If a VFC port gets unmapped in the VIOS, it may not respond with a CRQ
init complete following H_REG_CRQ. If this occurs, we can end up having
called scsi_block_requests and not a resulting unblock until the init
complete happens, which may never occur, and we end up hanging I/O
requests. This patch ensures the host action stay set to
IBMVFC_HOST_ACTION_TGT_DEL so we move all rports into devloss state and
unblock unless we receive an init complete.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Acked-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
This patch will fix regression caused by commit 1e793f6fc0db ("scsi:
megaraid_sas: Fix data integrity failure for JBOD (passthrough)
devices").
The problem was that the MEGASAS_IS_LOGICAL macro did not have braces
and as a result the driver ended up exposing a lot of non-existing SCSI
devices (all SCSI commands to channels 1,2,3 were returned as
SUCCESS-DID_OK by driver).
Commit 02b01e010afe ("megaraid_sas: return sync cache call with
success") modified the driver to successfully complete SYNCHRONIZE_CACHE
commands without passing them to the controller. Disk drive caches are
only explicitly managed by controller firmware when operating in RAID
mode. So this commit effectively disabled writeback cache flushing for
any drives used in JBOD mode, leading to data integrity failures.
[mkp: clarified patch description]
Fixes: 02b01e010afeeb49328d35650d70721d2ca3fd59 Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Ewan D. Milne <emilne@redhat.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Problem:
This is a work around for a bug with LSI Fusion MPT SAS2 when
pefroming secure erase. Due to the very long time the operation
takes commands issued during the erase will time out and will trigger
execution of abort hook. Even though the abort hook is called for
the specific command which timed out this leads to entire device halt
(scsi_state terminated) and premature termination of the secured erase.
Fix:
Set device state to busy while erase in progress to reject any incoming
commands until the erase is done. The device is blocked any way during
this time and cannot execute any other command.
More data and logs can be found here -
https://drive.google.com/file/d/0B9ocOHYHbbS1Q3VMdkkzeWFkTjg/view
P.S
This is a backport from the same fix for mpt3sas driver intended
for pre-4.4 stable trees.
Signed-off-by: Andrey Grodzovsky <andrey2805@gmail.com> Cc: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com> Cc: Hannes Reinecke <hare@suse.de> Cc: PDL-MPT-FUSIONLINUX <MPT-FusionLinux.pdl@broadcom.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
mpt3sas has a firmware failure where it can only handle one pass through
ATA command at a time. If another comes in, contrary to the SAT
standard, it will hang until the first one completes (causing long
commands like secure erase to timeout). The original fix was to block
the device when an ATA command came in, but this caused a regression
with
scsi: srp_transport: Move queuecommand() wait code to SCSI core
So fix the original fix of the secure erase timeout by properly
returning SAM_STAT_BUSY like the SAT recommends. The original patch
also had a concurrency problem since scsih_qcmd is lockless at that
point (this is fixed by using atomic bitops to set and test the flag).
[mkp: addressed feedback wrt. test_bit and fixed whitespace]
Fixes: 18f6084a989ba1b (mpt3sas: Fix secure erase premature termination) Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Acked-by: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reported-by: Ingo Molnar <mingo@kernel.org> Tested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[wt: adjust context] Signed-off-by: Willy Tarreau <w@1wt.eu>
While issuing any ATA passthrough command to firmware the driver will
block the device. But it will unblock the device only if the I/O
completes through the ISR path. If a controller reset occurs before
command completion the device will remain in blocked state.
Make sure we unblock the device following a controller reset if an ATA
passthrough command was queued.
[mkp: clarified patch description]
Cc: <stable@vger.kernel.org> # v4.4+ Fixes: ac6c2a93bd07 ("mpt3sas: Fix for SATA drive in blocked state, after diag reset") Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[wt: adjust context] Signed-off-by: Willy Tarreau <w@1wt.eu>
This is a work around for a bug with LSI Fusion MPT SAS2 when perfoming
secure erase. Due to the very long time the operation takes, commands
issued during the erase will time out and will trigger execution of the
abort hook. Even though the abort hook is called for the specific
command which timed out, this leads to entire device halt
(scsi_state terminated) and premature termination of the secure erase.
Set device state to busy while ATA passthrough commands are in progress.
