linux-user: move i386/x86_64 signal.c parts to i386 directory

No code change, only move code from signal.c to
i386/signal.c, except adding includes and
exporting setup_frame() and setup_rt_frame().

x86_64/signal.c includes i386/signal.c

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180424192635.6027-17-laurent@vivier.eu>

2 files changed, 589 insertions, 0 deletions

diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c
index 02ca338b6c..4a190e6435 100644
--- a/linux-user/i386/signal.c
+++ b/linux-user/i386/signal.c
@@ -16,3 +16,587 @@
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
+#include "qemu/osdep.h"
+#include "qemu.h"
+#include "target_signal.h"
+#include "signal-common.h"
+#include "linux-user/trace.h"
+
+/* from the Linux kernel - /arch/x86/include/uapi/asm/sigcontext.h */
+
+struct target_fpreg {
+    uint16_t significand[4];
+    uint16_t exponent;
+};
+
+struct target_fpxreg {
+    uint16_t significand[4];
+    uint16_t exponent;
+    uint16_t padding[3];
+};
+
+struct target_xmmreg {
+    uint32_t element[4];
+};
+
+struct target_fpstate_32 {
+    /* Regular FPU environment */
+    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 */
+    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];
+};
+
+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];
+};
+
+#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;
+    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;
+    uint32_t eflags;
+    uint32_t esp_at_signal;
+    uint16_t ss, __ssh;
+    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;
+    target_stack_t    tuc_stack;
+    struct target_sigcontext tuc_mcontext;
+    target_sigset_t   tuc_sigmask;  /* mask last for extensibility */
+};
+
+#ifndef TARGET_X86_64
+struct sigframe {
+    abi_ulong pretcode;
+    int sig;
+    struct target_sigcontext sc;
+    struct target_fpstate fpstate;
+    abi_ulong extramask[TARGET_NSIG_WORDS-1];
+    char retcode[8];
+};
+
+struct rt_sigframe {
+    abi_ulong pretcode;
+    int sig;
+    abi_ulong pinfo;
+    abi_ulong puc;
+    struct target_siginfo info;
+    struct target_ucontext uc;
+    struct target_fpstate fpstate;
+    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.
+ */
+
+/* XXX: save x87 state */
+static void setup_sigcontext(struct target_sigcontext *sc,
+        struct target_fpstate *fpstate, CPUX86State *env, abi_ulong mask,
+        abi_ulong fpstate_addr)
+{
+    CPUState *cs = CPU(x86_env_get_cpu(env));
+#ifndef TARGET_X86_64
+    uint16_t magic;
+
+    /* already locked in setup_frame() */
+    __put_user(env->segs[R_GS].selector, (unsigned int *)&sc->gs);
+    __put_user(env->segs[R_FS].selector, (unsigned int *)&sc->fs);
+    __put_user(env->segs[R_ES].selector, (unsigned int *)&sc->es);
+    __put_user(env->segs[R_DS].selector, (unsigned int *)&sc->ds);
+    __put_user(env->regs[R_EDI], &sc->edi);
+    __put_user(env->regs[R_ESI], &sc->esi);
+    __put_user(env->regs[R_EBP], &sc->ebp);
+    __put_user(env->regs[R_ESP], &sc->esp);
+    __put_user(env->regs[R_EBX], &sc->ebx);
+    __put_user(env->regs[R_EDX], &sc->edx);
+    __put_user(env->regs[R_ECX], &sc->ecx);
+    __put_user(env->regs[R_EAX], &sc->eax);
+    __put_user(cs->exception_index, &sc->trapno);
+    __put_user(env->error_code, &sc->err);
+    __put_user(env->eip, &sc->eip);
+    __put_user(env->segs[R_CS].selector, (unsigned int *)&sc->cs);
+    __put_user(env->eflags, &sc->eflags);
+    __put_user(env->regs[R_ESP], &sc->esp_at_signal);
+    __put_user(env->segs[R_SS].selector, (unsigned int *)&sc->ss);
+
+    cpu_x86_fsave(env, fpstate_addr, 1);
+    fpstate->status = fpstate->sw;
+    magic = 0xffff;
+    __put_user(magic, &fpstate->magic);
+    __put_user(fpstate_addr, &sc->fpstate);
+
+    /* 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
+}
+
+/*
+ * Determine which stack to use..
+ */
+
+static inline abi_ulong
+get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t frame_size)
+{
+    unsigned long esp;
+
+    /* 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() */
+void setup_frame(int sig, struct target_sigaction *ka,
+                 target_sigset_t *set, CPUX86State *env)
+{
+    abi_ulong frame_addr;
+    struct sigframe *frame;
+    int i;
+
+    frame_addr = get_sigframe(ka, env, sizeof(*frame));
+    trace_user_setup_frame(env, frame_addr);
+
+    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
+        goto give_sigsegv;
+
+    __put_user(sig, &frame->sig);
+
+    setup_sigcontext(&frame->sc, &frame->fpstate, env, set->sig[0],
+            frame_addr + offsetof(struct sigframe, fpstate));
+
+    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
+        __put_user(set->sig[i], &frame->extramask[i - 1]);
+    }
+
+    /* Set up to return from userspace.  If provided, use a stub
+       already in userspace.  */
+    if (ka->sa_flags & TARGET_SA_RESTORER) {
+        __put_user(ka->sa_restorer, &frame->pretcode);
+    } else {
+        uint16_t val16;
+        abi_ulong retcode_addr;
