amd64_edac: Fix incorrect wraparounds
dct_base and dct_limit obtain 32 bit register values when they read
their respective pci config space registers. A left shift beyond 32 bits
will cause them to wrap around. Similar case for chan_addr as can be
seen from the bug report (link below). In the patch, we rectify this by
casting chan_addr to u64 and by comparing dct_base and dct_limit against
properly shifted sys_addr in order to compare the correct bits.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Link: http://lkml.kernel.org/r/20130819132302.GA12171@elgon.mountain
Signed-off-by: Borislav Petkov <bp@suse.de>
diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index 6952d43..3c9e4e9 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1558,11 +1558,12 @@
}
/* Verify sys_addr is within DCT Range. */
- dct_base = (dct_sel_baseaddr(pvt) << 27);
- dct_limit = (((dct_cont_limit_reg >> 11) & 0x1FFF) << 27) | 0x7FFFFFF;
+ dct_base = (u64) dct_sel_baseaddr(pvt);
+ dct_limit = (dct_cont_limit_reg >> 11) & 0x1FFF;
if (!(dct_cont_base_reg & BIT(0)) &&
- !(dct_base <= sys_addr && dct_limit >= sys_addr))
+ !(dct_base <= (sys_addr >> 27) &&
+ dct_limit >= (sys_addr >> 27)))
return -EINVAL;
/* Verify number of dct's that participate in channel interleaving. */
@@ -1584,7 +1585,7 @@
if (leg_mmio_hole && (sys_addr >= BIT_64(32)))
chan_offset = dhar_offset;
else
- chan_offset = dct_base;
+ chan_offset = dct_base << 27;
chan_addr = sys_addr - chan_offset;
@@ -1614,7 +1615,7 @@
amd64_read_pci_cfg(pvt->F1,
DRAM_CONT_HIGH_OFF + (int) channel * 4,
&tmp);
- chan_addr += ((tmp >> 11) & 0xfff) << 27;
+ chan_addr += (u64) ((tmp >> 11) & 0xfff) << 27;
}
f15h_select_dct(pvt, channel);