[mkp: hand applied to 4.9/scsi-fixes, tweaked patch description]
Signed-off-by: Andrey Grodzovsky <andrey2805@gmail.com> Acked-by: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com> Cc: <linux-scsi@vger.kernel.org> Cc: Sathya Prakash <sathya.prakash@broadcom.com> Cc: Chaitra P B <chaitra.basappa@broadcom.com> Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com> Cc: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
We accidentally overwrite the original saved value of "flags" so that we
can't re-enable IRQs at the end of the function. Presumably this
function is mostly called with IRQs disabled or it would be obvious in
testing.
Fixes: aceeffbb59bb ("zfcp: trace full payload of all SAN records (req,resp,iels)") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
This was lost with commit 2c55b750a884b86dea8b4cc5f15e1484cc47a25c
("[SCSI] zfcp: Redesign of the debug tracing for SAN records.")
but is necessary for problem determination, e.g. to see the
currently active zone set during automatic port scan.
For the large GPN_FT response (4 pages), save space by not dumping
any empty residual entries.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 2c55b750a884 ("[SCSI] zfcp: Redesign of the debug tracing for SAN records.") Reviewed-by: Alexey Ishchuk <aishchuk@linux.vnet.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
commit 2c55b750a884b86dea8b4cc5f15e1484cc47a25c
("[SCSI] zfcp: Redesign of the debug tracing for SAN records.")
started to add FC_CT_HDR_LEN which made zfcp dump random data
out of bounds for RSPN GS responses because u.rspn.rsp
is the largest and last field in the union of struct zfcp_fc_req.
Other request/response types only happened to stay within bounds
due to the padding of the union or
due to the trace capping of u.gspn.rsp to ZFCP_DBF_SAN_MAX_PAYLOAD.
Timestamp : ...
Area : SAN
Subarea : 00
Level : 1
Exception : -
CPU id : ..
Caller : ...
Record id : 2
Tag : fsscth2
Request id : 0x...
Destination ID : 0x00fffffc
Payload short : 01000000fc0200008002000000000000
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx <=== 00000000000000000000000000000000
Payload length : 32 <===
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 2c55b750a884 ("[SCSI] zfcp: Redesign of the debug tracing for SAN records.") Reviewed-by: Alexey Ishchuk <aishchuk@linux.vnet.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
With commit 2c55b750a884b86dea8b4cc5f15e1484cc47a25c
("[SCSI] zfcp: Redesign of the debug tracing for SAN records.")
we lost the N_Port-ID where an ELS response comes from.
With commit 7c7dc196814b9e1d5cc254dc579a5fa78ae524f7
("[SCSI] zfcp: Simplify handling of ct and els requests")
we lost the N_Port-ID where a CT response comes from.
It's especially useful if the request SAN trace record
with D_ID was already lost due to trace buffer wrap.
GS uses an open WKA port handle and ELS just a D_ID, and
only for ELS we could get D_ID from QTCB bottom via zfcp_fsf_req.
To cover both cases, add a new field to zfcp_fsf_ct_els
and fill it in on request to use in SAN response trace.
Strictly speaking the D_ID on SAN response is the FC frame's S_ID.
We don't need a field for the other end which is always us.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 2c55b750a884 ("[SCSI] zfcp: Redesign of the debug tracing for SAN records.") Fixes: 7c7dc196814b ("[SCSI] zfcp: Simplify handling of ct and els requests") Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
This information was lost with
commit a54ca0f62f953898b05549391ac2a8a4dad6482b
("[SCSI] zfcp: Redesign of the debug tracing for HBA records.")
but is required to debug e.g. invalid handle situations.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: a54ca0f62f95 ("[SCSI] zfcp: Redesign of the debug tracing for HBA records.") Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Since commit a54ca0f62f953898b05549391ac2a8a4dad6482b
("[SCSI] zfcp: Redesign of the debug tracing for HBA records.")
HBA records no longer contain WWPN, D_ID, or LUN
to reduce duplicate information which is already in REC records.
In contrast to "regular" target ports, we don't use recovery to open
WKA ports such as directory/nameserver, so we don't get REC records.
Therefore, introduce pseudo REC running records without any
actual recovery action but including D_ID of WKA port on open/close.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: a54ca0f62f95 ("[SCSI] zfcp: Redesign of the debug tracing for HBA records.") Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: ae0904f60fab ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions.") Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
While retaining the actual filtering according to trace level,
the following commits started to write such filtered records
with a hardcoded record level of 1 instead of the actual record level:
commit 250a1352b95e1db3216e5c5d4f4365bea5122f4a
("[SCSI] zfcp: Redesign of the debug tracing for SCSI records.")
commit a54ca0f62f953898b05549391ac2a8a4dad6482b
("[SCSI] zfcp: Redesign of the debug tracing for HBA records.")
