Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
powerpc/mm: Use generic_get_unmapped_area() and call it from arch_get_unmapped_area()
Use the generic version of arch_get_unmapped_area() which
is now available at all time instead of its copy
radix__arch_get_unmapped_area()
To allow that for PPC64, add arch_get_mmap_base() and
arch_get_mmap_end() macros.
Instead of setting mm->get_unmapped_area() to either
arch_get_unmapped_area() or generic_get_unmapped_area(),
always set it to arch_get_unmapped_area() and call
generic_get_unmapped_area() from there when radix is enabled.
Do the same with radix__arch_get_unmapped_area_topdown()
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/393be1fa386446443682fdb74544d733f68ef3bb.1649523076.git.christophe.leroy@csgroup.eu
authored by
Christophe Leroy
and committed by
Michael Ellerman
76a345ed
f693d38d
+14
-121
+8
arch/powerpc/include/asm/task_size_64.h
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arch/powerpc/include/asm/task_size_64.h
···
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#define STACK_TOP_MAX TASK_SIZE_USER64
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#define STACK_TOP (is_32bit_task() ? STACK_TOP_USER32 : STACK_TOP_USER64)
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#define arch_get_mmap_base(addr, base) \
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(((addr) > DEFAULT_MAP_WINDOW) ? (base) + TASK_SIZE - DEFAULT_MAP_WINDOW : (base))
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#define arch_get_mmap_end(addr, len, flags) \
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(((addr) > DEFAULT_MAP_WINDOW) || \
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(((flags) & MAP_FIXED) && ((addr) + (len) > DEFAULT_MAP_WINDOW)) ? TASK_SIZE : \
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DEFAULT_MAP_WINDOW)
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#endif /* _ASM_POWERPC_TASK_SIZE_64_H */
+6
-121
arch/powerpc/mm/mmap.c
+6
-121
arch/powerpc/mm/mmap.c
···
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}
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#ifdef HAVE_ARCH_UNMAPPED_AREA
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#ifdef CONFIG_PPC_RADIX_MMU
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/*
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* Same function as generic code used only for radix, because we don't need to overload
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* the generic one. But we will have to duplicate, because hash select
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* HAVE_ARCH_UNMAPPED_AREA
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*/
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static unsigned long
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radix__arch_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff,
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unsigned long flags)
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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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int fixed = (flags & MAP_FIXED);
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unsigned long high_limit;
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struct vm_unmapped_area_info info;
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high_limit = DEFAULT_MAP_WINDOW;
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if (addr >= high_limit || (fixed && (addr + len > high_limit)))
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high_limit = TASK_SIZE;
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if (len > high_limit)
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return -ENOMEM;
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if (fixed) {
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if (addr > high_limit - len)
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return -ENOMEM;
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return addr;
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}
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if (addr) {
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (high_limit - len >= addr && addr >= mmap_min_addr &&
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(!vma || addr + len <= vm_start_gap(vma)))
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return addr;
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}
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info.flags = 0;
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info.length = len;
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info.low_limit = mm->mmap_base;
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info.high_limit = high_limit;
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info.align_mask = 0;
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return vm_unmapped_area(&info);
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}
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static unsigned long
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radix__arch_get_unmapped_area_topdown(struct file *filp,
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const unsigned long addr0,
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const unsigned long len,
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const unsigned long pgoff,
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const unsigned long flags)
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{
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struct vm_area_struct *vma;
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struct mm_struct *mm = current->mm;
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unsigned long addr = addr0;
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int fixed = (flags & MAP_FIXED);
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unsigned long high_limit;
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struct vm_unmapped_area_info info;
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high_limit = DEFAULT_MAP_WINDOW;
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if (addr >= high_limit || (fixed && (addr + len > high_limit)))
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high_limit = TASK_SIZE;
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if (len > high_limit)
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return -ENOMEM;
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if (fixed) {
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if (addr > high_limit - len)
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return -ENOMEM;
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return addr;
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}
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if (addr) {
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addr = PAGE_ALIGN(addr);
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vma = find_vma(mm, addr);
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if (high_limit - len >= addr && addr >= mmap_min_addr &&
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(!vma || addr + len <= vm_start_gap(vma)))
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return addr;
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}
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info.flags = VM_UNMAPPED_AREA_TOPDOWN;
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info.length = len;
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info.low_limit = max(PAGE_SIZE, mmap_min_addr);
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info.high_limit = mm->mmap_base + (high_limit - DEFAULT_MAP_WINDOW);
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info.align_mask = 0;
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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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VM_BUG_ON(addr != -ENOMEM);
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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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return radix__arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
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}
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#endif
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unsigned long arch_get_unmapped_area(struct file *filp,
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unsigned long addr,
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unsigned long len,
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unsigned long pgoff,
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unsigned long flags)
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{
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if (radix_enabled())
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return generic_get_unmapped_area(filp, addr, len, pgoff, flags);
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#ifdef CONFIG_PPC_64S_HASH_MMU
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return slice_get_unmapped_area(addr, len, flags,
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mm_ctx_user_psize(¤t->mm->context), 0);
···
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const unsigned long pgoff,
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const unsigned long flags)
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{
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if (radix_enabled())
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return generic_get_unmapped_area_topdown(filp, addr0, len, pgoff, flags);
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#ifdef CONFIG_PPC_64S_HASH_MMU
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return slice_get_unmapped_area(addr0, len, flags,
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mm_ctx_user_psize(¤t->mm->context), 1);
···
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#endif
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}
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#endif /* HAVE_ARCH_UNMAPPED_AREA */
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static void radix__arch_pick_mmap_layout(struct mm_struct *mm,
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unsigned long random_factor,
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struct rlimit *rlim_stack)
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{
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#ifdef CONFIG_PPC_RADIX_MMU
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if (mmap_is_legacy(rlim_stack)) {
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mm->mmap_base = TASK_UNMAPPED_BASE;
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mm->get_unmapped_area = radix__arch_get_unmapped_area;
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} else {
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mm->mmap_base = mmap_base(random_factor, rlim_stack);
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mm->get_unmapped_area = radix__arch_get_unmapped_area_topdown;
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}
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#endif
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}
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/*
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* This function, called very early during the creation of a new
···
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if (current->flags & PF_RANDOMIZE)
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random_factor = arch_mmap_rnd();
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if (radix_enabled())
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return radix__arch_pick_mmap_layout(mm, random_factor,
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rlim_stack);
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/*
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* Fall back to the standard layout if the personality
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* bit is set, or if the expected stack growth is unlimited: