linux-user: move aarch64 signal.c parts to aarch64 directory

No code change, only move code from signal.c to
aarch64/signal.c, except adding includes and
exporting setup_frame() and setup_rt_frame().

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: <20180424192635.6027-3-laurent@vivier.eu>

2 files changed, 573 insertions, 0 deletions

diff --git a/linux-user/aarch64/signal.c b/linux-user/aarch64/signal.c
index 02ca338b6c..d90e10a113 100644
--- a/linux-user/aarch64/signal.c
+++ b/linux-user/aarch64/signal.c
@@ -16,3 +16,571 @@
  *  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"
+
+struct target_sigcontext {
+    uint64_t fault_address;
+    /* AArch64 registers */
+    uint64_t regs[31];
+    uint64_t sp;
+    uint64_t pc;
+    uint64_t pstate;
+    /* 4K reserved for FP/SIMD state and future expansion */
+    char __reserved[4096] __attribute__((__aligned__(16)));
+};
+
+struct target_ucontext {
+    abi_ulong tuc_flags;
+    abi_ulong tuc_link;
+    target_stack_t tuc_stack;
+    target_sigset_t tuc_sigmask;
+    /* glibc uses a 1024-bit sigset_t */
+    char __unused[1024 / 8 - sizeof(target_sigset_t)];
+    /* last for future expansion */
+    struct target_sigcontext tuc_mcontext;
+};
+
+/*
+ * Header to be used at the beginning of structures extending the user
+ * context. Such structures must be placed after the rt_sigframe on the stack
+ * and be 16-byte aligned. The last structure must be a dummy one with the
+ * magic and size set to 0.
+ */
+struct target_aarch64_ctx {
+    uint32_t magic;
+    uint32_t size;
+};
+
+#define TARGET_FPSIMD_MAGIC 0x46508001
+
+struct target_fpsimd_context {
+    struct target_aarch64_ctx head;
+    uint32_t fpsr;
+    uint32_t fpcr;
+    uint64_t vregs[32 * 2]; /* really uint128_t vregs[32] */
+};
+
+#define TARGET_EXTRA_MAGIC  0x45585401
+
+struct target_extra_context {
+    struct target_aarch64_ctx head;
+    uint64_t datap; /* 16-byte aligned pointer to extra space cast to __u64 */
+    uint32_t size; /* size in bytes of the extra space */
+    uint32_t reserved[3];
+};
+
+#define TARGET_SVE_MAGIC    0x53564501
+
+struct target_sve_context {
+    struct target_aarch64_ctx head;
+    uint16_t vl;
+    uint16_t reserved[3];
+    /* The actual SVE data immediately follows.  It is layed out
+     * according to TARGET_SVE_SIG_{Z,P}REG_OFFSET, based off of
+     * the original struct pointer.
+     */
+};
+
+#define TARGET_SVE_VQ_BYTES  16
+
+#define TARGET_SVE_SIG_ZREG_SIZE(VQ)  ((VQ) * TARGET_SVE_VQ_BYTES)
+#define TARGET_SVE_SIG_PREG_SIZE(VQ)  ((VQ) * (TARGET_SVE_VQ_BYTES / 8))
+
+#define TARGET_SVE_SIG_REGS_OFFSET \
+    QEMU_ALIGN_UP(sizeof(struct target_sve_context), TARGET_SVE_VQ_BYTES)
+#define TARGET_SVE_SIG_ZREG_OFFSET(VQ, N) \
+    (TARGET_SVE_SIG_REGS_OFFSET + TARGET_SVE_SIG_ZREG_SIZE(VQ) * (N))
+#define TARGET_SVE_SIG_PREG_OFFSET(VQ, N) \
+    (TARGET_SVE_SIG_ZREG_OFFSET(VQ, 32) + TARGET_SVE_SIG_PREG_SIZE(VQ) * (N))
+#define TARGET_SVE_SIG_FFR_OFFSET(VQ) \
+    (TARGET_SVE_SIG_PREG_OFFSET(VQ, 16))
