zdump: Drop support of obsolete dumps and dumpers

Drop support of obsolete dump and dump-tool versions (single-volume DASD,
FBA and Tape) in order to simplify zgetdump logic:
- CCW dumpers written in assembler instructions as well as stage2 dumpers
  of size less than 0x3000 (STAGE2_DUMPER_SIZE_V1 or STAGE2_DUMPER_SIZE_V2)
  haven't been used for years. Remove its traces completely as a cleanup.
  Keep the last version (version 5) of non-extended DASD dumper as well as
  newer extended DASD dumpers.
- Rename STAGE2_DUMPER_SIZE_V3 and STAGE2_DUMPER_SIZE_ZLIB constants.
- Drop support of non-extended s390 dumps of version < 5. Dump files
  of s390 format version 5 can be still produced by zgetdump (dfo_s390).
- Drop excessive dump version checking in df_s390_cpu_info_add() and
  df_s390_hdr_add() considering that obsolete s390 dumps of version lower
  than 5 no longer supported.
- Use cpu_cnt field in s390 dump header instead of the s390 dump version to
  indicate no cpu info available (DFI_CPU_CONTENT_NONE) for dfo_s390.
- Make df_s390_dumper_read() return error code upon unknown dumper
  version/magic detection.

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

include/boot/loaders_layout.h

@@ -31,11 +31,9 @@
 #define ECKD2DUMP_STACK_SIZE		_AC(0x2000, UL)
 #define STAGE2_MAX_SIZE			_AC(0x3000, UL)
 
-#define STAGE2_DUMPER_SIZE_V1		_AC(0x1000, UL)
+#define STAGE2_DUMPER_SIZE_SV		_AC(0x3000, UL)
-#define STAGE2_DUMPER_SIZE_V2		_AC(0x2000, UL)
-#define STAGE2_DUMPER_SIZE_V3		_AC(0x3000, UL)
 #define STAGE2_DUMPER_SIZE_MV		_AC(0x4000, UL)
-#define STAGE2_DUMPER_SIZE_ZLIB		_AC(0x8000, UL)
+#define STAGE2_DUMPER_SIZE_SV_ZLIB	_AC(0x8000, UL)
 
 #define STAGE3_ENTRY			_AC(0xa000, UL)
 

include/dump/s390_dump.h

@@ -27,16 +27,12 @@
 #define DF_S390_CPU_MAX		512
 #define DF_S390_MAGIC_BLK_ECKD	3
 #define DF_S390_DUMPER_MAGIC_SIZE	7
-#define DF_S390_DUMPER_MAGIC32		"ZECKD31"
 #define DF_S390_DUMPER_MAGIC64		"ZECKD64"
 #define DF_S390_DUMPER_MAGIC_EXT	"XECKD64"
-#define DF_S390_DUMPER_MAGIC32_FBA	"ZDFBA31"
 #define DF_S390_DUMPER_MAGIC64_FBA	"ZDFBA64"
 #define DF_S390_DUMPER_MAGIC_FBA_EXT	"XDFBA64"
 #define DF_S390_DUMPER_MAGIC_MV		"ZMULT64"
 #define DF_S390_DUMPER_MAGIC_MV_EXT	"XMULT64"
-#define OLD_DUMPER_HEX_INSTR1 "\x0d\x10\x47\xf0" /* BASR + 1st halfword of BC */
-#define OLD_DUMPER_HEX_INSTR2 "\x0d\xd0" /* BASR 13,0 */
 
 /*
  * Architecture of dumped system

zdump/df_s390.c

@@ -44,11 +44,12 @@ int df_s390_cpu_info_add(struct df_s390_hdr *hdr, u64 addr_max)
 	unsigned int i;
 	int rc;
 
