Add amd64 ddb regress suite allowing the disassembler to be tested from

userspace.

4 files changed, 210 insertions, 0 deletions

diff --git a/regress/sys/arch/amd64/ddb/Makefile b/regress/sys/arch/amd64/ddb/Makefile
new file mode 100644
index 00000000000..483d24693fc
--- /dev/null
+++ b/regress/sys/arch/amd64/ddb/Makefile
@@ -0,0 +1,26 @@
+# $OpenBSD: Makefile,v 1.1 2024/11/19 05:50:41 anton Exp $
+
+.if "${MACHINE_ARCH}" == "amd64"
+
+SRCS+=		disasm.c
+SRCS+=		stubs.c
+SRCS+=		db_disasm.c
+SRCS+=		db_output.c
+SRCS+=		db_sym.c
+PROG=		disasm
+
+CPPFLAGS+=	-D_KERNEL
+CPPFLAGS+=	-I${.CURDIR}/../../../../../sys
+WARNINGS=	yes
+
+.PATH: ${.CURDIR}/../../../../../sys/arch/amd64/amd64
+.PATH: ${.CURDIR}/../../../../../sys/ddb
+
+.else
+
+regress:
+        @echo SKIPPED
+
+.endif
+
+.include <bsd.regress.mk>
diff --git a/regress/sys/arch/amd64/ddb/disasm.c b/regress/sys/arch/amd64/ddb/disasm.c
new file mode 100644
index 00000000000..33d401191a4
--- /dev/null
+++ b/regress/sys/arch/amd64/ddb/disasm.c
@@ -0,0 +1,68 @@
+/* $OpenBSD: disasm.c,v 1.1 2024/11/19 05:50:41 anton Exp $ */
+
+#include <stddef.h>	/* size_t */
+#include <stdio.h>
+#include <string.h>
+
+#include "disasm.h"
+
+#define test(instr, exp)						\
+	test_impl((instr), sizeof(instr) - 1,				\
+	    (exp), sizeof(exp) - 1,					\
+	    __func__, __LINE__)
+
+struct db_disasm_context *ctx = NULL;
+
+static int
+test_impl(const uint8_t *instr, size_t ninstr, const char *exp, size_t explen,
+    const char *fun, int lno)
+{
+	const char *act;
+	size_t actlen;
+
+	static struct db_disasm_context c;
+	memset(&c, 0, sizeof(c));
+	ctx = &c;
+
+	ctx->raw.buf = instr;
+	ctx->raw.len = ninstr;
+	ctx->act.len = 0;
+	ctx->act.siz = sizeof(ctx->act.buf);
+
+	db_disasm(0, 0);
+
+	act = ctx->act.buf;
+	actlen = ctx->act.len;
+	/* Remove trailing whitespace from instructions w/o operands. */
+	while (actlen > 0 && act[actlen - 1] == ' ')
+		actlen--;
+
+	if (explen != actlen || strncmp(exp, act, actlen) != 0) {
+		fprintf(stderr, "%s:%d:\n", fun, lno);
+		fprintf(stderr, "exp: \"%.*s\"\n", (int)explen, exp);
+		fprintf(stderr, "act: \"%.*s\"\n", (int)actlen, act);
+		return 1;
+	}
+
+	if (ctx->raw.len > 0) {
+		fprintf(stderr, "%s:%d: %zu byte(s) not consumed\n", fun, lno,
+		    ctx->raw.len);
+		return 1;
+	}
+
+	return 0;
+}
+
+int
+main(void)
+{
+	int error = 0;
+
+	error |= test("\x90", "nop");
+	error |= test("\x00", "addb %al,0(%rax)");
+	error |= test("\xf2\x48\xa5", "repne movsq (%rsi),%es:(%rdi)");
+	error |= test("\xf3\x48\xa5", "repe movsq (%rsi),%es:(%rdi)");
+	error |= test("\xf3\x0f\x1e\xfa", "endbr64");
+