Now we can distinguish written records again for offline level filtering.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 250a1352b95e ("[SCSI] zfcp: Redesign of the debug tracing for SCSI records.") Fixes: a54ca0f62f95 ("[SCSI] zfcp: Redesign of the debug tracing for HBA records.") Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
On a successful end of reopen port forced,
zfcp_erp_strategy_followup_success() re-uses the port erp_action
and the subsequent zfcp_erp_action_cleanup() now
sees ZFCP_ERP_SUCCEEDED with
erp_action->action==ZFCP_ERP_ACTION_REOPEN_PORT
instead of ZFCP_ERP_ACTION_REOPEN_PORT_FORCED
but must not perform zfcp_scsi_schedule_rport_register().
We can detect this because the fresh port reopen erp_action
is in its very first step ZFCP_ERP_STEP_UNINITIALIZED.
Otherwise this opens a time window with unblocked rport
(until the followup port reopen recovery would block it again).
If a scsi_cmnd timeout occurs during this time window
fc_timed_out() cannot work as desired and such command
would indeed time out and trigger scsi_eh. This prevents
a clean and timely path failover.
This should not happen if the path issue can be recovered
on FC transport layer such as path issues involving RSCNs.
Also, unnecessary and repeated DID_IMM_RETRY for pending and
undesired new requests occur because internally zfcp still
has its zfcp_port blocked.
As follow-on errors with scsi_eh, it can cause,
in the worst case, permanently lost paths due to one of:
sd <scsidev>: [<scsidisk>] Medium access timeout failure. Offlining disk!
sd <scsidev>: Device offlined - not ready after error recovery
For fix validation and to aid future debugging with other recoveries
we now also trace (un)blocking of rports.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 5767620c383a ("[SCSI] zfcp: Do not unblock rport from REOPEN_PORT_FORCED") Fixes: a2fa0aede07c ("[SCSI] zfcp: Block FC transport rports early on errors") Fixes: 5f852be9e11d ("[SCSI] zfcp: Fix deadlock between zfcp ERP and SCSI") Fixes: 338151e06608 ("[SCSI] zfcp: make use of fc_remote_port_delete when target port is unavailable") Fixes: 3859f6a248cb ("[PATCH] zfcp: add rports to enable scsi_add_device to work again") Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
In the hardware data router case, introduced with kernel 3.2
commit 86a9668a8d29 ("[SCSI] zfcp: support for hardware data router")
the ELS/GS request&response length needs to be initialized
as in the chained SBAL case.
Otherwise, the FCP channel rejects ELS requests with
FSF_REQUEST_SIZE_TOO_LARGE.
Such ELS requests can be issued by user space through BSG / HBA API,
or zfcp itself uses ADISC ELS for remote port link test on RSCN.
The latter can cause a short path outage due to
unnecessary remote target port recovery because the always
failing ADISC cannot detect extremely short path interruptions
beyond the local FCP channel.
Below example is decoded with zfcpdbf from s390-tools:
Timestamp : ...
Area : SAN
Subarea : 00
Level : 1
Exception : -
CPU id : ..
Caller : zfcp_dbf_san_req+0408
Record id : 1
Tag : fssels1
Request id : 0x<reqid>
Destination ID : 0x00<target d_id>
Payload info : 5200000000000000 <our wwpn > [ADISC]
<our wwnn > 00<s_id> 00000000 00000000000000000000000000000000
Timestamp : ...
Area : HBA
Subarea : 00
Level : 1
Exception : -
CPU id : ..
Caller : zfcp_dbf_hba_fsf_res+0740
Record id : 1
Tag : fs_ferr
Request id : 0x<reqid>
Request status : 0x00000010
FSF cmnd : 0x0000000b [FSF_QTCB_SEND_ELS]
FSF sequence no: 0x...
FSF issued : ...
