Hi Dave,
Am Donnerstag, den 04.09.2008, 11:19 -0400 schrieb Dave Anderson:
[snip]
My guess is that it might have something to do with the zero-based
kernel
virtual address space on s390/s390x.
I also guess that the trail would have been:
cmd_kmem
dump_memory_nodes
dump_mem_sections
section_mem_map_addr
read_mem_section
where read_mem_section() can legitimately return if the addr
passed is not kernel virtual address of a mem_section structure:
char *
read_mem_section(ulong addr)
{
if (!IS_KVADDR(addr))
return 0;
readmem(addr, KVADDR, vt->mem_section, SIZE(mem_section),
"memory section", FAULT_ON_ERROR);
return vt->mem_section;
}
But the s390/s390x implementation of IS_KVADDR() accepts a kernel
virtual address of zero. It tries to read it and craps out.
Right. Looks like we should check for NULL pointer instead of using
IS_KVADDR(). Since the mem_sec array is static, it is initialized with
zeroes. When I change the check, everything works fine.
What about the following patch...
---
diff -Naurp crash-4.0-7.1/defs.h crash-4.0-7.1-sparse-mem-s390/defs.h
--- crash-4.0-7.1/defs.h 2008-08-19 17:10:51.000000000 +0200
+++ crash-4.0-7.1-sparse-mem-s390/defs.h 2008-09-04 18:24:10.000000000 +0200
@@ -2636,6 +2636,9 @@ struct efi_memory_desc_t {
#define TIF_SIGPENDING (2)
+#define _SECTION_SIZE_BITS 25
+#define _MAX_PHYSMEM_BITS 31
+
#endif /* S390 */
#ifdef S390X
@@ -2658,6 +2661,9 @@ struct efi_memory_desc_t {
#define TIF_SIGPENDING (2)
+#define _SECTION_SIZE_BITS 28
+#define _MAX_PHYSMEM_BITS 42
+
#endif /* S390X */
#ifdef PLATFORM
diff -Naurp crash-4.0-7.1/memory.c crash-4.0-7.1-sparse-mem-s390/memory.c
--- crash-4.0-7.1/memory.c 2008-08-19 17:10:51.000000000 +0200
+++ crash-4.0-7.1-sparse-mem-s390/memory.c 2008-09-05 14:48:10.000000000 +0200
@@ -12653,7 +12653,7 @@ sparse_mem_init(void)
char *
read_mem_section(ulong addr)
{
- if (!IS_KVADDR(addr))
+ if (addr == 0)
return 0;
readmem(addr, KVADDR, vt->mem_section, SIZE(mem_section),
@@ -12668,7 +12668,7 @@ nr_to_section(ulong nr)
ulong addr;
ulong *mem_sec = vt->mem_sec;
- if (!IS_KVADDR(mem_sec[SECTION_NR_TO_ROOT(nr)]))
+ if (mem_sec[SECTION_NR_TO_ROOT(nr)] == 0)
return 0;
if (IS_SPARSEMEM_EX())
diff -Naurp crash-4.0-7.1/s390.c crash-4.0-7.1-sparse-mem-s390/s390.c
--- crash-4.0-7.1/s390.c 2008-08-19 17:10:51.000000000 +0200
+++ crash-4.0-7.1-sparse-mem-s390/s390.c 2008-09-05 14:49:25.000000000 +0200
@@ -130,6 +130,8 @@ s390_init(int when)
machdep->dump_irq = s390_dump_irq;
if (!machdep->hz)
machdep->hz = HZ;
+ machdep->section_size_bits = _SECTION_SIZE_BITS;
+ machdep->max_physmem_bits = _MAX_PHYSMEM_BITS;
break;
case POST_INIT:
diff -Naurp crash-4.0-7.1/s390x.c crash-4.0-7.1-sparse-mem-s390/s390x.c
--- crash-4.0-7.1/s390x.c 2008-08-19 17:10:51.000000000 +0200
+++ crash-4.0-7.1-sparse-mem-s390/s390x.c 2008-09-04 18:24:24.000000000 +0200
@@ -128,6 +128,8 @@ s390x_init(int when)
machdep->dump_irq = s390x_dump_irq;
if (!machdep->hz)
machdep->hz = HZ;
+ machdep->section_size_bits = _SECTION_SIZE_BITS;
+ machdep->max_physmem_bits = _MAX_PHYSMEM_BITS;
break;
case POST_INIT: