If we echo an address the hypervisor doesn't like to
/sys/devices/system/memory/probe we oops the box:
# echo 0x10000000000 > /sys/devices/system/memory/probe
kernel BUG at arch/powerpc/mm/hash_utils_64.c:541!
The backtrace is:
create_section_mapping
arch_add_memory
add_memory
memory_probe_store
sysdev_class_store
sysfs_write_file
vfs_write
SyS_write
In create_section_mapping we BUG if htab_bolt_mapping returned
an error. A better approach is to return an error which will
propagate back to userspace.
Rerunning the test with this patch applied:
# echo 0x10000000000 > /sys/devices/system/memory/probe
-bash: echo: write error: Invalid argument
Signed-off-by: Anton Blanchard <an...@samba.org>
Cc: sta...@kernel.org
---
Index: linux-build/arch/powerpc/mm/hash_utils_64.c
===================================================================
--- linux-build.orig/arch/powerpc/mm/hash_utils_64.c 2011-08-10
17:00:42.603007554 +1000
+++ linux-build/arch/powerpc/mm/hash_utils_64.c 2011-08-10 17:05:56.338457482
+1000
@@ -534,11 +534,11 @@ static unsigned long __init htab_get_tab
}
#ifdef CONFIG_MEMORY_HOTPLUG
-void create_section_mapping(unsigned long start, unsigned long end)
+int create_section_mapping(unsigned long start, unsigned long end)
{
- BUG_ON(htab_bolt_mapping(start, end, __pa(start),
+ return htab_bolt_mapping(start, end, __pa(start),
pgprot_val(PAGE_KERNEL), mmu_linear_psize,
- mmu_kernel_ssize));
+ mmu_kernel_ssize);
}
int remove_section_mapping(unsigned long start, unsigned long end)
Index: linux-build/arch/powerpc/include/asm/sparsemem.h
===================================================================
--- linux-build.orig/arch/powerpc/include/asm/sparsemem.h 2011-08-10
17:06:11.948728948 +1000
+++ linux-build/arch/powerpc/include/asm/sparsemem.h 2011-08-10
17:06:21.878901648 +1000
@@ -16,7 +16,7 @@
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_MEMORY_HOTPLUG
-extern void create_section_mapping(unsigned long start, unsigned long end);
+extern int create_section_mapping(unsigned long start, unsigned long end);
extern int remove_section_mapping(unsigned long start, unsigned long end);
#ifdef CONFIG_NUMA
extern int hot_add_scn_to_nid(unsigned long scn_addr);
Index: linux-build/arch/powerpc/mm/mem.c
===================================================================
--- linux-build.orig/arch/powerpc/mm/mem.c 2011-08-10 17:06:42.539260996
+1000
+++ linux-build/arch/powerpc/mm/mem.c 2011-08-10 17:06:45.269308484 +1000
@@ -123,7 +123,8 @@ int arch_add_memory(int nid, u64 start,
pgdata = NODE_DATA(nid);
start = (unsigned long)__va(start);
- create_section_mapping(start, start + size);
+ if (create_section_mapping(start, start + size))
+ return -EINVAL;
/* this should work for most non-highmem platforms */
zone = pgdata->node_zones;
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
