LoongArch: Linux ABI

sysdeps/loongarch/dl-irel.h

@@ -0,0 +1,54 @@
+/* Machine-dependent ELF indirect relocation inline functions.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _DL_IREL_H
+#define _DL_IREL_H
+
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/ifunc.h>
+
+#define ELF_MACHINE_IRELA 1
+
+static inline ElfW (Addr) __attribute ((always_inline))
+elf_ifunc_invoke (ElfW (Addr) addr)
+{
+  __ifunc_arg_t arg =
+  {
+    ._size = sizeof (__ifunc_arg_t),
+    ._hwcap = GLRO(dl_hwcap),
+  };
+  return ((ElfW(Addr) (*) (const __ifunc_arg_t *)) (addr)) (&arg);
+}
+
+static inline void __attribute ((always_inline))
+elf_irela (const ElfW (Rela) *reloc)
+{
+  ElfW (Addr) *const reloc_addr = (void *) reloc->r_offset;
+  const unsigned long int r_type = ELFW (R_TYPE) (reloc->r_info);
+
+  if (__glibc_likely (r_type == R_LARCH_IRELATIVE))
+    {
+      ElfW (Addr) value = elf_ifunc_invoke (reloc->r_addend);
+      *reloc_addr = value;
+    }
+  else
+    __libc_fatal ("Unexpected reloc type in static binary.\n");
+}
+
+#endif /* dl-irel.h */

sysdeps/loongarch/nptl/pthreaddef.h

@@ -0,0 +1,32 @@
+/* pthread machine parameter definitions.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* Default stack size.  */
+#define ARCH_STACK_DEFAULT_SIZE (2 * 1024 * 1024)
+
+/* Minimum guard size.  */
+#define ARCH_MIN_GUARD_SIZE 0
+
+/* Required stack pointer alignment at beginning.  */
+#define STACK_ALIGN 16
+
+/* Minimal stack size after allocating thread descriptor and guard size.  */
+#define MINIMAL_REST_STACK 2048
+
+/* Location of current stack frame.  */
+#define CURRENT_STACK_FRAME __builtin_frame_address (0)

sysdeps/loongarch/sys/ifunc.h

@@ -0,0 +1,30 @@
+/* Definitions used by LoongArch indirect function resolvers.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_IFUNC_H
+#define _SYS_IFUNC_H
+
+struct __ifunc_arg_t
+{
+  unsigned long _size; /* Size of the struct, so it can grow.  */
+  unsigned long _hwcap;
+};
+
+typedef struct __ifunc_arg_t __ifunc_arg_t;
+
+#endif

sysdeps/unix/sysv/linux/loongarch/bits/fcntl.h

@@ -0,0 +1,61 @@
+/* O_*, F_*, FD_* bit values for the generic Linux/LoongArch ABI.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _FCNTL_H
+#error "Never use <bits/fcntl.h> directly; include <fcntl.h> instead."
+#endif
+
+#include <bits/wordsize.h>
+
+/* In 64-bit ISA files are always with 64bit off_t and F_*LK64 are the same as
+   non-64-bit versions.  It will need to be revised for 128-bit.  */
+#if __WORDSIZE == 64
+#define __O_LARGEFILE 0
+
+#define F_GETLK64 5  /* Get record locking info.  */
+#define F_SETLK64 6  /* Set record locking info (non-blocking).  */
+#define F_SETLKW64 7 /* Set record locking info (blocking).  */
+#endif
+
+struct flock
+{
+  short int l_type;   /* Type of lock: F_RDLCK, F_WRLCK, or F_UNLCK.  */
+  short int l_whence; /* Where `l_start' is relative to (like `lseek').  */
+#ifndef __USE_FILE_OFFSET64
+  __off_t l_start; /* Offset where the lock begins.  */
+  __off_t l_len;   /* Size of the locked area; zero means until EOF.  */
+#else
+  __off64_t l_start; /* Offset where the lock begins.  */
+  __off64_t l_len;   /* Size of the locked area; zero means until EOF.  */
+#endif
+  __pid_t l_pid; /* Process holding the lock.  */
+};
+
+#ifdef __USE_LARGEFILE64
+struct flock64
+{
+  short int l_type;   /* Type of lock: F_RDLCK, F_WRLCK, or F_UNLCK.  */
+  short int l_whence; /* Where `l_start' is relative to (like `lseek').  */
+  __off64_t l_start;  /* Offset where the lock begins.  */
+  __off64_t l_len;    /* Size of the locked area; zero means until EOF.  */
+  __pid_t l_pid;      /* Process holding the lock.  */
+};
+#endif
+
+/* Include generic Linux declarations.  */
+#include <bits/fcntl-linux.h>

