zdump: Extract dfo_mem_chunk interface from DFO

The primary goal is to separate DFO code into multiple smaller modules
and make it unit testable.

This refactoring only moved the code around w/o changing any functionality.

Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

zdump/Makefile

@@ -47,7 +47,7 @@ OBJECTS = zgetdump.o opts.o zg.o \
 	  dfi_s390.o dfi_s390_ext.o\
 	  dfi_s390mv.o dfi_s390mv_ext.o \
 	  dfi_s390tape.o dfi_kdump.o \
-	  dfi_devmem.o dfo.o \
+	  dfi_devmem.o dfo.o dfo_mem_chunk.o \
 	  dfo_elf.o dfo_s390.o \
 	  df_s390.o \
 	  dt.o dt_s390sv.o dt_s390sv_ext.o \

zdump/dfo.c

@@ -9,16 +9,13 @@
  * it under the terms of the MIT license. See LICENSE for details.
  */
 
-#include <time.h>
+#include <string.h>
+#include <errno.h>
 
-#include "lib/util_list.h"
+#include "zg.h"
-
+#include "dfo_mem_chunk.h"
-#include "dfi_mem_chunk.h"
 #include "dfo.h"
 
-#define dfo_chunk_iterate(dfo_chunk) \
-	util_list_iterate(&l.dump.chunk_list, dfo_chunk)
-
 /*
  * DFO vector
  */
@@ -28,70 +25,14 @@ static struct dfo *dfo_vec[] = {
 	NULL,
 };
 
-/*
- * Dump (output) information
- */
-struct dump {
-	u64		off;		/* Current file offset in dump */
-	u64		size;		/* Size of dump in bytes */
-	unsigned int	chunk_cnt;	/* Number of dump chunks */
-	struct util_list	chunk_list;	/* DFO chunk list */
-};
-
 /*
  * File local static data
  */
 static struct {
-	struct dump	dump;
+	u64		off;		/* Current file offset in dump */
 	struct dfo	*dfo;
 } l;
 
-/*
- * Add dump chunk
- */
-void dfo_chunk_add(u64 start, u64 size, void *data, dfo_chunk_read_fn read_fn)
-{
-	struct dfo_chunk *dfo_chunk;
-
-	dfo_chunk = zg_alloc(sizeof(*dfo_chunk));
-	dfo_chunk->start = start;
-	dfo_chunk->end = start + size - 1;
-	dfo_chunk->data = data;
-	dfo_chunk->read_fn = read_fn;
-	util_list_add_head(&l.dump.chunk_list, dfo_chunk);
-	l.dump.chunk_cnt++;
-	l.dump.size = MAX(l.dump.size, dfo_chunk->end + 1);
-}
-
-/*
- * Dump chunk function: Copy zero pages for chunk
- */
-void dfo_chunk_zero_fn(struct dfo_chunk *dfo_chunk, u64 off, void *buf, u64 cnt)
-{
-	(void) dfo_chunk;
-	(void) off;
-
-	memset(buf, 0, cnt);
-}
-
-/*
- * Dump chunk function: Copy given buffer for chunk
- */
-void dfo_chunk_buf_fn(struct dfo_chunk *dfo_chunk, u64 off, void *buf, u64 cnt)
-{
-	memcpy(buf, dfo_chunk->data + off, cnt);
-}
-
-/*
- * Dump chunk function: Copy given memory range for chunk
- */
-void dfo_chunk_mem_fn(struct dfo_chunk *dfo_chunk, u64 off, void *buf, u64 cnt)
-{
-	struct dfi_mem_chunk *mem_chunk = dfo_chunk->data;
-
-	mem_chunk->read_fn(mem_chunk, off, buf, cnt);
-}
-
 /*
  * Get DFO name
  */
@@ -125,55 +66,17 @@ void dfo_init(void)
 {
 	if (!l.dfo)
 		ABORT("DFO not set");
-	util_list_init(&l.dump.chunk_list, struct dfo_chunk, list);
+	if (dfo_chunk_init())
+		ABORT("DFO memory chunk init failed");
 	l.dfo->init();
 }
 