+#define TARGET_SVE_SIG_CONTEXT_SIZE(VQ) \
+    (TARGET_SVE_SIG_PREG_OFFSET(VQ, 17))
+
+struct target_rt_sigframe {
+    struct target_siginfo info;
+    struct target_ucontext uc;
+};
+
+struct target_rt_frame_record {
+    uint64_t fp;
+    uint64_t lr;
+    uint32_t tramp[2];
+};
+
+static void target_setup_general_frame(struct target_rt_sigframe *sf,
+                                       CPUARMState *env, target_sigset_t *set)
+{
+    int i;
+
+    __put_user(0, &sf->uc.tuc_flags);
+    __put_user(0, &sf->uc.tuc_link);
+
+    __put_user(target_sigaltstack_used.ss_sp, &sf->uc.tuc_stack.ss_sp);
+    __put_user(sas_ss_flags(env->xregs[31]), &sf->uc.tuc_stack.ss_flags);
+    __put_user(target_sigaltstack_used.ss_size, &sf->uc.tuc_stack.ss_size);
+
+    for (i = 0; i < 31; i++) {
+        __put_user(env->xregs[i], &sf->uc.tuc_mcontext.regs[i]);
+    }
+    __put_user(env->xregs[31], &sf->uc.tuc_mcontext.sp);
+    __put_user(env->pc, &sf->uc.tuc_mcontext.pc);
+    __put_user(pstate_read(env), &sf->uc.tuc_mcontext.pstate);
+
+    __put_user(env->exception.vaddress, &sf->uc.tuc_mcontext.fault_address);
+
+    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
+        __put_user(set->sig[i], &sf->uc.tuc_sigmask.sig[i]);
+    }
+}
+
+static void target_setup_fpsimd_record(struct target_fpsimd_context *fpsimd,
+                                       CPUARMState *env)
+{
+    int i;
+
+    __put_user(TARGET_FPSIMD_MAGIC, &fpsimd->head.magic);
+    __put_user(sizeof(struct target_fpsimd_context), &fpsimd->head.size);
+    __put_user(vfp_get_fpsr(env), &fpsimd->fpsr);
+    __put_user(vfp_get_fpcr(env), &fpsimd->fpcr);
+
+    for (i = 0; i < 32; i++) {
+        uint64_t *q = aa64_vfp_qreg(env, i);
+#ifdef TARGET_WORDS_BIGENDIAN
+        __put_user(q[0], &fpsimd->vregs[i * 2 + 1]);
+        __put_user(q[1], &fpsimd->vregs[i * 2]);
+#else
+        __put_user(q[0], &fpsimd->vregs[i * 2]);
+        __put_user(q[1], &fpsimd->vregs[i * 2 + 1]);
+#endif
+    }
+}
+
+static void target_setup_extra_record(struct target_extra_context *extra,
+                                      uint64_t datap, uint32_t extra_size)
+{
+    __put_user(TARGET_EXTRA_MAGIC, &extra->head.magic);
+    __put_user(sizeof(struct target_extra_context), &extra->head.size);
+    __put_user(datap, &extra->datap);
+    __put_user(extra_size, &extra->size);
+}
+
+static void target_setup_end_record(struct target_aarch64_ctx *end)
+{
+    __put_user(0, &end->magic);
+    __put_user(0, &end->size);
+}
+
+static void target_setup_sve_record(struct target_sve_context *sve,
+                                    CPUARMState *env, int vq, int size)
+{
+    int i, j;
+
+    __put_user(TARGET_SVE_MAGIC, &sve->head.magic);
+    __put_user(size, &sve->head.size);
+    __put_user(vq * TARGET_SVE_VQ_BYTES, &sve->vl);
+
+    /* Note that SVE regs are stored as a byte stream, with each byte element
+     * at a subsequent address.  This corresponds to a little-endian store
+     * of our 64-bit hunks.
