ARC: ABI Implementation

This code deals with the ARC ABI.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

sysdeps/arc/__longjmp.S

@@ -0,0 +1,49 @@
+/* longjmp for ARC.
+   Copyright (C) 2020 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 <jmpbuf-offsets.h>
+
+/* @ r0 = jump buffer from which regs will be restored
+   @ r1 = value that setjmp( ) will return due to this longjmp.  */
+
+ENTRY (__longjmp)
+
+	LDR (blink, r0,  0)
+	LDR (sp,    r0,  1)
+	LDR (fp,    r0,  2)
+	LDR (gp,    r0,  3)
+
+	LDR (r13,   r0,  4)
+	LDR (r14,   r0,  5)
+	LDR (r15,   r0,  6)
+	LDR (r16,   r0,  7)
+	LDR (r17,   r0,  8)
+	LDR (r18,   r0,  9)
+	LDR (r19,   r0, 10)
+	LDR (r20,   r0, 11)
+	LDR (r21,   r0, 12)
+	LDR (r22,   r0, 13)
+	LDR (r23,   r0, 14)
+	LDR (r24,   r0, 15)
+
+	mov.f  r0, r1
+	j.d    [blink]
+	mov.z  r0, 1	/* don't return 0 to setjmp callsite from longjmp.  */
+
+END (__longjmp)

sysdeps/arc/abort-instr.h

@@ -0,0 +1,2 @@
+/* FLAG 1 is privilege mode only instruction, hence will crash any program.  */
+#define ABORT_INSTRUCTION asm ("flag 1")

sysdeps/arc/bits/endianness.h

@@ -0,0 +1,15 @@
+#ifndef _BITS_ENDIANNESS_H
+#define _BITS_ENDIANNESS_H 1
+
+#ifndef _BITS_ENDIAN_H
+# error "Never use <bits/endian.h> directly; include <endian.h> instead."
+#endif
+
+/* ARC has selectable endianness.  */
+#ifdef __BIG_ENDIAN__
+# define __BYTE_ORDER __BIG_ENDIAN
+#else
+# define __BYTE_ORDER __LITTLE_ENDIAN
+#endif
+
+#endif /* bits/endianness.h */

sysdeps/arc/bits/setjmp.h

@@ -0,0 +1,26 @@
+/* Define the machine-dependent type 'jmp_buf'.  ARC version.
+   Copyright (C) 2020 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 _ARC_BITS_SETJMP_H
+#define _ARC_BITS_SETJMP_H 1
+
+/* Saves r13-r25 (callee-saved), fp (frame pointer), sp (stack pointer),
+   blink (branch-n-link).  */
+typedef long int __jmp_buf[32];
+
+#endif

sysdeps/arc/bsd-_setjmp.S

@@ -0,0 +1 @@
+/* _setjmp is in setjmp.S.  */

sysdeps/arc/bsd-setjmp.S

@@ -0,0 +1 @@
+/* setjmp is in setjmp.S.  */

sysdeps/arc/dl-runtime.h

@@ -0,0 +1,42 @@
+/* Helpers for On-demand PLT fixup for shared objects.  ARC version.
+   Copyright (C) 2020 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/>.  */
+
+/* PLT jump into resolver passes PC of PLTn, while _dl_fixup expects the
+   address of corresponding .rela.plt entry.
+
+    - @plt0: runtime pc of first plt entry (DT_PLTGOT)
+    - @pltn: runtime pc of plt entry being resolved
+    - @size: size of .plt.rela entry (unused).  */
+static inline uintptr_t
+reloc_index (uintptr_t plt0, uintptr_t pltn, size_t size)
+{
+  unsigned long int idx = pltn - plt0;
+
+  /* PLT trampoline is 16 bytes.  */
+  idx /= 16;
+
+  /* Exclude PLT0 and PLT1.  */
+  return idx - 2;
+}
+
+static inline uintptr_t
+reloc_offset (uintptr_t plt0, uintptr_t pltn)
+{
+  size_t sz = sizeof (ElfW(Rela));
+  return reloc_index (plt0, pltn, sz) * sz;
+}

sysdeps/arc/dl-sysdep.h

@@ -0,0 +1,25 @@
+/* System-specific settings for dynamic linker code.  ARC version.
+   Copyright (C) 2020 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_next <dl-sysdep.h>
+
+/* _dl_argv cannot be attribute_relro, because _dl_start_user
+   might write into it after _dl_start returns.  */
+#define DL_ARGV_NOT_RELRO 1
+
+#define DL_EXTERN_PROTECTED_DATA

