| Message ID | 533EBD7D.6090403@monstr.eu (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Fri, Apr 4, 2014 at 9:11 AM, Michal Simek <monstr@monstr.eu> wrote: > On 04/04/2014 03:32 PM, Rob Herring wrote: >> On Fri, Apr 4, 2014 at 8:22 AM, Michal Simek <monstr@monstr.eu> wrote: >>> On 04/04/2014 03:00 PM, Rob Herring wrote: >>>> On Fri, Apr 4, 2014 at 7:16 AM, Michal Simek <monstr@monstr.eu> wrote: >>>>> On 04/04/2014 12:16 AM, Rob Herring wrote: >>>>>> From: Rob Herring <robh@kernel.org> >>>>>> >>>>>> Both powerpc and microblaze have the same FDT blob in debugfs feature. >>>>>> Move this to common location and remove the powerpc and microblaze >>>>>> implementations. This feature could become more useful when FDT >>>>>> overlay support is added. >>>> >>>> [snip] >> >>> Anyway I am testing it for microblaze and getting problem >>> caused by this patch: >>> commit 3d2ee8571ac0580d49c3f41fa28336289934900a >>> Author: Rob Herring <robh@kernel.org> >>> Date: Wed Apr 2 15:10:14 2014 -0500 >>> >>> of/fdt: Convert FDT functions to use libfdt >>> >>> And reason is that in unflatten_dt_node() >>> >>> pathp = fdt_get_name(blob, *poffset, &l); >>> >>> is returning NULL >>> and here >>> /* version 0x10 has a more compact unit name here instead of the full >>> * path. we accumulate the full path size using "fpsize", we'll rebuild >>> * it later. We detect this because the first character of the name is >>> * not '/'. >>> */ >>> if ((*pathp) != '/') { >>> >>> code is trying to read it which is causing this kernel bug: >>> Oops: kernel access of bad area, sig: 11 >>> >>> It means fdt_next_node(is doing something wrong) >>> >>> Any easy way how to debug it? >> >> I didn't think fdt_get_path should fail. Can you add a print of >> *poffset and pathp values. I think I've fixed this now and updated the branch. Please test again when you have a chance. Thanks, Rob
On 04/07/2014 02:42 AM, Rob Herring wrote: > On Fri, Apr 4, 2014 at 9:11 AM, Michal Simek <monstr@monstr.eu> wrote: >> On 04/04/2014 03:32 PM, Rob Herring wrote: >>> On Fri, Apr 4, 2014 at 8:22 AM, Michal Simek <monstr@monstr.eu> wrote: >>>> On 04/04/2014 03:00 PM, Rob Herring wrote: >>>>> On Fri, Apr 4, 2014 at 7:16 AM, Michal Simek <monstr@monstr.eu> wrote: >>>>>> On 04/04/2014 12:16 AM, Rob Herring wrote: >>>>>>> From: Rob Herring <robh@kernel.org> >>>>>>> >>>>>>> Both powerpc and microblaze have the same FDT blob in debugfs feature. >>>>>>> Move this to common location and remove the powerpc and microblaze >>>>>>> implementations. This feature could become more useful when FDT >>>>>>> overlay support is added. >>>>> >>>>> [snip] >>> >>>> Anyway I am testing it for microblaze and getting problem >>>> caused by this patch: >>>> commit 3d2ee8571ac0580d49c3f41fa28336289934900a >>>> Author: Rob Herring <robh@kernel.org> >>>> Date: Wed Apr 2 15:10:14 2014 -0500 >>>> >>>> of/fdt: Convert FDT functions to use libfdt >>>> >>>> And reason is that in unflatten_dt_node() >>>> >>>> pathp = fdt_get_name(blob, *poffset, &l); >>>> >>>> is returning NULL >>>> and here >>>> /* version 0x10 has a more compact unit name here instead of the full >>>> * path. we accumulate the full path size using "fpsize", we'll rebuild >>>> * it later. We detect this because the first character of the name is >>>> * not '/'. >>>> */ >>>> if ((*pathp) != '/') { >>>> >>>> code is trying to read it which is causing this kernel bug: >>>> Oops: kernel access of bad area, sig: 11 >>>> >>>> It means fdt_next_node(is doing something wrong) >>>> >>>> Any easy way how to debug it? >>> >>> I didn't think fdt_get_path should fail. Can you add a print of >>> *poffset and pathp values. > > I think I've fixed this now and updated the branch. Please test again > when you have a chance. yep. The updated branch works for Microblaze. Thanks, Michal
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index ee8853c..5422e4e 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -8,6 +8,7 @@ * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. */ +#define DEBUG #include <linux/kernel.h> #include <linux/initrd.h> @@ -116,9 +117,15 @@ static void * unflatten_dt_node(struct boot_param_header *blob, int has_name = 0; int new_format = 0; +printk("%s blob %x, %x %x\n", __func__, blob, poffset, *poffset); + pathp = fdt_get_name(blob, *poffset, &l); +printk("%s 1a %p/%s -- len %x\n", __func__, pathp, pathp ? pathp : "NULL", l); + allocl = l++; + if (!pathp) + while (1); /* version 0x10 has a more compact unit name here instead of the full * path. we accumulate the full path size using "fpsize", we'll rebuild * it later. We detect this because the first character of the name is @@ -267,7 +274,9 @@ static void * unflatten_dt_node(struct boot_param_header *blob, } old_depth = depth; +printk("%s 8 old offset %x\n", __func__, *poffset); *poffset = fdt_next_node(blob, *poffset, &depth); +printk("%s 8 new offset %x\n", __func__, *poffset); while (*poffset > 0 && depth > old_depth) { mem = unflatten_dt_node(blob, mem, poffset, np, allnextpp, fpsize);