-	if (hdr->version < 5 && hdr->magic == DF_S390_MAGIC) {
+	if (hdr->cpu_cnt == 0) {
 		/* No Prefix registers in header */
-		hdr->cpu_cnt = 0;
 		dfi_cpu_info_init(DFI_CPU_CONTENT_NONE);
-	} else if (check_addr_max(hdr, addr_max) != 0) {
+		return 0;
+	}
+	if (check_addr_max(hdr, addr_max) != 0) {
 		/* Only lowcore pointers available */
 		dfi_cpu_info_init(DFI_CPU_CONTENT_LC);
 	} else {
@@ -93,14 +94,11 @@ void df_s390_hdr_add(struct df_s390_hdr *hdr)
 	dfi_arch_set(df_s390_to_dfi_arch(hdr->arch));
 	if (hdr->cpu_id)
 		dfi_attr_cpu_id_set(hdr->cpu_id);
-	if ((hdr->version >= 2 || hdr->magic == DF_S390_MAGIC_EXT) &&
+	if (hdr->build_arch)
-	    hdr->build_arch)
 		dfi_attr_build_arch_set(df_s390_to_dfi_arch(hdr->build_arch));
-	if ((hdr->version >= 3 || hdr->magic == DF_S390_MAGIC_EXT) &&
+	if (hdr->mem_size_real)
-	    hdr->mem_size_real)
 		dfi_attr_mem_size_real_set(hdr->mem_size_real);
-	if ((hdr->version >= 5 || hdr->magic == DF_S390_MAGIC_EXT) &&
+	if (hdr->real_cpu_cnt)
-	    hdr->real_cpu_cnt)
 		dfi_attr_real_cpu_cnt_set(hdr->real_cpu_cnt);
 	if (!hdr->mvdump && hdr->zlib_version_s390 && hdr->zlib_entry_size)
 		dfi_attr_zlib_info_set(hdr->zlib_version_s390, hdr->zlib_entry_size);
@@ -134,50 +132,56 @@ int df_s390_em_verify(struct df_s390_em *em, struct df_s390_hdr *hdr)
 /*
  * Read s390 dump tool from DASD with given block size
  */
-void df_s390_dumper_read(struct zg_fh *fh, int blk_size,
+int df_s390_dumper_read(struct zg_fh *fh, int blk_size,
-			 struct df_s390_dumper *dumper)
+			struct df_s390_dumper *dumper)
 {
 	int bytes_to_read, offset = DF_S390_MAGIC_BLK_ECKD * blk_size;
 
 	/*
-	 * First read 3 fields at the start of the dumper. The magic number,
+	 * First read 2 fields at the start of the dumper. The magic number
-	 * version and one extra field for the old dumper case (no magic
+	 * and the version.
-	 * number, checking for specific assembler instructions).
 	 */
-	bytes_to_read = offsetof(struct df_s390_dumper, force);
+	bytes_to_read = offsetof(struct df_s390_dumper, size);
 	zg_seek(fh, offset, ZG_CHECK);
 	zg_read(fh, dumper, bytes_to_read, ZG_CHECK);
-	if (memcmp(dumper->magic, OLD_DUMPER_HEX_INSTR1, 4) == 0 &&
+	dumper->size = 0;
-	    memcmp(&dumper->size, OLD_DUMPER_HEX_INSTR2, 2) == 0)
-		/* We found basr r13,0 (old dumper) */
-		dumper->version = 0;
 	switch (dumper->version) {
+	/*
+	 * Versions 1 and 2 refer to the newer extended DASD dumpers
+	 * while version 5 refers to the old (non-extended) DASD dump-tools
+	 * we still support (either single-volume or multi-volume).
+	 * Magic numbers for SV and MV dumpers apply as well.
+	 * Pick a dumper size based on the Version and Magic combination.
+	 */
 	case 1:
 		if (strncmp(dumper->magic, DF_S390_DUMPER_MAGIC_EXT,
 			    DF_S390_DUMPER_MAGIC_SIZE) == 0 ||
 		    strncmp(dumper->magic, DF_S390_DUMPER_MAGIC_MV_EXT,
 			    DF_S390_DUMPER_MAGIC_SIZE) == 0)
-			dumper->size = STAGE2_DUMPER_SIZE_V3;
+			dumper->size = STAGE2_DUMPER_SIZE_SV;
-		else
-			dumper->size = STAGE2_DUMPER_SIZE_V1;
 		break;
 	case 2:
 		if (strncmp(dumper->magic, DF_S390_DUMPER_MAGIC_EXT,
 			    DF_S390_DUMPER_MAGIC_SIZE) == 0)
-			dumper->size = STAGE2_DUMPER_SIZE_ZLIB;
+			dumper->size = STAGE2_DUMPER_SIZE_SV_ZLIB;
 		else if (strncmp(dumper->magic, DF_S390_DUMPER_MAGIC_MV_EXT,
 				 DF_S390_DUMPER_MAGIC_SIZE) == 0)
 			dumper->size = STAGE2_DUMPER_SIZE_MV;
-		else
-			dumper->size = STAGE2_DUMPER_SIZE_V2;
 		break;
-	case 3:
+	case 5:
-	default:
+		if (strncmp(dumper->magic, DF_S390_DUMPER_MAGIC64,
-		dumper->size = STAGE2_DUMPER_SIZE_V3;
+			    DF_S390_DUMPER_MAGIC_SIZE) == 0 ||
+		    strncmp(dumper->magic, DF_S390_DUMPER_MAGIC_MV,
+			    DF_S390_DUMPER_MAGIC_SIZE) == 0)
+			dumper->size = STAGE2_DUMPER_SIZE_SV;
+		break;
 	}
+	if (dumper->size == 0)
+		return -1;
 	/* Read force and mem fields in the end of the dumper */
 	bytes_to_read = sizeof(dumper->force) + sizeof(dumper->mem);
 	offset += dumper->size - bytes_to_read;
 	zg_seek(fh, offset, ZG_CHECK);
 	zg_read(fh, &dumper->force, bytes_to_read, ZG_CHECK);
+	return 0;
 }