sysdeps/unix/sysv/linux/loongarch/bits/procfs.h

@@ -0,0 +1,52 @@
+/* Types for registers for sys/procfs.h.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_PROCFS_H
+# error "Never include <bits/procfs.h> directly; use <sys/procfs.h> instead."
+#endif
+
+/* Type for a general-purpose register.  */
+typedef __uint64_t elf_greg_t;
+
+/* And the whole bunch of them.  We could have used `struct
+   pt_regs' directly in the typedef, but tradition says that
+   the register set is an array, which does have some peculiar
+   semantics, so leave it that way.  */
+#define ELF_NGREG (sizeof (struct user_regs_struct) / sizeof (elf_greg_t))
+typedef elf_greg_t elf_gregset_t[ELF_NGREG];
+
+#define ELF_NFPREG 34 /* 32 FPRs + 8-byte byte-vec for fcc + 4-byte FCR */
+typedef union
+{
+  double d;
+  float f;
+} elf_fpreg_t;
+typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];
+
+typedef union
+{
+  double d[2];
+  float f[4];
+} __attribute__ ((__aligned__ (16))) elf_lsxregset_t[32];
+
+typedef union
+{
+  double d[4];
+  float f[8];
+} __attribute__ ((__aligned__ (32))) elf_lasxregset_t[32];

sysdeps/unix/sysv/linux/loongarch/bits/pthread_stack_min.h

@@ -0,0 +1,20 @@
+/* Definition of PTHREAD_STACK_MIN.  LoongArch Linux version.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* Minimum size for a thread.  At least two pages with 64k pages.  */
+#define PTHREAD_STACK_MIN	131072

sysdeps/unix/sysv/linux/loongarch/bits/sigstack.h

@@ -0,0 +1,32 @@
+/* sigstack, sigaltstack definitions.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _BITS_SIGSTACK_H
+#define _BITS_SIGSTACK_H 1
+
+#if !defined _SIGNAL_H && !defined _SYS_UCONTEXT_H
+# error "Never include this file directly.  Use <signal.h> instead"
+#endif
+
+/* Minimum stack size for a signal handler.  */
+#define MINSIGSTKSZ	4096
+
+/* System default stack size.  */
+#define SIGSTKSZ	16384
+
+#endif /* bits/sigstack.h */

sysdeps/unix/sysv/linux/loongarch/getcontext.S

@@ -0,0 +1,59 @@
+/* Save current context.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include "ucontext-macros.h"
+
+/* int getcontext (ucontext_t *ucp) */
+
+	.text
+LEAF (__getcontext)
+	SAVE_INT_REG (ra,   1, a0)
+	SAVE_INT_REG (sp,   3, a0)
+	SAVE_INT_REG (zero, 4, a0) /* return 0 by overwriting a0.  */
+	SAVE_INT_REG (x,   21, a0)
+	SAVE_INT_REG (fp,  22, a0)
+	SAVE_INT_REG (s0,  23, a0)
+	SAVE_INT_REG (s1,  24, a0)
+	SAVE_INT_REG (s2,  25, a0)
+	SAVE_INT_REG (s3,  26, a0)
+	SAVE_INT_REG (s4,  27, a0)
+	SAVE_INT_REG (s5,  28, a0)
+	SAVE_INT_REG (s6,  29, a0)
+	SAVE_INT_REG (s7,  30, a0)
+	SAVE_INT_REG (s8,  31, a0)
+	st.d		ra, a0, MCONTEXT_PC
+
+/* rt_sigprocmask (SIG_BLOCK, NULL, &ucp->uc_sigmask, _NSIG8) */
+	li.d		a3, _NSIG8
+	li.d		a2, UCONTEXT_SIGMASK
+	add.d		a2, a2, a0
+	ori		a1, zero,0
+	li.d		a0, SIG_BLOCK
+
+	li.d		a7, SYS_ify (rt_sigprocmask)
+	syscall		0
+	blt		a0, zero, 99f
+
+	jirl		$r0, $r1, 0
+
+99:
+	b		__syscall_error
+
+PSEUDO_END (__getcontext)
+
+weak_alias (__getcontext, getcontext)

