Messages in this thread Patch in this message | | | Date | Fri, 04 Apr 2014 16:11:09 +0200 | From | Michal Simek <> | Subject | Re: [PATCH 09/20] of/fdt: create common debugfs |
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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.
Early console on uart16650 at 0x40401000 bootconsole [earlyser0] enabled Ramdisk addr 0x00000000, FDT at 0x806b96d4 Linux version 3.14.0-rc8-next-20140331-12541-g43b5fdb-dirty (monstr@monstr-desktop) (gcc version 4.6.4 20120924 (prerelease) (crosstool-NG 1.18.0) ) #51 Fri Apr 4 16:09:17 CEST 2014 -> unflatten_device_tree() Unflattening device tree: magic: d00dfeed size: 00014e20 version: 00000011 unflatten_dt_node blob c0298b00, c0331f84 0 unflatten_dt_node 1a c0298b3c/ -- len 0 unflatten_dt_node 8 old offset 0 unflatten_dt_node 8 new offset 6c unflatten_dt_node blob c0298b00, c0331f84 6c unflatten_dt_node 1a c0298ba8/aliases -- len 7 unflatten_dt_node 8 old offset 6c unflatten_dt_node 8 new offset cc unflatten_dt_node blob c0298b00, c0331f84 cc unflatten_dt_node 1a c0298c08/chosen -- len 6 unflatten_dt_node 8 old offset cc unflatten_dt_node 8 new offset 130 unflatten_dt_node blob c0298b00, c0331f84 130 unflatten_dt_node 1a c0298c6c/cpus -- len 4 unflatten_dt_node 8 old offset 130 unflatten_dt_node 8 new offset 16c unflatten_dt_node blob c0298b00, c0331f84 16c unflatten_dt_node 1a c0298ca8/cpu@0 -- len 5 unflatten_dt_node 8 old offset 16c unflatten_dt_node 8 new offset 7bc unflatten_dt_node blob c0298b00, c0331f84 7bc unflatten_dt_node 1a (null)/NULL -- len fffffffc
Below is the possition of debug messages.
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);
-- Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91 w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/ Maintainer of Linux kernel - Xilinx Zynq ARM architecture Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform
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