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Commit b170bad4 authored by Sebastian Ott's avatar Sebastian Ott Committed by Martin Schwidefsky
Browse files

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: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent f0bacb7f

arch/s390/include/asm/pci_io.h

+4 −0
Original line number Diff line number Diff line
@@ -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;

}

arch/s390/pci/pci.c

+4 −4
Original line number Diff line number Diff line
@@ -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);

	if (!rc) {

		data = data << ((8 - len) * 8);

		data = le64_to_cpu(data);

	if (!rc)

		*val = (u32) data;

	else

	} else

		*val = 0xffffffff;

	return rc;

}

arch/s390/pci/pci_insn.c

+3 −1
Original line number Diff line number Diff line
@@ -103,7 +103,9 @@ static inline int __pcilg(u64 *data, u64 req, u64 offset, u8 *status) 
		:  "d" (__offset)

		: "cc");

	*status = __req >> 24 & 0xff;

	if (!cc)

		*data = __data;



	return cc;

}