-/*
- * Find dump chunk for offset "off"
- *
- * This function is a bit hacky. DFO chunks can overlap. If two DFO chunks
- * overlap, the last registered chunk wins. The dfo_chunk_find() function
- * reflects that by returning the first memory chunk that is found in
- * the dfo chunk list.
- *
- * In addition to that it calculates the "virtual end" of that chunk. An
- * overlapping chunk can limit the "virtual end" of an underlying chunk so
- * that the "virtual end" of that chunk is lower than the "real end".
- *
- * Example:
- *
- * chunk 1.:      |------|
- * chunk 2.: |---------------------|
- * off.....: ^
- * virt end:      ^
- * real end:                       ^
- *
- * In this case chunk 2 will be returned and "end" is set to the start of
- * chunk 1.
- */
-static struct dfo_chunk *dfo_chunk_find(u64 off, u64 *end)
-{
-	struct dfo_chunk *dfo_chunk;
-
-	*end = U64_MAX;
-	dfo_chunk_iterate(dfo_chunk) {
-		if (dfo_chunk->start <= off && dfo_chunk->end >= off) {
-			*end = MIN(*end, dfo_chunk->end);
-			return dfo_chunk;
-		} else if (dfo_chunk->start > off) {
-			*end = MIN(*end, dfo_chunk->start - 1);
-		}
-	}
-	return NULL;
-}
-
 /*
  * Seek to output dump offset "off"
  */
 void dfo_seek(u64 off)
 {
-	l.dump.off = off;
+	l.off = off;
 }
 
 /*
@@ -183,7 +86,7 @@ u64 dfo_read(void *buf, u64 cnt)
 {
 	struct dfo_chunk *dfo_chunk;
 	u64 copied = 0, end, size;
-	u64 off = l.dump.off;
+	u64 off = l.off;
 
 	while (copied != cnt) {
 		dfo_chunk = dfo_chunk_find(off, &end);
@@ -196,7 +99,7 @@ u64 dfo_read(void *buf, u64 cnt)
 		off += size;
 	}
 out:
-	l.dump.off = off;
+	l.off = off;
 	return copied;
 }
 
@@ -205,5 +108,5 @@ out:
  */
 u64 dfo_size(void)
 {
-	return l.dump.size;
+	return dfo_chunk_dump_size();
 }

zdump/dfo.h

@@ -12,37 +12,12 @@
 #ifndef DFO_H
 #define DFO_H
 
-#include "lib/util_list.h"
+u64 dfo_read(void *buf, u64 cnt);
-#include "zg.h"
+void dfo_seek(u64 addr);
-
+u64 dfo_size(void);
-struct dfo_chunk;
+const char *dfo_name(void);
-
+void dfo_init(void);
-typedef void (*dfo_chunk_read_fn)(struct dfo_chunk *chunk, u64 off,
+int dfo_set(const char *dfo_name);
-				    void *buf, u64 cnt);
-
-struct dfo_chunk {
-	struct util_list_node	list;
-	u64			start;
-	u64			end;
-	dfo_chunk_read_fn	read_fn;
-	void			*data;
-};
-
-extern void dfo_chunk_zero_fn(struct dfo_chunk *chunk, u64 off, void *buf,
-			      u64 cnt);
-extern void dfo_chunk_buf_fn(struct dfo_chunk *chunk, u64 off, void *buf,
-			     u64 cnt);
-extern void dfo_chunk_mem_fn(struct dfo_chunk *chunk, u64 off, void *buf,
-			     u64 cnt);
-extern void dfo_chunk_add(u64 start, u64 size, void *data,
-			  dfo_chunk_read_fn read_fn);
-
-extern u64 dfo_read(void *buf, u64 cnt);
-extern void dfo_seek(u64 addr);
-extern u64 dfo_size(void);
-extern const char *dfo_name(void);
-extern void dfo_init(void);
-extern int dfo_set(const char *dfo_name);
 
 /*
  * DFO operations

zdump/dfo_elf.c

@@ -19,6 +19,7 @@
 #include "df_elf.h"
 #include "dfi.h"
 #include "dfi_mem_chunk.h"
+#include "dfo_mem_chunk.h"
 #include "dfi_vmcoreinfo.h"
 #include "dfo.h"
 

