Add support to libsysdecode for decoding system call names.

A new sysdecode_syscallname() function accepts a system call code and
returns a string of the corresponding name (or NULL if the code is
unknown).  To support different process ABIs, the new function accepts a
value from a new sysdecode_abi enum as its first argument to select the
ABI in use.  Current ABIs supported include FREEBSD (native binaries),
FREEBSD32, LINUX, LINUX32, and CLOUDABI64.  Note that not all ABIs are
supported by all platforms.  In general, a given ABI is only supported
if a platform can execute binaries for that ABI.

To simplify the implementation, libsysdecode's build reuses the
existing pre-generated files from the kernel source tree rather than
duplicating new copies of said files during the build.

kdump(1) and truss(1) now use these functions to map system call
identifiers to names.  For kdump(1), a new 'syscallname()' function
consolidates duplicated code from ktrsyscall() and ktrsyscallret().
The Linux ABI no longer requires custom handling for ktrsyscall() and
linux_ktrsyscall() has been removed as a result.

Reviewed by:	bdrewery
Differential Revision:	https://reviews.freebsd.org/D4823

1 files changed, 105 insertions, 0 deletions

diff --git a/lib/libsysdecode/syscallnames.c b/lib/libsysdecode/syscallnames.c
new file mode 100644
index 0000000..cfe50a6
--- /dev/null
+++ b/lib/libsysdecode/syscallnames.c
@@ -0,0 +1,105 @@
+/*-
+ * Copyright (c) 2015 John H. Baldwin <jhb@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * Map system call codes to names for the supported ABIs on each
+ * platform.  Rather than regnerating system call name tables locally
+ * during the build, use the generated tables in the kernel source
+ * tree.
+ */
+
+#include <sys/param.h>
+#include <stdio.h>
+#include <sysdecode.h>
+
+static
+#include <kern/syscalls.c>
+
+#if defined(__amd64__) || defined(__powerpc64__)
+static
+#include <compat/freebsd32/freebsd32_syscalls.c>
+#endif
+
+#if defined(__amd64__) || defined(__i386__)
+static
+#ifdef __amd64__
+#include <amd64/linux/linux_syscalls.c>
+#else
+#include <i386/linux/linux_syscalls.c>
+#endif
+#endif
+
+#ifdef __amd64__
+static
+#include <amd64/linux32/linux32_syscalls.c>
+#endif
+
+#if defined(__amd64__) || defined(__aarch64__)
+static
+#include <compat/cloudabi64/cloudabi64_syscalls.c>
+#endif
+
+const char *
+sysdecode_syscallname(enum sysdecode_abi abi, unsigned int code)
+{
+
+	switch (abi) {
+	case FREEBSD:
+		if (code < nitems(syscallnames))
+			return (syscallnames[code]);
+		break;
+#if defined(__amd64__) || defined(__powerpc64__)
+	case FREEBSD32:
+		if (code < nitems(freebsd32_syscallnames))
+			return (freebsd32_syscallnames[code]);
+		break;
+#endif
+#if defined(__amd64__) || defined(__i386__)
+	case LINUX:
+		if (code < nitems(linux_syscallnames))
+			return (linux_syscallnames[code]);
+		break;
+#endif
+#ifdef __amd64__
+	case LINUX32:
+		if (code < nitems(linux32_syscallnames))
+			return (linux32_syscallnames[code]);
+		break;
+#endif
+#if defined(__amd64__) || defined(__aarch64__)
+	case CLOUDABI64:
+		if (code < nitems(cloudabi64_syscallnames))
+			return (cloudabi64_syscallnames[code]);
+		break;
+#endif
+	default:
+		break;
+	}
+	return (NULL);
+}