s390/mm/ptdump: Fix handling of identity mapping area

Since virtual and real addresses are not the same anymore the
assumption that the kernel image is contained within the identity
mapping is also not true anymore.

Fix this by adding two explicit areas and at the correct locations: one
for the 8kb lowcore area, and one for the identity mapping.

Fixes: c98d2eca ("s390/mm: Uncouple physical vs virtual address spaces")
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/mm/dump_pagetables.c

@@ -20,8 +20,8 @@ struct addr_marker {
 };
 
 enum address_markers_idx {
-	IDENTITY_BEFORE_NR = 0,
-	IDENTITY_BEFORE_END_NR,
+	LOWCORE_START_NR = 0,
+	LOWCORE_END_NR,
 	AMODE31_START_NR,
 	AMODE31_END_NR,
 	KERNEL_START_NR,
@@ -30,8 +30,8 @@ enum address_markers_idx {
 	KFENCE_START_NR,
 	KFENCE_END_NR,
 #endif
-	IDENTITY_AFTER_NR,
-	IDENTITY_AFTER_END_NR,
+	IDENTITY_START_NR,
+	IDENTITY_END_NR,
 	VMEMMAP_NR,
 	VMEMMAP_END_NR,
 	VMALLOC_NR,
@@ -59,8 +59,10 @@ enum address_markers_idx {
 };
 
 static struct addr_marker address_markers[] = {
-	[IDENTITY_BEFORE_NR]	= {0, "Identity Mapping Start"},
-	[IDENTITY_BEFORE_END_NR] = {(unsigned long)_stext, "Identity Mapping End"},
+	[LOWCORE_START_NR]	= {0, "Lowcore Start"},
+	[LOWCORE_END_NR]	= {0, "Lowcore End"},
+	[IDENTITY_START_NR]	= {0, "Identity Mapping Start"},
+	[IDENTITY_END_NR]	= {0, "Identity Mapping End"},
 	[AMODE31_START_NR]	= {0, "Amode31 Area Start"},
 	[AMODE31_END_NR]	= {0, "Amode31 Area End"},
 	[KERNEL_START_NR]	= {(unsigned long)_stext, "Kernel Image Start"},
@@ -69,8 +71,6 @@ static struct addr_marker address_markers[] = {
 	[KFENCE_START_NR]	= {0, "KFence Pool Start"},
 	[KFENCE_END_NR]		= {0, "KFence Pool End"},
 #endif
-	[IDENTITY_AFTER_NR]	= {(unsigned long)_end, "Identity Mapping Start"},
-	[IDENTITY_AFTER_END_NR]	= {0, "Identity Mapping End"},
 	[VMEMMAP_NR]		= {0, "vmemmap Area Start"},
 	[VMEMMAP_END_NR]	= {0, "vmemmap Area End"},
 	[VMALLOC_NR]		= {0, "vmalloc Area Start"},
@@ -310,7 +310,10 @@ static int pt_dump_init(void)
 	 */
 	max_addr = (get_lowcore()->kernel_asce.val & _REGION_ENTRY_TYPE_MASK) >> 2;
 	max_addr = 1UL << (max_addr * 11 + 31);
-	address_markers[IDENTITY_AFTER_END_NR].start_address = ident_map_size;
+	address_markers[LOWCORE_START_NR].start_address = 0;
+	address_markers[LOWCORE_END_NR].start_address = sizeof(struct lowcore);
+	address_markers[IDENTITY_START_NR].start_address = __identity_base;
+	address_markers[IDENTITY_END_NR].start_address = __identity_base + ident_map_size;
 	address_markers[AMODE31_START_NR].start_address = (unsigned long)__samode31;
 	address_markers[AMODE31_END_NR].start_address = (unsigned long)__eamode31;
 	address_markers[MODULES_NR].start_address = MODULES_VADDR;