sh64: switch to PTRACE_GETREGS API

Implement PTRACE_GETREGS API introduced on sh64 by Linux kernel commit
v2.6.28-rc1~99^2~56.

* configure.ac [sh64]: Remove arch_enable_Werror=no.
* linux/sh64/arch_regs.h: Remove.
* linux/sh64/get_syscall_result.c: Likewise.
* Makefile.am (EXTRA_DIST): Remove them.
* linux/sh64/arch_regs.c (sh64_regs): New variable.
(ARCH_REGS_FOR_GETREGS, ARCH_PC_REG, ARCH_SP_REG): New macros.
(sh64_r9, ARCH_PC_PEEK_ADDR, ARCH_SP_PEEK_ADDR): Remove.
* linux/sh64/get_error.c (arch_get_error): Use sh64_regs.regs[9].
* linux/sh64/get_scno.c (arch_get_scno): Use sh64_regs.regs[9].
* linux/sh64/get_syscall_args.c (arch_get_syscall_args): Use sh64_regs.regs.
* linux/sh64/set_error.c (arch_set_error, arch_set_success): Use
sh64_regs.gr[9].
* linux/sh64/set_scno.c (arch_set_scno): Use sh64_regs.regs[9].
* NEWS: Mention this change.

11 files changed, 20 insertions, 62 deletions

diff --git a/Makefile.am b/Makefile.am
index 4fd612465..54d7ff679 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -809,11 +809,9 @@ EXTRA_DIST =				\
 	linux/sh/userent0.h		\
 	linux/sh64/arch_defs_.h		\
 	linux/sh64/arch_regs.c		\
-	linux/sh64/arch_regs.h		\
 	linux/sh64/get_error.c		\
 	linux/sh64/get_scno.c		\
 	linux/sh64/get_syscall_args.c	\
-	linux/sh64/get_syscall_result.c	\
 	linux/sh64/ioctls_arch0.h	\
 	linux/sh64/ioctls_inc0.h	\
 	linux/sh64/raw_syscall.h	\
diff --git a/NEWS b/NEWS
index 9e7a3464d..46f83f638 100644
--- a/NEWS
+++ b/NEWS
@@ -13,7 +13,7 @@ Noteworthy changes in release ?.? (????-??-??)
    * Ability to set precision for the absolute timestamp, relative timestamp,
      and syscall time output (using --absolute-timestamps,
      --relative-timestamps, and --syscall-times options, respectively).
-  * Implemented PTRACE_GETREGS API support on hppa and sh.
+  * Implemented PTRACE_GETREGS API support on hppa, sh, and sh64.
   * Enhanced decoding of BPF_MAP_CREATE and BPF_PROG_ATTACH bpf syscall
     commands.
   * Updated lists of BPF_* constants.
@@ -23,7 +23,7 @@ Noteworthy changes in release ?.? (????-??-??)
 
 * Portability
   * On hppa, linux kernel >= 4.7 is required.
-    On sh, linux kernel >= 2.6.28 is required.
+    On sh and sh64, linux kernel >= 2.6.28 is required.
     Older versions without a decent PTRACE_GETREGS support will not work.
 
 Noteworthy changes in release 5.5 (2020-02-06)
diff --git a/configure.ac b/configure.ac
index 846529790..4ca867c40 100644
--- a/configure.ac
+++ b/configure.ac
@@ -164,7 +164,6 @@ s390x)
 	;;
 sh64*)
 	arch=sh64
-	arch_enable_Werror=no
 	AC_DEFINE([SH64], 1, [Define for the SH64 architecture.])
 	;;
 sh*)
diff --git a/linux/sh64/arch_regs.c b/linux/sh64/arch_regs.c
index 9b3d4eb3b..06f8a2ea5 100644
--- a/linux/sh64/arch_regs.c
+++ b/linux/sh64/arch_regs.c
@@ -5,6 +5,7 @@
  * SPDX-License-Identifier: LGPL-2.1-or-later
  */
 
