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authorGerald Schaefer <gerald.schaefer@de.ibm.com>2009-10-06 10:34:14 +0200
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>2009-10-06 10:35:10 +0200
commitaf9d2ff9afaae8040dbf09238b2579f92c93579e (patch)
tree61ceddb80062cae529b9c5a34cdf7a07566f1a30
parentea2a4d3a3a929ef494952bba57a0ef1a8a877881 (diff)
[S390] Add EX_TABLE for addressing exception in usercopy functions.
This patch adds an EX_TABLE entry to mvc{p|s|os} usercopy functions that may be called with KERNEL_DS. In combination with collaborative memory management, kernel pages marked as unused may trigger an adressing exception in the usercopy functions. This fixes an unhandled addressing exception bug where strncpy_from_user() is used with len > strnlen and KERNEL_DS, crossing a page boundary to an unused page. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/lib/uaccess_mvcos.c12
-rw-r--r--arch/s390/lib/uaccess_std.c14
2 files changed, 14 insertions, 12 deletions
diff --git a/arch/s390/lib/uaccess_mvcos.c b/arch/s390/lib/uaccess_mvcos.c
index 3f15aaf5485..58da3f46121 100644
--- a/arch/s390/lib/uaccess_mvcos.c
+++ b/arch/s390/lib/uaccess_mvcos.c
@@ -36,7 +36,7 @@ static size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
tmp1 = -4096UL;
asm volatile(
"0: .insn ss,0xc80000000000,0(%0,%2),0(%1),0\n"
- " jz 7f\n"
+ "9: jz 7f\n"
"1:"ALR" %0,%3\n"
" "SLR" %1,%3\n"
" "SLR" %2,%3\n"
@@ -47,7 +47,7 @@ static size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
" "CLR" %0,%4\n" /* copy crosses next page boundary? */
" jnh 4f\n"
"3: .insn ss,0xc80000000000,0(%4,%2),0(%1),0\n"
- " "SLR" %0,%4\n"
+ "10:"SLR" %0,%4\n"
" "ALR" %2,%4\n"
"4:"LHI" %4,-1\n"
" "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
@@ -61,7 +61,7 @@ static size_t copy_from_user_mvcos(size_t size, const void __user *ptr, void *x)
" j 8f\n"
"7:"SLR" %0,%0\n"
"8: \n"
- EX_TABLE(0b,2b) EX_TABLE(3b,4b)
+ EX_TABLE(0b,2b) EX_TABLE(3b,4b) EX_TABLE(9b,2b) EX_TABLE(10b,4b)
: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: "d" (reg0) : "cc", "memory");
return size;
@@ -82,7 +82,7 @@ static size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
tmp1 = -4096UL;
asm volatile(
"0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
- " jz 4f\n"
+ "6: jz 4f\n"
"1:"ALR" %0,%3\n"
" "SLR" %1,%3\n"
" "SLR" %2,%3\n"
@@ -93,11 +93,11 @@ static size_t copy_to_user_mvcos(size_t size, void __user *ptr, const void *x)
" "CLR" %0,%4\n" /* copy crosses next page boundary? */
" jnh 5f\n"
"3: .insn ss,0xc80000000000,0(%4,%1),0(%2),0\n"
- " "SLR" %0,%4\n"
+ "7:"SLR" %0,%4\n"
" j 5f\n"
"4:"SLR" %0,%0\n"
"5: \n"
- EX_TABLE(0b,2b) EX_TABLE(3b,5b)
+ EX_TABLE(0b,2b) EX_TABLE(3b,5b) EX_TABLE(6b,2b) EX_TABLE(7b,5b)
: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: "d" (reg0) : "cc", "memory");
return size;
diff --git a/arch/s390/lib/uaccess_std.c b/arch/s390/lib/uaccess_std.c
index d2ffbadb51a..07deaeee14c 100644
--- a/arch/s390/lib/uaccess_std.c
+++ b/arch/s390/lib/uaccess_std.c
@@ -36,12 +36,12 @@ size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
tmp1 = -256UL;
asm volatile(
"0: mvcp 0(%0,%2),0(%1),%3\n"
- " jz 8f\n"
+ "10:jz 8f\n"
"1:"ALR" %0,%3\n"
" la %1,256(%1)\n"
" la %2,256(%2)\n"
"2: mvcp 0(%0,%2),0(%1),%3\n"
- " jnz 1b\n"
+ "11:jnz 1b\n"
" j 8f\n"
"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
" "LHI" %3,-4096\n"
@@ -50,7 +50,7 @@ size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
" "CLR" %0,%4\n" /* copy crosses next page boundary? */
" jnh 5f\n"
"4: mvcp 0(%4,%2),0(%1),%3\n"
- " "SLR" %0,%4\n"
+ "12:"SLR" %0,%4\n"
" "ALR" %2,%4\n"
"5:"LHI" %4,-1\n"
" "ALR" %4,%0\n" /* copy remaining size, subtract 1 */
@@ -65,6 +65,7 @@ size_t copy_from_user_std(size_t size, const void __user *ptr, void *x)
"8:"SLR" %0,%0\n"
"9: \n"
EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,5b)
+ EX_TABLE(10b,3b) EX_TABLE(11b,3b) EX_TABLE(12b,5b)
: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: : "cc", "memory");
return size;
@@ -85,12 +86,12 @@ size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
tmp1 = -256UL;
asm volatile(
"0: mvcs 0(%0,%1),0(%2),%3\n"
- " jz 5f\n"
+ "7: jz 5f\n"
"1:"ALR" %0,%3\n"
" la %1,256(%1)\n"
" la %2,256(%2)\n"
"2: mvcs 0(%0,%1),0(%2),%3\n"
- " jnz 1b\n"
+ "8: jnz 1b\n"
" j 5f\n"
"3: la %4,255(%1)\n" /* %4 = ptr + 255 */
" "LHI" %3,-4096\n"
@@ -99,11 +100,12 @@ size_t copy_to_user_std(size_t size, void __user *ptr, const void *x)
" "CLR" %0,%4\n" /* copy crosses next page boundary? */
" jnh 6f\n"
"4: mvcs 0(%4,%1),0(%2),%3\n"
- " "SLR" %0,%4\n"
+ "9:"SLR" %0,%4\n"
" j 6f\n"
"5:"SLR" %0,%0\n"
"6: \n"
EX_TABLE(0b,3b) EX_TABLE(2b,3b) EX_TABLE(4b,6b)
+ EX_TABLE(7b,3b) EX_TABLE(8b,3b) EX_TABLE(9b,6b)
: "+a" (size), "+a" (ptr), "+a" (x), "+a" (tmp1), "=a" (tmp2)
: : "cc", "memory");
return size;