From 5fd9c6e214547a32d3da6ee4284c79004d667bc8 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Sat, 26 Jan 2008 14:11:00 +0100 Subject: [S390] Change vmalloc defintions Currently the vmalloc area starts at a dynamic address depending on the memory size. There was also an 8MB security hole after the physical memory to catch out-of-bounds accesses. We can simplify the code by putting the vmalloc area explicitely at the top of the kernel mapping and setting the vmalloc size to a fixed value of 128MB/128GB for 31bit/64bit systems. Part of the vmalloc area will be used for the vmem_map. This leaves an area of 96MB/1GB for normal vmalloc allocations. Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/setup.c | 6 +++--- arch/s390/mm/vmem.c | 20 +++++++------------- 2 files changed, 10 insertions(+), 16 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index d68a4025486e..d071a81b62da 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -617,7 +617,7 @@ EXPORT_SYMBOL_GPL(real_memory_size); static void __init setup_memory_end(void) { unsigned long memory_size; - unsigned long max_mem, max_phys; + unsigned long max_mem; int i; #if defined(CONFIG_ZFCPDUMP) || defined(CONFIG_ZFCPDUMP_MODULE) @@ -625,10 +625,10 @@ static void __init setup_memory_end(void) memory_end = ZFCPDUMP_HSA_SIZE; #endif memory_size = 0; - max_phys = VMALLOC_END_INIT - VMALLOC_MIN_SIZE; memory_end &= PAGE_MASK; - max_mem = memory_end ? min(max_phys, memory_end) : max_phys; + max_mem = memory_end ? min(VMALLOC_START, memory_end) : VMALLOC_START; + memory_end = min(max_mem, memory_end); for (i = 0; i < MEMORY_CHUNKS; i++) { struct mem_chunk *chunk = &memory_chunk[i]; diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c index fb9c5a85aa56..ee625c8c3b28 100644 --- a/arch/s390/mm/vmem.c +++ b/arch/s390/mm/vmem.c @@ -15,10 +15,6 @@ #include #include -unsigned long vmalloc_end; -EXPORT_SYMBOL(vmalloc_end); - -static struct page *vmem_map; static DEFINE_MUTEX(vmem_mutex); struct memory_segment { @@ -188,8 +184,8 @@ static int vmem_add_mem_map(unsigned long start, unsigned long size) pte_t pte; int ret = -ENOMEM; - map_start = vmem_map + PFN_DOWN(start); - map_end = vmem_map + PFN_DOWN(start + size); + map_start = VMEM_MAP + PFN_DOWN(start); + map_end = VMEM_MAP + PFN_DOWN(start + size); start_addr = (unsigned long) map_start & PAGE_MASK; end_addr = PFN_ALIGN((unsigned long) map_end); @@ -254,7 +250,7 @@ static int insert_memory_segment(struct memory_segment *seg) { struct memory_segment *tmp; - if (PFN_DOWN(seg->start + seg->size) > max_pfn || + if (seg->start + seg->size >= VMALLOC_START || seg->start + seg->size < seg->start) return -ERANGE; @@ -357,17 +353,15 @@ out: /* * map whole physical memory to virtual memory (identity mapping) + * we reserve enough space in the vmalloc area for vmemmap to hotplug + * additional memory segments. */ void __init vmem_map_init(void) { - unsigned long map_size; int i; - map_size = ALIGN(max_low_pfn, MAX_ORDER_NR_PAGES) * sizeof(struct page); - vmalloc_end = PFN_ALIGN(VMALLOC_END_INIT) - PFN_ALIGN(map_size); - vmem_map = (struct page *) vmalloc_end; - NODE_DATA(0)->node_mem_map = vmem_map; - + BUILD_BUG_ON((unsigned long)VMEM_MAP + VMEM_MAP_SIZE > VMEM_MAP_MAX); + NODE_DATA(0)->node_mem_map = VMEM_MAP; for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) vmem_add_mem(memory_chunk[i].addr, memory_chunk[i].size); } -- cgit v1.2.3