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| author | Gerald Schaefer <gerald.schaefer@de.ibm.com> | 2009-10-06 10:34:14 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2009-10-06 10:35:10 +0200 |
| commit | af9d2ff9afaae8040dbf09238b2579f92c93579e (patch) | |
| tree | 61ceddb80062cae529b9c5a34cdf7a07566f1a30 /arch/s390/lib/uaccess_std.c | |
| parent | ea2a4d3a3a929ef494952bba57a0ef1a8a877881 (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>
Diffstat (limited to 'arch/s390/lib/uaccess_std.c')
| -rw-r--r-- | arch/s390/lib/uaccess_std.c | 14 |
1 files changed, 8 insertions, 6 deletions
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; |