sysdeps/unix/sysv/linux/loongarch/localplt.data

@@ -0,0 +1,12 @@
+# See scripts/check-localplt.awk for how this file is processed.
+# PLT use is required for the malloc family and for matherr because
+# users can define their own functions and have library internals call them.
+libc.so: calloc
+libc.so: free
+libc.so: malloc
+libc.so: realloc
+# The TLS-enabled version of these functions is interposed from libc.so.
+ld.so: _dl_signal_error
+ld.so: _dl_catch_error
+ld.so: _dl_signal_exception
+ld.so: _dl_catch_exception

sysdeps/unix/sysv/linux/loongarch/makecontext.c

@@ -0,0 +1,81 @@
+/* Create new context.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <sys/asm.h>
+#include <sys/ucontext.h>
+#include <stdarg.h>
+#include <assert.h>
+
+void
+__makecontext (ucontext_t *ucp, void (*func) (void), int argc, long int a0,
+	       long int a1, long int a2, long int a3, long int a4, ...)
+{
+  extern void __start_context (void) attribute_hidden;
+  unsigned long int *sp;
+
+  _Static_assert(LARCH_REG_NARGS == 8,
+		 "__makecontext assumes 8 argument registers");
+
+  /* Set up the stack.  */
+  sp = (unsigned long int *)
+       (((uintptr_t) ucp->uc_stack.ss_sp + ucp->uc_stack.ss_size) & ALMASK);
+
+  /* Set up the register context.
+     ra = s0 = 0, terminating the stack for backtracing purposes.
+     s1 = the function we must call.
+     s2 = the subsequent context to run.  */
+  ucp->uc_mcontext.__gregs[LARCH_REG_RA] = (uintptr_t) 0;
+  ucp->uc_mcontext.__gregs[LARCH_REG_S0] = (uintptr_t) 0;
+  ucp->uc_mcontext.__gregs[LARCH_REG_S1] = (uintptr_t) func;
+  ucp->uc_mcontext.__gregs[LARCH_REG_S2] = (uintptr_t) ucp->uc_link;
+  ucp->uc_mcontext.__gregs[LARCH_REG_SP] = (uintptr_t) sp;
+  ucp->uc_mcontext.__pc = (uintptr_t) &__start_context;
+
+  /* Put args in a0-a7, then put any remaining args on the stack.  */
+  ucp->uc_mcontext.__gregs[LARCH_REG_A0 + 0] = (uintptr_t) a0;
+  ucp->uc_mcontext.__gregs[LARCH_REG_A0 + 1] = (uintptr_t) a1;
+  ucp->uc_mcontext.__gregs[LARCH_REG_A0 + 2] = (uintptr_t) a2;
+  ucp->uc_mcontext.__gregs[LARCH_REG_A0 + 3] = (uintptr_t) a3;
+  ucp->uc_mcontext.__gregs[LARCH_REG_A0 + 4] = (uintptr_t) a4;
+
+  if (__glibc_unlikely (argc > 5))
+    {
+      va_list vl;
+      va_start (vl, a4);
+
+      long int reg_args = argc < LARCH_REG_NARGS ? argc : LARCH_REG_NARGS;
+      for (long int i = 5; i < reg_args; i++)
+	ucp->uc_mcontext.__gregs[LARCH_REG_A0 + i] = va_arg (vl, unsigned long int);
+
+      long int stack_args = argc - reg_args;
+      if (stack_args > 0)
+	{
+	  sp = (unsigned long int *)
+	       (((uintptr_t) sp - stack_args * sizeof (long int)) & ALMASK);
+	  ucp->uc_mcontext.__gregs[LARCH_REG_SP] = (uintptr_t) sp;
+	  for (long int i = 0; i < stack_args; i++)
+	    sp[i] = va_arg (vl, unsigned long int);
+	}
+
+      va_end (vl);
+    }
+}
+
+weak_alias (__makecontext, makecontext)