zdump/dfo_mem_chunk.c

@@ -0,0 +1,128 @@
+/*
+ * Copyright IBM Corp. 2001, 2017, 2021
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#include <string.h>
+
+#include "zg.h"
+#include "dfi_mem_chunk.h"
+#include "dfo_mem_chunk.h"
+
+/*
+ * File local static data
+ */
+static struct {
+	u64			size;		/* Size of dump in bytes */
+	unsigned int		chunk_cnt;	/* Number of dump chunks */
+	struct util_list	chunk_list;	/* DFO chunk list */
+} l;
+
+/*
+ * Add dump chunk
+ */
+void dfo_chunk_add(u64 start, u64 size, void *data, dfo_chunk_read_fn read_fn)
+{
+	struct dfo_chunk *dfo_chunk;
+
+	dfo_chunk = zg_alloc(sizeof(*dfo_chunk));
+	dfo_chunk->start = start;
+	dfo_chunk->end = start + size - 1;
+	dfo_chunk->data = data;
+	dfo_chunk->read_fn = read_fn;
+	util_list_add_head(&l.chunk_list, dfo_chunk);
+	l.chunk_cnt++;
+	l.size = MAX(l.size, dfo_chunk->end + 1);
+}
+
+/*
+ * Dump chunk function: Copy zero pages for chunk
+ */
+void dfo_chunk_zero_fn(struct dfo_chunk *dfo_chunk, u64 off, void *buf, u64 cnt)
+{
+	(void) dfo_chunk;
+	(void) off;
+
+	memset(buf, 0, cnt);
+}
+
+/*
+ * Dump chunk function: Copy given buffer for chunk
+ */
+void dfo_chunk_buf_fn(struct dfo_chunk *dfo_chunk, u64 off, void *buf, u64 cnt)
+{
+	memcpy(buf, dfo_chunk->data + off, cnt);
+}
+
+/*
+ * Dump chunk function: Copy given memory range for chunk
+ */
+void dfo_chunk_mem_fn(struct dfo_chunk *dfo_chunk, u64 off, void *buf, u64 cnt)
+{
+	struct dfi_mem_chunk *mem_chunk = dfo_chunk->data;
+
+	mem_chunk->read_fn(mem_chunk, off, buf, cnt);
+}
+
+/*
+ * Find dump chunk for offset "off"
+ *
+ * This function is a bit hacky. DFO chunks can overlap. If two DFO chunks
+ * overlap, the last registered chunk wins. The dfo_chunk_find() function
+ * reflects that by returning the first memory chunk that is found in
+ * the dfo chunk list.
+ *
+ * In addition to that it calculates the "virtual end" of that chunk. An
+ * overlapping chunk can limit the "virtual end" of an underlying chunk so
+ * that the "virtual end" of that chunk is lower than the "real end".
+ *
+ * Example:
+ *
+ * chunk 1.:      |------|
+ * chunk 2.: |---------------------|
+ * off.....: ^
+ * virt end:      ^
+ * real end:                       ^
+ *
+ * In this case chunk 2 will be returned and "end" is set to the start of
+ * chunk 1.
+ */
+struct dfo_chunk *dfo_chunk_find(u64 off, u64 *end)
+{
+	struct dfo_chunk *dfo_chunk;
+
+	*end = U64_MAX;
+	dfo_chunk_iterate(dfo_chunk) {
+		if (dfo_chunk->start <= off && dfo_chunk->end >= off) {
+			*end = MIN(*end, dfo_chunk->end);
+			return dfo_chunk;
+		} else if (dfo_chunk->start > off) {
+			*end = MIN(*end, dfo_chunk->start - 1);
+		}
+	}
+	return NULL;
+}
+
+struct util_list *dfo_chunk_list(void)
+{
+	return &l.chunk_list;
+}
+
+u64 dfo_chunk_dump_size(void)
+{
+	return l.size;
+}
+
+int dfo_chunk_init(void)
+{
+	util_list_init(&l.chunk_list, struct dfo_chunk, list);
+
+	return 0;
+}
+
+void dfo_chunk_deinit(void)
+{
+	memset(&l, 0, sizeof(l));
+}

zdump/dfo_mem_chunk.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright IBM Corp. 2001, 2017, 2021
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef DFO_MEM_CHUNK_H
+#define DFO_MEM_CHUNK_H
+
+#include "lib/zt_common.h"
+#include "lib/util_list.h"
+
+struct dfo_chunk;
+
+typedef void (*dfo_chunk_read_fn)(struct dfo_chunk *chunk, u64 off,
+				  void *buf, u64 cnt);
+
+struct dfo_chunk {
+	struct util_list_node	list;
+	u64			start;
+	u64			end;
+	dfo_chunk_read_fn	read_fn;
+	void			*data;
+};
+
+void dfo_chunk_zero_fn(struct dfo_chunk *chunk, u64 off, void *buf, u64 cnt);
+void dfo_chunk_buf_fn(struct dfo_chunk *chunk, u64 off, void *buf, u64 cnt);
+void dfo_chunk_mem_fn(struct dfo_chunk *chunk, u64 off, void *buf, u64 cnt);
+void dfo_chunk_add(u64 start, u64 size, void *data, dfo_chunk_read_fn read_fn);
+struct dfo_chunk *dfo_chunk_find(u64 off, u64 *end);
+
+struct util_list *dfo_chunk_list(void);
+#define dfo_chunk_iterate(dfo_chunk) \
+	util_list_iterate(dfo_chunk_list(), dfo_chunk)
+
+u64 dfo_chunk_dump_size(void);
+
+int dfo_chunk_init(void);
+void dfo_chunk_deinit(void);
+
+#endif /* DFO_MEM_CHUNK_H */

zdump/dfo_s390.c

@@ -19,6 +19,7 @@
 
 #include "df_s390.h"
 #include "dfi_mem_chunk.h"
+#include "dfo_mem_chunk.h"
 #include "dfo.h"
 
 /*