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[PATCH] powerpc: More hugepage boundary case fixes 

Blah.  The patch [0] I recently sent fixing errors with
in_hugepage_area() and prepare_hugepage_range() for powerpc itself has
an off-by-one bug.  Furthermore, the related functions
touches_hugepage_*_range() and within_hugepage_*_range() are also
buggy.  Some of the bugs, like those addressed in [0] originated with
commit 7d24f0b8a5 where we tweaked the
semantics of where hugepages are allowed.  Other bugs have been there
essentially forever, and are due to the undefined behaviour of '<<'
with shift counts greater than the type width (LOW_ESID_MASK could
return non-zero for high ranges with the right congruences).

The good news is that I now have a testsuite which should pick up
things like this if they creep in again.

[0] "powerpc-fix-for-hugepage-areas-straddling-4gb-boundary"

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
David Gibson 2005-11-24 13:34:56 +11:00 committed by Paul Mackerras
parent 26925c5910
commit 9a94c5793a
2 changed files with 12 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/powerpc/mm/hugetlbpage.c
View File

@ -295,7 +295,7 @@ int prepare_hugepage_range(unsigned long addr, unsigned long len)
if (addr < 0x100000000UL)
err = open_low_hpage_areas(current->mm,
LOW_ESID_MASK(addr, len));
if ((addr + len) >= 0x100000000UL)
if ((addr + len) > 0x100000000UL)
err = open_high_hpage_areas(current->mm,
HTLB_AREA_MASK(addr, len));
if (err) {

17
include/asm-powerpc/page_64.h
View File

@ -103,8 +103,9 @@ extern unsigned int HPAGE_SHIFT;
#define HTLB_AREA_SIZE (1UL << HTLB_AREA_SHIFT)
#define GET_HTLB_AREA(x) ((x) >> HTLB_AREA_SHIFT)
#define LOW_ESID_MASK(addr, len) (((1U << (GET_ESID(addr+len-1)+1)) \
- (1U << GET_ESID(addr))) & 0xffff)
#define LOW_ESID_MASK(addr, len) \
(((1U << (GET_ESID(min((addr)+(len)-1, 0x100000000UL))+1)) \
- (1U << GET_ESID(min((addr), 0x100000000UL)))) & 0xffff)
#define HTLB_AREA_MASK(addr, len) (((1U << (GET_HTLB_AREA(addr+len-1)+1)) \
- (1U << GET_HTLB_AREA(addr))) & 0xffff)
@ -113,17 +114,21 @@ extern unsigned int HPAGE_SHIFT;
#define ARCH_HAS_SETCLEAR_HUGE_PTE
#define touches_hugepage_low_range(mm, addr, len) \
(LOW_ESID_MASK((addr), (len)) & (mm)->context.low_htlb_areas)
(((addr) < 0x100000000UL) \
&& (LOW_ESID_MASK((addr), (len)) & (mm)->context.low_htlb_areas))
#define touches_hugepage_high_range(mm, addr, len) \
(HTLB_AREA_MASK((addr), (len)) & (mm)->context.high_htlb_areas)
((((addr) + (len)) > 0x100000000UL) \
&& (HTLB_AREA_MASK((addr), (len)) & (mm)->context.high_htlb_areas))
#define __within_hugepage_low_range(addr, len, segmask) \
((LOW_ESID_MASK((addr), (len)) | (segmask)) == (segmask))
( (((addr)+(len)) <= 0x100000000UL) \
&& ((LOW_ESID_MASK((addr), (len)) | (segmask)) == (segmask)))
#define within_hugepage_low_range(addr, len) \
__within_hugepage_low_range((addr), (len), \
current->mm->context.low_htlb_areas)
#define __within_hugepage_high_range(addr, len, zonemask) \
((HTLB_AREA_MASK((addr), (len)) | (zonemask)) == (zonemask))
( ((addr) >= 0x100000000UL) \
&& ((HTLB_AREA_MASK((addr), (len)) | (zonemask)) == (zonemask)))
#define within_hugepage_high_range(addr, len) \
__within_hugepage_high_range((addr), (len), \
current->mm->context.high_htlb_areas)