sysdeps/unix/sysv/linux/loongarch/setcontext.S

@@ -0,0 +1,100 @@
+/* Set current context.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+#include "sys/regdef.h"
+#include "ucontext-macros.h"
+
+/*  int __setcontext (const ucontext_t *ucp)
+
+  Restores the machine context in UCP and thereby resumes execution
+  in that context.
+
+  This implementation is intended to be used for *synchronous* context
+  switches only.  Therefore, it does not have to restore anything
+  other than the PRESERVED state.  */
+
+	.text
+LEAF (__setcontext)
+
+	addi.d		sp, sp, -16
+	st.d		a0, sp, 0	/* Save ucp to stack */
+
+/* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, NULL, _NSIG8) */
+	li.d		a3, _NSIG8
+	li.d		a2, 0
+	li.d		a1, UCONTEXT_SIGMASK
+	add.d		a1, a1, a0
+	li.d		a0, SIG_SETMASK
+
+	li.d		a7, SYS_ify (rt_sigprocmask)
+	syscall		0
+
+	blt		a0, $r0, 99f
+
+	ld.d		t0, sp, 0	/* Load ucp to t0 */
+	cfi_def_cfa (12, 0)
+
+/* Note the contents of argument registers will be random
+   unless makecontext() has been called.  */
+	RESTORE_INT_REG(ra,   1, t0)
+	RESTORE_INT_REG(sp,   3, t0)
+	RESTORE_INT_REG(a0,   4, t0)
+	RESTORE_INT_REG(a1,   5, t0)
+	RESTORE_INT_REG(a2,   6, t0)
+	RESTORE_INT_REG(a3,   7, t0)
+	RESTORE_INT_REG(a4,   8, t0)
+	RESTORE_INT_REG(a5,   9, t0)
+	RESTORE_INT_REG(a6,  10, t0)
+	RESTORE_INT_REG(a7,  11, t0)
+	RESTORE_INT_REG(x,   21, t0)
+	RESTORE_INT_REG(fp,  22, t0)
+	RESTORE_INT_REG(s0,  23, t0)
+	RESTORE_INT_REG(s1,  24, t0)
+	RESTORE_INT_REG(s2,  25, t0)
+	RESTORE_INT_REG(s3,  26, t0)
+	RESTORE_INT_REG(s4,  27, t0)
+	RESTORE_INT_REG(s5,  28, t0)
+	RESTORE_INT_REG(s6,  29, t0)
+	RESTORE_INT_REG(s7,  30, t0)
+	RESTORE_INT_REG(s8,  31, t0)
+
+	ld.d		t1, t0, MCONTEXT_PC
+	jirl		$r0,t1,0
+
+99:
+	addi.d		sp, sp, 16
+	b		__syscall_error
+
+PSEUDO_END (__setcontext)
+weak_alias (__setcontext, setcontext)
+
+LEAF (__start_context)
+
+	/* Terminate call stack by noting ra == 0.  Happily, s0 == 0 here.  */
+	cfi_register (1, 23)
+
+	/* Call the function passed to makecontext.  */
+	jirl		$r1,s1,0
+
+	/* Invoke subsequent context if present, else exit(0).  */
+	ori		a0, s2, 0
+	beqz		s2, 1f
+	bl		__setcontext
+1:
+	b		HIDDEN_JUMPTARGET(exit)
+
+PSEUDO_END (__start_context)

sysdeps/unix/sysv/linux/loongarch/sigcontextinfo.h

@@ -0,0 +1,32 @@
+/* LoongArch definitions for signal handling calling conventions.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SIGCONTEXTINFO_H
+#define _SIGCONTEXTINFO_H
+
+#include <stdint.h>
+#include <sys/ucontext.h>
+
+static inline uintptr_t
+sigcontext_get_pc (const ucontext_t *ctx)
+{
+  return ctx->uc_mcontext.__pc;
+}
+
+#endif

