powerpc: Fix oops when echoing bad values to /sys/devices/system/memory/probe
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>
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index 1f8b2a0..1628201 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -531,11 +531,11 @@
}
#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)