new file mode 100644
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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * LoongArch emulation of Linux signals
+ *
+ * Copyright (c) 2021 Loongson Technology Corporation Limited
+ */
+
+#include "qemu/osdep.h"
+#include "qemu.h"
+#include "signal-common.h"
+#include "user-internals.h"
+#include "linux-user/trace.h"
+
+#define FPU_REG_WIDTH 256
+union fpureg {
+ uint32_t val32[FPU_REG_WIDTH / 32];
+ uint64_t val64[FPU_REG_WIDTH / 64];
+};
+
+struct target_sigcontext {
+ uint64_t sc_pc;
+ uint64_t sc_regs[32];
+ uint32_t sc_flags;
+ uint32_t sc_fcsr;
+ uint32_t sc_vcsr;
+ uint64_t sc_fcc;
+ uint64_t sc_scr[4];
+ union fpureg sc_fpregs[32] __attribute__((aligned(32)));
+ uint8_t sc_reserved[4096] __attribute__((aligned(16)));
+};
+
+struct target_ucontext {
+ target_ulong tuc_flags;
+ struct target_ucontext *tuc_link;
+ target_stack_t tuc_stack;
+ target_sigset_t tuc_sigmask;
+ uint8_t __unused[1024 / 8 - sizeof(target_sigset_t)];
+ struct target_sigcontext tuc_mcontext;
+};
+
+struct target_rt_sigframe {
+ struct target_siginfo rs_info;
+ struct target_ucontext rs_uc;
+};
+
+static uint64_t read_all_fcc(CPULoongArchState *env)
+{
+ uint64_t ret = 0;
+
+ for (int i = 0; i < 8; ++i) {
+ ret |= (uint64_t)env->cf[i] << (i * 8);
+ }
+
+ return ret;
+}
+
+static void write_all_fcc(CPULoongArchState *env, uint64_t val)
+{
+ for (int i = 0; i < 8; ++i) {
+ env->cf[i] = (val >> (i * 8)) & 1;
+ }
+}
+
+static inline void setup_sigcontext(CPULoongArchState *env,
+ struct target_sigcontext *sc)
+{
+ int i;
+
+ __put_user(env->pc, &sc->sc_pc);
+ __put_user(0, &sc->sc_regs[0]);
+ __put_user(env->fcsr0, &sc->sc_fcsr);
+ __put_user(0, &sc->sc_vcsr);
+ sc->sc_fcc = read_all_fcc(env);
+
+ for (i = 0; i < 4; ++i) {
+ __put_user(0, &sc->sc_scr[i]);
+ }
+
+ for (i = 1; i < 32; ++i) {
+ __put_user(env->gpr[i], &sc->sc_regs[i]);
+ }
+
+ for (i = 0; i < 32; ++i) {
+ __put_user(env->fpr[i], &sc->sc_fpregs[i].val64[0]);
+ }
+}
+
+static inline void
+restore_sigcontext(CPULoongArchState *env, struct target_sigcontext *sc)
+{
+ int i;
+
+ __get_user(env->pc, &sc->sc_pc);
+ __get_user(env->fcsr0, &sc->sc_fcsr);
+ write_all_fcc(env, sc->sc_fcc);
+
+ for (i = 1; i < 32; ++i) {
+ __get_user(env->gpr[i], &sc->sc_regs[i]);
+ }
+
+ for (i = 0; i < 32; ++i) {
+ __get_user(env->fpr[i], &sc->sc_fpregs[i].val64[0]);
+ }
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline abi_ulong
+get_sigframe(struct target_sigaction *ka, CPULoongArchState *env,
+ size_t frame_size)
+{
+ unsigned long sp;
+
+ sp = target_sigsp(get_sp_from_cpustate(env) - 32, ka);
+
+ return (sp - frame_size) & ~15;
+}
+
+void setup_rt_frame(int sig, struct target_sigaction *ka,
+ target_siginfo_t *info,
+ target_sigset_t *set, CPULoongArchState *env)
+{
+ struct target_rt_sigframe *frame;
+ abi_ulong frame_addr;
+ 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;
+ }
+
+ tswap_siginfo(&frame->rs_info, info);
+
+ __put_user(0, &frame->rs_uc.tuc_flags);
+ __put_user(0, &frame->rs_uc.tuc_link);
+ target_save_altstack(&frame->rs_uc.tuc_stack, env);
+
+ setup_sigcontext(env, &frame->rs_uc.tuc_mcontext);
+
+ for (i = 0; i < TARGET_NSIG_WORDS; i++) {
+ __put_user(set->sig[i], &frame->rs_uc.tuc_sigmask.sig[i]);
+ }
+
+ env->gpr[4] = sig;
+ env->gpr[5] = frame_addr + offsetof(struct target_rt_sigframe, rs_info);
+ env->gpr[6] = frame_addr + offsetof(struct target_rt_sigframe, rs_uc);
+ env->gpr[3] = frame_addr;
+ env->gpr[1] = default_rt_sigreturn;
+
+ env->pc = ka->_sa_handler;
+ unlock_user_struct(frame, frame_addr, 1);
+ return;
+
+give_sigsegv:
+ unlock_user_struct(frame, frame_addr, 1);
+ force_sigsegv(sig);
+}
+
+long do_rt_sigreturn(CPULoongArchState *env)
+{
+ struct target_rt_sigframe *frame;
+ abi_ulong frame_addr;
+ sigset_t blocked;
+
+ frame_addr = env->gpr[3];
+ trace_user_do_rt_sigreturn(env, frame_addr);
+ if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
+ goto badframe;
+ }
+
+ target_to_host_sigset(&blocked, &frame->rs_uc.tuc_sigmask);
+ set_sigmask(&blocked);
+
+ restore_sigcontext(env, &frame->rs_uc.tuc_mcontext);
+ target_restore_altstack(&frame->rs_uc.tuc_stack, env);
+
+ 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;
+}
+
+void setup_sigtramp(abi_ulong sigtramp_page)
+{
+ uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 8, 0);
+ assert(tramp != NULL);
+
+ __put_user(0x03822c0b, tramp + 0); /* ori a7, zero, 0x8b */
+ __put_user(0x002b0000, tramp + 1); /* syscall 0 */
+
+ default_rt_sigreturn = sigtramp_page;
+ unlock_user(tramp, sigtramp_page, 8);
+}
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@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2021 Loongson Technology Corporation Limited
+ */
+
+#ifndef LOONGARCH_TARGET_SIGNAL_H
+#define LOONGARCH_TARGET_SIGNAL_H
+
+#include "../generic/signal.h"
+
+#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1
+
+#endif /* LOONGARCH_TARGET_SIGNAL_H */