xtensa: switch to PTRACE_GETREGS API

Implement PTRACE_GETREGS API introduced on xtensa by Linux kernel commit
v2.6.13-rc1~68^2~366.

* configure.ac [xtensa]: Remove arch_enable_Werror=no.
* linux/xtensa/get_syscall_result.c: Remove.
* Makefile.am (EXTRA_DIST): Remove it.
* linux/xtensa/arch_regs.c (xtensa_regs): New variable.
(ARCH_REGS_FOR_GETREGS, ARCH_PC_REG, ARCH_SP_REG): New macros.
(xtensa_a2, ARCH_PC_PEEK_ADDR, ARCH_SP_PEEK_ADDR): Remove.
* linux/xtensa/get_error.c (arch_get_error): Use xtensa_regs.a[2].
* linux/xtensa/get_syscall_args.c (arch_get_syscall_args): Use
xtensa_regs.a.
* linux/xtensa/set_error.c (arch_set_error, arch_set_success): Use
xtensa_regs.a[2].
* NEWS: Mention this change.

8 files changed, 15 insertions, 38 deletions

diff --git a/Makefile.am b/Makefile.am
index 54d7ff679..9afd430c8 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -947,7 +947,6 @@ EXTRA_DIST =				\
 	linux/xtensa/get_error.c	\
 	linux/xtensa/get_scno.c		\
 	linux/xtensa/get_syscall_args.c	\
-	linux/xtensa/get_syscall_result.c	\
 	linux/xtensa/ioctls_arch0.h	\
 	linux/xtensa/ioctls_inc0.h	\
 	linux/xtensa/raw_syscall.h	\
diff --git a/NEWS b/NEWS
index 46f83f638..4632ac0ff 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, sh, and sh64.
+  * Implemented PTRACE_GETREGS API support on hppa, sh, sh64, and xtensa.
   * Enhanced decoding of BPF_MAP_CREATE and BPF_PROG_ATTACH bpf syscall
     commands.
   * Updated lists of BPF_* constants.
diff --git a/configure.ac b/configure.ac
index 4ca867c40..ac566c4e0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -198,7 +198,6 @@ x86?64*)
 	;;
 xtensa*)
 	arch=xtensa
-	arch_enable_Werror=no
 	AC_DEFINE([XTENSA], 1, [Define for the Xtensa architecture])
 	;;
 *)
diff --git a/linux/xtensa/arch_regs.c b/linux/xtensa/arch_regs.c
index 557e5bacd..616cd8d7c 100644
--- a/linux/xtensa/arch_regs.c
+++ b/linux/xtensa/arch_regs.c
@@ -5,6 +5,7 @@
  * SPDX-License-Identifier: LGPL-2.1-or-later
  */
 
-static unsigned long xtensa_a2;
-#define ARCH_PC_PEEK_ADDR REG_PC
-#define ARCH_SP_PEEK_ADDR (REG_A_BASE + 1)
+static struct user_pt_regs xtensa_regs;
+#define ARCH_REGS_FOR_GETREGS xtensa_regs
+#define ARCH_PC_REG xtensa_regs.pc
+#define ARCH_SP_REG xtensa_regs.a[1]
diff --git a/linux/xtensa/get_error.c b/linux/xtensa/get_error.c
index 7fc8ac2c0..5ffd57918 100644
--- a/linux/xtensa/get_error.c
+++ b/linux/xtensa/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(xtensa_a2)) {
+	if (check_errno && is_negated_errno(xtensa_regs.a[2])) {
 		tcp->u_rval = -1;
-		tcp->u_error = -xtensa_a2;
+		tcp->u_error = -xtensa_regs.a[2];
 	} else {
-		tcp->u_rval = xtensa_a2;
+		tcp->u_rval = xtensa_regs.a[2];
 	}
 }
diff --git a/linux/xtensa/get_syscall_args.c b/linux/xtensa/get_syscall_args.c
index 69b981c36..8d937e064 100644
--- a/linux/xtensa/get_syscall_args.c
+++ b/linux/xtensa/get_syscall_args.c
@@ -9,19 +9,9 @@
 static int
 arch_get_syscall_args(struct tcb *tcp)
 {
-	/* arg0: a6, arg1: a3, arg2: a4, arg3: a5, arg4: a8, arg5: a9 */
-	static const int xtensaregs[MAX_ARGS] = {
-		REG_A_BASE + 6,
-		REG_A_BASE + 3,
-		REG_A_BASE + 4,
-		REG_A_BASE + 5,
-		REG_A_BASE + 8,
-		REG_A_BASE + 9
-	};
-	unsigned int i;
+	static const unsigned int syscall_regs[MAX_ARGS] = { 6, 3, 4, 5, 8, 9 };
 
-	for (i = 0; i < n_args(tcp); ++i)
-		if (upeek(tcp, xtensaregs[i], &tcp->u_arg[i]) < 0)
-			return -1;
+	for (unsigned int i = 0; i < n_args(tcp); ++i)
+		tcp->u_arg[i] = xtensa_regs.a[syscall_regs[i]];
 	return 1;
 }
diff --git a/linux/xtensa/get_syscall_result.c b/linux/xtensa/get_syscall_result.c
deleted file mode 100644
index bbb091c92..000000000
--- a/linux/xtensa/get_syscall_result.c
+++ /dev/null
@@ -1,12 +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)
-{
-	return upeek(tcp, REG_A_BASE + 2, &xtensa_a2) < 0 ? -1 : 0;
-}
diff --git a/linux/xtensa/set_error.c b/linux/xtensa/set_error.c
index cd6d627bc..c8dba2df4 100644
--- a/linux/xtensa/set_error.c
+++ b/linux/xtensa/set_error.c
@@ -8,13 +8,13 @@
 static int
 arch_set_error(struct tcb *tcp)
 {
-	xtensa_a2 = -tcp->u_error;
-	return upoke(tcp, REG_A_BASE + 2, xtensa_a2);
+	xtensa_regs.a[2] = -tcp->u_error;
+	return set_regs(tcp->pid);
 }
 
 static int
 arch_set_success(struct tcb *tcp)
 {
-	xtensa_a2 = tcp->u_rval;
-	return upoke(tcp, REG_A_BASE + 2, xtensa_a2);
+	xtensa_regs.a[2] = tcp->u_rval;
+	return set_regs(tcp->pid);
 }