![Paul Gortmaker](/assets/img/avatar_default.png)
Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance for the presence of either and replace as needed. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14033/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
207 lines
4.7 KiB
C
207 lines
4.7 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2011 Wind River Systems,
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* written by Ralf Baechle <ralf@linux-mips.org>
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*/
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#include <linux/compiler.h>
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#include <linux/errno.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/export.h>
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#include <linux/personality.h>
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#include <linux/random.h>
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#include <linux/sched.h>
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unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
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EXPORT_SYMBOL(shm_align_mask);
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/* gap between mmap and stack */
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#define MIN_GAP (128*1024*1024UL)
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#define MAX_GAP ((TASK_SIZE)/6*5)
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static int mmap_is_legacy(void)
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{
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if (current->personality & ADDR_COMPAT_LAYOUT)
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return 1;
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if (rlimit(RLIMIT_STACK) == RLIM_INFINITY)
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return 1;
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return sysctl_legacy_va_layout;
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}
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static unsigned long mmap_base(unsigned long rnd)
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{
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unsigned long gap = rlimit(RLIMIT_STACK);
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if (gap < MIN_GAP)
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gap = MIN_GAP;
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else if (gap > MAX_GAP)
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gap = MAX_GAP;
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return PAGE_ALIGN(TASK_SIZE - gap - rnd);
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}
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#define COLOUR_ALIGN(addr, pgoff) \
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((((addr) + shm_align_mask) & ~shm_align_mask) + \
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(((pgoff) << PAGE_SHIFT) & shm_align_mask))
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enum mmap_allocation_direction {UP, DOWN};
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static unsigned long arch_get_unmapped_area_common(struct file *filp,
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unsigned long addr0, unsigned long len, unsigned long pgoff,
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unsigned long flags, enum mmap_allocation_direction dir)
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{
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struct mm_struct *mm = current->mm;
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struct vm_area_struct *vma;
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unsigned long addr = addr0;
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int do_color_align;
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struct vm_unmapped_area_info info;
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if (unlikely(len > TASK_SIZE))
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return -ENOMEM;
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if (flags & MAP_FIXED) {
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/* Even MAP_FIXED mappings must reside within TASK_SIZE */
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if (TASK_SIZE - len < addr)
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return -EINVAL;
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/*
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* We do not accept a shared mapping if it would violate
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* cache aliasing constraints.
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*/
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if ((flags & MAP_SHARED) &&
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((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
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return -EINVAL;
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return addr;
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}
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do_color_align = 0;
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if (filp || (flags & MAP_SHARED))
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do_color_align = 1;
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/* requesting a specific address */
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if (addr) {
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if (do_color_align)
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addr = COLOUR_ALIGN(addr, pgoff);
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else
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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return addr;
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}
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info.length = len;
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info.align_mask = do_color_align ? (PAGE_MASK & shm_align_mask) : 0;
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info.align_offset = pgoff << PAGE_SHIFT;
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if (dir == DOWN) {
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info.flags = VM_UNMAPPED_AREA_TOPDOWN;
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info.low_limit = PAGE_SIZE;
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info.high_limit = mm->mmap_base;
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addr = vm_unmapped_area(&info);
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if (!(addr & ~PAGE_MASK))
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return addr;
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/*
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* A failed mmap() very likely causes application failure,
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* so fall back to the bottom-up function here. This scenario
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* can happen with large stack limits and large mmap()
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* allocations.
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*/
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}
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info.flags = 0;
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info.low_limit = mm->mmap_base;
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info.high_limit = TASK_SIZE;
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return vm_unmapped_area(&info);
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}
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unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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return arch_get_unmapped_area_common(filp,
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addr0, len, pgoff, flags, UP);
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}
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/*
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* There is no need to export this but sched.h declares the function as
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* extern so making it static here results in an error.
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*/
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unsigned long arch_get_unmapped_area_topdown(struct file *filp,
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unsigned long addr0, unsigned long len, unsigned long pgoff,
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unsigned long flags)
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{
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return arch_get_unmapped_area_common(filp,
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addr0, len, pgoff, flags, DOWN);
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}
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unsigned long arch_mmap_rnd(void)
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{
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unsigned long rnd;
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rnd = get_random_long();
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rnd <<= PAGE_SHIFT;
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if (TASK_IS_32BIT_ADDR)
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rnd &= 0xfffffful;
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else
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rnd &= 0xffffffful;
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return rnd;
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}
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void arch_pick_mmap_layout(struct mm_struct *mm)
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{
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unsigned long random_factor = 0UL;
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if (current->flags & PF_RANDOMIZE)
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random_factor = arch_mmap_rnd();
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if (mmap_is_legacy()) {
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mm->mmap_base = TASK_UNMAPPED_BASE + random_factor;
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mm->get_unmapped_area = arch_get_unmapped_area;
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} else {
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mm->mmap_base = mmap_base(random_factor);
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mm->get_unmapped_area = arch_get_unmapped_area_topdown;
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}
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}
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static inline unsigned long brk_rnd(void)
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{
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unsigned long rnd = get_random_long();
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rnd = rnd << PAGE_SHIFT;
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/* 8MB for 32bit, 256MB for 64bit */
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if (TASK_IS_32BIT_ADDR)
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rnd = rnd & 0x7ffffful;
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else
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rnd = rnd & 0xffffffful;
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return rnd;
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}
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unsigned long arch_randomize_brk(struct mm_struct *mm)
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{
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unsigned long base = mm->brk;
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unsigned long ret;
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ret = PAGE_ALIGN(base + brk_rnd());
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if (ret < mm->brk)
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return mm->brk;
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return ret;
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}
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int __virt_addr_valid(const volatile void *kaddr)
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{
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return pfn_valid(PFN_DOWN(virt_to_phys(kaddr)));
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}
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EXPORT_SYMBOL_GPL(__virt_addr_valid);
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