FSF stat : 0x00000061 [FSF_REQUEST_SIZE_TOO_LARGE]
FSF stat qual : 00000000000000000000000000000000
Prot stat : 0x00000100
Prot stat qual : 00000000000000000000000000000000
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 86a9668a8d29 ("[SCSI] zfcp: support for hardware data router") Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
For an NPIV-enabled FCP device, zfcp can erroneously show
"NPort (fabric via point-to-point)" instead of "NPIV VPORT"
for the port_type sysfs attribute of the corresponding
fc_host.
s390-tools that can be affected are dbginfo.sh and ziomon.
zfcp_fsf_exchange_config_evaluate() ignores
fsf_qtcb_bottom_config.connection_features indicating NPIV
and only sets fc_host_port_type to FC_PORTTYPE_NPORT if
fsf_qtcb_bottom_config.fc_topology is FSF_TOPO_FABRIC.
Only the independent zfcp_fsf_exchange_port_evaluate()
evaluates connection_features to overwrite fc_host_port_type
to FC_PORTTYPE_NPIV in case of NPIV.
Code was introduced with upstream kernel 2.6.30
commit 0282985da5923fa6365adcc1a1586ae0c13c1617
("[SCSI] zfcp: Report fc_host_port_type as NPIV").
This works during FCP device recovery (such as set online)
because it performs FSF_QTCB_EXCHANGE_CONFIG_DATA followed by
FSF_QTCB_EXCHANGE_PORT_DATA in sequence.
However, the zfcp-specific scsi host sysfs attributes
"requests", "megabytes", or "seconds_active" trigger only
zfcp_fsf_exchange_config_evaluate() resetting fc_host
port_type to FC_PORTTYPE_NPORT despite NPIV.
The zfcp-specific scsi host sysfs attribute "utilization"
triggers only zfcp_fsf_exchange_port_evaluate() correcting
the fc_host port_type again in case of NPIV.
Evaluate fsf_qtcb_bottom_config.connection_features
in zfcp_fsf_exchange_config_evaluate() where it belongs to.
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com> Fixes: 0282985da592 ("[SCSI] zfcp: Report fc_host_port_type as NPIV") Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Currently kill_fasync() is called outside the stream lock in
snd_pcm_period_elapsed(). This is potentially racy, since the stream
may get released even during the irq handler is running. Although
snd_pcm_release_substream() calls snd_pcm_drop(), this doesn't
guarantee that the irq handler finishes, thus the kill_fasync() call
outside the stream spin lock may be invoked after the substream is
detached, as recently reported by KASAN.
As a quick workaround, move kill_fasync() call inside the stream
lock. The fasync is rarely used interface, so this shouldn't have a
big impact from the performance POV.
Ideally, we should implement some sync mechanism for the proper finish
of stream and irq handler. But this oneliner should suffice for most
cases, so far.
The pointer callbacks of ali5451 driver may return the value at the
boundary occasionally, and it results in the kernel warning like
snd_ali5451 0000:00:06.0: BUG: , pos = 16384, buffer size = 16384, period size = 1024
It seems that folding the position offset is enough for fixing the
warning and no ill-effect has been seen by that.
The problem happens when you call ioctl(SNDRV_TIMER_IOCTL_CONTINUE) on a
completely new/unused timer -- it will have ->sticks == 0, which causes a
divide by 0 in snd_hrtimer_callback().
- ioctl(SNDRV_TIMER_IOCTL_SELECT), which potentially sets
tu->queue/tu->tqueue to NULL on memory allocation failure, so read()
would get a NULL pointer dereference like the above splat
- the same ioctl() can free tu->queue/to->tqueue which means read()
could potentially see (and dereference) the freed pointer
We can fix both by taking the ioctl_lock mutex when dereferencing
->queue/->tqueue, since that's always held over all the ioctl() code.
Just looking at the code I find it likely that there are more problems
here such as tu->qhead pointing outside the buffer if the size is
changed concurrently using SNDRV_TIMER_IOCTL_PARAMS.
When a seq-virmidi driver is initialized, it registers a rawmidi
instance with its callback to create an associated seq kernel client.
Currently it's done throughly in rawmidi's register_mutex context.
Recently it was found that this may lead to a deadlock another rawmidi
device that is being attached with the sequencer is accessed, as both
open with the same register_mutex. This was actually triggered by
syzkaller, as Dmitry Vyukov reported:
======================================================
[ INFO: possible circular locking dependency detected ]
4.8.0-rc1+ #11 Not tainted
-------------------------------------------------------
syz-executor/7154 is trying to acquire lock:
(register_mutex#5){+.+.+.}, at: [<ffffffff84fd6d4b>] snd_rawmidi_kernel_open+0x4b/0x260 sound/core/rawmidi.c:341
but task is already holding lock:
(&grp->list_mutex){++++.+}, at: [<ffffffff850138bb>] check_and_subscribe_port+0x5b/0x5c0 sound/core/seq/seq_ports.c:495
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
The fix is to simply move the registration parts in
snd_rawmidi_dev_register() to the outside of the register_mutex lock.