+     */
+    for (i = 0; i < 32; ++i) {
+        uint64_t *z = (void *)sve + TARGET_SVE_SIG_ZREG_OFFSET(vq, i);
+        for (j = 0; j < vq * 2; ++j) {
+            __put_user_e(env->vfp.zregs[i].d[j], z + j, le);
+        }
+    }
+    for (i = 0; i <= 16; ++i) {
+        uint16_t *p = (void *)sve + TARGET_SVE_SIG_PREG_OFFSET(vq, i);
+        for (j = 0; j < vq; ++j) {
+            uint64_t r = env->vfp.pregs[i].p[j >> 2];
+            __put_user_e(r >> ((j & 3) * 16), p + j, le);
+        }
+    }
+}
+
+static void target_restore_general_frame(CPUARMState *env,
+                                         struct target_rt_sigframe *sf)
+{
+    sigset_t set;
+    uint64_t pstate;
+    int i;
+
+    target_to_host_sigset(&set, &sf->uc.tuc_sigmask);
+    set_sigmask(&set);
+
+    for (i = 0; i < 31; i++) {
+        __get_user(env->xregs[i], &sf->uc.tuc_mcontext.regs[i]);
+    }
+
+    __get_user(env->xregs[31], &sf->uc.tuc_mcontext.sp);
+    __get_user(env->pc, &sf->uc.tuc_mcontext.pc);
+    __get_user(pstate, &sf->uc.tuc_mcontext.pstate);
+    pstate_write(env, pstate);
+}
+
+static void target_restore_fpsimd_record(CPUARMState *env,
+                                         struct target_fpsimd_context *fpsimd)
+{
+    uint32_t fpsr, fpcr;
+    int i;
+
+    __get_user(fpsr, &fpsimd->fpsr);
+    vfp_set_fpsr(env, fpsr);
+    __get_user(fpcr, &fpsimd->fpcr);
+    vfp_set_fpcr(env, fpcr);
+
+    for (i = 0; i < 32; i++) {
+        uint64_t *q = aa64_vfp_qreg(env, i);
+#ifdef TARGET_WORDS_BIGENDIAN
+        __get_user(q[0], &fpsimd->vregs[i * 2 + 1]);
+        __get_user(q[1], &fpsimd->vregs[i * 2]);
+#else
+        __get_user(q[0], &fpsimd->vregs[i * 2]);
+        __get_user(q[1], &fpsimd->vregs[i * 2 + 1]);
+#endif
+    }
+}
+
+static void target_restore_sve_record(CPUARMState *env,
+                                      struct target_sve_context *sve, int vq)
+{
+    int i, j;
+
+    /* Note that SVE regs are stored as a byte stream, with each byte element
+     * at a subsequent address.  This corresponds to a little-endian load
+     * of our 64-bit hunks.
+     */
+    for (i = 0; i < 32; ++i) {
+        uint64_t *z = (void *)sve + TARGET_SVE_SIG_ZREG_OFFSET(vq, i);
+        for (j = 0; j < vq * 2; ++j) {
+            __get_user_e(env->vfp.zregs[i].d[j], z + j, le);
+        }
+    }
+    for (i = 0; i <= 16; ++i) {
+        uint16_t *p = (void *)sve + TARGET_SVE_SIG_PREG_OFFSET(vq, i);
+        for (j = 0; j < vq; ++j) {
+            uint16_t r;
+            __get_user_e(r, p + j, le);
+            if (j & 3) {
+                env->vfp.pregs[i].p[j >> 2] |= (uint64_t)r << ((j & 3) * 16);
+            } else {
+                env->vfp.pregs[i].p[j >> 2] = r;
+            }
+        }
+    }
+}
+
+static int target_restore_sigframe(CPUARMState *env,
+                                   struct target_rt_sigframe *sf)
+{
+    struct target_aarch64_ctx *ctx, *extra = NULL;
+    struct target_fpsimd_context *fpsimd = NULL;
+    struct target_sve_context *sve = NULL;
+    uint64_t extra_datap = 0;
+    bool used_extra = false;
+    bool err = false;
+    int vq = 0, sve_size = 0;
+
+    target_restore_general_frame(env, sf);
+
+    ctx = (struct target_aarch64_ctx *)sf->uc.tuc_mcontext.__reserved;
+    while (ctx) {
+        uint32_t magic, size, extra_size;
+
+        __get_user(magic, &ctx->magic);
+        __get_user(size, &ctx->size);
+        switch (magic) {
+        case 0:
+            if (size != 0) {
+                err = true;
+                goto exit;
+            }
+            if (used_extra) {
+                ctx = NULL;
+            } else {
+                ctx = extra;
+                used_extra = true;
+            }
+            continue;
+
+        case TARGET_FPSIMD_MAGIC:
+            if (fpsimd || size != sizeof(struct target_fpsimd_context)) {
+                err = true;
+                goto exit;
+            }
+            fpsimd = (struct target_fpsimd_context *)ctx;
+            break;
+
+        case TARGET_SVE_MAGIC:
+            if (arm_feature(env, ARM_FEATURE_SVE)) {
+                vq = (env->vfp.zcr_el[1] & 0xf) + 1;
+                sve_size = QEMU_ALIGN_UP(TARGET_SVE_SIG_CONTEXT_SIZE(vq), 16);
+                if (!sve && size == sve_size) {
+                    sve = (struct target_sve_context *)ctx;
+                    break;
+                }
+            }
+            err = true;
+            goto exit;
+
+        case TARGET_EXTRA_MAGIC:
+            if (extra || size != sizeof(struct target_extra_context)) {
+                err = true;
+                goto exit;
+            }
+            __get_user(extra_datap,
+                       &((struct target_extra_context *)ctx)->datap);
+            __get_user(extra_size,
+                       &((struct target_extra_context *)ctx)->size);
+            extra = lock_user(VERIFY_READ, extra_datap, extra_size, 0);
+            break;
+
+        default:
+            /* Unknown record -- we certainly didn't generate it.
