diff options
author | Zhang, Yanmin <yanmin_zhang@linux.intel.com> | 2006-03-22 03:08:50 -0500 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-22 10:54:03 -0500 |
commit | 8f860591ffb29738cf5539b6fbf27f50dcdeb380 (patch) | |
tree | 4265e45c4a79d86a16cd5175a836e8c531be8117 /mm/mprotect.c | |
parent | aed75ff3caafce404d9be7f0c088716375be5279 (diff) |
[PATCH] Enable mprotect on huge pages
2.6.16-rc3 uses hugetlb on-demand paging, but it doesn_t support hugetlb
mprotect.
From: David Gibson <david@gibson.dropbear.id.au>
Remove a test from the mprotect() path which checks that the mprotect()ed
range on a hugepage VMA is hugepage aligned (yes, really, the sense of
is_aligned_hugepage_range() is the opposite of what you'd guess :-/).
In fact, we don't need this test. If the given addresses match the
beginning/end of a hugepage VMA they must already be suitably aligned. If
they don't, then mprotect_fixup() will attempt to split the VMA. The very
first test in split_vma() will check for a badly aligned address on a
hugepage VMA and return -EINVAL if necessary.
From: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
On i386 and x86-64, pte flag _PAGE_PSE collides with _PAGE_PROTNONE. The
identify of hugetlb pte is lost when changing page protection via mprotect.
A page fault occurs later will trigger a bug check in huge_pte_alloc().
The fix is to always make new pte a hugetlb pte and also to clean up
legacy code where _PAGE_PRESENT is forced on in the pre-faulting day.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm/mprotect.c')
-rw-r--r-- | mm/mprotect.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/mm/mprotect.c b/mm/mprotect.c index 653b8571c1e..4c14d4289b6 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c | |||
@@ -124,7 +124,7 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, | |||
124 | * a MAP_NORESERVE private mapping to writable will now reserve. | 124 | * a MAP_NORESERVE private mapping to writable will now reserve. |
125 | */ | 125 | */ |
126 | if (newflags & VM_WRITE) { | 126 | if (newflags & VM_WRITE) { |
127 | if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) { | 127 | if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED))) { |
128 | charged = nrpages; | 128 | charged = nrpages; |
129 | if (security_vm_enough_memory(charged)) | 129 | if (security_vm_enough_memory(charged)) |
130 | return -ENOMEM; | 130 | return -ENOMEM; |
@@ -166,7 +166,10 @@ success: | |||
166 | */ | 166 | */ |
167 | vma->vm_flags = newflags; | 167 | vma->vm_flags = newflags; |
168 | vma->vm_page_prot = newprot; | 168 | vma->vm_page_prot = newprot; |
169 | change_protection(vma, start, end, newprot); | 169 | if (is_vm_hugetlb_page(vma)) |
170 | hugetlb_change_protection(vma, start, end, newprot); | ||
171 | else | ||
172 | change_protection(vma, start, end, newprot); | ||
170 | vm_stat_account(mm, oldflags, vma->vm_file, -nrpages); | 173 | vm_stat_account(mm, oldflags, vma->vm_file, -nrpages); |
171 | vm_stat_account(mm, newflags, vma->vm_file, nrpages); | 174 | vm_stat_account(mm, newflags, vma->vm_file, nrpages); |
172 | return 0; | 175 | return 0; |
@@ -240,11 +243,6 @@ sys_mprotect(unsigned long start, size_t len, unsigned long prot) | |||
240 | 243 | ||
241 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ | 244 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ |
242 | 245 | ||
243 | if (is_vm_hugetlb_page(vma)) { | ||
244 | error = -EACCES; | ||
245 | goto out; | ||
246 | } | ||
247 | |||
248 | newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); | 246 | newflags = vm_flags | (vma->vm_flags & ~(VM_READ | VM_WRITE | VM_EXEC)); |
249 | 247 | ||
250 | /* newflags >> 4 shift VM_MAY% in place of VM_% */ | 248 | /* newflags >> 4 shift VM_MAY% in place of VM_% */ |