linux-user: move s390x signal.c parts to s390x directory

No code change, only move code from signal.c to
s390x/signal.c, except adding includes and
exporting setup_frame() and setup_rt_frame().

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180424192635.6027-10-laurent@vivier.eu>

2 files changed, 314 insertions, 1 deletions

diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c
index 02ca338..a204a85 100644
--- a/linux-user/s390x/signal.c
+++ b/linux-user/s390x/signal.c
@@ -16,3 +16,312 @@
  *  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"
+
+#define __NUM_GPRS 16
+#define __NUM_FPRS 16
+#define __NUM_ACRS 16
+
+#define S390_SYSCALL_SIZE   2
+#define __SIGNAL_FRAMESIZE      160 /* FIXME: 31-bit mode -> 96 */
+
+#define _SIGCONTEXT_NSIG        64
+#define _SIGCONTEXT_NSIG_BPW    64 /* FIXME: 31-bit mode -> 32 */
+#define _SIGCONTEXT_NSIG_WORDS  (_SIGCONTEXT_NSIG / _SIGCONTEXT_NSIG_BPW)
+#define _SIGMASK_COPY_SIZE    (sizeof(unsigned long)*_SIGCONTEXT_NSIG_WORDS)
+#define PSW_ADDR_AMODE            0x0000000000000000UL /* 0x80000000UL for 31-bit */
+#define S390_SYSCALL_OPCODE ((uint16_t)0x0a00)
+
+typedef struct {
+    target_psw_t psw;
+    target_ulong gprs[__NUM_GPRS];
+    unsigned int acrs[__NUM_ACRS];
+} target_s390_regs_common;
+
+typedef struct {
+    unsigned int fpc;
+    double   fprs[__NUM_FPRS];
+} target_s390_fp_regs;
+
+typedef struct {
+    target_s390_regs_common regs;
+    target_s390_fp_regs     fpregs;
+} target_sigregs;
+
+struct target_sigcontext {
+    target_ulong   oldmask[_SIGCONTEXT_NSIG_WORDS];
+    target_sigregs *sregs;
+};
+
+typedef struct {
+    uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
+    struct target_sigcontext sc;
+    target_sigregs sregs;
+    int signo;
+    uint8_t retcode[S390_SYSCALL_SIZE];
+} sigframe;
+
+struct target_ucontext {
+    target_ulong tuc_flags;
+    struct target_ucontext *tuc_link;
+    target_stack_t tuc_stack;
+    target_sigregs tuc_mcontext;
+    target_sigset_t tuc_sigmask;   /* mask last for extensibility */
+};
+
+typedef struct {
+    uint8_t callee_used_stack[__SIGNAL_FRAMESIZE];
+    uint8_t retcode[S390_SYSCALL_SIZE];
+    struct target_siginfo info;
+    struct target_ucontext uc;
+} rt_sigframe;
+
+static inline abi_ulong
+get_sigframe(struct target_sigaction *ka, CPUS390XState *env, size_t frame_size)
+{
+    abi_ulong sp;
+
+    /* Default to using normal stack */
+    sp = env->regs[15];
+
+    /* This is the X/Open sanctioned signal stack switching.  */
+    if (ka->sa_flags & TARGET_SA_ONSTACK) {
+        if (!sas_ss_flags(sp)) {
+            sp = target_sigaltstack_used.ss_sp +
+                 target_sigaltstack_used.ss_size;
+        }
+    }
+
+    /* This is the legacy signal stack switching. */
+    else if (/* FIXME !user_mode(regs) */ 0 &&
+             !(ka->sa_flags & TARGET_SA_RESTORER) &&
+             ka->sa_restorer) {
+        sp = (abi_ulong) ka->sa_restorer;
+    }
+
+    return (sp - frame_size) & -8ul;
+}
+
+static void save_sigregs(CPUS390XState *env, target_sigregs *sregs)
+{
+    int i;
+    //save_access_regs(current->thread.acrs); FIXME
+
+    /* Copy a 'clean' PSW mask to the user to avoid leaking
+       information about whether PER is currently on.  */
+    __put_user(env->psw.mask, &sregs->regs.psw.mask);
+    __put_user(env->psw.addr, &sregs->regs.psw.addr);
+    for (i = 0; i < 16; i++) {
+        __put_user(env->regs[i], &sregs->regs.gprs[i]);
+    }
+    for (i = 0; i < 16; i++) {
+        __put_user(env->aregs[i], &sregs->regs.acrs[i]);
+    }
+    /*
+     * We have to store the fp registers to current->thread.fp_regs
+     * to merge them with the emulated registers.
+     */
+    //save_fp_regs(&current->thread.fp_regs); FIXME
+    for (i = 0; i < 16; i++) {
+        __put_user(get_freg(env, i)->ll, &sregs->fpregs.fprs[i]);
+    }
+}
+
+void setup_frame(int sig, struct target_sigaction *ka,
+                 target_sigset_t *set, CPUS390XState *env)
+{
+    sigframe *frame;
+    abi_ulong frame_addr;
+
+    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(set->sig[0], &frame->sc.oldmask[0]);
+
+    save_sigregs(env, &frame->sregs);
+
+    __put_user((abi_ulong)(unsigned long)&frame->sregs,
+               (abi_ulong *)&frame->sc.sregs);
+
+    /* Set up to return from userspace.  If provided, use a stub
+       already in userspace.  */
+    if (ka->sa_flags & TARGET_SA_RESTORER) {
+        env->regs[14] = (unsigned long)
+                ka->sa_restorer | PSW_ADDR_AMODE;
+    } else {
+        env->regs[14] = (frame_addr + offsetof(sigframe, retcode))
+                        | PSW_ADDR_AMODE;
+        __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn,
+                   (uint16_t *)(frame->retcode));
+    }
+
+    /* Set up backchain. */
+    __put_user(env->regs[15], (abi_ulong *) frame);
+
