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Linux kernel mirror (for testing)
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kernel
os
linux
[S390] make page table upgrade work again
After TASK_SIZE now gives the current size of the address space the
upgrade of a 64 bit process from 3 to 4 levels of page table needs
to use the arch_mmap_check hook to catch large mmap lengths. The
get_unmapped_area* functions need to check for -ENOMEM from the
arch_get_unmapped_area*, upgrade the page table and retry.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
+35
-14
+5
arch/s390/include/asm/mman.h
+5
arch/s390/include/asm/mman.h
···
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#define MCL_CURRENT 1 /* lock all current mappings */
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#define MCL_FUTURE 2 /* lock all future mappings */
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+
#if defined(__KERNEL__) && !defined(__ASSEMBLY__) && defined(CONFIG_64BIT)
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int s390_mmap_check(unsigned long addr, unsigned long len);
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#define arch_mmap_check(addr,len,flags) s390_mmap_check(addr,len)
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#endif
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+
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#endif /* __S390_MMAN_H__ */
+30
-14
arch/s390/mm/mmap.c
+30
-14
arch/s390/mm/mmap.c
···
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#else
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int s390_mmap_check(unsigned long addr, unsigned long len)
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{
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if (!test_thread_flag(TIF_31BIT) &&
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len >= TASK_SIZE && TASK_SIZE < (1UL << 53))
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return crst_table_upgrade(current->mm, 1UL << 53);
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return 0;
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}
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+
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static unsigned long
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s390_get_unmapped_area(struct file *filp, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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unsigned long area;
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int rc;
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-
addr = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
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-
if (addr & ~PAGE_MASK)
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-
return addr;
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-
if (unlikely(mm->context.asce_limit < addr + len)) {
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-
rc = crst_table_upgrade(mm, addr + len);
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area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
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if (!(area & ~PAGE_MASK))
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return area;
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if (area == -ENOMEM &&
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!test_thread_flag(TIF_31BIT) && TASK_SIZE < (1UL << 53)) {
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/* Upgrade the page table to 4 levels and retry. */
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rc = crst_table_upgrade(mm, 1UL << 53);
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if (rc)
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return (unsigned long) rc;
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area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
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}
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-
return addr;
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return area;
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}
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static unsigned long
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-
s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
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s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
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const unsigned long len, const unsigned long pgoff,
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const unsigned long flags)
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{
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struct mm_struct *mm = current->mm;
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-
unsigned long addr = addr0;
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unsigned long area;
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int rc;
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addr = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
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if (addr & ~PAGE_MASK)
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return addr;
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-
if (unlikely(mm->context.asce_limit < addr + len)) {
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-
rc = crst_table_upgrade(mm, addr + len);
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area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
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if (!(area & ~PAGE_MASK))
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return area;
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if (area == -ENOMEM &&
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!test_thread_flag(TIF_31BIT) && TASK_SIZE < (1UL << 53)) {
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/* Upgrade the page table to 4 levels and retry. */
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rc = crst_table_upgrade(mm, 1UL << 53);
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if (rc)
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return (unsigned long) rc;
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area = arch_get_unmapped_area_topdown(filp, addr, len,
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pgoff, flags);
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}
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-
return addr;
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return area;
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}
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/*
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* This function, called very early during the creation of a new