-static unsigned long sh64_r9;
-#define ARCH_PC_PEEK_ADDR REG_PC
-#define ARCH_SP_PEEK_ADDR REG_GENERAL(15)
+static struct pt_regs sh64_regs;
+#define ARCH_REGS_FOR_GETREGS sh64_regs
+#define ARCH_PC_REG sh64_regs.pc
+#define ARCH_SP_REG sh64_regs.regs[15]
diff --git a/linux/sh64/arch_regs.h b/linux/sh64/arch_regs.h
deleted file mode 100644
index 5bf759d64..000000000
--- a/linux/sh64/arch_regs.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/*
- * Copyright (c) 2015-2018 The strace developers.
- * All rights reserved.
- *
- * SPDX-License-Identifier: LGPL-2.1-or-later
- */
-
-/* SH64 Linux - this code assumes the following kernel API for system calls:
-	PC           Offset 0
-	System Call  Offset 16 (actually, (syscall no.) | (0x1n << 16),
-		     where n = no. of parameters.
-	Other regs   Offset 24+
-
-	On entry:    R2-7 = parameters 1-6 (as many as necessary)
-	On return:   R9   = result.
-*/
-
-/* Offset for peeks of registers */
-#define REG_OFFSET	(24)
-#define REG_GENERAL(x)	(8*(x)+REG_OFFSET)
-#define REG_PC		(0*8)
-#define REG_SYSCALL	(2*8)
diff --git a/linux/sh64/get_error.c b/linux/sh64/get_error.c
index 795031c95..ac1ae3fab 100644
--- a/linux/sh64/get_error.c
+++ b/linux/sh64/get_error.c
@@ -10,10 +10,10 @@
 static void
 arch_get_error(struct tcb *tcp, const bool check_errno)
 {
-	if (check_errno && is_negated_errno(sh64_r9)) {
+	if (check_errno && is_negated_errno(sh64_regs.regs[9])) {
 		tcp->u_rval = -1;
-		tcp->u_error = -sh64_r9;
+		tcp->u_error = -sh64_regs.regs[9];
 	} else {
-		tcp->u_rval = sh64_r9;
+		tcp->u_rval = sh64_regs.regs[9];
 	}
 }
diff --git a/linux/sh64/get_scno.c b/linux/sh64/get_scno.c
index c85786bd7..cff360d6e 100644
--- a/linux/sh64/get_scno.c
+++ b/linux/sh64/get_scno.c
@@ -9,8 +9,6 @@
 static int
 arch_get_scno(struct tcb *tcp)
 {
-	if (upeek(tcp, REG_SYSCALL, &tcp->scno) < 0)
-		return -1;
-	tcp->scno &= 0xffff;
+	tcp->scno = sh64_regs.regs[9];
 	return 1;
 }
diff --git a/linux/sh64/get_syscall_args.c b/linux/sh64/get_syscall_args.c
index 4b53e20ea..d5fc9f6e6 100644
--- a/linux/sh64/get_syscall_args.c
+++ b/linux/sh64/get_syscall_args.c
@@ -9,13 +9,7 @@
 static int
 arch_get_syscall_args(struct tcb *tcp)
 {
-	/* Registers used by SH5 Linux system calls for parameters */
-	static const int syscall_regs[MAX_ARGS] = { 2, 3, 4, 5, 6, 7 };
-	unsigned int i;
-
-	for (i = 0; i < n_args(tcp); ++i)
-		if (upeek(tcp, REG_GENERAL(syscall_regs[i]),
-			  &tcp->u_arg[i]) < 0)
-			return -1;
+	for (unsigned int i = 0; i < n_args(tcp); ++i)
+		tcp->u_arg[i] = sh64_regs.regs[i + 2];
 	return 1;
 }
diff --git a/linux/sh64/get_syscall_result.c b/linux/sh64/get_syscall_result.c
deleted file mode 100644
index 1183f6873..000000000
--- a/linux/sh64/get_syscall_result.c
+++ /dev/null
@@ -1,13 +0,0 @@
-/*
- * Copyright (c) 2015-2018 The strace developers.
- * All rights reserved.
- *
- * SPDX-License-Identifier: LGPL-2.1-or-later
- */
-
-static int
-get_syscall_result_regs(struct tcb *tcp)
-{
-	/* ABI defines result returned in r9 */
-	return upeek(tcp, REG_GENERAL(9), &sh64_r9) < 0 ? -1 : 0;
-}
diff --git a/linux/sh64/set_error.c b/linux/sh64/set_error.c
index 4a9835718..eee443bdd 100644
--- a/linux/sh64/set_error.c
+++ b/linux/sh64/set_error.c
@@ -8,13 +8,13 @@
 static int
 arch_set_error(struct tcb *tcp)
 {
-	sh64_r9 = -tcp->u_error;
-	return upoke(tcp, REG_GENERAL(9), sh64_r9);
+	sh64_regs.regs[9] = -tcp->u_error;
+	return set_regs(tcp->pid);
 }
 
 static int
 arch_set_success(struct tcb *tcp)
 {
-	sh64_r9 = tcp->u_rval;
-	return upoke(tcp, REG_GENERAL(9), sh64_r9);
+	sh64_regs.regs[9] = tcp->u_rval;
+	return set_regs(tcp->pid);
 }
diff --git a/linux/sh64/set_scno.c b/linux/sh64/set_scno.c
index f7e0fdfa5..101e03f8e 100644
--- a/linux/sh64/set_scno.c
+++ b/linux/sh64/set_scno.c
@@ -8,5 +8,8 @@
 static int
 arch_set_scno(struct tcb *tcp, kernel_ulong_t scno)
 {
-	return upoke(tcp, REG_SYSCALL, scno);
+	if (ptrace_syscall_info_is_valid() && get_regs(tcp) < 0)
+		return -1;
+	sh64_regs.regs[9] = scno;
+	return set_regs(tcp->pid);
 }