new file mode 100644
@@ -0,0 +1,312 @@
+/* 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 "user-internals.h"
+#include "signal-common.h"
+#include "linux-user/trace.h"
+
+#include "target/loongarch/internals.h"
+
+/* FP context was used */
+#define SC_USED_FP (1 << 0)
+
+struct target_sigcontext {
+ uint64_t sc_pc;
+ uint64_t sc_regs[32];
+ uint32_t sc_flags;
+ uint64_t sc_extcontext[0] __attribute__((aligned(16)));
+};
+
+struct target_fpu_context {
+ uint64_t regs[32];
+ uint64_t fcc;
+ uint32_t fcsr;
+};
+
+struct target_sctx_info {
+ uint32_t magic;
+ uint32_t size;
+ uint64_t padding; /* padding to 16 bytes */
+};
+
+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;
+};
+
+struct ctx_layout {
+ abi_ulong addr;
+ unsigned int size;
+};
+
+struct extctx_layout {
+ unsigned int size;
+ unsigned int flags;
+ struct ctx_layout fpu;
+ struct ctx_layout end;
+};
+
+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 void *get_ctx(struct target_sctx_info *info)
+{
+ return (char *)info + sizeof(struct target_sctx_info);
+}
+
+static void copy_fpu_to_sigcontext(CPULoongArchState *env,
+ struct extctx_layout *extctx)
+{
+ int i;
+ struct target_sctx_info *info = (struct target_sctx_info *)extctx->fpu.addr;
+ struct target_fpu_context *fpu_ctx = get_ctx(info);
+
+ for (i = 1; i < 32; ++i) {
+ __put_user(env->fpr[i], &fpu_ctx->regs[i]);
+ }
+
+ fpu_ctx->fcc = read_all_fcc(env);
+ __put_user(env->fcsr0, &fpu_ctx->fcsr);
+ __put_user(extctx->fpu.size, &info->size);
+}
+
+static abi_ulong extframe_alloc(struct extctx_layout *extctx,
+ struct ctx_layout *layout,
+ size_t size, abi_ulong base)
+{
+ abi_ulong new_base = base - size;
+
+ new_base -= sizeof(struct target_sctx_info);
+ layout->addr = new_base;
+ layout->size = (unsigned int)(base - new_base);
+ extctx->size += layout->size;
+
+ return new_base;
+}
+
+static abi_ulong setup_extcontext(struct extctx_layout *extctx, abi_ulong sp)
+{
+ abi_ulong new_sp = sp;
+
+ memset(extctx, 0, sizeof(struct extctx_layout));
+ new_sp -= sizeof(struct target_sctx_info);
+
+ extctx->end.addr = new_sp;
+ extctx->end.size = (unsigned int)sizeof(struct target_sctx_info);
+ extctx->size += extctx->end.size;
+ extctx->flags = SC_USED_FP;
+
+ new_sp = extframe_alloc(extctx, &extctx->fpu,
+ sizeof(struct target_fpu_context), new_sp);
+
+ return new_sp;
+}
+
+static void setup_sigcontext(CPULoongArchState *env,
+ struct target_sigcontext *sc,
+ struct extctx_layout *extctx)
+{
+ int i;
+
+ __put_user(extctx->flags, &sc->sc_flags);
+ __put_user(env->pc, &sc->sc_pc);
+
+ for (i = 1; i < 32; ++i) {
+ __put_user(env->gpr[i], &sc->sc_regs[i]);
+ }
+
+ copy_fpu_to_sigcontext(env, extctx);
+}
+
+static void copy_fpu_from_sigcontext(CPULoongArchState *env,
+ struct extctx_layout *extctx)
+{
+ int i;
+ struct target_sctx_info *info = (struct target_sctx_info *)extctx->fpu.addr;
+ struct target_fpu_context *fpu_ctx = get_ctx(info);
+
+ for (i = 1; i < 32; ++i) {
+ __get_user(env->fpr[i], &fpu_ctx->regs[i]);
+ }
+ write_all_fcc(env, fpu_ctx->fcc);
+ __get_user(env->fcsr0, &fpu_ctx->fcsr);
+}
+
+static int parse_extcontext(struct target_sigcontext *sc,
+ struct extctx_layout *extctx)
+{
+ unsigned int size;
+ struct target_sctx_info *info = (struct target_sctx_info *)
+ &sc->sc_extcontext;
+
+ __get_user(size, &info->size);
+
+ if (size < (sizeof(struct target_sctx_info) +
+ sizeof(struct target_fpu_context))) {
+ return -TARGET_EINVAL;
+ }
+
+ extctx->fpu.addr = (abi_ulong)info;
+ info = (struct target_sctx_info *)((char *)info + size);
+
+ return 0;
+}
+
+static int restore_sigcontext(CPULoongArchState *env,
+ struct target_sigcontext *sc)
+{
+ int i;
+ int ret = 0;
+ struct extctx_layout extctx;
+
+ memset(&extctx, 0, sizeof(struct extctx_layout));
+
+ __get_user(extctx.flags, &sc->sc_flags);
+
+ ret = parse_extcontext(sc, &extctx);
+ if (ret < 0) {
+ goto bad;
+ }
+
+ __get_user(env->pc, &sc->sc_pc);
+ for (i = 1; i < 32; ++i) {
+ __get_user(env->gpr[i], &sc->sc_regs[i]);
+ }
+
+ copy_fpu_from_sigcontext(env, &extctx);
+ restore_fp_status(env);
+
+bad:
+ return ret;
+}
+
+/*
+ * Determine which stack to use.
+ */
+static abi_ulong get_sigframe(struct target_sigaction *ka,
+ CPULoongArchState *env, size_t frame_size,
+ struct extctx_layout *extctx)
+{
+ abi_ulong sp;
+
+ sp = target_sigsp(get_sp_from_cpustate(env) - 32, ka);
+ sp = setup_extcontext(extctx, sp);
+
+ 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;
+ struct extctx_layout extctx;
+ abi_ulong frame_addr;
+ int i;
+
+ frame_addr = get_sigframe(ka, env, sizeof(*frame), &extctx);
+ 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, &extctx);
+
+ 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)
+{
+ int ret = 0;
+ 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);
+
+ ret = restore_sigcontext(env, &frame->rs_uc.tuc_mcontext);
+ if (ret < 0) {
+ goto badframe;
+ }
+
+ target_restore_altstack(&frame->rs_uc.tuc_stack, env);
+
+ unlock_user_struct(frame, frame_addr, 0);
+ return -QEMU_ESIGRETURN;
+
+badframe:
+ unlock_user_struct(frame, frame_addr, 0);
+ force_sig(TARGET_SIGSEGV);
+ return -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);
+}
new file mode 100644
@@ -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 */