Commit 1c1df019 authored by Pranith Kumar's avatar Pranith Kumar Committed by Laurent Vivier
Browse files

linux-user: Add signal handling support for x86_64 



Note that x86_64 has only _rt signal handlers. This implementation
attempts to share code with the x86_32 implementation.

CC: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: default avatarAllan Wirth <awirth@akamai.com>
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: default avatarPranith Kumar <bobby.prani@gmail.com>
Reviewed-by: default avatarLaurent Vivier <laurent@vivier.eu>
Message-Id: <20170226165345.8757-1-bobby.prani@gmail.com>
Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
parent ee1ac3a1

linux-user/signal.c

+227 −51
Original line number Diff line number Diff line
@@ -254,7 +254,7 @@ int do_sigprocmask(int how, const sigset_t *set, sigset_t *oldset) 
}



#if !defined(TARGET_OPENRISC) && !defined(TARGET_UNICORE32) && \

    !defined(TARGET_X86_64) && !defined(TARGET_NIOS2)

    !defined(TARGET_NIOS2)

/* Just set the guest's signal mask to the specified value; the

 * caller is assumed to have called block_signals() already.

 */
@@ -512,7 +512,7 @@ void signal_init(void) 
    }

}



#if !(defined(TARGET_X86_64) || defined(TARGET_UNICORE32))

#ifndef TARGET_UNICORE32

/* Force a synchronously taken signal. The kernel force_sig() function

 * also forces the signal to "not blocked, not ignored", but for QEMU

 * that work is done in process_pending_signals().
@@ -819,9 +819,8 @@ int do_sigaction(int sig, const struct target_sigaction *act, 
    return ret;

}



#if defined(TARGET_I386) && TARGET_ABI_BITS == 32



/* from the Linux kernel */

#if defined(TARGET_I386)

/* from the Linux kernel - /arch/x86/include/uapi/asm/sigcontext.h */



struct target_fpreg {

    uint16_t significand[4];
@@ -835,58 +834,120 @@ struct target_fpxreg { 
};



struct target_xmmreg {

    abi_ulong element[4];

    uint32_t element[4];

};



struct target_fpstate {

struct target_fpstate_32 {

    /* Regular FPU environment */

    abi_ulong cw;

    abi_ulong sw;

    abi_ulong tag;

    abi_ulong ipoff;

    abi_ulong cssel;

    abi_ulong dataoff;

    abi_ulong datasel;

    struct target_fpreg _st[8];

    uint32_t cw;

    uint32_t sw;

    uint32_t tag;

    uint32_t ipoff;

    uint32_t cssel;

    uint32_t dataoff;

    uint32_t datasel;

    struct target_fpreg st[8];

    uint16_t  status;

    uint16_t  magic;          /* 0xffff = regular FPU data only */



    /* FXSR FPU environment */

    abi_ulong _fxsr_env[6];   /* FXSR FPU env is ignored */

    abi_ulong mxcsr;

    abi_ulong reserved;

    struct target_fpxreg _fxsr_st[8]; /* FXSR FPU reg data is ignored */

    struct target_xmmreg _xmm[8];

    abi_ulong padding[56];

    uint32_t _fxsr_env[6];   /* FXSR FPU env is ignored */

    uint32_t mxcsr;

    uint32_t reserved;

    struct target_fpxreg fxsr_st[8]; /* FXSR FPU reg data is ignored */

    struct target_xmmreg xmm[8];

    uint32_t padding[56];

};



#define X86_FXSR_MAGIC		0x0000

struct target_fpstate_64 {

    /* FXSAVE format */

    uint16_t cw;

    uint16_t sw;

    uint16_t twd;

    uint16_t fop;

    uint64_t rip;

    uint64_t rdp;

    uint32_t mxcsr;

    uint32_t mxcsr_mask;

    uint32_t st_space[32];

    uint32_t xmm_space[64];

    uint32_t reserved[24];