sysdeps/arc/dl-trampoline.S

@@ -0,0 +1,72 @@
+/* PLT trampolines.  ARC version.
+   Copyright (C) 2020 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 <libc-symbols.h>
+
+#include <sysdep.h>
+#include <sys/syscall.h>
+
+/* resolver has atypical calling ABI (r11 and r12)
+        PLTn which lands us here, sets up
+	r11 = Module info (tpnt pointer as expected by resolver)
+	r12 = PC of the PLTn itself - needed by resolver to find
+	      corresponding .rela.plt entry.  */
+
+ENTRY (_dl_runtime_resolve)
+
+	/* save args to func being resolved before entering resolver.  */
+	push_s	r0
+	push_s	r1
+	push_s	r2
+	push_s	r3
+	st.a	r4, [sp, -4]
+	st.a	r5, [sp, -4]
+	st.a	r6, [sp, -4]
+	st.a	r7, [sp, -4]
+	st.a	r8, [sp, -4]
+	st.a	r9, [sp, -4]
+	cfi_adjust_cfa_offset (40)
+	push_s	blink
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (blink, 0)
+
+	mov_s 	r1, r12
+	bl.d  	_dl_fixup
+	mov   	r0, r11
+
+	/* restore regs back.  */
+	ld.ab	blink,[sp, 4]
+	cfi_adjust_cfa_offset (-4)
+	cfi_restore (blink)
+	ld.ab	r9, [sp, 4]
+	ld.ab	r8, [sp, 4]
+	ld.ab	r7, [sp, 4]
+	ld.ab	r6, [sp, 4]
+	ld.ab	r5, [sp, 4]
+	ld.ab	r4, [sp, 4]
+	pop_s   r3
+	pop_s   r2
+	pop_s   r1
+	cfi_adjust_cfa_offset (-36)
+
+	j_s.d   [r0]    /* r0 has resolved function addr.  */
+	pop_s   r0      /* restore first arg to resolved call.  */
+	cfi_adjust_cfa_offset (-4)
+	cfi_restore (r0)
+END (_dl_runtime_resolve)

sysdeps/arc/gccframe.h

@@ -0,0 +1,21 @@
+/* Definition of object in frame unwind info.  ARC version.
+   Copyright (C) 2020 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/>.  */
+
+#define FIRST_PSEUDO_REGISTER 40
+
+#include <sysdeps/generic/gccframe.h>

sysdeps/arc/jmpbuf-offsets.h

@@ -0,0 +1,22 @@
+/* Private macros for accessing __jmp_buf contents.  ARC version.
+   Copyright (C) 2020 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/>.  */
+
+#define JB_SP	1
+
+/* Helper for generic ____longjmp_chk.  */
+#define JB_FRAME_ADDRESS(buf) ((void *) (unsigned long int) (buf[JB_SP]))

sysdeps/arc/jmpbuf-unwind.h

@@ -0,0 +1,47 @@
+/* Examine __jmp_buf for unwinding frames.  ARC version.
+   Copyright (C) 2020 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 <setjmp.h>
+#include <jmpbuf-offsets.h>
+#include <stdint.h>
+#include <unwind.h>
+
+/* Test if longjmp to JMPBUF would unwind the frame
+   containing a local variable at ADDRESS.  */
+
+#define _JMPBUF_UNWINDS(jmpbuf, address, demangle) \
+  ((void *) (address) < (void *) demangle (jmpbuf[JB_SP]))
+
+#define _JMPBUF_CFA_UNWINDS_ADJ(_jmpbuf, _context, _adj) \
+  _JMPBUF_UNWINDS_ADJ (_jmpbuf, (void *) _Unwind_GetCFA (_context), _adj)
+
+static inline uintptr_t __attribute__ ((unused))
+_jmpbuf_sp (__jmp_buf jmpbuf)
+{
+  uintptr_t sp = jmpbuf[JB_SP];
+#ifdef PTR_DEMANGLE
+  PTR_DEMANGLE (sp);
+#endif
+  return sp;
+}
+
+#define _JMPBUF_UNWINDS_ADJ(_jmpbuf, _address, _adj) \
+  ((uintptr_t) (_address) - (_adj) < (uintptr_t) (_jmpbuf_sp (_jmpbuf) - (_adj)))
+
+/* We use the normal longjmp for unwinding.  */
+#define __libc_unwind_longjmp(buf, val) __libc_longjmp (buf, val)

sysdeps/arc/machine-gmon.h

@@ -0,0 +1,35 @@
+/* Machine-dependent definitions for profiling support.  ARC version.
+   Copyright (C) 2020 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>
+
+#define _MCOUNT_DECL(frompc, selfpc)					\
+static void								\
+__mcount_internal (unsigned long int frompc, unsigned long int selfpc)
+
+/* This is very simple as gcc does all the heavy lifting at _mcount call site
+    - sets up caller's blink in r0, so frompc is setup correctly
+    - preserve argument registers for original call.  */
+
+#define MCOUNT								\
+void									\
+_mcount (void *frompc)							\
+{									\
+  __mcount_internal ((unsigned long int) frompc,			\
+		     (unsigned long int) __builtin_return_address (0));	\
+}