zdump/df_s390.h

@@ -53,8 +53,8 @@ extern void df_s390_hdr_add(struct df_s390_hdr *hdr);
 extern void df_s390_em_add(struct df_s390_em *em);
 extern int df_s390_cpu_info_add(struct df_s390_hdr *hdr, u64 addr_max);
 extern int df_s390_em_verify(struct df_s390_em *em, struct df_s390_hdr *hdr);
-extern void df_s390_dumper_read(struct zg_fh *fh, int32_t blk_size,
+extern int df_s390_dumper_read(struct zg_fh *fh, int32_t blk_size,
-				struct df_s390_dumper *dumper);
+			       struct df_s390_dumper *dumper);
 
 /*
  * DASD dt and dfi functions

zdump/dfi_s390mv.c

@@ -211,7 +211,9 @@ static void check_vol_table(struct vol *vol)
 static void vol_read(struct vol *vol)
 {
 	zg_ioctl(vol->fh, BLKFLSBUF, NULL, "BLKFLSBUF", ZG_CHECK);
-	df_s390_dumper_read(vol->fh, vol->blk_size, &vol->dumper);
+	if (df_s390_dumper_read(vol->fh, vol->blk_size, &vol->dumper))
+		ERR_EXIT("No dump tool found on the multi-volume dump device '%s'",
+			 vol->bus_id);
 	check_vol_table(vol);
 	zg_seek(vol->fh, vol->part_off, ZG_CHECK);
 	zg_read(vol->fh, &vol->hdr, DF_S390_HDR_SIZE, ZG_CHECK);
@@ -506,7 +508,8 @@ static int mv_dumper_read(void)
 	if (zg_ioctl(g.fh, BLKSSZGET, &l.blk_size, "BLKSSZGET",
 		     ZG_CHECK_NONE) == -1)
 		return -ENODEV;
-	df_s390_dumper_read(g.fh, l.blk_size, &l.dumper);
+	if (df_s390_dumper_read(g.fh, l.blk_size, &l.dumper))
+		return -ENODEV;
 	if (strncmp(l.dumper.magic, l.dumper_magic, DF_S390_DUMPER_MAGIC_SIZE) != 0)
 		return -ENODEV;
 	table_read(g.fh, l.blk_size, &l.table);

