Merge branch 'dynamic-debug' into elflinksyslinux-5.11-pre8

10 files changed, 182 insertions, 6 deletions

diff --git a/NEWS b/NEWS
index 56f9d93d..a1c56177 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,10 @@ Starting with 1.47, changes marked with SYSLINUX, PXELINUX, ISOLINUX
 or EXTLINUX apply to that specific program only; other changes apply
 to all derivatives.
 
+Changes in 5.11:
+	* Dynamic debug support: Add new module, debug.c32, that allows
+	  debug code to be dynamically enabled and disabled at runtime.
+
 Changes in 5.10:
 	* PXELINUX: An entirely new network implementation based on
 	  the lwIP embedded TCP/IP stack.  As a result, plain PXELINUX
diff --git a/com32/include/dprintf.h b/com32/include/dprintf.h
index 26ca734b..51d5c61d 100644
--- a/com32/include/dprintf.h
+++ b/com32/include/dprintf.h
@@ -5,6 +5,8 @@
 #ifndef _DPRINTF_H
 #define _DPRINTF_H
 
+#include <syslinux/debug.h>
+
 #if !defined(DEBUG_PORT) && !defined(DEBUG_STDIO)
 # undef DEBUG
 #endif
@@ -23,8 +25,12 @@ void vdprintf(const char *, va_list);
 
 #else
 
-# define dprintf(fmt, ...)	((void)(0))
-# define vdprintf(fmt, ap)	((void)(0))
+#define dprintf(...) \
+    if (syslinux_debug_enabled) \
+        printf(__VA_ARGS__)
+#define vdprintf(fmt, ap) \
+    if (syslinux_debug_enabled) \
+        vprintf(fmt, ap)
 
 #endif /* DEBUG */
 
diff --git a/com32/include/syslinux/debug.h b/com32/include/syslinux/debug.h
new file mode 100644
index 00000000..aee6fdbb
--- /dev/null
+++ b/com32/include/syslinux/debug.h
@@ -0,0 +1,15 @@
+#ifndef DEBUG_H
+#define DEBUG_H
+
+#include <stdbool.h>
+
+#ifdef DYNAMIC_DEBUG
+#define syslinux_debug_enabled	__syslinux_debug_enabled(__func__)
+extern bool __syslinux_debug_enabled(const char *func);
+#else
+#define syslinux_debug_enabled	(0)
+#endif /* DYNAMIC_DEBUG */
+
+extern int syslinux_debug(const char *str, bool enable);
+
+#endif /* DEBUG_H */
diff --git a/com32/lib/Makefile b/com32/lib/Makefile
index a7cfe770..d1b6bf7f 100644
--- a/com32/lib/Makefile
+++ b/com32/lib/Makefile
@@ -176,6 +176,7 @@ CORELIBOBJS = \
 	libgcc/__negdi2.o libgcc/__ashrdi3.o libgcc/__lshrdi3.o		\
 	libgcc/__muldi3.o libgcc/__udivmoddi4.o libgcc/__umoddi3.o	\
 	libgcc/__divdi3.o libgcc/__moddi3.o				\
+	syslinux/debug.o						\
 	$(LIBENTRY_OBJS) \
 	$(LIBMODULE_OBJS)
 
