[RFC PATCH glibc 16/34] hurd: Add sys/ucontext.h and sigcontext.h for x86_64

[Sergey Bugaev <bugaevc@gmail.com>]

This is based on the Linux port's version, but laid out to match Mach's
struct i386_thread_state, much like the i386 version does.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
---

I'm not very sure about the FP stuff, nor about any of this, really. Please
do review.

 sysdeps/mach/hurd/x86_64/bits/sigcontext.h | 131 +++++++++++++++++
 sysdeps/mach/hurd/x86_64/sys/ucontext.h    | 157 +++++++++++++++++++++
 sysdeps/mach/hurd/x86_64/ucontext_i.sym    |  38 +++++
 3 files changed, 326 insertions(+)
 create mode 100644 sysdeps/mach/hurd/x86_64/bits/sigcontext.h
 create mode 100644 sysdeps/mach/hurd/x86_64/sys/ucontext.h
 create mode 100644 sysdeps/mach/hurd/x86_64/ucontext_i.sym

diff --git a/sysdeps/mach/hurd/x86_64/bits/sigcontext.h b/sysdeps/mach/hurd/x86_64/bits/sigcontext.h
new file mode 100644
index 00000000..3a3b34bc
--- /dev/null
+++ b/sysdeps/mach/hurd/x86_64/bits/sigcontext.h
@@ -0,0 +1,131 @@
+/* Machine-dependent signal context structure for GNU Hurd.  x86_64 version.
+   Copyright (C) 1991-2023 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_SIGCONTEXT_H
+#define _BITS_SIGCONTEXT_H 1
+
+#if !defined _SIGNAL_H && !defined _SYS_UCONTEXT_H
+# error "Never use <bits/sigcontext.h> directly; include <signal.h> instead."
+#endif
+
+/* Signal handlers are actually called:
+   void handler (int sig, int code, struct sigcontext *scp);  */
+
+#include <bits/types/__sigset_t.h>
+#include <mach/machine/fp_reg.h>
+
+/* State of this thread when the signal was taken.  */
+struct sigcontext
+  {
+    /* These first members are machine-independent.  */
+
+    int sc_onstack;		/* Nonzero if running on sigstack.  */
+    __sigset_t sc_mask;		/* Blocked signals to restore.  */
+
+    /* MiG reply port this thread is using.  */
+    unsigned int sc_reply_port;
+
+    /* Port this thread is doing an interruptible RPC on.  */
+    unsigned int sc_intr_port;
+
+    /* Error code associated with this signal (interpreted as `error_t').  */
+    int sc_error;
+
+    /* All following members are machine-dependent.  The rest of this
+       structure is written to be laid out identically to:
+       {
+	 struct i386_thread_state basic;
+	 struct i386_float_state fpu;
+       }
+       trampoline.c knows this, so it must be changed if this changes.  */
+
+#define sc_i386_thread_state sc_gs /* Beginning of correspondence.  */
+    /* Segment registers.  */
+    int sc_gs;
+    int sc_fs;
+    int sc_es;
+    int sc_ds;
+
+    long sc_r8;
+    long sc_r9;
+    long sc_r10;
+    long sc_r11;
+    long sc_r12;
+    long sc_r13;
+    long sc_r14;
+    long sc_r15;
+    long sc_rdi;
+    long sc_rsi;
+    long sc_rbp;
+    long sc_rsp;		/* Not used; sc_ursp is used instead.  */
+    long sc_rbx;
+    long sc_rdx;
+    long sc_rcx;
+    long sc_rax;
+    long sc_rip;		/* Instruction pointer.  */
+
+    int sc_cs;			/* Code segment register.  */
+
+    long sc_rfl;		/* Processor flags.  */
+
+    long sc_ursp;		/* This stack pointer is used.  */
