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-rw-r--r--arch/s390/include/asm/elf.h13
-rw-r--r--arch/s390/kernel/process.c6
-rw-r--r--arch/s390/mm/init.c30
-rw-r--r--arch/s390/mm/mmap.c60
4 files changed, 23 insertions, 86 deletions
diff --git a/arch/s390/include/asm/elf.h b/arch/s390/include/asm/elf.h
index 3ad48f22de78..bab6739a1154 100644
--- a/arch/s390/include/asm/elf.h
+++ b/arch/s390/include/asm/elf.h
@@ -206,9 +206,16 @@ do { \
} while (0)
#endif /* CONFIG_COMPAT */
-extern unsigned long mmap_rnd_mask;
-
-#define STACK_RND_MASK (test_thread_flag(TIF_31BIT) ? 0x7ff : mmap_rnd_mask)
+/*
+ * Cache aliasing on the latest machines calls for a mapping granularity
+ * of 512KB. For 64-bit processes use a 512KB alignment and a randomization
+ * of up to 1GB. For 31-bit processes the virtual address space is limited,
+ * use no alignment and limit the randomization to 8MB.
+ */
+#define BRK_RND_MASK (is_32bit_task() ? 0x7ffUL : 0x3ffffUL)
+#define MMAP_RND_MASK (is_32bit_task() ? 0x7ffUL : 0x3ff80UL)
+#define MMAP_ALIGN_MASK (is_32bit_task() ? 0 : 0x7fUL)
+#define STACK_RND_MASK MMAP_RND_MASK
#define ARCH_DLINFO \
do { \
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index 688a3aad9c79..114ee8b96f17 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -243,11 +243,7 @@ unsigned long arch_align_stack(unsigned long sp)
static inline unsigned long brk_rnd(void)
{
- /* 8MB for 32bit, 1GB for 64bit */
- if (is_32bit_task())
- return (get_random_int() & 0x7ffUL) << PAGE_SHIFT;
- else
- return (get_random_int() & 0x3ffffUL) << PAGE_SHIFT;
+ return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT;
}
unsigned long arch_randomize_brk(struct mm_struct *mm)
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index c3c07d3505ba..c722400c7697 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -48,37 +48,13 @@ EXPORT_SYMBOL(zero_page_mask);
static void __init setup_zero_pages(void)
{
- struct cpuid cpu_id;
unsigned int order;
struct page *page;
int i;
- get_cpu_id(&cpu_id);
- switch (cpu_id.machine) {
- case 0x9672: /* g5 */
- case 0x2064: /* z900 */
- case 0x2066: /* z900 */
- case 0x2084: /* z990 */
- case 0x2086: /* z990 */
- case 0x2094: /* z9-109 */
- case 0x2096: /* z9-109 */
- order = 0;
- break;
- case 0x2097: /* z10 */
- case 0x2098: /* z10 */
- case 0x2817: /* z196 */
- case 0x2818: /* z196 */
- order = 2;
- break;
- case 0x2827: /* zEC12 */
- case 0x2828: /* zEC12 */
- order = 5;
- break;
- case 0x2964: /* z13 */
- default:
- order = 7;
- break;
- }
+ /* Latest machines require a mapping granularity of 512KB */
+ order = 7;
+
/* Limit number of empty zero pages for small memory sizes */
while (order > 2 && (totalram_pages >> 10) < (1UL << order))
order--;
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index 6e552af08c76..ea01477b4aa6 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -31,9 +31,6 @@
#include <linux/security.h>
#include <asm/pgalloc.h>
-unsigned long mmap_rnd_mask;
-static unsigned long mmap_align_mask;
-
static unsigned long stack_maxrandom_size(void)
{
if (!(current->flags & PF_RANDOMIZE))
@@ -62,10 +59,7 @@ static inline int mmap_is_legacy(void)
unsigned long arch_mmap_rnd(void)
{
- if (is_32bit_task())
- return (get_random_int() & 0x7ff) << PAGE_SHIFT;
- else
- return (get_random_int() & mmap_rnd_mask) << PAGE_SHIFT;
+ return (get_random_int() & MMAP_RND_MASK) << PAGE_SHIFT;
}
static unsigned long mmap_base_legacy(unsigned long rnd)
@@ -92,7 +86,6 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
struct vm_unmapped_area_info info;
- int do_color_align;
if (len > TASK_SIZE - mmap_min_addr)
return -ENOMEM;
@@ -108,15 +101,14 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
return addr;
}
- do_color_align = 0;
- if (filp || (flags & MAP_SHARED))
- do_color_align = !is_32bit_task();
-
info.flags = 0;
info.length = len;
info.low_limit = mm->mmap_base;
info.high_limit = TASK_SIZE;
- info.align_mask = do_color_align ? (mmap_align_mask << PAGE_SHIFT) : 0;
+ if (filp || (flags & MAP_SHARED))
+ info.align_mask = MMAP_ALIGN_MASK << PAGE_SHIFT;
+ else
+ info.align_mask = 0;
info.align_offset = pgoff << PAGE_SHIFT;
return vm_unmapped_area(&info);
}
@@ -130,7 +122,6 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
struct vm_unmapped_area_info info;
- int do_color_align;
/* requested length too big for entire address space */
if (len > TASK_SIZE - mmap_min_addr)
@@ -148,15 +139,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
return addr;
}
- do_color_align = 0;
- if (filp || (flags & MAP_SHARED))
- do_color_align = !is_32bit_task();
-
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
info.low_limit = max(PAGE_SIZE, mmap_min_addr);
info.high_limit = mm->mmap_base;
- info.align_mask = do_color_align ? (mmap_align_mask << PAGE_SHIFT) : 0;
+ if (filp || (flags & MAP_SHARED))
+ info.align_mask = MMAP_ALIGN_MASK << PAGE_SHIFT;
+ else
+ info.align_mask = 0;
info.align_offset = pgoff << PAGE_SHIFT;
addr = vm_unmapped_area(&info);
@@ -254,35 +244,3 @@ void arch_pick_mmap_layout(struct mm_struct *mm)
mm->get_unmapped_area = s390_get_unmapped_area_topdown;
}
}
-
-static int __init setup_mmap_rnd(void)
-{
- struct cpuid cpu_id;
-
- get_cpu_id(&cpu_id);
- switch (cpu_id.machine) {
- case 0x9672:
- case 0x2064:
- case 0x2066:
- case 0x2084:
- case 0x2086:
- case 0x2094:
- case 0x2096:
- case 0x2097:
- case 0x2098:
- case 0x2817:
- case 0x2818:
- case 0x2827:
- case 0x2828:
- mmap_rnd_mask = 0x7ffUL;
- mmap_align_mask = 0UL;
- break;
- case 0x2964: /* z13 */
- default:
- mmap_rnd_mask = 0x3ff80UL;
- mmap_align_mask = 0x7fUL;
- break;
- }
- return 0;
-}
-early_initcall(setup_mmap_rnd);
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