[S390] memory detection misses 128k.

From: Martin Schwidefsky
Date: Sun Jan 07 2007 - 05:44:27 EST


From: Hongjie Yang <hongjie@xxxxxxxxxx>

[S390] memory detection misses 128k.

Fix a memory leak problem in the memory detection routines. A memory leak
of 128k occurs when we have a contiguous memory with mixed access-mode
(read or write) ranges.

Signed-off-by: Hongjie Yang <hongjie@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---

arch/s390/kernel/head31.S | 12 +++++++++++-
arch/s390/kernel/head64.S | 12 +++++++++++-
2 files changed, 22 insertions(+), 2 deletions(-)

diff -urpN linux-2.6/arch/s390/kernel/head31.S linux-2.6-patched/arch/s390/kernel/head31.S
--- linux-2.6/arch/s390/kernel/head31.S 2007-01-06 15:20:00.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/head31.S 2007-01-06 15:20:27.000000000 +0100
@@ -164,11 +164,14 @@ startup_continue:
srl %r7,28
clr %r6,%r7 # compare cc with last access code
be .Lsame-.LPG1(%r13)
- b .Lchkmem-.LPG1(%r13)
+ lhi %r8,0 # no program checks
+ b .Lsavchk-.LPG1(%r13)
.Lsame:
ar %r5,%r1 # add 128KB to end of chunk
bno .Lloop-.LPG1(%r13) # r1 < 0x80000000 -> loop
.Lchkmem: # > 2GB or tprot got a program check
+ lhi %r8,1 # set program check flag
+.Lsavchk:
clr %r4,%r5 # chunk size > 0?
be .Lchkloop-.LPG1(%r13)
st %r4,0(%r3) # store start address of chunk
@@ -190,8 +193,15 @@ startup_continue:
je .Ldonemem # if not, leave
chi %r10,0 # do we have chunks left?
je .Ldonemem
+ chi %r8,1 # program check ?
+ je .Lpgmchk
+ lr %r4,%r5 # potential new chunk
+ alr %r5,%r1 # add 128KB to end of chunk
+ j .Llpcnt
+.Lpgmchk:
alr %r5,%r1 # add 128KB to end of chunk
lr %r4,%r5 # potential new chunk
+.Llpcnt:
clr %r5,%r9 # should we go on?
jl .Lloop
.Ldonemem:
diff -urpN linux-2.6/arch/s390/kernel/head64.S linux-2.6-patched/arch/s390/kernel/head64.S
--- linux-2.6/arch/s390/kernel/head64.S 2007-01-06 15:20:00.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/head64.S 2007-01-06 15:20:27.000000000 +0100
@@ -172,12 +172,15 @@ startup_continue:
srl %r7,28
clr %r6,%r7 # compare cc with last access code
je .Lsame
- j .Lchkmem
+ lghi %r8,0 # no program checks
+ j .Lsavchk
.Lsame:
algr %r5,%r1 # add 128KB to end of chunk
# no need to check here,
brc 12,.Lloop # this is the same chunk
.Lchkmem: # > 16EB or tprot got a program check
+ lghi %r8,1 # set program check flag
+.Lsavchk:
clgr %r4,%r5 # chunk size > 0?
je .Lchkloop
stg %r4,0(%r3) # store start address of chunk
@@ -204,8 +207,15 @@ startup_continue:
chi %r10, 0 # do we have chunks left?
je .Ldonemem
.Lhsaskip:
+ chi %r8,1 # program check ?
+ je .Lpgmchk
+ lgr %r4,%r5 # potential new chunk
+ algr %r5,%r1 # add 128KB to end of chunk
+ j .Llpcnt
+.Lpgmchk:
algr %r5,%r1 # add 128KB to end of chunk
lgr %r4,%r5 # potential new chunk
+.Llpcnt:
clgr %r5,%r9 # should we go on?
jl .Lloop
.Ldonemem:
-
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