zdump/dfo_s390.c

@@ -234,10 +234,7 @@ static void df_s390_dump_init(void)
 	dh->hdr_size = DF_S390_HDR_SIZE;
 	dh->page_size = PAGE_SIZE;
 	dh->dump_level = 4;
-	if (dfi_cpu_content() == DFI_CPU_CONTENT_NONE)
+	dh->version = 5;
-		dh->version = 4;
-	else
-		dh->version = 5;
 	dh->mem_start = 0;
 	dh->mem_end = dfi_mem_end();
 	dh->mem_size = dh->mem_end + 1;
@@ -246,6 +243,8 @@ static void df_s390_dump_init(void)
 	if (dfi_attr_build_arch())
 		dh->build_arch = df_s390_from_dfi_arch(*dfi_attr_build_arch());
 	dh->cpu_cnt = dfi_cpu_cnt();
+	if (dfi_cpu_content() == DFI_CPU_CONTENT_NONE)
+		dh->cpu_cnt = 0;
 	if (dfi_attr_real_cpu_cnt())
 		dh->real_cpu_cnt = *dfi_attr_real_cpu_cnt();
 	if (dfi_attr_cpu_id())

zdump/dt_s390sv.c

@@ -31,28 +31,18 @@ static struct {
  */
 static int dumper_read_eckd(int blk_size)
 {
-	df_s390_dumper_read(g.fh, blk_size, &l.dumper);
+	if (df_s390_dumper_read(g.fh, blk_size, &l.dumper))
-
+		return -ENODEV;
 	if (l.extended) {
 		if (strncmp(l.dumper.magic, DF_S390_DUMPER_MAGIC_EXT,
 			    DF_S390_DUMPER_MAGIC_SIZE) != 0)
 			return -ENODEV;
-		l.dumper_arch = DFI_ARCH_64;
-		return 0;
-	}
-	if (strncmp(l.dumper.magic, DF_S390_DUMPER_MAGIC64,
-		    DF_S390_DUMPER_MAGIC_SIZE) == 0) {
-		l.dumper_arch = DFI_ARCH_64;
-	} else if (strncmp(l.dumper.magic, DF_S390_DUMPER_MAGIC32,
-			   DF_S390_DUMPER_MAGIC_SIZE) == 0) {
-		l.dumper_arch = DFI_ARCH_32;
-	} else if (memcmp(l.dumper.magic, OLD_DUMPER_HEX_INSTR1, 4) == 0 &&
-		   l.dumper.version == 0) {
-		/* We found the old dumper */
-		l.dumper_arch = DFI_ARCH_UNKNOWN;
 	} else {
-		return -ENODEV;
+		if (strncmp(l.dumper.magic, DF_S390_DUMPER_MAGIC64,
+			    DF_S390_DUMPER_MAGIC_SIZE) != 0)
+			return -ENODEV;
 	}
+	l.dumper_arch = DFI_ARCH_64;
 	return 0;
 }
 
@@ -65,47 +55,12 @@ static int dumper_check_fba(struct df_s390_dumper *dumper)
 		if (strncmp(dumper->magic, DF_S390_DUMPER_MAGIC_FBA_EXT,
 			    DF_S390_DUMPER_MAGIC_SIZE) != 0)
 			return -ENODEV;
-		l.dumper_arch = DFI_ARCH_64;
-		return 0;
-	}
-	if (strncmp(dumper->magic, DF_S390_DUMPER_MAGIC64_FBA,
-		    DF_S390_DUMPER_MAGIC_SIZE) == 0) {
-		l.dumper_arch = DFI_ARCH_64;
-	} else if (strncmp(dumper->magic, DF_S390_DUMPER_MAGIC32_FBA,
-			   DF_S390_DUMPER_MAGIC_SIZE) == 0) {
-		l.dumper_arch = DFI_ARCH_32;
-	} else if (memcmp(dumper->magic, OLD_DUMPER_HEX_INSTR1, 4) == 0 &&
-		   memcmp(&dumper->size, OLD_DUMPER_HEX_INSTR2, 2) == 0) {
-		/* We found basr r13,0 (old dumper) */
-		dumper->version = 0;
-		l.dumper_arch = DFI_ARCH_UNKNOWN;
 	} else {
-		return -ENODEV;
+		if (strncmp(dumper->magic, DF_S390_DUMPER_MAGIC64_FBA,
+			    DF_S390_DUMPER_MAGIC_SIZE) != 0)
+			return -ENODEV;
 	}
-	return 0;
+	l.dumper_arch = DFI_ARCH_64;
-}
-
-/*
- * Read dump tool from FBA device
- */
-static int dumper_read_validate_fba(int size, struct df_s390_dumper *dumper)
-{
-	int bytes_to_read;
-
-	/*
-	 * On FBA device the dumper is written at the end of the volume because
-	 * there is not enough space to place it at the beginning due to the
-	 * linux disk layout
-	 */
-	zg_seek_end(g.fh, -size, ZG_CHECK);
-	bytes_to_read = offsetof(struct df_s390_dumper, force);
-	zg_read(g.fh, dumper, bytes_to_read, ZG_CHECK);
-	if (dumper_check_fba(dumper) != 0)
-		return -ENODEV;
-	dumper->size = size;
-	bytes_to_read = sizeof(dumper->force) + sizeof(dumper->mem);
-	zg_seek_end(g.fh, -bytes_to_read, ZG_CHECK);
-	zg_read(g.fh, &dumper->force, bytes_to_read, ZG_CHECK);
 	return 0;
 }
 
