/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 2011 Wind River Systems, * written by Ralf Baechle */ #include #include #include #include #include #include #include #include unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ EXPORT_SYMBOL(shm_align_mask); /* gap between mmap and stack */ #define MIN_GAP (128*1024*1024UL) #define MAX_GAP ((TASK_SIZE)/6*5) static int mmap_is_legacy(void) { if (current->personality & ADDR_COMPAT_LAYOUT) return 1; if (rlimit(RLIMIT_STACK) == RLIM_INFINITY) return 1; return sysctl_legacy_va_layout; } static unsigned long mmap_base(unsigned long rnd) { unsigned long gap = rlimit(RLIMIT_STACK); if (gap < MIN_GAP) gap = MIN_GAP; else if (gap > MAX_GAP) gap = MAX_GAP; return PAGE_ALIGN(TASK_SIZE - gap - rnd); } #define COLOUR_ALIGN(addr, pgoff) \ ((((addr) + shm_align_mask) & ~shm_align_mask) + \ (((pgoff) << PAGE_SHIFT) & shm_align_mask)) enum mmap_allocation_direction {UP, DOWN}; static unsigned long arch_get_unmapped_area_common(struct file *filp, unsigned long addr0, unsigned long len, unsigned long pgoff, unsigned long flags, enum mmap_allocation_direction dir) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma; unsigned long addr = addr0; int do_color_align; struct vm_unmapped_area_info info; if (unlikely(len > TASK_SIZE)) return -ENOMEM; if (flags & MAP_FIXED) { /* Even MAP_FIXED mappings must reside within TASK_SIZE */ if (TASK_SIZE - len < addr) return -EINVAL; /* * We do not accept a shared mapping if it would violate * cache aliasing constraints. */ if ((flags & MAP_SHARED) && ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) return -EINVAL; return addr; } do_color_align = 0; if (filp || (flags & MAP_SHARED)) do_color_align = 1; /* requesting a specific address */ if (addr) { if (do_color_align) addr = COLOUR_ALIGN(addr, pgoff); else addr = PAGE_ALIGN(addr); vma = find_vma(mm, addr); if (TASK_SIZE - len >= addr && (!vma || addr + len <= vma->vm_start)) return addr; } info.length = len; info.align_mask = do_color_align ? (PAGE_MASK & shm_align_mask) : 0; info.align_offset = pgoff << PAGE_SHIFT; if (dir == DOWN) { info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.low_limit = PAGE_SIZE; info.high_limit = mm->mmap_base; addr = vm_unmapped_area(&info); if (!(addr & ~PAGE_MASK)) return addr; /* * A failed mmap() very likely causes application failure, * so fall back to the bottom-up function here. This scenario * can happen with large stack limits and large mmap() * allocations. */ } info.flags = 0; info.low_limit = mm->mmap_base; info.high_limit = TASK_SIZE; return vm_unmapped_area(&info); } unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0, unsigned long len, unsigned long pgoff, unsigned long flags) { return arch_get_unmapped_area_common(filp, addr0, len, pgoff, flags, UP); } /* * There is no need to export this but sched.h declares the function as * extern so making it static here results in an error. */ unsigned long arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr0, unsigned long len, unsigned long pgoff, unsigned long flags) { return arch_get_unmapped_area_common(filp, addr0, len, pgoff, flags, DOWN); } unsigned long arch_mmap_rnd(void) { unsigned long rnd; rnd = get_random_long(); rnd <<= PAGE_SHIFT; if (TASK_IS_32BIT_ADDR) rnd &= 0xfffffful; else rnd &= 0xffffffful; return rnd; } void arch_pick_mmap_layout(struct mm_struct *mm) { unsigned long random_factor = 0UL; if (current->flags & PF_RANDOMIZE) random_factor = arch_mmap_rnd(); if (mmap_is_legacy()) { mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; mm->get_unmapped_area = arch_get_unmapped_area; } else { mm->mmap_base = mmap_base(random_factor); mm->get_unmapped_area = arch_get_unmapped_area_topdown; } } static inline unsigned long brk_rnd(void) { unsigned long rnd = get_random_long(); rnd = rnd << PAGE_SHIFT; /* 8MB for 32bit, 256MB for 64bit */ if (TASK_IS_32BIT_ADDR) rnd = rnd & 0x7ffffful; else rnd = rnd & 0xffffffful; return rnd; } unsigned long arch_randomize_brk(struct mm_struct *mm) { unsigned long base = mm->brk; unsigned long ret; ret = PAGE_ALIGN(base + brk_rnd()); if (ret < mm->brk) return mm->brk; return ret; } int __virt_addr_valid(const volatile void *kaddr) { return pfn_valid(PFN_DOWN(virt_to_phys(kaddr))); } EXPORT_SYMBOL_GPL(__virt_addr_valid); ted'>unified
authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-27 12:44:32 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-27 12:44:32 -0800
commit3365135d43f861003555c963b309672d053a2228 (patch)
treebfef4adec5da118bf1b3df7e5cff74f45af9e02d /include/uapi/mtd/Kbuild
parent5906374446386fd16fe562b042429d905d231ec3 (diff)
parente0d76fa4475ef2cf4b52d18588b8ce95153d021b (diff)
Merge tag 'xfs-for-linus-4.10-rc6-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs uodates from Darrick Wong: "I have some more fixes this week: better input validation, corruption avoidance, build fixes, memory leak fixes, and a couple from Christoph to avoid an ENOSPC failure. Summary: - Fix race conditions in the CoW code - Fix some incorrect input validation checks - Avoid crashing fs by running out of space when freeing inodes - Fix toctou race wrt whether or not an inode has an attr - Fix build error on arm - Fix page refcount corruption when readahead fails - Don't corrupt userspace in the bmap ioctl" * tag 'xfs-for-linus-4.10-rc6-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: prevent quotacheck from overloading inode lru xfs: fix bmv_count confusion w/ shared extents xfs: clear _XBF_PAGES from buffers when readahead page xfs: extsize hints are not unlikely in xfs_bmap_btalloc xfs: remove racy hasattr check from attr ops xfs: use per-AG reservations for the finobt xfs: only update mount/resv fields on success in __xfs_ag_resv_init xfs: verify dirblocklog correctly xfs: fix COW writeback race
Diffstat (limited to 'include/uapi/mtd/Kbuild')