https://github.com/torvalds/linux
Revision a73914c35b05d80f8ce78288e10056c91090b666 authored by Mark Salyzyn on 22 September 2011, 15:32:23 UTC, committed by James Bottomley on 02 October 2011, 18:28:55 UTC
When a wide port is being utilized to a target, if one disables only one
of the
phys, we get an OS crash:

BUG: unable to handle kernel NULL pointer dereference at
0000000000000238
IP: [<ffffffff814ca9b1>] mutex_lock+0x21/0x50
PGD 4103f5067 PUD 41dba9067 PMD 0
Oops: 0002 [#1] SMP
last sysfs file: /sys/bus/pci/slots/5/address
CPU 0
Modules linked in: pm8001(U) ses enclosure fuse nfsd exportfs autofs4
ipmi_devintf ipmi_si ipmi_msghandler nfs lockd fscache nfs_acl
auth_rpcgss 8021q fcoe libfcoe garp libfc scsi_transport_fc stp scsi_tgt
llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table ipv6 sr_mod cdrom
dm_mirror dm_region_hash dm_log uinput sg i2c_i801 i2c_core iTCO_wdt
iTCO_vendor_support e1000e mlx4_ib ib_mad ib_core mlx4_en mlx4_core ext3
jbd mbcache sd_mod crc_t10dif usb_storage ata_generic pata_acpi ata_piix
libsas(U) scsi_transport_sas dm_mod [last unloaded: pm8001]

Modules linked in: pm8001(U) ses enclosure fuse nfsd exportfs autofs4
ipmi_devintf ipmi_si ipmi_msghandler nfs lockd fscache nfs_acl
auth_rpcgss 8021q fcoe libfcoe garp libfc scsi_transport_fc stp scsi_tgt
llc sunrpc cpufreq_ondemand acpi_cpufreq freq_table ipv6 sr_mod cdrom
dm_mirror dm_region_hash dm_log uinput sg i2c_i801 i2c_core iTCO_wdt
iTCO_vendor_support e1000e mlx4_ib ib_mad ib_core mlx4_en mlx4_core ext3
jbd mbcache sd_mod crc_t10dif usb_storage ata_generic pata_acpi ata_piix
libsas(U) scsi_transport_sas dm_mod [last unloaded: pm8001]
Pid: 5146, comm: scsi_wq_5 Not tainted
2.6.32-71.29.1.el6.lustre.7.x86_64 #1 Storage Server
RIP: 0010:[<ffffffff814ca9b1>]  [<ffffffff814ca9b1>]
mutex_lock+0x21/0x50
RSP: 0018:ffff8803e4e33d30  EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000238 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8803e664c800 RDI: 0000000000000238
RBP: ffff8803e4e33d40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000238 R14: ffff88041acb7200 R15: ffff88041c51ada0
FS:  0000000000000000(0000) GS:ffff880028200000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000238 CR3: 0000000410143000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process scsi_wq_5 (pid: 5146, threadinfo ffff8803e4e32000, task
ffff8803e4e294a0)
Stack:
 ffff8803e664c800 0000000000000000 ffff8803e4e33d70 ffffffffa001f06e
<0> ffff8803e4e33d60 ffff88041c51ada0 ffff88041acb7200 ffff88041bc0aa00
<0> ffff8803e4e33d90 ffffffffa0032b6c 0000000000000014 ffff88041acb7200
Call Trace:
 [<ffffffffa001f06e>] sas_port_delete_phy+0x2e/0xa0 [scsi_transport_sas]
 [<ffffffffa0032b6c>] sas_unregister_devs_sas_addr+0xac/0xe0 [libsas]
 [<ffffffffa0034914>] sas_ex_revalidate_domain+0x204/0x330 [libsas]
 [<ffffffffa00307f0>] ? sas_revalidate_domain+0x0/0x90 [libsas]
 [<ffffffffa0030855>] sas_revalidate_domain+0x65/0x90 [libsas]
 [<ffffffff8108c7d0>] worker_thread+0x170/0x2a0
 [<ffffffff81091ea0>] ? autoremove_wake_function+0x0/0x40
 [<ffffffff8108c660>] ? worker_thread+0x0/0x2a0
 [<ffffffff81091b36>] kthread+0x96/0xa0
 [<ffffffff810141ca>] child_rip+0xa/0x20
 [<ffffffff81091aa0>] ? kthread+0x0/0xa0
 [<ffffffff810141c0>] ? child_rip+0x0/0x20
Code: ff ff 85 c0 75 ed eb d6 66 90 55 48 89 e5 48 83 ec 10 48 89 1c 24
4c 89 64 24 08 0f 1f 44 00 00 48 89 fb e8 92 f4 ff ff 48 89 df <f0> ff
0f 79 05 e8 25 00 00 00 65 48 8b 04 25 08 cc 00 00 48 2d
RIP  [<ffffffff814ca9b1>] mutex_lock+0x21/0x50
 RSP <ffff8803e4e33d30>
CR2: 0000000000000238

