summaryrefslogtreecommitdiff
path: root/arch/s390
diff options
context:
space:
mode:
authorSebastian Ott <sebott@linux.vnet.ibm.com>2013-04-16 16:17:15 +0400
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-04-17 16:07:38 +0400
commitb170bad40dab1a1684d629b37cb65a5281d35bd8 (patch)
tree40f24811118d28edda9a99b40599f59913f01615 /arch/s390
parentf0bacb7fc4f7defb15a6575d92f8ea4342f8f09e (diff)
downloadlinux-b170bad40dab1a1684d629b37cb65a5281d35bd8.tar.xz
s390/pci: do not read data after failed load
If a pci load instruction fails the content of the register where the data is stored is possibly unchanged. Fix the inline assembly wrapper __pcilg to not return stale data. Additionally fix the callers of this function who access uninitialized variables. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/pci_io.h4
-rw-r--r--arch/s390/pci/pci.c8
-rw-r--r--arch/s390/pci/pci_insn.c4
3 files changed, 11 insertions, 5 deletions
diff --git a/arch/s390/include/asm/pci_io.h b/arch/s390/include/asm/pci_io.h
index 0e0bec9a3fb7..83a9caa6ae53 100644
--- a/arch/s390/include/asm/pci_io.h
+++ b/arch/s390/include/asm/pci_io.h
@@ -92,6 +92,9 @@ static inline int zpci_read_single(u64 req, u64 *dst, u64 offset, u8 len)
int cc;
cc = s390pci_load(&data, req, offset);
+ if (cc)
+ goto out;
+
switch (len) {
case 1:
*((u8 *) dst) = (u8) data;
@@ -106,6 +109,7 @@ static inline int zpci_read_single(u64 req, u64 *dst, u64 offset, u8 len)
*((u64 *) dst) = (u64) data;
break;
}
+out:
return cc;
}
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 2b21749cc2b3..51d16f1fb5ea 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -281,11 +281,11 @@ static int zpci_cfg_load(struct zpci_dev *zdev, int offset, u32 *val, u8 len)
int rc;
rc = s390pci_load(&data, req, offset);
- data = data << ((8 - len) * 8);
- data = le64_to_cpu(data);
- if (!rc)
+ if (!rc) {
+ data = data << ((8 - len) * 8);
+ data = le64_to_cpu(data);
*val = (u32) data;
- else
+ } else
*val = 0xffffffff;
return rc;
}
diff --git a/arch/s390/pci/pci_insn.c b/arch/s390/pci/pci_insn.c
index 4bc32f368f7d..22eeb9d7ffeb 100644
--- a/arch/s390/pci/pci_insn.c
+++ b/arch/s390/pci/pci_insn.c
@@ -103,7 +103,9 @@ static inline int __pcilg(u64 *data, u64 req, u64 offset, u8 *status)
: "d" (__offset)
: "cc");
*status = __req >> 24 & 0xff;
- *data = __data;
+ if (!cc)
+ *data = __data;
+
return cc;
}