Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2

Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2

[Sachin Sant]

[-- Attachment #1: Type: text/plain, Size: 2569 bytes --]

I found this following problem while executing cat/proc/iomem. The 
command causes following BUG.

x236:/linux-2.6.17-rc1/fs # cat /proc/iomem
Segmentation fault
x236:/linux-2.6.17-rc1/fs #

Dmesg has this following stack trace.

Same problem with 2.6.17-rc2. But not with 2.6.16-rc6 [ some old 
precompiled 2.6.16 kernel i had on my machine ]. cat on /proc/ioports 
also causes similar BUG.

Attaching the dmesg log for reference. Arch is IA32.

BUG: unable to handle kernel NULL pointer dereference at virtual address 
00000010
  printing eip:
c011cdef
*pde = 00000000
Oops: 0000 [#1]
Modules linked in:
CPU:    0
EIP:    0060:[<c011cdef>]    Not tainted VLI
EFLAGS: 00010246   (2.6.17-rc1 #12)
EIP is at r_show+0x134/0x157
eax: 00000000   ebx: c05358e8   ecx: ffffffff   edx: 00000000
esi: f54a26c7   edi: c05358eb   ebp: f44f7f14   esp: f44f7ecc
ds: 007b   es: 007b   ss: 0068
Process cat (pid: 11983, threadinfo=f44f6000 task=f54a2540)
Stack: <0>c0157422 c70ff7c0 f4790920 00000000 c70fd6c8 f44f7eec c04ffb30 
c05bd9b8
        f44f7f14 c011cc45 f44f6000 f44f7f14 00000008 00000000 c05bd99c 
c721d280
        f54a26c5 c053961d f44f7f60 c017acf9 f5d94cc0 c721d280 f5f9e2c0 
f47afddc
Call Trace:
  <c01034c8> show_stack_log_lvl+0xcf/0xdf   <c01036b8> 
show_registers+0x192/0x208
  <c01038b1> die+0x100/0x1ee   <c0111858> do_page_fault+0x460/0x670
  <c01030bb> error_code+0x4f/0x54   <c017acf9> seq_read+0xc6/0x3f1
  <c015a3b4> vfs_read+0xa8/0x177   <c015a748> sys_read+0x47/0x6e
  <c0102e2b> sysenter_past_esp+0x54/0x75
Code: c0 83 c4 3c 5b 5e 5f 5d c3 8b 55 ec 8b 42 10 89 54 24 04 c7 04 24 
50 6a 53 c0 89 44 24 08 e8 af af ff ff e9 69 ff ff ff 8b 55 ec <8b> 42 
10 89 54 24 08 89 44 24 0c 8b 45 08 c7 04 24 74 6a 53 c0
  BUG: cat/11983, active lock [f5d94ce0(f5d94cc0-f5d94d40)] freed!
  <c01033f7> show_trace+0x20/0x22   <c0103524> dump_stack+0x1e/0x20
  <c012e199> mutex_debug_check_no_locks_freed+0x10e/0x17e   <c01578f2> 
kfree+0x40/0x73
  <c017b32e> seq_release+0x22/0x2a   <c015b4e9> __fput+0x163/0x192
  <c015b384> fput+0x18/0x1a   <c0159cb9> filp_close+0x45/0x6f
  <c0119428> close_files+0x7f/0x9e   <c0119497> put_files_struct+0x22/0x51
  <c0119f5c> do_exit+0x13b/0x404   <c010399f> do_trap+0x0/0xb4
  <c0111858> do_page_fault+0x460/0x670   <c01030bb> error_code+0x4f/0x54
  <c017acf9> seq_read+0xc6/0x3f1   <c015a3b4> vfs_read+0xa8/0x177
  <c015a748> sys_read+0x47/0x6e   <c0102e2b> sysenter_past_esp+0x54/0x75
  [f5d94ce0] {seq_open}
.. held by:               cat:11983 [f54a2540, 115]
... acquired at:               seq_read+0x27/0x3f1

Thanks
-Sachin

[-- Attachment #2: dmesg.log --]
[-- Type: text/plain, Size: 12886 bytes --]