};



struct target_sigcontext {

#ifndef TARGET_X86_64

# define target_fpstate target_fpstate_32

#else

# define target_fpstate target_fpstate_64

#endif



struct target_sigcontext_32 {

    uint16_t gs, __gsh;

    uint16_t fs, __fsh;

    uint16_t es, __esh;

    uint16_t ds, __dsh;

    abi_ulong edi;

    abi_ulong esi;

    abi_ulong ebp;

    abi_ulong esp;

    abi_ulong ebx;

    abi_ulong edx;

    abi_ulong ecx;

    abi_ulong eax;

    abi_ulong trapno;

    abi_ulong err;

    abi_ulong eip;

    uint32_t edi;

    uint32_t esi;

    uint32_t ebp;

    uint32_t esp;

    uint32_t ebx;

    uint32_t edx;

    uint32_t ecx;

    uint32_t eax;

    uint32_t trapno;

    uint32_t err;

    uint32_t eip;

    uint16_t cs, __csh;

    abi_ulong eflags;

    abi_ulong esp_at_signal;

    uint32_t eflags;

    uint32_t esp_at_signal;

    uint16_t ss, __ssh;

    abi_ulong fpstate; /* pointer */

    abi_ulong oldmask;

    abi_ulong cr2;

    uint32_t fpstate; /* pointer */

    uint32_t oldmask;

    uint32_t cr2;

};



struct target_sigcontext_64 {

    uint64_t r8;

    uint64_t r9;

    uint64_t r10;

    uint64_t r11;

    uint64_t r12;

    uint64_t r13;

    uint64_t r14;

    uint64_t r15;



    uint64_t rdi;

    uint64_t rsi;

    uint64_t rbp;

    uint64_t rbx;

    uint64_t rdx;

    uint64_t rax;

    uint64_t rcx;

    uint64_t rsp;

    uint64_t rip;



    uint64_t eflags;



    uint16_t cs;

    uint16_t gs;

    uint16_t fs;

    uint16_t ss;



    uint64_t err;

    uint64_t trapno;

    uint64_t oldmask;

    uint64_t cr2;



    uint64_t fpstate; /* pointer */

    uint64_t padding[8];

};



#ifndef TARGET_X86_64

# define target_sigcontext target_sigcontext_32

#else

# define target_sigcontext target_sigcontext_64

#endif



/* see Linux/include/uapi/asm-generic/ucontext.h */

struct target_ucontext {

    abi_ulong         tuc_flags;

    abi_ulong         tuc_link;
@@ -895,8 +956,8 @@ struct target_ucontext { 
    target_sigset_t   tuc_sigmask;  /* mask last for extensibility */

};



struct sigframe

{

#ifndef TARGET_X86_64

struct sigframe {

    abi_ulong pretcode;

    int sig;

    struct target_sigcontext sc;
@@ -905,8 +966,7 @@ struct sigframe 
    char retcode[8];

};



struct rt_sigframe

{

struct rt_sigframe {

    abi_ulong pretcode;

    int sig;

    abi_ulong pinfo;
@@ -917,6 +977,17 @@ struct rt_sigframe 
    char retcode[8];

};



#else



struct rt_sigframe {

    abi_ulong pretcode;

    struct target_ucontext uc;

    struct target_siginfo info;

    struct target_fpstate fpstate;

};



#endif



/*

 * Set up a signal frame.

