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/mem.c b/arch/powerpc/mm/mem.c
index ad9cf49..5db316c 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -123,7 +123,8 @@
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;