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    SubjectRe: [patch v3] edac i5000, i5400: fix pointer math in i5000_get_mc_regs()


    Am 06.03.2012 07:38, schrieb Dan Carpenter:
    > "pvt->ambase" is a u64 datatype. The intent here is to fill the first
    > half in the first call to pci_read_config_dword() and the other half in
    > the second. Unfortunately the pointer math is wrong so we set the wrong
    > data.
    >
    > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
    > ---
    > v2: Redid it as with a union as Walter Harms suggested.
    > Fixed the same bug in i5400_edac.c as well.
    > v3: Make the struct __packed just in case.
    >
    > I don't have this hardware, so please review carefully.
    >
    > diff --git a/drivers/edac/i5400_edac.c b/drivers/edac/i5400_edac.c
    > index 74d6ec34..083e80a 100644
    > --- a/drivers/edac/i5400_edac.c
    > +++ b/drivers/edac/i5400_edac.c
    > @@ -343,7 +343,13 @@ struct i5400_pvt {
    > struct pci_dev *branch_1; /* 22.0 */
    >
    > u16 tolm; /* top of low memory */
    > - u64 ambase; /* AMB BAR */
    > + union {
    > + u64 ambase; /* AMB BAR */
    > + struct {
    > + u32 ambase_bottom;
    > + u32 ambase_top;
    > + } u __packed;
    > + };
    >
    > u16 mir0, mir1;
    >
    > @@ -1024,9 +1030,9 @@ static void i5400_get_mc_regs(struct mem_ctl_info *mci)
    > pvt = mci->pvt_info;
    >
    > pci_read_config_dword(pvt->system_address, AMBASE,
    > - (u32 *) &pvt->ambase);
    > + &pvt->u.ambase_bottom);
    > pci_read_config_dword(pvt->system_address, AMBASE + sizeof(u32),
    > - ((u32 *) &pvt->ambase) + sizeof(u32));
    > + &pvt->u.ambase_top);
    >
    > maxdimmperch = pvt->maxdimmperch;
    > maxch = pvt->maxch;
    > diff --git a/drivers/edac/i5000_edac.c b/drivers/edac/i5000_edac.c
    > index 4dc3ac2..ecc2401 100644
    > --- a/drivers/edac/i5000_edac.c
    > +++ b/drivers/edac/i5000_edac.c
    > @@ -343,7 +343,13 @@ struct i5000_pvt {
    > struct pci_dev *branch_1; /* 22.0 */
    >
    > u16 tolm; /* top of low memory */
    > - u64 ambase; /* AMB BAR */
    > + union {
    > + u64 ambase; /* AMB BAR */
    > + struct {
    > + u32 ambase_bottom;
    > + u32 ambase_top;
    > + } u __packed;
    > + };
    >
    > u16 mir0, mir1, mir2;
    >
    > @@ -1128,9 +1134,9 @@ static void i5000_get_mc_regs(struct mem_ctl_info *mci)
    > pvt = mci->pvt_info;
    >
    > pci_read_config_dword(pvt->system_address, AMBASE,
    > - (u32 *) & pvt->ambase);
    > + &pvt->u.ambase_bottom);
    > pci_read_config_dword(pvt->system_address, AMBASE + sizeof(u32),
    > - ((u32 *) & pvt->ambase) + sizeof(u32));
    > + &pvt->u.ambase_top);
    >
    > maxdimmperch = pvt->maxdimmperch;
    > maxch = pvt->maxch;
    >

    nice work dan,
    i can not find anything to worry about.


    Acked-by: walter harms <wharms@bfs.de>



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