The lock is needed only to manage the linked list, and it's not
necessarily to cover the whole initialization process.
Some code (all error handling) submits CDBs that are allocated
on the stack. This breaks with CB/CBI code that tries to create
URB directly from SCSI command buffer - which happens to be in
vmalloced memory with vmalloced kernel stacks.
Let's make copy of the command in usb_stor_CB_transport.
Signed-off-by: Petr Vandrovec <petr@vandrovec.name> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
According to Dave Miller "the networking stack has a
hard requirement that all SKBs which are transmitted
must have their completion signalled in a fininte
amount of time. This is because, until the SKB is
freed by the driver, it holds onto socket,
netfilter, and other subsystem resources."
In summary, this means that using TX IRQ throttling
for the networking gadgets is, at least, complex and
we should avoid it for the time being.
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Suggested-by: David Miller <davem@davemloft.net> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
The current tiocmget implementation would fail to report errors up the
stack and instead leaked a few bits from the stack as a mask of
modem-status flags.
Fixes: 39a66b8d22a3 ("[PATCH] USB: CP2101 Add support for flow control") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
If we don't guarantee that we will always get an
interrupt at least when we're queueing our very last
request, we could fall into situation where we queue
every request with 'no_interrupt' set. This will
cause the link to get stuck.
The behavior above has been triggered with g_ether
and dwc3.
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
This patch fixes a NULL pointer dereference caused by a race codition in
the probe function of the legousbtower driver. It re-structures the
probe function to only register the interface after successfully reading
the board's firmware ID.
The probe function does not deregister the usb interface after an error
receiving the devices firmware ID. The device file registered
(/dev/usb/legousbtower%d) may be read/written globally before the probe
function returns. When tower_delete is called in the probe function
(after an r/w has been initiated), core dev structures are deleted while
the file operation functions are still running. If the 0 address is
mappable on the machine, this vulnerability can be used to create a
Local Priviege Escalation exploit via a write-what-where condition by
remapping dev->interrupt_out_buffer in tower_write. A forged USB device
and local program execution would be required for LPE. The USB device
would have to delay the control message in tower_probe and accept
the control urb in tower_open whilst guest code initiated a write to the
device file as tower_delete is called from the error in tower_probe.
This bug has existed since 2003. Patch tested by emulated device.
Reported-by: James Patrick-Evans <james@jmp-e.com> Tested-by: James Patrick-Evans <james@jmp-e.com> Signed-off-by: James Patrick-Evans <james@jmp-e.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Some full-speed mceusb infrared transceivers contain invalid endpoint
descriptors for their interrupt endpoints, with bInterval set to 0.
In the past they have worked out okay with the mceusb driver, because
the driver sets the bInterval field in the descriptor to 1,
overwriting whatever value may have been there before. However, this
approach was never sanctioned by the USB core, and in fact it does not
work with xHCI controllers, because they use the bInterval value that
was present when the configuration was installed.
Currently usbcore uses 32 ms as the default interval if the value in
the endpoint descriptor is invalid. It turns out that these IR
transceivers don't work properly unless the interval is set to 10 ms
or below. To work around this mceusb problem, this patch changes the
endpoint-descriptor parsing routine, making the default interval value
be 10 ms rather than 32 ms.
The previous driver is possible to stop the transfer wrongly.
For example:
1) An interrupt happens, but not BRDY interruption.
2) Read INTSTS0. And than state->intsts0 is not set to BRDY.
3) BRDY is set to 1 here.
4) Read BRDYSTS.
5) Clear the BRDYSTS. And then. the BRDY is cleared wrongly.
Remarks:
- The INTSTS0.BRDY is read only.
- If any bits of BRDYSTS are set to 1, the BRDY is set to 1.
- If BRDYSTS is 0, the BRDY is set to 0.
So, this patch adds condition to avoid such situation. (And about
NRDYSTS, this is not used for now. But, avoiding any side effects,
this patch doesn't touch it.)
udriver struct allocated by kzalloc() will not be freed
if usb_register() and next calls fail. This patch fixes this
by adding one more step with kfree(udriver) in error path.