@@ -114,13 +69,27 @@ static int dumper_read_validate_fba(int size, struct df_s390_dumper *dumper)
  */
 static int dumper_read_fba(void)
 {
-	if (dumper_read_validate_fba(STAGE2_DUMPER_SIZE_V3, &l.dumper) == 0)
+	struct df_s390_dumper *dumper = &l.dumper;
-		return 0;
+	int bytes_to_read;
-	if (dumper_read_validate_fba(STAGE2_DUMPER_SIZE_V2, &l.dumper) == 0)
+
-		return 0;
+	/*
-	if (dumper_read_validate_fba(STAGE2_DUMPER_SIZE_V1, &l.dumper) == 0)
+	 * On FBA device the dumper is written at the end of the volume because
-		return 0;
+	 * there is not enough space to place it at the beginning due to the
-	return -ENODEV;
+	 * linux disk layout.
+	 * First read 2 fields at the start of the dumper. The magic number
+	 * and the version.
+	 */
+	zg_seek_end(g.fh, -STAGE2_DUMPER_SIZE_SV, ZG_CHECK);
+	bytes_to_read = offsetof(struct df_s390_dumper, size);
+	zg_read(g.fh, dumper, bytes_to_read, ZG_CHECK);
+	if (dumper_check_fba(dumper) != 0)
+		return -ENODEV;
+	dumper->size = STAGE2_DUMPER_SIZE_SV;
+	/* Read force and mem fields in the end of the dumper */
+	bytes_to_read = sizeof(dumper->force) + sizeof(dumper->mem);
+	zg_seek_end(g.fh, -bytes_to_read, ZG_CHECK);
+	zg_read(g.fh, &dumper->force, bytes_to_read, ZG_CHECK);
+	return 0;
 }
 
 /*

zipl/boot/eckd2dump.lds.S

@@ -49,7 +49,7 @@ SECTIONS
     ASSERT(__stage2dump_tail_end - __stage2_head == STAGE2_DUMPER_SIZE_MV,
            "MV dumper size doesn't conform to the described memory layout");
 #else
-    ASSERT(__stage2dump_tail_end - __stage2_head == STAGE2_DUMPER_SIZE_ZLIB,
+    ASSERT(__stage2dump_tail_end - __stage2_head == STAGE2_DUMPER_SIZE_SV_ZLIB,
            "SV dumper size doesn't conform to the described memory layout");
 #endif
   }

zipl/src/install.c

@@ -367,8 +367,7 @@ static int clear_ccw_dumper(const struct disk_info *info, int fd)
 	/*
 	 * Check if the dump tool is present and clear its first block with zeroes.
 	 */
-	if (strncmp(dumper_magic, DF_S390_DUMPER_MAGIC32, sizeof(dumper_magic)) == 0 ||
+	if (strncmp(dumper_magic, DF_S390_DUMPER_MAGIC64, sizeof(dumper_magic)) == 0 ||
-	    strncmp(dumper_magic, DF_S390_DUMPER_MAGIC64, sizeof(dumper_magic)) == 0 ||
 	    strncmp(dumper_magic, DF_S390_DUMPER_MAGIC_EXT, sizeof(dumper_magic)) == 0 ||
 	    strncmp(dumper_magic, DF_S390_DUMPER_MAGIC_MV, sizeof(dumper_magic)) == 0 ||
 	    strncmp(dumper_magic, DF_S390_DUMPER_MAGIC_MV_EXT, sizeof(dumper_magic)) == 0) {