+    int sc_ss;			/* Stack segment register.  */
+
+    /* Following mimics struct i386_float_state.  Structures and symbolic
+       values can be found in <mach/i386/fp_reg.h>.  */
+#define sc_i386_float_state sc_fpkind
+    int sc_fpkind;		/* FP_NO, FP_387, etc.  */
+    int sc_fpused;		/* If zero, ignore rest of float state.  */
+    struct i386_fp_save sc_fpsave;
+    struct i386_fp_regs sc_fpregs;
+    int sc_fpexcsr;		/* FPSR including exception bits.  */
+  };
+
+/* Traditional BSD names for some members.  */
+#define sc_sp	sc_ursp		/* Stack pointer.  */
+#define sc_fp	sc_rbp		/* Frame pointer.  */
+#define sc_pc	sc_rip		/* Process counter.  */
+#define sc_ps	sc_rfl
+
+
+/* The deprecated sigcode values below are passed as an extra, non-portable
+   argument to regular signal handlers.  You should use SA_SIGINFO handlers
+   instead, which use the standard POSIX signal codes.  */
+
+/* Codes for SIGFPE.  */
+#define FPE_INTOVF_TRAP		0x1 /* integer overflow */
+#define FPE_INTDIV_FAULT	0x2 /* integer divide by zero */
+#define FPE_FLTOVF_FAULT	0x3 /* floating overflow */
+#define FPE_FLTDIV_FAULT	0x4 /* floating divide by zero */
+#define FPE_FLTUND_FAULT	0x5 /* floating underflow */
+#define FPE_SUBRNG_FAULT	0x7 /* BOUNDS instruction failed */
+#define FPE_FLTDNR_FAULT	0x8 /* denormalized operand */
+#define FPE_FLTINX_FAULT	0x9 /* floating loss of precision */
+#define FPE_EMERR_FAULT		0xa /* mysterious emulation error 33 */
+#define FPE_EMBND_FAULT		0xb /* emulation BOUNDS instruction failed */
+
+/* Codes for SIGILL.  */
+#define ILL_INVOPR_FAULT	0x1 /* invalid operation */
+#define ILL_STACK_FAULT		0x2 /* fault on microkernel stack access */
+#define ILL_FPEOPR_FAULT	0x3 /* invalid floating operation */
+
+/* Codes for SIGTRAP.  */
+#define DBG_SINGLE_TRAP		0x1 /* single step */
+#define DBG_BRKPNT_FAULT	0x2 /* breakpoint instruction */
+
+#endif /* bits/sigcontext.h */
diff --git a/sysdeps/mach/hurd/x86_64/sys/ucontext.h b/sysdeps/mach/hurd/x86_64/sys/ucontext.h
new file mode 100644
index 00000000..d73a8937
--- /dev/null
+++ b/sysdeps/mach/hurd/x86_64/sys/ucontext.h
@@ -0,0 +1,157 @@
+/* Copyright (C) 2001-2023 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_UCONTEXT_H
+#define _SYS_UCONTEXT_H	1
+
+#include <features.h>
+
+#include <bits/types.h>
+#include <bits/types/sigset_t.h>
+#include <bits/types/stack_t.h>
+
+
+#ifdef __USE_MISC
+# define __ctx(fld) fld
+#else
+# define __ctx(fld) __ ## fld
+#endif
+
+/* Type for general register.  */
+__extension__ typedef long long int greg_t;
+
+/* Number of general registers.  */
+#define __NGREG	23
+#ifdef __USE_MISC
+# define NGREG	__NGREG
+#endif
+
+/* Container for all general registers.  */
+typedef greg_t gregset_t[__NGREG];
+
+#ifdef __USE_GNU
+/* Number of each register in the `gregset_t' array.  */
+enum
+{
+  REG_GSFS = 0,		/* Actually int gs, fs.  */
+# define REG_GSFS	REG_GSFS
+  REG_ESDS,		/* Actually int es, ds.  */
+# define REG_ESDS	REG_ESDS
+  REG_R8,
+# define REG_R8		REG_R8
+  REG_R9,
+# define REG_R9		REG_R9
+  REG_R10,
+# define REG_R10	REG_R10
+  REG_R11,
+# define REG_R11	REG_R11
