From a11940978bd598e65996b4f807cf4904793f7025 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Wed, 10 Aug 2011 20:44:24 +0000 Subject: [PATCH] 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 Cc: stable@kernel.org Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/sparsemem.h | 2 +- arch/powerpc/mm/hash_utils_64.c | 6 +++--- arch/powerpc/mm/mem.c | 3 ++- 3 files changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/sparsemem.h b/arch/powerpc/include/asm/sparsemem.h index 54a47ea2c3aa..0c5fa3145615 100644 --- a/arch/powerpc/include/asm/sparsemem.h +++ b/arch/powerpc/include/asm/sparsemem.h @@ -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); diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index 1f8b2a05e3d0..1628201c8cea 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -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) diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index ad9cf49dfb89..5db316cad47b 100644 --- a/arch/powerpc/mm/mem.c +++ b/arch/powerpc/mm/mem.c @@ -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; -- 2.39.5