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authorHeiko Carstens <heiko.carstens@de.ibm.com>2012-06-05 09:59:52 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-06-14 09:09:02 +0200
commitfbe765680d1fe9d08187ea4dad5041a7955a2c3a (patch)
treecfa5ba11106bb5535552cf6b29ff6aa81f32c606 /arch/s390/include
parent72f6e3a8bc956fddf6e004ae9b804977d1458e77 (diff)
s390/smp: make absolute lowcore / cpu restart parameter accesses more robust
Setting the cpu restart parameters is done in three different fashions: - directly setting the four parameters individually - copying the four parameters with memcpy (using 4 * sizeof(long)) - copying the four parameters using a private structure In addition code in entry*.S relies on a certain order of the restart members of struct _lowcore. Make all of this more robust to future changes by adding a mem_absolute_assign(dest, val) define, which assigns val to dest using absolute addressing mode. Also the load multiple instructions in entry*.S have been split into separate load instruction so the order of the struct _lowcore members doesn't matter anymore. In addition move the prototypes of memcpy_real/absolute from uaccess.h to processor.h. These memcpy* variants are not related to uaccess at all. string.h doesn't seem to match as well, so lets use processor.h. Also replace the eight byte array in struct _lowcore which represents a misaliged u64 with a u64. The compiler will always create code that handles the misaligned u64 correctly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include')
-rw-r--r--arch/s390/include/asm/lowcore.h7
-rw-r--r--arch/s390/include/asm/processor.h10
-rw-r--r--arch/s390/include/asm/uaccess.h2
3 files changed, 11 insertions, 8 deletions
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
index 47853debb3b..a47c6e221a9 100644
--- a/arch/s390/include/asm/lowcore.h
+++ b/arch/s390/include/asm/lowcore.h
@@ -302,12 +302,7 @@ struct _lowcore {
*/
__u64 ipib; /* 0x0e00 */
__u32 ipib_checksum; /* 0x0e08 */
- /*
- * Because the vmcore_info pointer is not 8 byte aligned it never
- * should not be accessed directly. For accessing the pointer, first
- * copy it to a local pointer variable.
- */
- __u8 vmcore_info[8]; /* 0x0e0c */
+ __u64 vmcore_info; /* 0x0e0c */
__u8 pad_0x0e14[0x0e18-0x0e14]; /* 0x0e14 */
__u64 os_info; /* 0x0e18 */
__u8 pad_0x0e20[0x0f00-0x0e20]; /* 0x0e20 */
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 20d0585cf90..f1700c5c888 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -348,4 +348,14 @@ extern void (*s390_base_ext_handler_fn)(void);
".previous\n"
#endif
+extern int memcpy_real(void *, void *, size_t);
+extern void memcpy_absolute(void *, void *, size_t);
+
+#define mem_assign_absolute(dest, val) { \
+ __typeof__(dest) __tmp = (val); \
+ \
+ BUILD_BUG_ON(sizeof(__tmp) != sizeof(val)); \
+ memcpy_absolute(&(dest), &__tmp, sizeof(__tmp)); \
+}
+
#endif /* __ASM_S390_PROCESSOR_H */
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 1f3a79bcd26..7e7285179aa 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -381,8 +381,6 @@ clear_user(void __user *to, unsigned long n)
return n;
}
-extern int memcpy_real(void *, void *, size_t);
-extern void memcpy_absolute(void *, void *, size_t);
extern int copy_to_user_real(void __user *dest, void *src, size_t count);
extern int copy_from_user_real(void *dest, void __user *src, size_t count);