0:0: FAST-160 WIDE SCSI 320.0 MB/s DT IU RTI (6.25 ns, offset 127)
 target1:0:0: Ending Domain Validation
I/O scheduler cfq not found
  Vendor: IBM-ESXS  Model: GNS146C3ESTT0ZFN  Rev: JP83
  Type:   Direct-Access                      ANSI SCSI revision: 04
 target1:0:1: asynchronous
scsi1:A:1:0: Tagged Queuing enabled.  Depth 32
 target1:0:1: Beginning Domain Validation
 target1:0:1: wide asynchronous
 target1:0:1: FAST-160 WIDE SCSI 320.0 MB/s DT IU RTI (6.25 ns, offset 127)
 target1:0:1: Ending Domain Validation
I/O scheduler cfq not found
  Vendor: IBM-ESXS  Model: GNS146C3ESTT0ZFN  Rev: JP83
  Type:   Direct-Access                      ANSI SCSI revision: 04
 target1:0:2: asynchronous
scsi1:A:2:0: Tagged Queuing enabled.  Depth 32
 target1:0:2: Beginning Domain Validation
 target1:0:2: wide asynchronous
 target1:0:2: FAST-160 WIDE SCSI 320.0 MB/s DT IU RTI (6.25 ns, offset 127)
 target1:0:2: Ending Domain Validation
I/O scheduler cfq not found
  Vendor: IBM-ESXS  Model: MAT3147NC     FN  Rev: B411
  Type:   Direct-Access                      ANSI SCSI revision: 04
 target1:0:3: asynchronous
scsi1:A:3:0: Tagged Queuing enabled.  Depth 32
 target1:0:3: Beginning Domain Validation
 target1:0:3: wide asynchronous
 target1:0:3: FAST-160 WIDE SCSI 320.0 MB/s DT IU RDSTRM RTI WRFLOW PCOMP (6.25 ns, offset 127)
 target1:0:3: Ending Domain Validation
I/O scheduler cfq not found
  Vendor: IBM-ESXS  Model: GNS146C3ESTT0ZFN  Rev: JP83
  Type:   Direct-Access                      ANSI SCSI revision: 04
 target1:0:4: asynchronous
scsi1:A:4:0: Tagged Queuing enabled.  Depth 32
 target1:0:4: Beginning Domain Validation
 target1:0:4: wide asynchronous
 target1:0:4: FAST-160 WIDE SCSI 320.0 MB/s DT IU RTI (6.25 ns, offset 127)
 target1:0:4: Ending Domain Validation
I/O scheduler cfq not found
  Vendor: IBM-ESXS  Model: GNS146C3ESTT0ZFN  Rev: JP83
  Type:   Direct-Access                      ANSI SCSI revision: 04
 target1:0:5: asynchronous
scsi1:A:5:0: Tagged Queuing enabled.  Depth 32
 target1:0:5: Beginning Domain Validation
 target1:0:5: wide asynchronous
 target1:0:5: FAST-160 WIDE SCSI 320.0 MB/s DT IU RTI (6.25 ns, offset 127)
 target1:0:5: Ending Domain Validation
I/O scheduler cfq not found
I/O scheduler cfq not found
  Vendor: IBM       Model: 02R0962a S320  1  Rev: 1   
  Type:   Processor                          ANSI SCSI revision: 02
 target1:0:8: asynchronous
 target1:0:8: Beginning Domain Validation
 target1:0:8: Ending Domain Validation
I/O scheduler cfq not found
I/O scheduler cfq not found
I/O scheduler cfq not found
I/O scheduler cfq not found
I/O scheduler cfq not found
I/O scheduler cfq not found
I/O scheduler cfq not found
libata version 1.20 loaded.
SCSI device sda: 286748000 512-byte hdwr sectors (146815 MB)
sda: Write Protect is off
sda: Mode Sense: cb 00 10 08
SCSI device sda: drive cache: write through w/ FUA
SCSI device sda: 286748000 512-byte hdwr sectors (146815 MB)
sda: Write Protect is off
sda: Mode Sense: cb 00 10 08
SCSI device sda: drive cache: write through w/ FUA
 sda: sda1 sda2 < sda5 sda6 sda7 sda8 sda9 >
sd 1:0:0:0: Attached scsi disk sda
SCSI device sdb: 286748000 512-byte hdwr sectors (146815 MB)
sdb: Write Protect is off