+             * Did we in fact get out of sync?
+             */
+            err = true;
+            goto exit;
+        }
+        ctx = (void *)ctx + size;
+    }
+
+    /* Require FPSIMD always.  */
+    if (fpsimd) {
+        target_restore_fpsimd_record(env, fpsimd);
+    } else {
+        err = true;
+    }
+
+    /* SVE data, if present, overwrites FPSIMD data.  */
+    if (sve) {
+        target_restore_sve_record(env, sve, vq);
+    }
+
+ exit:
+    unlock_user(extra, extra_datap, 0);
+    return err;
+}
+
+static abi_ulong get_sigframe(struct target_sigaction *ka,
+                              CPUARMState *env, int size)
+{
+    abi_ulong sp;
+
+    sp = env->xregs[31];
+
+    /*
+     * This is the X/Open sanctioned signal stack switching.
+     */
+    if ((ka->sa_flags & TARGET_SA_ONSTACK) && !sas_ss_flags(sp)) {
+        sp = target_sigaltstack_used.ss_sp + target_sigaltstack_used.ss_size;
+    }
+
+    sp = (sp - size) & ~15;
+
+    return sp;
+}
+
+typedef struct {
+    int total_size;
+    int extra_base;
+    int extra_size;
+    int std_end_ofs;
+    int extra_ofs;
+    int extra_end_ofs;
+} target_sigframe_layout;
+
+static int alloc_sigframe_space(int this_size, target_sigframe_layout *l)
+{
+    /* Make sure there will always be space for the end marker.  */
+    const int std_size = sizeof(struct target_rt_sigframe)
+                         - sizeof(struct target_aarch64_ctx);
+    int this_loc = l->total_size;
+
+    if (l->extra_base) {
+        /* Once we have begun an extra space, all allocations go there.  */
+        l->extra_size += this_size;
+    } else if (this_size + this_loc > std_size) {
+        /* This allocation does not fit in the standard space.  */
+        /* Allocate the extra record.  */
+        l->extra_ofs = this_loc;
+        l->total_size += sizeof(struct target_extra_context);
+
+        /* Allocate the standard end record.  */
+        l->std_end_ofs = l->total_size;
+        l->total_size += sizeof(struct target_aarch64_ctx);
+
+        /* Allocate the requested record.  */
+        l->extra_base = this_loc = l->total_size;
+        l->extra_size = this_size;
+    }
+    l->total_size += this_size;
+
+    return this_loc;
+}
+
+static void target_setup_frame(int usig, struct target_sigaction *ka,
+                               target_siginfo_t *info, target_sigset_t *set,
+                               CPUARMState *env)
+{
+    target_sigframe_layout layout = {
+        /* Begin with the size pointing to the reserved space.  */
+        .total_size = offsetof(struct target_rt_sigframe,
+                               uc.tuc_mcontext.__reserved),
+    };
+    int fpsimd_ofs, fr_ofs, sve_ofs = 0, vq = 0, sve_size = 0;
+    struct target_rt_sigframe *frame;
+    struct target_rt_frame_record *fr;
+    abi_ulong frame_addr, return_addr;
+
+    /* FPSIMD record is always in the standard space.  */
+    fpsimd_ofs = alloc_sigframe_space(sizeof(struct target_fpsimd_context),
+                                      &layout);
+
+    /* SVE state needs saving only if it exists.  */
+    if (arm_feature(env, ARM_FEATURE_SVE)) {
+        vq = (env->vfp.zcr_el[1] & 0xf) + 1;
+        sve_size = QEMU_ALIGN_UP(TARGET_SVE_SIG_CONTEXT_SIZE(vq), 16);
+        sve_ofs = alloc_sigframe_space(sve_size, &layout);
+    }
+
+    if (layout.extra_ofs) {
+        /* Reserve space for the extra end marker.  The standard end marker
+         * will have been allocated when we allocated the extra record.
+         */
+        layout.extra_end_ofs
+            = alloc_sigframe_space(sizeof(struct target_aarch64_ctx), &layout);
+    } else {
+        /* Reserve space for the standard end marker.
+         * Do not use alloc_sigframe_space because we cheat
+         * std_size therein to reserve space for this.
+         */
+        layout.std_end_ofs = layout.total_size;
+        layout.total_size += sizeof(struct target_aarch64_ctx);
+    }
+
+    /* We must always provide at least the standard 4K reserved space,
+     * even if we don't use all of it (this is part of the ABI)
+     */
+    layout.total_size = MAX(layout.total_size,
+                            sizeof(struct target_rt_sigframe));
+
+    /* Reserve space for the return code.  On a real system this would
+     * be within the VDSO.  So, despite the name this is not a "real"
+     * record within the frame.
