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authorChristian Borntraeger <borntraeger@de.ibm.com>2008-01-26 16:11:00 +0300
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-01-26 16:11:12 +0300
commit5fd9c6e214547a32d3da6ee4284c79004d667bc8 (patch)
treedef2e218393c9867e9db939f1d379c005895a912 /arch/s390
parent8ffd74a0924e4e04f6455eb2d2187a9564678d01 (diff)
downloadlinux-5fd9c6e214547a32d3da6ee4284c79004d667bc8.tar.xz
[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 <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/setup.c6
-rw-r--r--arch/s390/mm/vmem.c20
2 files changed, 10 insertions, 16 deletions
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 <asm/setup.h>
#include <asm/tlbflush.h>
-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);
}