sdb: Mode Sense: cb 00 10 08
SCSI device sdb: drive cache: write through w/ FUA
SCSI device sdb: 286748000 512-byte hdwr sectors (146815 MB)
sdb: Write Protect is off
sdb: Mode Sense: cb 00 10 08
SCSI device sdb: drive cache: write through w/ FUA
 sdb: sdb1 < sdb5 sdb6 sdb7 sdb8 >
sd 1:0:1:0: Attached scsi disk sdb
SCSI device sdc: 286748000 512-byte hdwr sectors (146815 MB)
sdc: Write Protect is off
sdc: Mode Sense: cb 00 10 08
SCSI device sdc: drive cache: write through w/ FUA
SCSI device sdc: 286748000 512-byte hdwr sectors (146815 MB)
sdc: Write Protect is off
sdc: Mode Sense: cb 00 10 08
SCSI device sdc: drive cache: write through w/ FUA
 sdc: sdc1 < sdc5 sdc6 sdc7 sdc8 sdc9 sdc10 >
sd 1:0:2:0: Attached scsi disk sdc
SCSI device sdd: 286748000 512-byte hdwr sectors (146815 MB)
sdd: Write Protect is off
sdd: Mode Sense: cf 00 00 08
SCSI device sdd: drive cache: write through
SCSI device sdd: 286748000 512-byte hdwr sectors (146815 MB)
sdd: Write Protect is off
sdd: Mode Sense: cf 00 00 08
SCSI device sdd: drive cache: write through
 sdd: sdd1 < sdd5 >
sd 1:0:3:0: Attached scsi disk sdd
SCSI device sde: 286748000 512-byte hdwr sectors (146815 MB)
sde: Write Protect is off
sde: Mode Sense: cb 00 10 08
SCSI device sde: drive cache: write through w/ FUA
SCSI device sde: 286748000 512-byte hdwr sectors (146815 MB)
sde: Write Protect is off
sde: Mode Sense: cb 00 10 08
SCSI device sde: drive cache: write through w/ FUA
 sde: unknown partition table
sd 1:0:4:0: Attached scsi disk sde
SCSI device sdf: 286748000 512-byte hdwr sectors (146815 MB)
sdf: Write Protect is off
sdf: Mode Sense: cb 00 10 08
SCSI device sdf: drive cache: write through w/ FUA
SCSI device sdf: 286748000 512-byte hdwr sectors (146815 MB)
sdf: Write Protect is off
sdf: Mode Sense: cb 00 10 08
SCSI device sdf: drive cache: write through w/ FUA
 sdf: sdf1 < sdf5 sdf6 sdf7 sdf8 >
sd 1:0:5:0: Attached scsi disk sdf
sd 1:0:0:0: Attached scsi generic sg0 type 0
sd 1:0:1:0: Attached scsi generic sg1 type 0
sd 1:0:2:0: Attached scsi generic sg2 type 0
sd 1:0:3:0: Attached scsi generic sg3 type 0
sd 1:0:4:0: Attached scsi generic sg4 type 0
sd 1:0:5:0: Attached scsi generic sg5 type 0
 1:0:8:0: Attached scsi generic sg6 type 3
ieee1394: raw1394: /dev/raw1394 device initialized
ACPI: PCI Interrupt Link [LP07] enabled at IRQ 5
ACPI: PCI Interrupt 0000:00:1d.7[D] -> Link [LP07] -> GSI 5 (level, low) -> IRQ 5
PCI: Setting latency timer of device 0000:00:1d.7 to 64
ehci_hcd 0000:00:1d.7: EHCI Host Controller
ehci_hcd 0000:00:1d.7: new USB bus registered, assigned bus number 1
ehci_hcd 0000:00:1d.7: debug port 1
PCI: cache line size of 128 is not supported by device 0000:00:1d.7
ehci_hcd 0000:00:1d.7: irq 5, io mem 0xf0000000
ehci_hcd 0000:00:1d.7: USB 2.0 started, EHCI 1.00, driver 10 Dec 2004
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 4 ports detected
USB Universal Host Controller Interface driver v3.0
ACPI: PCI Interrupt 0000:00:1d.0[A] -> Link [LP00] -> GSI 5 (level, low) -> IRQ 5
PCI: Setting latency timer of device 0000:00:1d.0 to 64
uhci_hcd 0000:00:1d.0: UHCI Host Controller
uhci_hcd 0000:00:1d.0: new USB bus registered, assigned bus number 2
uhci_hcd 0000:00:1d.0: irq 5, io base 0x00002200