 */
@@ -927,6 +998,7 @@ static void setup_sigcontext(struct target_sigcontext *sc, 
        abi_ulong fpstate_addr)

{

    CPUState *cs = CPU(x86_env_get_cpu(env));

#ifndef TARGET_X86_64

    uint16_t magic;



    /* already locked in setup_frame() */
@@ -959,6 +1031,44 @@ static void setup_sigcontext(struct target_sigcontext *sc, 
    /* non-iBCS2 extensions.. */

    __put_user(mask, &sc->oldmask);

    __put_user(env->cr[2], &sc->cr2);

#else

    __put_user(env->regs[R_EDI], &sc->rdi);

    __put_user(env->regs[R_ESI], &sc->rsi);

    __put_user(env->regs[R_EBP], &sc->rbp);

    __put_user(env->regs[R_ESP], &sc->rsp);

    __put_user(env->regs[R_EBX], &sc->rbx);

    __put_user(env->regs[R_EDX], &sc->rdx);

    __put_user(env->regs[R_ECX], &sc->rcx);

    __put_user(env->regs[R_EAX], &sc->rax);



    __put_user(env->regs[8], &sc->r8);

    __put_user(env->regs[9], &sc->r9);

    __put_user(env->regs[10], &sc->r10);

    __put_user(env->regs[11], &sc->r11);

    __put_user(env->regs[12], &sc->r12);

    __put_user(env->regs[13], &sc->r13);

    __put_user(env->regs[14], &sc->r14);

    __put_user(env->regs[15], &sc->r15);



    __put_user(cs->exception_index, &sc->trapno);

    __put_user(env->error_code, &sc->err);

    __put_user(env->eip, &sc->rip);



    __put_user(env->eflags, &sc->eflags);

    __put_user(env->segs[R_CS].selector, &sc->cs);

    __put_user((uint16_t)0, &sc->gs);

    __put_user((uint16_t)0, &sc->fs);

    __put_user(env->segs[R_SS].selector, &sc->ss);



    __put_user(mask, &sc->oldmask);

    __put_user(env->cr[2], &sc->cr2);



    /* fpstate_addr must be 16 byte aligned for fxsave */

    assert(!(fpstate_addr & 0xf));



    cpu_x86_fxsave(env, fpstate_addr);

    __put_user(fpstate_addr, &sc->fpstate);

#endif

}



/*
@@ -972,23 +1082,34 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t frame_size) 


    /* Default to using normal stack */

    esp = env->regs[R_ESP];

#ifdef TARGET_X86_64

    esp -= 128; /* this is the redzone */

#endif



    /* This is the X/Open sanctioned signal stack switching.  */

    if (ka->sa_flags & TARGET_SA_ONSTACK) {

        if (sas_ss_flags(esp) == 0) {

            esp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;

        }

    } else {



#ifndef TARGET_X86_64

        /* This is the legacy signal stack switching. */

        if ((env->segs[R_SS].selector & 0xffff) != __USER_DS &&

                !(ka->sa_flags & TARGET_SA_RESTORER) &&

                ka->sa_restorer) {

            esp = (unsigned long) ka->sa_restorer;

        }

#endif

    }



#ifndef TARGET_X86_64

    return (esp - frame_size) & -8ul;

#else

    return ((esp - frame_size) & (~15ul)) - 8;

#endif

}



#ifndef TARGET_X86_64

/* compare linux/arch/i386/kernel/signal.c:setup_frame() */

static void setup_frame(int sig, struct target_sigaction *ka,

                        target_sigset_t *set, CPUX86State *env)
@@ -1029,7 +1150,6 @@ static void setup_frame(int sig, struct target_sigaction *ka, 
        __put_user(val16, (uint16_t *)(frame->retcode+6));

    }





    /* Set up registers for signal handler */

    env->regs[R_ESP] = frame_addr;

    env->eip = ka->_sa_handler;
@@ -1047,13 +1167,17 @@ static void setup_frame(int sig, struct target_sigaction *ka, 
give_sigsegv:

    force_sigsegv(sig);

}

#endif



/* compare linux/arch/i386/kernel/signal.c:setup_rt_frame() */

/* compare linux/arch/x86/kernel/signal.c:setup_rt_frame() */

static void setup_rt_frame(int sig, struct target_sigaction *ka,

                           target_siginfo_t *info,

                           target_sigset_t *set, CPUX86State *env)

{

    abi_ulong frame_addr, addr;

    abi_ulong frame_addr;