Signed-off-by: Alexey Klimov <klimov.linux@gmail.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
After a device is disconnected, xhci_stop_device() will be invoked
in xhci_bus_suspend().
Also the "disconnect" IRQ will have ISR to invoke
xhci_free_virt_device() in this sequence.
xhci_irq -> xhci_handle_event -> handle_cmd_completion ->
xhci_handle_cmd_disable_slot -> xhci_free_virt_device
If xhci->devs[slot_id] has been assigned to NULL in
xhci_free_virt_device(), then virt_dev->eps[i].ring in
xhci_stop_device() may point to an invlid address to cause kernel
panic.
virt_dev = xhci->devs[slot_id];
:
if (virt_dev->eps[i].ring && virt_dev->eps[i].ring->dequeue)
Erroneous or malicious endpoint descriptors may have non-zero bits in
reserved positions, or out-of-bounds values. This patch helps prevent
these from causing problems by bounds-checking the wMaxPacketValue
entries in endpoint descriptors and capping the values at the maximum
allowed.
This issue was first discovered and tests were conducted by Jake Lamberson
<jake.lamberson1@gmail.com>, an intern working for Rosie Hall.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: roswest <roswest@cisco.com> Tested-by: roswest <roswest@cisco.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[wt: adjusted to 3.10 -- no USB_SPEED_SUPER_PLUS]
When using SG lists, we would end up setting
request->actual to:
num_mapped_sgs * (request->length - count)
Let's fix that up by incrementing request->actual
only once.
Reported-by: Brian E Rogers <brian.e.rogers@intel.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
It could be not possible to freeze coredumping task when it waits for
'core_state->startup' completion, because threads are frozen in
get_signal() before they got a chance to complete 'core_state->startup'.
Inability to freeze a task during suspend will cause suspend to fail.
Also CRIU uses cgroup freezer during dump operation. So with an
unfreezable task the CRIU dump will fail because it waits for a
transition from 'FREEZING' to 'FROZEN' state which will never happen.
Use freezer_do_not_count() to tell freezer to ignore coredumping task
while it waits for core_state->startup completion.
Link: http://lkml.kernel.org/r/1475225434-3753-1-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
When root activates a swap partition whose header has the wrong
endianness, nr_badpages elements of badpages are swabbed before
nr_badpages has been checked, leading to a buffer overrun of up to 8GB.
This normally is not a security issue because it can only be exploited
by root (more specifically, a process with CAP_SYS_ADMIN or the ability
to modify a swap file/partition), and such a process can already e.g.
modify swapped-out memory of any other userspace process on the system.
Linus Torvalds [Tue, 8 Nov 2016 10:17:00 +0000 (11:17 +0100)]
Fix potential infoleak in older kernels
Not upstream as it is not needed there.
So a patch something like this might be a safe way to fix the
potential infoleak in older kernels.
THIS IS UNTESTED. It's a very obvious patch, though, so if it compiles
it probably works. It just initializes the output variable with 0 in
the inline asm description, instead of doing it in the exception
handler.
It will generate slightly worse code (a few unnecessary ALU
operations), but it doesn't have any interactions with the exception
handler implementation.
On faulting sigreturn we do get SIGSEGV, all right, but anything
we'd put into pt_regs could end up in the coredump. And since
__copy_from_user() never zeroed on arc, we'd better bugger off
on its failure without copying random uninitialized bits of
kernel stack into pt_regs...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Switching iov_iter fault-in to multipages variants has exposed an old
bug in underlying fault_in_multipages_...(); they break if the range
passed to them wraps around. Normally access_ok() done by callers will
prevent such (and it's a guaranteed EFAULT - ERR_PTR() values fall into
such a range and they should not point to any valid objects).
However, on architectures where userland and kernel live in different
MMU contexts (e.g. s390) access_ok() is a no-op and on those a range
with a wraparound can reach fault_in_multipages_...().
Since any wraparound means EFAULT there, the fix is trivial - turn
those
while (uaddr <= end)
...
into
if (unlikely(uaddr > end))
return -EFAULT;
do
...
while (uaddr <= end);
Reported-by: Jan Stancek <jstancek@redhat.com> Tested-by: Jan Stancek <jstancek@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
Since commit acb2505d0119 ("openrisc: fix copy_from_user()"),
copy_from_user() returns the number of bytes requested, not the
number of bytes not copied.