usb usb2: configuration #1 chosen from 1 choice
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 2 ports detected
ACPI: PCI Interrupt 0000:00:1d.1[B] -> Link [LP03] -> GSI 11 (level, low) -> IRQ 11
PCI: Setting latency timer of device 0000:00:1d.1 to 64
uhci_hcd 0000:00:1d.1: UHCI Host Controller
uhci_hcd 0000:00:1d.1: new USB bus registered, assigned bus number 3
uhci_hcd 0000:00:1d.1: irq 11, io base 0x00002600
usb usb3: configuration #1 chosen from 1 choice
hub 3-0:1.0: USB hub found
hub 3-0:1.0: 2 ports detected
usbcore: registered new driver usblp
drivers/usb/class/usblp.c: v0.13: USB Printer Device Class driver
Initializing USB Mass Storage driver...
usbcore: registered new driver usb-storage
USB Mass Storage support registered.
usbcore: registered new driver usbhid
drivers/usb/input/hid-core.c: v2.6:USB HID core driver
PNP: PS/2 Controller [PNP0303:PS2K,PNP0f13:PS2M] at 0x64,0x60 irq 1,12
PNP: PS/2 controller has invalid data port 0x64; using default 0x60
PNP: PS/2 controller has invalid command port 0x60; using default 0x64
serio: i8042 AUX port at 0x60,0x64 irq 12
serio: i8042 KBD port at 0x60,0x64 irq 1
mice: PS/2 mouse device common for all mice
Advanced Linux Sound Architecture Driver Version 1.0.11rc4 (Wed Mar 22 10:27:24 2006 UTC).
ALSA device list:
  No soundcards found.
oprofile: using timer interrupt.
NET: Registered protocol family 2
input: AT Translated Set 2 keyboard as /class/input/input0
IP route cache hash table entries: 131072 (order: 7, 524288 bytes)
TCP established hash table entries: 262144 (order: 10, 4194304 bytes)
TCP bind hash table entries: 65536 (order: 8, 1310720 bytes)
TCP: Hash tables configured (established 262144 bind 65536)
TCP reno registered
ip_conntrack version 2.4 (8192 buckets, 65536 max) - 172 bytes per conntrack
TCP bic registered
NET: Registered protocol family 1
NET: Registered protocol family 17
Using IPI Shortcut mode
ACPI wakeup devices: 
PCI0 
ACPI: (supports S0 S4 S5)
kjournald starting.  Commit interval 5 seconds
EXT3-fs: mounted filesystem with ordered data mode.
VFS: Mounted root (ext3 filesystem) readonly.
Freeing unused kernel memory: 204k freed
input: ImExPS/2 Generic Explorer Mouse as /class/input/input1
EXT3 FS on sda5, internal journal
Adding 4200956k swap on /dev/sda9.  Priority:42 extents:1 across:4200956k
kjournald starting.  Commit interval 5 seconds
EXT3 FS on sda8, internal journal
EXT3-fs: mounted filesystem with ordered data mode.
kjournald starting.  Commit interval 5 seconds
EXT3 FS on sda1, internal journal
EXT3-fs: mounted filesystem with ordered data mode.
ReiserFS: sdb5: found reiserfs format "3.6" with standard journal
ReiserFS: sdb5: warning: CONFIG_REISERFS_CHECK is set ON
ReiserFS: sdb5: warning: - it is slow mode for debugging.
ReiserFS: sdb5: using ordered data mode
ReiserFS: sdb5: journal params: device sdb5, size 8192, journal first block 18, max trans len 1024, max batch 900, max commit age 30, max trans age 30
ReiserFS: sdb5: checking transaction log (sdb5)
ReiserFS: sdb5: journal-1153: found in header: first_unflushed_offset 2566, last_flushed_trans_id 324114
ReiserFS: sdb5: journal-1206: Starting replay from offset 1392063325145606, trans_id 0
ReiserFS: sdb5: journal-1299: Setting newest_mount_id to 57
