs, ka, &frame->retcode, frame_addr, usig,
                     frame_addr + offsetof(struct sigframe_v1, retcode));

end:
	unlock_user_struct(frame, frame_addr, 1);
}

static void setup_frame_v2(int usig, struct emulated_sigaction *ka,
			   target_sigset_t *set, CPUState *regs)
{
	struct sigframe_v2 *frame;
	abi_ulong frame_addr = get_sigframe(ka, regs, sizeof(*frame));

	if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
		return;

        setup_sigframe_v2(&frame->uc, set, regs);

        setup_return(regs, ka, &frame->retcode, frame_addr, usig,
                     frame_addr + offsetof(struct sigframe_v2, retcode));

	unlock_user_struct(frame, frame_addr, 1);
}

static void setup_frame(int usig, struct emulated_sigaction *ka,
			target_sigset_t *set, CPUState *regs)
{
    if (get_osversion() >= 0x020612) {
        setup_frame_v2(usig, ka, set, regs);
    } else {
        setup_frame_v1(usig, ka, set, regs);
    }
}

/* compare linux/arch/arm/kernel/signal.c:setup_rt_frame() */
static void setup_rt_frame_v1(int usig, struct emulated_sigaction *ka,
                              target_siginfo_t *info,
			      target_sigset_t *set, CPUState *env)
{
	struct rt_sigframe_v1 *frame;
	abi_ulong frame_addr = get_sigframe(ka, env, sizeof(*frame));
	struct target_sigaltstack stack;
	int i;
        abi_ulong info_addr, uc_addr;

	if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
            return /* 1 */;

        info_addr = frame_addr + offsetof(struct rt_sigframe_v1, info);
	__put_user(info_addr, &frame->pinfo);
        uc_addr = frame_addr + offsetof(struct rt_sigframe_v1, uc);
	__put_user(uc_addr, &frame->puc);
	copy_siginfo_to_user(&frame->info, info);

	/* Clear all the bits of the ucontext we don't use.  */
	memset(&frame->uc, 0, offsetof(struct target_ucontext_v1, tuc_mcontext));

        memset(&stack, 0, sizeof(stack));
        __put_user(target_sigaltstack_used.ss_sp, &stack.ss_sp);
        __put_user(target_sigaltstack_used.ss_size, &stack.ss_size);
        __put_user(sas_ss_flags(get_sp_from_cpustate(env)), &stack.ss_flags);
        memcpy(&frame->uc.tuc_stack, &stack, sizeof(stack));

	setup_sigcontext(&frame->uc.tuc_mcontext, env, set->sig[0]);
        for(i = 0; i < TARGET_NSIG_WORDS; i++) {
            if (__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]))
                goto end;
        }

        setup_return(env, ka, &frame->retcode, frame_addr, usig,
                     frame_addr + offsetof(struct rt_sigframe_v1, retcode));

        env->regs[1] = info_addr;
        env->regs[2] = uc_addr;

end:
	unlock_user_struct(frame, frame_addr, 1);
}

static void setup_rt_frame_v2(int usig, struct emulated_sigaction *ka,
                              target_siginfo_t *info,
                              target_sigset_t *set, CPUState *env)
{
	struct rt_sigframe_v2 *frame;
	abi_ulong frame_addr = get_sigframe(ka, env, sizeof(*frame));
        abi_ulong info_addr, uc_addr;

	if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
            return /* 1 */;

        info_addr = frame_addr + offsetof(struct rt_sigframe_v2, info);
        uc_addr = frame_addr + offsetof(struct rt_sigframe_v2, uc);
	copy_siginfo_to_user(&frame->info, info);

        setup_sigframe_v2(&frame->uc, set, env);

        setup_return(env, ka, &frame->retcode, frame_addr, usig,
                     frame_addr + offsetof(struct rt_sigframe_v2, retcode));

        env->regs[1] = info_addr;
        env->regs[2] = uc_addr;

	unlock_user_struct(frame, frame_addr, 1);
}

static void setup_rt_frame(int usig, struct emulated_sigaction *ka,
                           target_siginfo_t *info,
			   target_sigset_t *set, CPUState *env)
{
    if (get_osversion() >= 0x020612) {
        setup_rt_frame_v2(usig, ka, info, set, env);
    } else {