sysdeps/arc/memusage.h

@@ -0,0 +1,23 @@
+/* Machine-specific definitions for memory usage profiling, ARC version.
+   Copyright (C) 2020 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/>.  */
+
+#define GETSP() ({ register uintptr_t stack_ptr asm ("sp"); stack_ptr; })
+
+#define uatomic32_t unsigned int
+
+#include <sysdeps/generic/memusage.h>

sysdeps/arc/setjmp.S

@@ -0,0 +1,66 @@
+/* setjmp for ARC.
+   Copyright (C) 2020 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>
+
+/* Upon entry r0 = jump buffer into which regs will be saved.  */
+ENTRY (setjmp)
+	b.d	__sigsetjmp
+	mov	r1, 1		/* save signals.  */
+END (setjmp)
+
+/* Upon entry r0 = jump buffer into which regs will be saved.  */
+ENTRY (_setjmp)
+	b.d	__sigsetjmp
+	mov	r1, 0		/* don't save signals.  */
+END (_setjmp)
+libc_hidden_def (_setjmp)
+
+/* Upon entry
+   r0 = jump buffer into which regs will be saved
+   r1 = do we need to save signals.  */
+ENTRY (__sigsetjmp)
+
+	/* Make a note of where longjmp will return to.
+	   that will be right next to this setjmp call-site in BLINK
+	   since "C" caller of this routine will do a branch-n-link.  */
+
+	STR (blink, r0,  0)
+	STR (sp,    r0,  1)
+	STR (fp,    r0,  2)
+	STR (gp,    r0,  3)
+
+	STR (r13,   r0,  4)
+	STR (r14,   r0,  5)
+	STR (r15,   r0,  6)
+	STR (r16,   r0,  7)
+	STR (r17,   r0,  8)
+	STR (r18,   r0,  9)
+	STR (r19,   r0, 10)
+	STR (r20,   r0, 11)
+	STR (r21,   r0, 12)
+	STR (r22,   r0, 13)
+	STR (r23,   r0, 14)
+	STR (r24,   r0, 15)
+
+	b    __sigjmp_save
+
+END (__sigsetjmp)
+
+libc_hidden_def (__sigsetjmp)

sysdeps/arc/sysdep.h

@@ -0,0 +1,53 @@
+/* Assembler macros for ARC.
+   Copyright (C) 2020 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 <sysdeps/generic/sysdep.h>
+
+#ifdef	__ASSEMBLER__
+
+/* Syntactic details of assembler.
+   ; is not newline but comment, # is also for comment.  */
+# define ASM_SIZE_DIRECTIVE(name) .size name,.-name
+
+# define ENTRY(name)						\
+	.align 4				ASM_LINE_SEP	\
+	.globl C_SYMBOL_NAME(name)		ASM_LINE_SEP	\
+	.type C_SYMBOL_NAME(name),%function	ASM_LINE_SEP	\
+	C_LABEL(name)				ASM_LINE_SEP	\
+	cfi_startproc				ASM_LINE_SEP	\
+	CALL_MCOUNT
+
+# undef  END
+# define END(name)						\
+	cfi_endproc				ASM_LINE_SEP	\
+	ASM_SIZE_DIRECTIVE(name)
+
+# ifdef SHARED
+#  define PLTJMP(_x)	_x##@plt
+# else
+#  define PLTJMP(_x)	_x
+# endif
+
+# define L(label) .L##label
+
+# define CALL_MCOUNT		/* Do nothing for now.  */
+
+# define STR(reg, rbase, off)	st  reg, [rbase, off * 4]
+# define LDR(reg, rbase, off)	ld  reg, [rbase, off * 4]
+
+#endif	/* __ASSEMBLER__ */

sysdeps/arc/tls-macros.h

@@ -0,0 +1,47 @@
+/* Macros to support TLS testing in times of missing compiler support.  ARC version.
+   Copyright (C) 2020 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/>.  */
+
+
+/* For now.  */
+#define TLS_LD(x)	TLS_IE(x)
+
+#define TLS_GD(x)					\
+  ({ void *__result;					\
+     __asm__ ("add r0, pcl, @" #x "@tlsgd      \n"     	\
+	  ".tls_gd_ld " #x "`bl __tls_get_addr@plt \n"	\
+	  "mov %0, r0                    \n"		\
+	  : "=&r" (__result)				\
+	  ::"r0","r1","r2","r3","r4","r5","r6","r7",	\
+	    "r8","r9","r10","r11","r12");		\
+     __result; })
+
+#define TLS_LE(x)					\
+  ({ void *__result;					\
+     void *tp = __builtin_thread_pointer ();		\
+     __asm__ ("add %0, %1, @" #x "@tpoff   \n"		\
+	  : "=r" (__result) : "r"(tp));	        	\
+     __result; })
+
+#define TLS_IE(x)					\
+  ({ void *__result;					\
+     void *tp = __builtin_thread_pointer ();		\
+     __asm__ ("ld %0, [pcl, @" #x "@tlsie]      \n"     \
+	  "add %0, %1, %0                       \n"	\
+	  : "=&r" (__result) : "r" (tp));		\
+     __result; })