#ifndef TARGET_X86_64

    abi_ulong addr;

#endif

    struct rt_sigframe *frame;

    int i;
@@ -1063,12 +1187,17 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka, 
    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))

        goto give_sigsegv;



    /* These fields are only in rt_sigframe on 32 bit */

#ifndef TARGET_X86_64

    __put_user(sig, &frame->sig);

    addr = frame_addr + offsetof(struct rt_sigframe, info);

    __put_user(addr, &frame->pinfo);

    addr = frame_addr + offsetof(struct rt_sigframe, uc);

    __put_user(addr, &frame->puc);

#endif

    if (ka->sa_flags & TARGET_SA_SIGINFO) {

        tswap_siginfo(&frame->info, info);

    }



    /* Create the ucontext.  */

    __put_user(0, &frame->uc.tuc_flags);
@@ -1087,6 +1216,7 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka, 


    /* Set up to return from userspace.  If provided, use a stub

       already in userspace.  */

#ifndef TARGET_X86_64

    if (ka->sa_flags & TARGET_SA_RESTORER) {

        __put_user(ka->sa_restorer, &frame->pretcode);

    } else {
@@ -1099,15 +1229,31 @@ static void setup_rt_frame(int sig, struct target_sigaction *ka, 
        val16 = 0x80cd;

        __put_user(val16, (uint16_t *)(frame->retcode+5));

    }

#else

    /* XXX: Would be slightly better to return -EFAULT here if test fails

       assert(ka->sa_flags & TARGET_SA_RESTORER); */

    __put_user(ka->sa_restorer, &frame->pretcode);

#endif



    /* Set up registers for signal handler */

    env->regs[R_ESP] = frame_addr;

    env->eip = ka->_sa_handler;



#ifndef TARGET_X86_64

    env->regs[R_EAX] = sig;

    env->regs[R_EDX] = (unsigned long)&frame->info;

    env->regs[R_ECX] = (unsigned long)&frame->uc;

#else

    env->regs[R_EAX] = 0;

    env->regs[R_EDI] = sig;

    env->regs[R_ESI] = (unsigned long)&frame->info;

    env->regs[R_EDX] = (unsigned long)&frame->uc;

#endif



    cpu_x86_load_seg(env, R_DS, __USER_DS);

    cpu_x86_load_seg(env, R_ES, __USER_DS);

    cpu_x86_load_seg(env, R_SS, __USER_DS);

    cpu_x86_load_seg(env, R_CS, __USER_CS);

    cpu_x86_load_seg(env, R_SS, __USER_DS);

    env->eflags &= ~TF_MASK;



    unlock_user_struct(frame, frame_addr, 1);
@@ -1125,6 +1271,7 @@ restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc) 
    abi_ulong fpstate_addr;

    unsigned int tmpflags;



#ifndef TARGET_X86_64

    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));
@@ -1138,7 +1285,29 @@ restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc) 
    env->regs[R_EDX] = tswapl(sc->edx);

    env->regs[R_ECX] = tswapl(sc->ecx);

    env->regs[R_EAX] = tswapl(sc->eax);



    env->eip = tswapl(sc->eip);

#else

    env->regs[8] = tswapl(sc->r8);

    env->regs[9] = tswapl(sc->r9);

    env->regs[10] = tswapl(sc->r10);

    env->regs[11] = tswapl(sc->r11);

    env->regs[12] = tswapl(sc->r12);

    env->regs[13] = tswapl(sc->r13);

    env->regs[14] = tswapl(sc->r14);

    env->regs[15] = tswapl(sc->r15);



    env->regs[R_EDI] = tswapl(sc->rdi);

    env->regs[R_ESI] = tswapl(sc->rsi);

    env->regs[R_EBP] = tswapl(sc->rbp);

    env->regs[R_EBX] = tswapl(sc->rbx);

    env->regs[R_EDX] = tswapl(sc->rdx);

    env->regs[R_EAX] = tswapl(sc->rax);

    env->regs[R_ECX] = tswapl(sc->rcx);

    env->regs[R_ESP] = tswapl(sc->rsp);



    env->eip = tswapl(sc->rip);

