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[S390] make page table upgrade work again

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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>
This commit is contained in:
Martin Schwidefsky 2009-03-18 13:27:37 +01:00
parent f481bfafd3
commit 0fb1d9bcbc
2 changed files with 35 additions and 14 deletions
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5
arch/s390/include/asm/mman.h
View File

@ -22,4 +22,9 @@
#define MCL_CURRENT 1 /* lock all current mappings */
#define MCL_FUTURE 2 /* lock all future mappings */
#if defined(__KERNEL__) && !defined(__ASSEMBLY__) && defined(CONFIG_64BIT)
int s390_mmap_check(unsigned long addr, unsigned long len);
#define arch_mmap_check(addr,len,flags) s390_mmap_check(addr,len)
#endif
#endif /* __S390_MMAN_H__ */

44
arch/s390/mm/mmap.c
View File

@ -89,42 +89,58 @@ EXPORT_SYMBOL_GPL(arch_pick_mmap_layout);
#else
int s390_mmap_check(unsigned long addr, unsigned long len)
{
if (!test_thread_flag(TIF_31BIT) &&
len >= TASK_SIZE && TASK_SIZE < (1UL << 53))
return crst_table_upgrade(current->mm, 1UL << 53);
return 0;
}
static unsigned long
s390_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct mm_struct *mm = current->mm;
unsigned long area;
int rc;
addr = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
if (addr & ~PAGE_MASK)
return addr;
if (unlikely(mm->context.asce_limit < addr + len)) {
rc = crst_table_upgrade(mm, addr + len);
area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
if (!(area & ~PAGE_MASK))
return area;
if (area == -ENOMEM &&
!test_thread_flag(TIF_31BIT) && TASK_SIZE < (1UL << 53)) {
/* Upgrade the page table to 4 levels and retry. */
rc = crst_table_upgrade(mm, 1UL << 53);
if (rc)
return (unsigned long) rc;
area = arch_get_unmapped_area(filp, addr, len, pgoff, flags);
}
return addr;
return area;
}
static unsigned long
s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
s390_get_unmapped_area_topdown(struct file *filp, const unsigned long addr,
const unsigned long len, const unsigned long pgoff,
const unsigned long flags)
{
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
unsigned long area;
int rc;
addr = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
if (addr & ~PAGE_MASK)
return addr;
if (unlikely(mm->context.asce_limit < addr + len)) {
rc = crst_table_upgrade(mm, addr + len);
area = arch_get_unmapped_area_topdown(filp, addr, len, pgoff, flags);
if (!(area & ~PAGE_MASK))
return area;
if (area == -ENOMEM &&
!test_thread_flag(TIF_31BIT) && TASK_SIZE < (1UL << 53)) {
/* Upgrade the page table to 4 levels and retry. */
rc = crst_table_upgrade(mm, 1UL << 53);
if (rc)
return (unsigned long) rc;
area = arch_get_unmapped_area_topdown(filp, addr, len,
pgoff, flags);
}
return addr;
return area;
}
/*
* This function, called very early during the creation of a new