ReiserFS: sdb5: Using r5 hash to sort names
jfs_mount: Mount Failure: File System Dirty.
Mount JFS Failure: -22
jfs_mount failed w/return code = -22
XFS mounting filesystem sdb7
Ending clean XFS mount for filesystem: sdb7
kjournald starting.  Commit interval 5 seconds
EXT3 FS on sda6, internal journal
EXT3-fs: mounted filesystem with ordered data mode.
kjournald starting.  Commit interval 5 seconds
EXT3 FS on sda7, internal journal
EXT3-fs: mounted filesystem with ordered data mode.
e1000: eth0: e1000_watchdog_task: NIC Link is Up 100 Mbps Full Duplex
end_request: I/O error, dev fd0, sector 0
end_request: I/O error, dev fd0, sector 0
program hwscan is using a deprecated SCSI ioctl, please convert it to SG_IO
program hwscan is using a deprecated SCSI ioctl, please convert it to SG_IO
program hwscan is using a deprecated SCSI ioctl, please convert it to SG_IO
program hwscan is using a deprecated SCSI ioctl, please convert it to SG_IO
program hwscan is using a deprecated SCSI ioctl, please convert it to SG_IO
program hwscan is using a deprecated SCSI ioctl, please convert it to SG_IO
BUG: unable to handle kernel NULL pointer dereference at virtual address 00000010
 printing eip:
c011cdef
*pde = 00000000
Oops: 0000 [#1]
Modules linked in:
CPU:    0
EIP:    0060:[<c011cdef>]    Not tainted VLI
EFLAGS: 00010246   (2.6.17-rc1 #12) 
EIP is at r_show+0x134/0x157
eax: 00000000   ebx: c05358e8   ecx: ffffffff   edx: 00000000
esi: f54a26c7   edi: c05358eb   ebp: f44f7f14   esp: f44f7ecc
ds: 007b   es: 007b   ss: 0068
Process cat (pid: 11983, threadinfo=f44f6000 task=f54a2540)
Stack: <0>c0157422 c70ff7c0 f4790920 00000000 c70fd6c8 f44f7eec c04ffb30 c05bd9b8 
       f44f7f14 c011cc45 f44f6000 f44f7f14 00000008 00000000 c05bd99c c721d280 
       f54a26c5 c053961d f44f7f60 c017acf9 f5d94cc0 c721d280 f5f9e2c0 f47afddc 
Call Trace:
 <c01034c8> show_stack_log_lvl+0xcf/0xdf   <c01036b8> show_registers+0x192/0x208
 <c01038b1> die+0x100/0x1ee   <c0111858> do_page_fault+0x460/0x670
 <c01030bb> error_code+0x4f/0x54   <c017acf9> seq_read+0xc6/0x3f1
 <c015a3b4> vfs_read+0xa8/0x177   <c015a748> sys_read+0x47/0x6e
 <c0102e2b> sysenter_past_esp+0x54/0x75  
Code: c0 83 c4 3c 5b 5e 5f 5d c3 8b 55 ec 8b 42 10 89 54 24 04 c7 04 24 50 6a 53 c0 89 44 24 08 e8 af af ff ff e9 69 ff ff ff 8b 55 ec <8b> 42 10 89 54 24 08 89 44 24 0c 8b 45 08 c7 04 24 74 6a 53 c0 
 BUG: cat/11983, active lock [f5d94ce0(f5d94cc0-f5d94d40)] freed!
 <c01033f7> show_trace+0x20/0x22   <c0103524> dump_stack+0x1e/0x20
 <c012e199> mutex_debug_check_no_locks_freed+0x10e/0x17e   <c01578f2> kfree+0x40/0x73
 <c017b32e> seq_release+0x22/0x2a   <c015b4e9> __fput+0x163/0x192
 <c015b384> fput+0x18/0x1a   <c0159cb9> filp_close+0x45/0x6f
 <c0119428> close_files+0x7f/0x9e   <c0119497> put_files_struct+0x22/0x51
 <c0119f5c> do_exit+0x13b/0x404   <c010399f> do_trap+0x0/0xb4
 <c0111858> do_page_fault+0x460/0x670   <c01030bb> error_code+0x4f/0x54
 <c017acf9> seq_read+0xc6/0x3f1   <c015a3b4> vfs_read+0xa8/0x177
 <c015a748> sys_read+0x47/0x6e   <c0102e2b> sysenter_past_esp+0x54/0x75
 [f5d94ce0] {seq_open}
.. held by:               cat:11983 [f54a2540, 115]
... acquired at:               seq_read+0x27/0x3f1
 

