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authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-24 16:10:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-24 16:10:23 -0700
commit9c9fa97a8edbc3668dfc7a25de516e80c146e86f (patch)
tree2dc0e90203796a4b346ce190f9521c3294104058 /arch/arm64/mm/mmap.c
parent5184d449600f501a8688069f35c138c6b3bf8b94 (diff)
parent2b38d01b4de8b1bbda7f5f7e91252609557635fc (diff)
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - a few hot fixes - ocfs2 updates - almost all of -mm (slab-generic, slab, slub, kmemleak, kasan, cleanups, debug, pagecache, memcg, gup, pagemap, memory-hotplug, sparsemem, vmalloc, initialization, z3fold, compaction, mempolicy, oom-kill, hugetlb, migration, thp, mmap, madvise, shmem, zswap, zsmalloc) * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (132 commits) mm/zsmalloc.c: fix a -Wunused-function warning zswap: do not map same object twice zswap: use movable memory if zpool support allocate movable memory zpool: add malloc_support_movable to zpool_driver shmem: fix obsolete comment in shmem_getpage_gfp() mm/madvise: reduce code duplication in error handling paths mm: mmap: increase sockets maximum memory size pgoff for 32bits mm/mmap.c: refine find_vma_prev() with rb_last() riscv: make mmap allocation top-down by default mips: use generic mmap top-down layout and brk randomization mips: replace arch specific way to determine 32bit task with generic version mips: adjust brk randomization offset to fit generic version mips: use STACK_TOP when computing mmap base address mips: properly account for stack randomization and stack guard gap arm: use generic mmap top-down layout and brk randomization arm: use STACK_TOP when computing mmap base address arm: properly account for stack randomization and stack guard gap arm64, mm: make randomization selected by generic topdown mmap layout arm64, mm: move generic mmap layout functions to mm arm64: consider stack randomization for mmap base only when necessary ...
Diffstat (limited to 'arch/arm64/mm/mmap.c')
-rw-r--r--arch/arm64/mm/mmap.c72
1 files changed, 0 insertions, 72 deletions
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c
index b050641b5139..3028bacbc4e9 100644
--- a/arch/arm64/mm/mmap.c
+++ b/arch/arm64/mm/mmap.c
@@ -21,78 +21,6 @@
#include <asm/cputype.h>
/*
- * Leave enough space between the mmap area and the stack to honour ulimit in
- * the face of randomisation.
- */
-#define MIN_GAP (SZ_128M)
-#define MAX_GAP (STACK_TOP/6*5)
-
-static int mmap_is_legacy(struct rlimit *rlim_stack)
-{
- if (current->personality & ADDR_COMPAT_LAYOUT)
- return 1;
-
- if (rlim_stack->rlim_cur == RLIM_INFINITY)
- return 1;
-
- return sysctl_legacy_va_layout;
-}
-
-unsigned long arch_mmap_rnd(void)
-{
- unsigned long rnd;
-
-#ifdef CONFIG_COMPAT
- if (test_thread_flag(TIF_32BIT))
- rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1);
- else
-#endif
- rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1);
- return rnd << PAGE_SHIFT;
-}
-
-static unsigned long mmap_base(unsigned long rnd, struct rlimit *rlim_stack)
-{
- unsigned long gap = rlim_stack->rlim_cur;
- unsigned long pad = (STACK_RND_MASK << PAGE_SHIFT) + stack_guard_gap;
-
- /* Values close to RLIM_INFINITY can overflow. */
- if (gap + pad > gap)
- gap += pad;
-
- if (gap < MIN_GAP)
- gap = MIN_GAP;
- else if (gap > MAX_GAP)
- gap = MAX_GAP;
-
- return PAGE_ALIGN(STACK_TOP - gap - rnd);
-}
-
-/*
- * This function, called very early during the creation of a new process VM
- * image, sets up which VM layout function to use:
- */
-void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack)
-{
- unsigned long random_factor = 0UL;
-
- if (current->flags & PF_RANDOMIZE)
- random_factor = arch_mmap_rnd();
-
- /*
- * Fall back to the standard layout if the personality bit is set, or
- * if the expected stack growth is unlimited:
- */
- if (mmap_is_legacy(rlim_stack)) {
- mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
- mm->get_unmapped_area = arch_get_unmapped_area;
- } else {
- mm->mmap_base = mmap_base(random_factor, rlim_stack);
- mm->get_unmapped_area = arch_get_unmapped_area_topdown;
- }
-}
-
-/*
* You really shouldn't be using read() or write() on /dev/mem. This might go
* away in the future.
*/