The following patch is admittedly a band-aid, and does not solve the
root cause, but it still is a good candidate for hardening as a pointer
check before reference.

Signed-off-by: Mark Salyzyn <mark_salyzyn@us.xyratex.com>
Tested-by: Jack Wang <jack_wang@usish.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
1 parent 9bfacd0
Raw File
Tip revision: a73914c35b05d80f8ce78288e10056c91090b666 authored by Mark Salyzyn on 22 September 2011, 15:32:23 UTC
[SCSI] libsas: fix panic when single phy is disabled on a wide port
Tip revision: a73914c
mkcompile_h
#!/bin/sh

TARGET=$1
ARCH=$2
SMP=$3
PREEMPT=$4
CC=$5

vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }

# If compile.h exists already and we don't own autoconf.h
# (i.e. we're not the same user who did make *config), don't
# modify compile.h
# So "sudo make install" won't change the "compiled by <user>"
# do "compiled by root"

if [ -r $TARGET -a ! -O include/generated/autoconf.h ]; then
  vecho "  SKIPPED $TARGET"
  exit 0
fi

# Do not expand names
set -f

# Fix the language to get consistent output
LC_ALL=C
export LC_ALL

if [ -z "$KBUILD_BUILD_VERSION" ]; then
	if [ -r .version ]; then
		VERSION=`cat .version`
	else
		VERSION=0
		echo 0 > .version
	fi
else
	VERSION=$KBUILD_BUILD_VERSION
fi

if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
	TIMESTAMP=`date`
else
	TIMESTAMP=$KBUILD_BUILD_TIMESTAMP
fi
if test -z "$KBUILD_BUILD_USER"; then
	LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
else
	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
fi
if test -z "$KBUILD_BUILD_HOST"; then
	LINUX_COMPILE_HOST=`hostname`
else
	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
fi

UTS_VERSION="#$VERSION"
CONFIG_FLAGS=""
if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"

# Truncate to maximum length

UTS_LEN=64
UTS_TRUNCATE="cut -b -$UTS_LEN"

# Generate a temporary compile.h

( echo /\* This file is auto generated, version $VERSION \*/
  if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi
  
  echo \#define UTS_MACHINE \"$ARCH\"

  echo \#define UTS_VERSION \"`echo $UTS_VERSION | $UTS_TRUNCATE`\"

  echo \#define LINUX_COMPILE_BY \"`echo $LINUX_COMPILE_BY | $UTS_TRUNCATE`\"
  echo \#define LINUX_COMPILE_HOST \"`echo $LINUX_COMPILE_HOST | $UTS_TRUNCATE`\"

  echo \#define LINUX_COMPILER \"`$CC -v 2>&1 | tail -n 1`\"
) > .tmpcompile

# Only replace the real compile.h if the new one is different,
# in order to preserve the timestamp and avoid unnecessary
# recompilations.
# We don't consider the file changed if only the date/time changed.
# A kernel config change will increase the generation number, thus
# causing compile.h to be updated (including date/time) due to the 
# changed comment in the
# first line.

if [ -r $TARGET ] && \
      grep -v 'UTS_VERSION' $TARGET > .tmpver.1 && \
      grep -v 'UTS_VERSION' .tmpcompile > .tmpver.2 && \
      cmp -s .tmpver.1 .tmpver.2; then
   rm -f .tmpcompile
else
   vecho "  UPD     $TARGET"
   mv -f .tmpcompile $TARGET
fi
rm -f .tmpver.1 .tmpver.2
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