diff --git a/com32/lib/syslinux/debug.c b/com32/lib/syslinux/debug.c
new file mode 100644
index 00000000..d9ab863f
--- /dev/null
+++ b/com32/lib/syslinux/debug.c
@@ -0,0 +1,95 @@
+#include <linux/list.h>
+#include <string.h>
+#include <stdbool.h>
+
+#ifdef DYNAMIC_DEBUG
+
+static LIST_HEAD(debug_funcs);
+
+struct debug_func_entry {
+    const char *name;
+    struct list_head list;
+};
+
+static struct debug_func_entry *lookup_entry(const char *func)
+{
+    struct debug_func_entry *e, *entry = NULL;
+
+    list_for_each_entry(e, &debug_funcs, list) {
+	if (!strcmp(e->name, func)) {
+	    entry = e;
+	    break;
+	}
+    }
+
+    return entry;
+}
+
+bool __syslinux_debug_enabled(const char *func)
+{
+    struct debug_func_entry *entry;
+
+    entry = lookup_entry(func);
+    if (entry)
+	return true;
+
+    return false;
+}
+
+static int __enable(const char *func)
+{
+    struct debug_func_entry *entry;
+
+    entry = lookup_entry(func);
+    if (entry)
+	return 0;	/* already enabled */
+
+    entry = malloc(sizeof(*entry));
+    if (!entry)
+	return -1;
+
+    entry->name = func;
+    list_add(&entry->list, &debug_funcs);
+    return 0;
+}
+
+static int __disable(const char *func)
+{
+    struct debug_func_entry *entry;
+
+    entry = lookup_entry(func);
+    if (!entry)
+	return 0;	/* already disabled */
+
+    list_del(&entry->list);
+    free(entry);
+    return 0;
+}
+
+/*
+ * Enable or disable debug code for function 'func'.
+ */
+int syslinux_debug(const char *func, bool enable)
+{
+    int rv;
+
+    if (enable)
+	rv = __enable(func);
+    else
+	rv = __disable(func);
+
+    return rv;
+}
+
+#else
+
+int syslinux_debug(const char *func, bool enable)
+{
+    (void)func;
+    (void)enable;
+
+    printf("Dynamic debug unavailable\n");
+    return -1;
+}
+
+#endif /* DYNAMIC_DEBUG */
diff --git a/com32/modules/Makefile b/com32/modules/Makefile
index 682e1b22..d801a260 100644
--- a/com32/modules/Makefile
+++ b/com32/modules/Makefile
@@ -25,7 +25,7 @@ MODULES	  = config.c32 ethersel.c32 dmitest.c32 cpuidtest.c32 \
 	    kbdmap.c32 cmd.c32 vpdtest.c32 host.c32 ls.c32 gpxecmd.c32 \
 	    ifcpu.c32 cpuid.c32 cat.c32 pwd.c32 ifplop.c32 zzjson.c32 \
 	    whichsys.c32 prdhcp.c32 pxechn.c32 kontron_wdt.c32 ifmemdsk.c32 \
-	    hexdump.c32 poweroff.c32 cptime.c32
+	    hexdump.c32 poweroff.c32 cptime.c32 debug.c32
 
 TESTFILES =
 
diff --git a/com32/modules/debug.c b/com32/modules/debug.c
new file mode 100644
index 00000000..1026ebf3
--- /dev/null
+++ b/com32/modules/debug.c
@@ -0,0 +1,54 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 2013 Intel Corporation; author: Matt Fleming
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ *   Boston MA 02110-1301, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+#include <syslinux/debug.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static char *progname;
+
+static void usage(void)
+{
+    fprintf(stderr, "Usage: %s [-e|-d] <func1> [<func2>, ...]\n", progname);
+}
+
+int main(int argc, char *argv[])
+{
+    bool enable;
+    int i;
+
+    progname = argv[0];
+
+    if (argc < 3) {
+	usage();
+	return -1;
+    }
+
+    if (!strncmp(argv[1], "-e", 2))
+	enable = true;
+    else if (!strncmp(argv[1], "-d", 2))
+	enable = false;
+    else {
+	usage();
+	return -1;
+    }
+
+    for (i = 2; i < argc; i++) {
+	char *str = argv[i];
+
+	if (syslinux_debug(str, enable) < 0)
+	    fprintf(stderr, "Failed to debug symbol \"%s\"\n", str);
+    }
+
+    return 0;
+}
diff --git a/com32/modules/prdhcp.c b/com32/modules/prdhcp.c
index e1785a03..4ae295e8 100644
--- a/com32/modules/prdhcp.c
+++ b/com32/modules/prdhcp.c
@@ -39,11 +39,11 @@
 #include <unistd.h>
 #include <getkey.h>
 
-#define DEBUG 0
+#define PRDHCP_DEBUG 0
 
 #define dprintf0(f, ...)		((void)0)
 
-#ifdef DEBUG
+#ifdef PRDHCP_DEBUG
 #  define dpressanykey			pressanykey
 #  define dprintf			printf
 #  define dprint_pxe_bootp_t		print_pxe_bootp_t
diff --git a/mk/devel.mk b/mk/devel.mk
index d1a5fff2..041e876e 100644
--- a/mk/devel.mk
+++ b/mk/devel.mk
@@ -2,3 +2,4 @@
 GCCWARN += -Wno-clobbered 
 #GCCWARN += -DDEBUG_MALLOC
 # GCCWARN += -DDEBUG_PORT=0x3f8 -DDEBUG=1 
+GCCWARN += -DDYNAMIC_DEBUG
diff --git a/mk/elf.mk b/mk/elf.mk
index 109e0a65..8bc6be08 100644
--- a/mk/elf.mk
+++ b/mk/elf.mk
@@ -42,7 +42,7 @@ GPLLIB     =
 GPLINCLUDE =
 endif
 
-CFLAGS     = $(GCCOPT) -W -Wall -march=i386 \
+CFLAGS     = $(GCCOPT) $(GCCWARN) -W -Wall -march=i386 \
 	     -fomit-frame-pointer -D__COM32__ -DDYNAMIC_MODULE \
 	     -nostdinc -iwithprefix include \
 	     -I$(com32)/libutil/include -I$(com32)/include $(GPLINCLUDE) \