linux/arch/powerpc/include/asm/sparsemem.h
Anton Blanchard a11940978b 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>
2011-09-20 15:53:23 +10:00

33 lines
905 B
C

#ifndef _ASM_POWERPC_SPARSEMEM_H
#define _ASM_POWERPC_SPARSEMEM_H 1
#ifdef __KERNEL__
#ifdef CONFIG_SPARSEMEM
/*
* SECTION_SIZE_BITS 2^N: how big each section will be
* MAX_PHYSADDR_BITS 2^N: how much physical address space we have
* MAX_PHYSMEM_BITS 2^N: how much memory we can have in that space
*/
#define SECTION_SIZE_BITS 24
#define MAX_PHYSADDR_BITS 44
#define MAX_PHYSMEM_BITS 44
#endif /* CONFIG_SPARSEMEM */
#ifdef CONFIG_MEMORY_HOTPLUG
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);
#else
static inline int hot_add_scn_to_nid(unsigned long scn_addr)
{
return 0;
}
#endif /* CONFIG_NUMA */
#endif /* CONFIG_MEMORY_HOTPLUG */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_SPARSEMEM_H */