#endif



    cpu_x86_load_seg(env, R_CS, lduw_p(&sc->cs) | 3);

    cpu_x86_load_seg(env, R_SS, lduw_p(&sc->ss) | 3);
@@ -1152,7 +1321,11 @@ restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc) 
        if (!access_ok(VERIFY_READ, fpstate_addr,

                       sizeof(struct target_fpstate)))

            goto badframe;

#ifndef TARGET_X86_64

        cpu_x86_frstor(env, fpstate_addr, 1);

#else

        cpu_x86_fxrstor(env, fpstate_addr);

#endif

    }



    return err;
@@ -1160,6 +1333,8 @@ badframe: 
    return 1;

}



/* Note: there is no sigreturn on x86_64, there is only rt_sigreturn */

#ifndef TARGET_X86_64

long do_sigreturn(CPUX86State *env)

{

    struct sigframe *frame;
@@ -1191,6 +1366,7 @@ badframe: 
    force_sig(TARGET_SIGSEGV);

    return -TARGET_QEMU_ESIGRETURN;

}

#endif



long do_rt_sigreturn(CPUX86State *env)

{
@@ -1198,7 +1374,7 @@ long do_rt_sigreturn(CPUX86State *env) 
    struct rt_sigframe *frame;

    sigset_t set;



    frame_addr = env->regs[R_ESP] - 4;

    frame_addr = env->regs[R_ESP] - sizeof(abi_ulong);

    trace_user_do_rt_sigreturn(env, frame_addr);

    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))

        goto badframe;
@@ -6418,7 +6594,7 @@ static void handle_pending_signal(CPUArchState *cpu_env, int sig, 
#if defined(TARGET_ABI_MIPSN32) || defined(TARGET_ABI_MIPSN64) \

        || defined(TARGET_OPENRISC) || defined(TARGET_TILEGX) \

        || defined(TARGET_PPC64) || defined(TARGET_HPPA) \

        || defined(TARGET_NIOS2)

        || defined(TARGET_NIOS2) || defined(TARGET_X86_64)

        /* These targets do not have traditional signals.  */

        setup_rt_frame(sig, sa, &k->info, &target_old_set, cpu_env);

#else

target/i386/cpu.h

+2 −0
Original line number Diff line number Diff line
@@ -1417,6 +1417,8 @@ floatx80 cpu_set_fp80(uint64_t mant, uint16_t upper); 
void cpu_x86_load_seg(CPUX86State *s, int seg_reg, int selector);

void cpu_x86_fsave(CPUX86State *s, target_ulong ptr, int data32);

void cpu_x86_frstor(CPUX86State *s, target_ulong ptr, int data32);

void cpu_x86_fxsave(CPUX86State *s, target_ulong ptr);

void cpu_x86_fxrstor(CPUX86State *s, target_ulong ptr);



/* you can call this signal handler from your SIGBUS and SIGSEGV

   signal handlers to inform the virtual CPU of exceptions. non zero

target/i386/fpu_helper.c

+12 −0
Original line number Diff line number Diff line
@@ -1377,6 +1377,18 @@ void helper_fxrstor(CPUX86State *env, target_ulong ptr) 
    }

}



#if defined(CONFIG_USER_ONLY)

void cpu_x86_fxsave(CPUX86State *env, target_ulong ptr)

{

    helper_fxsave(env, ptr);

}



void cpu_x86_fxrstor(CPUX86State *env, target_ulong ptr)

{

    helper_fxrstor(env, ptr);

}

#endif



void helper_xrstor(CPUX86State *env, target_ulong ptr, uint64_t rfbm)

{

    uintptr_t ra = GETPC();