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| author | Sebastian Ott <sebott@linux.vnet.ibm.com> | 2013-04-16 14:17:15 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2013-04-17 14:07:38 +0200 |
| commit | b170bad40dab1a1684d629b37cb65a5281d35bd8 (patch) | |
| tree | 40f24811118d28edda9a99b40599f59913f01615 /arch/s390 | |
| parent | s390/pci: add exception table to load/store instructions (diff) | |
| download | linux-b170bad40dab1a1684d629b37cb65a5281d35bd8.tar.xz linux-b170bad40dab1a1684d629b37cb65a5281d35bd8.zip | |
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.h | 4 | ||||
| -rw-r--r-- | arch/s390/pci/pci.c | 8 | ||||
| -rw-r--r-- | arch/s390/pci/pci_insn.c | 4 |
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; } |