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[S390] missing sacf in uaccess

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The uaccess functions copy_in_user_std and clear_user_std fail to
switch back from secondary space mode to primary space mode with sacf
in case of an unresolvable page fault. We need to make sure that the
switch back to primary mode is done in all cases, otherwise the code
following the uaccess inline assembly will crash.

Reported-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2011-01-31 11:30:05 +01:00 committed by Martin Schwidefsky
parent f1be77bb21
commit e4d82692f4
1 changed files with 4 additions and 6 deletions
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10
arch/s390/lib/uaccess_std.c
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@ -125,9 +125,9 @@ static size_t copy_in_user_std(size_t size, void __user *to,
unsigned long tmp1;
asm volatile(
" sacf 256\n"
" "AHI" %0,-1\n"
" jo 5f\n"
" sacf 256\n"
" bras %3,3f\n"
"0:"AHI" %0,257\n"
"1: mvc 0(1,%1),0(%2)\n"
@ -142,9 +142,8 @@ static size_t copy_in_user_std(size_t size, void __user *to,
"3:"AHI" %0,-256\n"
" jnm 2b\n"
"4: ex %0,1b-0b(%3)\n"
" sacf 0\n"
"5: "SLR" %0,%0\n"
"6:\n"
"6: sacf 0\n"
EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
: "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
: : "cc", "memory");
@ -156,9 +155,9 @@ static size_t clear_user_std(size_t size, void __user *to)
unsigned long tmp1, tmp2;
asm volatile(
" sacf 256\n"
" "AHI" %0,-1\n"
" jo 5f\n"
" sacf 256\n"
" bras %3,3f\n"
" xc 0(1,%1),0(%1)\n"
"0:"AHI" %0,257\n"
@ -178,9 +177,8 @@ static size_t clear_user_std(size_t size, void __user *to)
"3:"AHI" %0,-256\n"
" jnm 2b\n"
"4: ex %0,0(%3)\n"
" sacf 0\n"
"5: "SLR" %0,%0\n"
"6:\n"
"6: sacf 0\n"
EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
: "+a" (size), "+a" (to), "=a" (tmp1), "=a" (tmp2)
: : "cc", "memory");