Re: Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2

[Arjan van de Ven]

On Tue, 2006-04-25 at 16:13 +0530, Sachin Sant wrote:
> I found this following problem while executing cat/proc/iomem. The 
> command causes following BUG.
> 
> x236:/linux-2.6.17-rc1/fs # cat /proc/iomem
> Segmentation fault


this tends to be a driver bug; could you compile all the drivers you
need as module, and then try to not load them as much as possible. See
if it still crashes, if not, load the rest one at a time until it
crashes, and then you've found the culprit :)

Re: Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2

[Sharyathi Nagesh]

I was able to replicate the Bug, even when all the drivers are built into the kernel. 
It looks like while traversing through p->parent field of resource structure is leading to NULL pointer. 
Would it be appropriate to make the following code change. 
	But I found cat /proc/iomem hangs after line kernel data..

--- kernel/resource.c.old       2006-05-11 05:29:33.000000000 -0700
+++ kernel/resource.c   2006-05-11 05:29:58.000000000 -0700
@@ -81,7 +81,7 @@ static int r_show(struct seq_file *m, vo
        int depth;

        for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent){
-               if (p->parent == root)
+               if (p->parent == root || p->parent == NULL)
                        break;
        }
        seq_printf(m, "%*s%0*lx-%0*lx : %s\n",
Regards
Sharyathi Nagesh

On Tue, 2006-04-25 at 12:48 +0200, Arjan van de Ven wrote:
> On Tue, 2006-04-25 at 16:13 +0530, Sachin Sant wrote:
> > I found this following problem while executing cat/proc/iomem. The 
> > command causes following BUG.
> > 
> > x236:/linux-2.6.17-rc1/fs # cat /proc/iomem
> > Segmentation fault
> 
> 
> this tends to be a driver bug; could you compile all the drivers you
> need as module, and then try to not load them as much as possible. See
> if it still crashes, if not, load the rest one at a time until it
> crashes, and then you've found the culprit :)
> 
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
> 

Re: Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2

[Russell King]

On Thu, May 11, 2006 at 12:57:48PM +0530, Sharyathi Nagesh wrote:
> I was able to replicate the Bug, even when all the drivers are built into the kernel. 
> It looks like while traversing through p->parent field of resource structure is leading to NULL pointer. 
> Would it be appropriate to make the following code change. 
> 	But I found cat /proc/iomem hangs after line kernel data..
> 
> --- kernel/resource.c.old       2006-05-11 05:29:33.000000000 -0700
> +++ kernel/resource.c   2006-05-11 05:29:58.000000000 -0700
> @@ -81,7 +81,7 @@ static int r_show(struct seq_file *m, vo
>         int depth;
> 
>         for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent){
> -               if (p->parent == root)
> +               if (p->parent == root || p->parent == NULL)
>                         break;
>         }
>         seq_printf(m, "%*s%0*lx-%0*lx : %s\n",

Only the root should have a NULL parent, so this is just covering up some
other problem - you have a resource which somehow has illegally ended up
with a NULL parent pointer while it's been registered.