sysdeps/unix/sysv/linux/loongarch/swapcontext.S

@@ -0,0 +1,95 @@
+/* Save and set current context.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include "ucontext-macros.h"
+
+/* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */
+
+LEAF (__swapcontext)
+	ori		a2, sp, 0		/* Save sp to a2 */
+	addi.d		sp, sp, -16
+	st.d		a1, sp, 0
+	ori		t0, a1, 0
+
+	SAVE_INT_REG (ra,   1, a0)
+	SAVE_INT_REG (a2,   3, a0)		/* Store sp */
+	SAVE_INT_REG (zero, 4, a0)		/* return 0 by overwriting a0 */
+	SAVE_INT_REG (x,   21, a0)
+	SAVE_INT_REG (fp,  22, a0)
+	SAVE_INT_REG (s0,  23, a0)
+	SAVE_INT_REG (s1,  24, a0)
+	SAVE_INT_REG (s2,  25, a0)
+	SAVE_INT_REG (s3,  26, a0)
+	SAVE_INT_REG (s4,  27, a0)
+	SAVE_INT_REG (s5,  28, a0)
+	SAVE_INT_REG (s6,  29, a0)
+	SAVE_INT_REG (s7,  30, a0)
+	SAVE_INT_REG (s8,  31, a0)
+
+	st.d		ra, a0, MCONTEXT_PC
+
+/* rt_sigprocmask (SIG_SETMASK, &ucp->uc_sigmask, &oucp->uc_sigmask, _NSIG8) */
+	li.d		a3, _NSIG8
+	li.d		a2, UCONTEXT_SIGMASK
+	add.d		a2, a2, a0
+	li.d		a1, UCONTEXT_SIGMASK
+	add.d		a1, a1, t0
+	li.d		a0, SIG_SETMASK
+
+	li.d		a7, SYS_ify (rt_sigprocmask)
+	syscall		0
+
+	blt		a0, zero, 99f
+
+	ld.d		t0, sp, 0		/* Load a1 to t0 */
+
+/* Note the contents of argument registers will be random
+   unless makecontext() has been called.  */
+	RESTORE_INT_REG (ra,   1, t0)
+	RESTORE_INT_REG (sp,   3, t0)
+	RESTORE_INT_REG (a0,   4, t0)
+	RESTORE_INT_REG (a1,   5, t0)
+	RESTORE_INT_REG (a2,   6, t0)
+	RESTORE_INT_REG (a3,   7, t0)
+	RESTORE_INT_REG (a4,   8, t0)
+	RESTORE_INT_REG (a5,   9, t0)
+	RESTORE_INT_REG (a6,  10, t0)
+	RESTORE_INT_REG (a7,  11, t0)
+	RESTORE_INT_REG (x,   21, t0)
+	RESTORE_INT_REG (fp,  22, t0)
+	RESTORE_INT_REG (s0,  23, t0)
+	RESTORE_INT_REG (s1,  24, t0)
+	RESTORE_INT_REG (s2,  25, t0)
+	RESTORE_INT_REG (s3,  26, t0)
+	RESTORE_INT_REG (s4,  27, t0)
+	RESTORE_INT_REG (s5,  28, t0)
+	RESTORE_INT_REG (s6,  29, t0)
+	RESTORE_INT_REG (s7,  30, t0)
+	RESTORE_INT_REG (s8,  31, t0)
+
+	ld.d		t1, t0, MCONTEXT_PC
+	jirl		$r0, t1, 0
+
+
+99:
+	addi.d		sp, sp, 16
+	b		__syscall_error
+
+PSEUDO_END (__swapcontext)
+
+weak_alias (__swapcontext, swapcontext)

