[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>

1 files changed, 3 insertions, 3 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];