+        retcode_addr = frame_addr + offsetof(struct sigframe, retcode);
+        __put_user(retcode_addr, &frame->pretcode);
+        /* This is popl %eax ; movl $,%eax ; int $0x80 */
+        val16 = 0xb858;
+        __put_user(val16, (uint16_t *)(frame->retcode+0));
+        __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2));
+        val16 = 0x80cd;
+        __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;
+
+    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);
+    env->eflags &= ~TF_MASK;
+
+    unlock_user_struct(frame, frame_addr, 1);
+
+    return;
+
+give_sigsegv:
+    force_sigsegv(sig);
+}
+#endif
+
+/* compare linux/arch/x86/kernel/signal.c:setup_rt_frame() */
+void setup_rt_frame(int sig, struct target_sigaction *ka,
+                    target_siginfo_t *info,
+                    target_sigset_t *set, CPUX86State *env)
+{
+    abi_ulong frame_addr;
+#ifndef TARGET_X86_64
+    abi_ulong addr;
+#endif
+    struct rt_sigframe *frame;
+    int i;
+
+    frame_addr = get_sigframe(ka, env, sizeof(*frame));
+    trace_user_setup_rt_frame(env, frame_addr);
+
+    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);
+    __put_user(0, &frame->uc.tuc_link);
+    __put_user(target_sigaltstack_used.ss_sp, &frame->uc.tuc_stack.ss_sp);
+    __put_user(sas_ss_flags(get_sp_from_cpustate(env)),
+               &frame->uc.tuc_stack.ss_flags);
+    __put_user(target_sigaltstack_used.ss_size,
+               &frame->uc.tuc_stack.ss_size);
+    setup_sigcontext(&frame->uc.tuc_mcontext, &frame->fpstate, env,
+            set->sig[0], frame_addr + offsetof(struct rt_sigframe, fpstate));
+
+    for(i = 0; i < TARGET_NSIG_WORDS; i++) {
+        __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
+    }
+
+    /* 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 {
+        uint16_t val16;
+        addr = frame_addr + offsetof(struct rt_sigframe, retcode);
+        __put_user(addr, &frame->pretcode);
+        /* This is movl $,%eax ; int $0x80 */
+        __put_user(0xb8, (char *)(frame->retcode+0));
+        __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1));
+        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_CS, __USER_CS);
+    cpu_x86_load_seg(env, R_SS, __USER_DS);
+    env->eflags &= ~TF_MASK;
+
+    unlock_user_struct(frame, frame_addr, 1);
+
+    return;
+
+give_sigsegv:
+    force_sigsegv(sig);
+}
+
+static int
+restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc)
+{
+    unsigned int err = 0;
+    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));
+    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->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);
+
+    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;
+#ifndef TARGET_X86_64
+        cpu_x86_frstor(env, fpstate_addr, 1);
+#else
+        cpu_x86_fxrstor(env, fpstate_addr);
+#endif
+    }
+
+    return err;
+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;
+    abi_ulong frame_addr = env->regs[R_ESP] - 8;
+    target_sigset_t target_set;
+    sigset_t set;
+    int i;
+
+    trace_user_do_sigreturn(env, frame_addr);
+    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
+        goto badframe;
+    /* set blocked signals */
+    __get_user(target_set.sig[0], &frame->sc.oldmask);
+    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
+        __get_user(target_set.sig[i], &frame->extramask[i - 1]);
+    }
+
+    target_to_host_sigset_internal(&set, &target_set);
+    set_sigmask(&set);
+
+    /* restore registers */
+    if (restore_sigcontext(env, &frame->sc))
+        goto badframe;
+    unlock_user_struct(frame, frame_addr, 0);
+    return -TARGET_QEMU_ESIGRETURN;
+
+badframe:
+    unlock_user_struct(frame, frame_addr, 0);
+    force_sig(TARGET_SIGSEGV);
+    return -TARGET_QEMU_ESIGRETURN;
+}
+#endif
+
+long do_rt_sigreturn(CPUX86State *env)
+{
+    abi_ulong frame_addr;
+    struct rt_sigframe *frame;
+    sigset_t set;
+
+    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;
+    target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
+    set_sigmask(&set);
+
+    if (restore_sigcontext(env, &frame->uc.tuc_mcontext)) {
+        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 -TARGET_QEMU_ESIGRETURN;
+
+badframe:
+    unlock_user_struct(frame, frame_addr, 0);
+    force_sig(TARGET_SIGSEGV);
+    return -TARGET_QEMU_ESIGRETURN;
+}
diff --git a/linux-user/i386/target_signal.h b/linux-user/i386/target_signal.h
index 837e90fc4c..ec5a3e3373 100644
--- a/linux-user/i386/target_signal.h
+++ b/linux-user/i386/target_signal.h
@@ -26,4 +26,9 @@ static inline abi_ulong get_sp_from_cpustate(CPUX86State *state)
     return state->regs[R_ESP];
 }
 
+void setup_frame(int sig, struct target_sigaction *ka,
+                 target_sigset_t *set, CPUX86State *env);
+void setup_rt_frame(int sig, struct target_sigaction *ka,
+                    target_siginfo_t *info,
+                    target_sigset_t *set, CPUX86State *env);
 #endif /* I386_TARGET_SIGNAL_H */