Maybe try adding:

		if (p->parent == NULL) {
			printk("resource with null parent: %lx-%lx: %s\n",
				p->start, p->end, p->name);
			break;
		}

just before the test in that loop, and then finding out why that resource
is becoming invalid.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core

Re: Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2

[Sachin Sant]

Russell King wrote:

>Only the root should have a NULL parent, so this is just covering up some
>other problem - you have a resource which somehow has illegally ended up
>with a NULL parent pointer while it's been registered.
>
>Maybe try adding:
>
>		if (p->parent == NULL) {
>			printk("resource with null parent: %lx-%lx: %s\n",
>				p->start, p->end, p->name);
>			break;
>		}
>
>just before the test in that loop, and then finding out why that resource
>is becoming invalid.
>
>  
>
I get this output in dmesg with the above code.

resource with null parent: 0-57ffffff: System RAM
resource with null parent: 0-57ffffff: System RAM

x236:/home/sharyathi/linux-2.6.17-rc1/kernel # cat /proc/iomem
00000000-0009dbff : System RAM
0009dc00-0009ffff : reserved
000a0000-000bffff : Video RAM area
000c0000-000cafff : Video ROM
000cb000-000cc5ff : Adapter ROM
000f0000-000fffff : System ROM
00100000-c7fcb5ff : System RAM
  00100000-004ff436 : Kernel code
  004ff437-0068881f : Kernel data
x236:/home/sharyathi/linux-2.6.17-rc1/kernel #

Re: Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2

[Maneesh Soni]

On Thu, May 11, 2006 at 02:08:12PM +0530, Sachin Sant wrote:
> Russell King wrote:
> 
> >Only the root should have a NULL parent, so this is just covering up some
> >other problem - you have a resource which somehow has illegally ended up
> >with a NULL parent pointer while it's been registered.
> >
> >Maybe try adding:
> >
> >		if (p->parent == NULL) {
> >			printk("resource with null parent: %lx-%lx: %s\n",
> >				p->start, p->end, p->name);
> >			break;
> >		}
> >
> >just before the test in that loop, and then finding out why that resource
> >is becoming invalid.
> >
> > 
> >
> I get this output in dmesg with the above code.
> 
> resource with null parent: 0-57ffffff: System RAM
> resource with null parent: 0-57ffffff: System RAM
> 
> x236:/home/sharyathi/linux-2.6.17-rc1/kernel # cat /proc/iomem
> 00000000-0009dbff : System RAM
> 0009dc00-0009ffff : reserved
> 000a0000-000bffff : Video RAM area
> 000c0000-000cafff : Video ROM
> 000cb000-000cc5ff : Adapter ROM
> 000f0000-000fffff : System ROM
> 00100000-c7fcb5ff : System RAM
>  00100000-004ff436 : Kernel code
>  004ff437-0068881f : Kernel data
> x236:/home/sharyathi/linux-2.6.17-rc1/kernel #
> 

Backing out 

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=10dbe196a8da6b3196881269c6639c0ec11c36cb

solves this problem for me. This patch adds memory more than 4G to /proc/iomem
but without 64-bit fields for struct resource it ends up in confusing 
iomem_resource list. I think this patch needs the core 64-bit struct resource
related changes also.


Thanks
Maneesh

Re: Bug while executing : cat /proc/iomem on 2.6.17-rc1/rc2

[Linus Torvalds]

On Sat, 13 May 2006, Maneesh Soni wrote:
> 
> Backing out 
> 
> http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=10dbe196a8da6b3196881269c6639c0ec11c36cb
> 
> solves this problem for me. This patch adds memory more than 4G to /proc/iomem
> but without 64-bit fields for struct resource it ends up in confusing 
> iomem_resource list. I think this patch needs the core 64-bit struct resource
> related changes also.

Yeah, let's revert that for now. I don't think the people involved 
realized how it was dependent on the 64-bit struct resource changes.

Thanks,

		Linus