sysdeps/unix/sysv/linux/loongarch/sys/ucontext.h

@@ -0,0 +1,61 @@
+/* struct ucontext definition.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+/* Don't rely on this, the interface is currently messed up and may need to
+   be broken to be fixed.  */
+#ifndef _SYS_UCONTEXT_H
+#define _SYS_UCONTEXT_H 1
+
+#include <features.h>
+
+#include <bits/types/sigset_t.h>
+#include <bits/types/stack_t.h>
+
+#ifdef __USE_MISC
+#define LARCH_NGREG 32
+
+#define LARCH_REG_RA 1
+#define LARCH_REG_SP 3
+#define LARCH_REG_S0 23
+#define LARCH_REG_S1 24
+#define LARCH_REG_A0 4
+#define LARCH_REG_S2 25
+#define LARCH_REG_NARGS 8
+
+#endif
+
+typedef struct mcontext_t
+{
+  unsigned long long __pc;
+  unsigned long long __gregs[32];
+  unsigned int __flags;
+  unsigned long long __extcontext[0] __attribute__((__aligned__(16)));
+} mcontext_t;
+
+/* Userlevel context.  */
+typedef struct ucontext_t
+{
+  unsigned long int __uc_flags;
+  struct ucontext_t *uc_link;
+  stack_t uc_stack;
+  sigset_t uc_sigmask;
+  mcontext_t uc_mcontext;
+} ucontext_t;
+
+#endif /* sys/ucontext.h */

sysdeps/unix/sysv/linux/loongarch/sys/user.h

@@ -0,0 +1,42 @@
+/* struct user_regs_struct definition for LoongArch.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_USER_H
+#define _SYS_USER_H 1
+
+#include <stdint.h>
+
+struct user_regs_struct
+{
+  /* Saved main processor registers. */
+  uint64_t regs[32];
+
+  /* Saved special registers. */
+  uint64_t orig_a0;
+  uint64_t csr_era;
+  uint64_t csr_badv;
+  uint64_t reserved[10];
+};
+
+struct user_fp_struct {
+  uint64_t    fpr[32];
+  uint64_t    fcc;
+  uint32_t    fcsr;
+};
+
+#endif /* _SYS_USER_H */

sysdeps/unix/sysv/linux/loongarch/ucontext-macros.h

@@ -0,0 +1,32 @@
+/* Macros for ucontext routines.
+   Copyright (C) 2022 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _LINUX_LOONGARCH_UCONTEXT_MACROS_H
+#define _LINUX_LOONGARCH_UCONTEXT_MACROS_H
+
+#include <sysdep.h>
+#include <sys/asm.h>
+#include "ucontext_i.h"
+
+#define SAVE_INT_REG(name, num, base) \
+  REG_S name, base, ((num) *SZREG + MCONTEXT_GREGS)
+
+#define RESTORE_INT_REG(name, num, base) \
+  REG_L name, base, ((num) *SZREG + MCONTEXT_GREGS)
+
+#endif /* _LINUX_LOONGARCH_UCONTEXT_MACROS_H */

sysdeps/unix/sysv/linux/loongarch/ucontext_i.sym

@@ -0,0 +1,31 @@
+#include <inttypes.h>
+#include <signal.h>
+#include <stddef.h>
+#include <sys/ucontext.h>
+
+-- Constants used by the rt_sigprocmask call.
+
+SIG_BLOCK
+SIG_SETMASK
+
+_NSIG8				(_NSIG / 8)
+
+-- Offsets of the fields in the ucontext_t structure.
+#define ucontext(member)	offsetof (ucontext_t, member)
+#define stack(member)		ucontext (uc_stack.member)
+#define mcontext(member)	ucontext (uc_mcontext.member)
+
+UCONTEXT_FLAGS			ucontext (__uc_flags)
+UCONTEXT_LINK			ucontext (uc_link)
+UCONTEXT_STACK			ucontext (uc_stack)
+UCONTEXT_MCONTEXT		ucontext (uc_mcontext)
+UCONTEXT_SIGMASK		ucontext (uc_sigmask)
+
+STACK_SP			stack (ss_sp)
+STACK_SIZE			stack (ss_size)
+STACK_FLAGS			stack (ss_flags)
+
+MCONTEXT_PC			mcontext (__pc)
+MCONTEXT_GREGS			mcontext (__gregs)
+
+UCONTEXT_SIZE			sizeof (ucontext_t)