+  REG_R12,
+# define REG_R12	REG_R12
+  REG_R13,
+# define REG_R13	REG_R13
+  REG_R14,
+# define REG_R14	REG_R14
+  REG_R15,
+# define REG_R15	REG_R15
+  REG_RDI,
+# define REG_RDI	REG_RDI
+  REG_RSI,
+# define REG_RSI	REG_RSI
+  REG_RBP,
+# define REG_RBP	REG_RBP
+  REG_RSP,
+# define REG_RSP	REG_RSP
+  REG_RBX,
+# define REG_RBX	REG_RBX
+  REG_RDX,
+# define REG_RDX	REG_RDX
+  REG_RCX,
+# define REG_RCX	REG_RCX
+  REG_RAX,
+# define REG_RAX	REG_RAX
+  REG_RIP,
+# define REG_RIP	REG_RIP
+  REG_CS,		/* Actually int cs, pad.  */
+# define REG_CS		REG_CS
+  REG_RFL,
+# define REG_RFL	REG_RFL
+  REG_ERR,
+# define REG_ERR	REG_ERR
+  REG_TRAPNO,
+# define REG_TRAPNO	REG_TRAPNO
+  REG_OLDMASK,
+# define REG_OLDMASK	REG_OLDMASK
+  REG_CR2
+# define REG_CR2	REG_CR2
+};
+#endif
+
+struct _libc_fpxreg
+{
+  unsigned short int __ctx(significand)[4];
+  unsigned short int __ctx(exponent);
+  unsigned short int __glibc_reserved1[3];
+};
+
+struct _libc_xmmreg
+{
+  __uint32_t	__ctx(element)[4];
+};
+
+struct _libc_fpstate
+{
+  /* 64-bit FXSAVE format.  */
+  __uint16_t		__ctx(cwd);
+  __uint16_t		__ctx(swd);
+  __uint16_t		__ctx(ftw);
+  __uint16_t		__ctx(fop);
+  __uint64_t		__ctx(rip);
+  __uint64_t		__ctx(rdp);
+  __uint32_t		__ctx(mxcsr);
+  __uint32_t		__ctx(mxcr_mask);
+  struct _libc_fpxreg	_st[8];
+  struct _libc_xmmreg	_xmm[16];
+  __uint32_t		__glibc_reserved1[24];
+};
+
+/* Structure to describe FPU registers.  */
+typedef struct _libc_fpstate *fpregset_t;
+
+/* Context to describe whole processor state.  */
+typedef struct
+  {
+    gregset_t __ctx(gregs);
+    /* Note that fpregs is a pointer.  */
+    fpregset_t __ctx(fpregs);
+    __extension__ unsigned long long __reserved1 [8];
+} mcontext_t;
+
+/* Userlevel context.  */
+typedef struct ucontext_t
+  {
+    unsigned long int __ctx(uc_flags);
+    struct ucontext_t *uc_link;
+    stack_t uc_stack;
+    mcontext_t uc_mcontext;
+    sigset_t uc_sigmask;
+    struct _libc_fpstate __fpregs_mem;
+    __extension__ unsigned long long int __ssp[4];
+  } ucontext_t;
+
+#undef __ctx
+
+#endif /* sys/ucontext.h */
diff --git a/sysdeps/mach/hurd/x86_64/ucontext_i.sym b/sysdeps/mach/hurd/x86_64/ucontext_i.sym
new file mode 100644
index 00000000..7e536956
--- /dev/null
+++ b/sysdeps/mach/hurd/x86_64/ucontext_i.sym
@@ -0,0 +1,38 @@
+#include <stddef.h>
+#include <signal.h>
+#include <sys/ucontext.h>
+
+--
+
+SIG_BLOCK
+SIG_SETMASK
+
+_NSIG8		(_NSIG / 8)
+
+#define ucontext(member)	offsetof (ucontext_t, member)
+#define mcontext(member)	ucontext (uc_mcontext.member)
+#define mreg(reg)		mcontext (gregs[REG_##reg])
+
+oRBP		mreg (RBP)
+oRSP		mreg (RSP)
+oRBX		mreg (RBX)
+oR8		mreg (R8)
+oR9		mreg (R9)
+oR10		mreg (R10)
+oR11		mreg (R11)
+oR12		mreg (R12)
+oR13		mreg (R13)
+oR14		mreg (R14)
+oR15		mreg (R15)
+oRDI		mreg (RDI)
+oRSI		mreg (RSI)
+oRDX		mreg (RDX)
+oRAX		mreg (RAX)
+oRCX		mreg (RCX)
+oRIP		mreg (RIP)
+oRFL		mreg (RFL)
+oFPREGS		mcontext (fpregs)
+oSIGMASK	ucontext (uc_sigmask)
+oFPREGSMEM	ucontext (__fpregs_mem)
+oMXCSR		ucontext (__fpregs_mem.mxcsr)
+oSSP		ucontext (__ssp)
-- 
2.39.2