+    /* Set up registers for signal handler */
+    env->regs[15] = frame_addr;
+    env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
+
+    env->regs[2] = sig; //map_signal(sig);
+    env->regs[3] = frame_addr += offsetof(typeof(*frame), sc);
+
+    /* We forgot to include these in the sigcontext.
+       To avoid breaking binary compatibility, they are passed as args. */
+    env->regs[4] = 0; // FIXME: no clue... current->thread.trap_no;
+    env->regs[5] = 0; // FIXME: no clue... current->thread.prot_addr;
+
+    /* Place signal number on stack to allow backtrace from handler.  */
+    __put_user(env->regs[2], &frame->signo);
+    unlock_user_struct(frame, frame_addr, 1);
+    return;
+
+give_sigsegv:
+    force_sigsegv(sig);
+}
+
+void setup_rt_frame(int sig, struct target_sigaction *ka,
+                    target_siginfo_t *info,
+                    target_sigset_t *set, CPUS390XState *env)
+{
+    int i;
+    rt_sigframe *frame;
+    abi_ulong frame_addr;
+
+    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;
+    }
+
+    tswap_siginfo(&frame->info, info);
+
+    /* Create the ucontext.  */
+    __put_user(0, &frame->uc.tuc_flags);
+    __put_user((abi_ulong)0, (abi_ulong *)&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);
+    save_sigregs(env, &frame->uc.tuc_mcontext);
+    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
+        __put_user((abi_ulong)set->sig[i],
+                   (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]);
+    }
+
+    /* Set up to return from userspace.  If provided, use a stub
+       already in userspace.  */
+    if (ka->sa_flags & TARGET_SA_RESTORER) {
+        env->regs[14] = (unsigned long) ka->sa_restorer | PSW_ADDR_AMODE;
+    } else {
+        env->regs[14] = (unsigned long) frame->retcode | PSW_ADDR_AMODE;
+        __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn,
+                   (uint16_t *)(frame->retcode));
+    }
+
+    /* Set up backchain. */
+    __put_user(env->regs[15], (abi_ulong *) frame);
+
+    /* Set up registers for signal handler */
+    env->regs[15] = frame_addr;
+    env->psw.addr = (target_ulong) ka->_sa_handler | PSW_ADDR_AMODE;
+
+    env->regs[2] = sig; //map_signal(sig);
+    env->regs[3] = frame_addr + offsetof(typeof(*frame), info);
+    env->regs[4] = frame_addr + offsetof(typeof(*frame), uc);
+    return;
+
+give_sigsegv:
+    force_sigsegv(sig);
+}
+
+static int
+restore_sigregs(CPUS390XState *env, target_sigregs *sc)
+{
+    int err = 0;
+    int i;
+
+    for (i = 0; i < 16; i++) {
+        __get_user(env->regs[i], &sc->regs.gprs[i]);
+    }
+
+    __get_user(env->psw.mask, &sc->regs.psw.mask);
+    trace_user_s390x_restore_sigregs(env, (unsigned long long)sc->regs.psw.addr,
+                                     (unsigned long long)env->psw.addr);
+    __get_user(env->psw.addr, &sc->regs.psw.addr);
+    /* FIXME: 31-bit -> | PSW_ADDR_AMODE */
+
+    for (i = 0; i < 16; i++) {
+        __get_user(env->aregs[i], &sc->regs.acrs[i]);
+    }
+    for (i = 0; i < 16; i++) {
+        __get_user(get_freg(env, i)->ll, &sc->fpregs.fprs[i]);
+    }
+
+    return err;
+}
+
+long do_sigreturn(CPUS390XState *env)
+{
+    sigframe *frame;
+    abi_ulong frame_addr = env->regs[15];
+    target_sigset_t target_set;
+    sigset_t set;
+
+    trace_user_do_sigreturn(env, frame_addr);
+    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
+        goto badframe;
+    }
+    __get_user(target_set.sig[0], &frame->sc.oldmask[0]);
+
+    target_to_host_sigset_internal(&set, &target_set);
+    set_sigmask(&set); /* ~_BLOCKABLE? */
+
+    if (restore_sigregs(env, &frame->sregs)) {
+        goto badframe;
+    }
+
+    unlock_user_struct(frame, frame_addr, 0);
+    return -TARGET_QEMU_ESIGRETURN;
+
+badframe:
+    force_sig(TARGET_SIGSEGV);
+    return -TARGET_QEMU_ESIGRETURN;
+}
+
+long do_rt_sigreturn(CPUS390XState *env)
+{
+    rt_sigframe *frame;
+    abi_ulong frame_addr = env->regs[15];
+    sigset_t set;
+
+    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); /* ~_BLOCKABLE? */
+
+    if (restore_sigregs(env, &frame->uc.tuc_mcontext)) {
+        goto badframe;
+    }
+
+    if (do_sigaltstack(frame_addr + offsetof(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/s390x/target_signal.h b/linux-user/s390x/target_signal.h
index 6f7b6ab..9e3733b 100644
--- a/linux-user/s390x/target_signal.h
+++ b/linux-user/s390x/target_signal.h
@@ -23,5 +23,9 @@ static inline abi_ulong get_sp_from_cpustate(CPUS390XState *state)
    return state->regs[15];
 }
 
-
+void setup_frame(int sig, struct target_sigaction *ka,
+                 target_sigset_t *set, CPUS390XState *env);
+void setup_rt_frame(int sig, struct target_sigaction *ka,
+                    target_siginfo_t *info,
+                    target_sigset_t *set, CPUS390XState *env);
 #endif /* S390X_TARGET_SIGNAL_H */