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powerpc: Fix oops when echoing bad values to /sys/devices/system/memory/probe

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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 <anton@samba.org>
Cc: stable@kernel.org
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Anton Blanchard 2011-08-10 20:44:24 +00:00 committed by Benjamin Herrenschmidt
parent dfbe93a222
commit a11940978b
3 changed files with 6 additions and 5 deletions
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2
arch/powerpc/include/asm/sparsemem.h
View File

@ -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);

6
arch/powerpc/mm/hash_utils_64.c
View File

@ -531,11 +531,11 @@ static unsigned long __init htab_get_table_size(void)
}
#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)

3
arch/powerpc/mm/mem.c
View File

@ -123,7 +123,8 @@ int arch_add_memory(int nid, u64 start, u64 size)
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;