+	return error;
+}
diff --git a/regress/sys/arch/amd64/ddb/disasm.h b/regress/sys/arch/amd64/ddb/disasm.h
new file mode 100644
index 00000000000..7130ef6d0df
--- /dev/null
+++ b/regress/sys/arch/amd64/ddb/disasm.h
@@ -0,0 +1,22 @@
+/* $OpenBSD: disasm.h,v 1.1 2024/11/19 05:50:41 anton Exp $ */
+
+#include <sys/types.h>	/* vaddr_t */
+#include <stddef.h>	/* size_t */
+#include <stdint.h>
+
+struct db_disasm_context {
+	struct {
+		const uint8_t	*buf;
+		size_t		 len;
+	} raw;
+
+	struct {
+		char	buf[128];
+		size_t	siz;
+		size_t	len;
+	} act;
+};
+
+vaddr_t	db_disasm(vaddr_t, int);
+
+extern struct db_disasm_context	*ctx;
diff --git a/regress/sys/arch/amd64/ddb/stubs.c b/regress/sys/arch/amd64/ddb/stubs.c
new file mode 100644
index 00000000000..4a8a2fa69e0
--- /dev/null
+++ b/regress/sys/arch/amd64/ddb/stubs.c
@@ -0,0 +1,94 @@
+/* $OpenBSD: stubs.c,v 1.1 2024/11/19 05:50:41 anton Exp $ */
+
+#include <err.h>
+#include <stdarg.h>
+#include <stdio.h>
+
+#include <machine/db_machdep.h>
+#include <machine/cpu_full.h>
+#include <ddb/db_access.h>
+#include <ddb/db_interface.h>
+#include <ddb/db_command.h>
+#include <ddb/db_output.h>
+#include <ddb/db_sym.h>
+
+#include "disasm.h"
+
+void			 (*cnputc)(int) = NULL;
+int			 (*cngetc)(void) = NULL;
+char			*esym = NULL;
+char			*ssym = NULL;
+struct cpu_info_full	 cpu_info_full_primary = {0};
+
+int
+db_elf_sym_init(int symsize, void *symtab, void *esymtab, const char *name)
+{
+	return 0;
+}
+
+Elf_Sym *
+db_elf_sym_search(vaddr_t off, db_strategy_t strategy, db_expr_t *diffp)
+{
+	return NULL;
+}
+
+int
+db_elf_line_at_pc(Elf_Sym *cursym, const char **filename, int *linenum,
+    db_expr_t off)
+{
+	return 0;
+}
+
+void
+db_error(char *s)
+{
+}
+
+void
+db_stack_trace_print(db_expr_t addr, int have_addr, db_expr_t count,
+    char *modif, int (*pr)(const char *, ...))
+{
+}
+
+void
+db_symbol_values(Elf_Sym *sym, const char **namep, db_expr_t *valuep)
+{
+}
+
+db_expr_t
+db_get_value(vaddr_t addr, size_t size, int is_signed)
+{
+	db_expr_t c;
+
+	if (ctx->raw.len == 0)
+		return 0;
+
+	c = ctx->raw.buf[0];
+	ctx->raw.buf++;
+	ctx->raw.len--;
+	return c;
+}
+
+int
+db_printf(const char *fmt, ...)
+{
+	int n = 0;
+
+	if (strcmp(fmt, "\n") == 0) {
+		/* nothing */
+	} else if (strcmp(fmt, "\t") == 0) {
+		n = snprintf(&ctx->act.buf[ctx->act.len], ctx->act.siz, " ");
+	} else {
+		va_list ap;
+
+		va_start(ap, fmt);
+		n = vsnprintf(&ctx->act.buf[ctx->act.len], ctx->act.siz, fmt,
+		    ap);
+		va_end(ap);
+	}
+	if (n < 0 || (size_t)n >= ctx->act.siz)
+		errx(1, "buffer too small");
+	ctx->act.len += n;
+	ctx->act.siz -= n;
+	return 0;
+}