+     */
+    fr_ofs = layout.total_size;
+    layout.total_size += sizeof(struct target_rt_frame_record);
+
+    frame_addr = get_sigframe(ka, env, layout.total_size);
+    trace_user_setup_frame(env, frame_addr);
+    frame = lock_user(VERIFY_WRITE, frame_addr, layout.total_size, 0);
+    if (!frame) {
+        goto give_sigsegv;
+    }
+
+    target_setup_general_frame(frame, env, set);
+    target_setup_fpsimd_record((void *)frame + fpsimd_ofs, env);
+    target_setup_end_record((void *)frame + layout.std_end_ofs);
+    if (layout.extra_ofs) {
+        target_setup_extra_record((void *)frame + layout.extra_ofs,
+                                  frame_addr + layout.extra_base,
+                                  layout.extra_size);
+        target_setup_end_record((void *)frame + layout.extra_end_ofs);
+    }
+    if (sve_ofs) {
+        target_setup_sve_record((void *)frame + sve_ofs, env, vq, sve_size);
+    }
+
+    /* Set up the stack frame for unwinding.  */
+    fr = (void *)frame + fr_ofs;
+    __put_user(env->xregs[29], &fr->fp);
+    __put_user(env->xregs[30], &fr->lr);
+
+    if (ka->sa_flags & TARGET_SA_RESTORER) {
+        return_addr = ka->sa_restorer;
+    } else {
+        /*
+         * mov x8,#__NR_rt_sigreturn; svc #0
+         * Since these are instructions they need to be put as little-endian
+         * regardless of target default or current CPU endianness.
+         */
+        __put_user_e(0xd2801168, &fr->tramp[0], le);
+        __put_user_e(0xd4000001, &fr->tramp[1], le);
+        return_addr = frame_addr + fr_ofs
+            + offsetof(struct target_rt_frame_record, tramp);
+    }
+    env->xregs[0] = usig;
+    env->xregs[31] = frame_addr;
+    env->xregs[29] = frame_addr + fr_ofs;
+    env->pc = ka->_sa_handler;
+    env->xregs[30] = return_addr;
+    if (info) {
+        tswap_siginfo(&frame->info, info);
+        env->xregs[1] = frame_addr + offsetof(struct target_rt_sigframe, info);
+        env->xregs[2] = frame_addr + offsetof(struct target_rt_sigframe, uc);
+    }
+
+    unlock_user(frame, frame_addr, layout.total_size);
+    return;
+
+ give_sigsegv:
+    unlock_user(frame, frame_addr, layout.total_size);
+    force_sigsegv(usig);
+}
+
+void setup_rt_frame(int sig, struct target_sigaction *ka,
+                    target_siginfo_t *info, target_sigset_t *set,
+                    CPUARMState *env)
+{
+    target_setup_frame(sig, ka, info, set, env);
+}
+
+void setup_frame(int sig, struct target_sigaction *ka,
+                 target_sigset_t *set, CPUARMState *env)
+{
+    target_setup_frame(sig, ka, 0, set, env);
+}
+
+long do_rt_sigreturn(CPUARMState *env)
+{
+    struct target_rt_sigframe *frame = NULL;
+    abi_ulong frame_addr = env->xregs[31];
+
+    trace_user_do_rt_sigreturn(env, frame_addr);
+    if (frame_addr & 15) {
+        goto badframe;
+    }
+
+    if  (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
+        goto badframe;
+    }
+
+    if (target_restore_sigframe(env, frame)) {
+        goto badframe;
+    }
+
+    if (do_sigaltstack(frame_addr +
+            offsetof(struct target_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;
+}
+
+long do_sigreturn(CPUARMState *env)
+{
+    return do_rt_sigreturn(env);
+}
diff --git a/linux-user/aarch64/target_signal.h b/linux-user/aarch64/target_signal.h
index e66367cac1..af1f1320e2 100644
--- a/linux-user/aarch64/target_signal.h
+++ b/linux-user/aarch64/target_signal.h
@@ -26,4 +26,9 @@ static inline abi_ulong get_sp_from_cpustate(CPUARMState *state)
    return state->xregs[31];
 }
 
+void setup_frame(int sig, struct target_sigaction *ka,
+                 target_sigset_t *set, CPUARMState *env);
+void setup_rt_frame(int sig, struct target_sigaction *ka,
+                    target_siginfo_t *info, target_sigset_t *set,
+                    CPUARMState *env);
 #endif /* AARCH64_TARGET_SIGNAL_H */