... that should zero on faults. Also remove the <censored> helpful
logics wrt range truncation copied from ppc32. Where it had ever
been needed only in case of copy_from_user() *and* had not been merged
into the mainline until a month after the need had disappeared.
A decade before openrisc went into mainline, I might add...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
... in all cases, including the failing access_ok()
Note that some architectures using asm-generic/uaccess.h have
__copy_from_user() not zeroing the tail on failure halfway
through. This variant works either way.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[wt: s/might_fault/might_sleep]
* copy_from_user() on access_ok() failure ought to zero the destination
* none of those primitives should skip the access_ok() check in case of
small constant size.
It could be done in exception-handling bits in __get_user_b() et.al.,
but the surgery involved would take more knowledge of sh64 details
than I have or _want_ to have.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
We have one critical section in the syscall entry path in which we switch from
the userspace stack to kernel stack. In the event of an external interrupt, the
interrupt code distinguishes between those two states by analyzing the value of
sr7. If sr7 is zero, it uses the kernel stack. Therefore it's important, that
the value of sr7 is in sync with the currently enabled stack.
This patch now disables interrupts while executing the critical section. This
prevents the interrupt handler to possibly see an inconsistent state which in
the worst case can lead to crashes.
Interestingly, in the syscall exit path interrupts were already disabled in the
critical section which switches back to the userspace stack.
Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Willy Tarreau <w@1wt.eu>
When a device is in a status where CIO has killed all I/O by itself the
interrupt for a clear request may not contain an irb to determine the
clear function. Instead it contains an error pointer -EIO.
This was ignored by the DASD int_handler leading to a hanging device
waiting for a clear interrupt.
Handle -EIO error pointer correctly for requests that are clear pending and
treat the clear as successful.
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com> Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
arch/avr32/kernel/built-in.o: In function `arch_ptrace':
(.text+0x650): undefined reference to `___copy_from_user'
arch/avr32/kernel/built-in.o:(___ksymtab+___copy_from_user+0x0): undefined
reference to `___copy_from_user'
kernel/built-in.o: In function `proc_doulongvec_ms_jiffies_minmax':
(.text+0x5dd8): undefined reference to `___copy_from_user'
kernel/built-in.o: In function `proc_dointvec_minmax_sysadmin':
sysctl.c:(.text+0x6174): undefined reference to `___copy_from_user'
kernel/built-in.o: In function `ptrace_has_cap':
ptrace.c:(.text+0x69c0): undefined reference to `___copy_from_user'
kernel/built-in.o:ptrace.c:(.text+0x6b90): more undefined references to
`___copy_from_user' follow
really ugly, but apparently avr32 compilers turns access_ok() into
something so bad that they want it in assembler. Left that way,
zeroing added in inline wrapper.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
When we merge two contiguous partitions whose signatures are marked
NVRAM_SIG_FREE, We need update prev's length and checksum, then write it
to nvram, not cur's. So lets fix this mistake now.
Also use memset instead of strncpy to set the partition's name. It's
more readable if we want to fill up with duplicate chars .
Fixes: fa2b4e54d41f ("powerpc/nvram: Improve partition removal") Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Willy Tarreau <w@1wt.eu>
Debugging a data corruption issue with virtio-net/vhost-net led to
the observation that __copy_tofrom_user was occasionally returning
a value 16 larger than it should. Since the return value from
__copy_tofrom_user is the number of bytes not copied, this means
that __copy_tofrom_user can occasionally return a value larger
than the number of bytes it was asked to copy. In turn this can
cause higher-level copy functions such as copy_page_to_iter_iovec
to corrupt memory by copying data into the wrong memory locations.
It turns out that the failing case involves a fault on the store
at label 79, and at that point the first unmodified byte of the
destination is at R3 + 16. Consequently the exception handler
for that store needs to add 16 to R3 before using it to work out
how many bytes were not copied, but in this one case it was not
adding the offset to R3. To fix it, this moves the label 179 to
the point where we add 16 to R3. I have checked manually all the
exception handlers for the loads and stores in this code and the
rest of them are correct (it would be excellent to have an
automated test of all the exception cases).
This bug has been present since this code was initially
committed in May 2002 to Linux version 2.5.20.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Willy Tarreau <w@1wt.eu>
__kernel_get_syscall_map() and __kernel_clock_getres() use cmpli to
check if the passed in pointer is non zero. cmpli maps to a 32 bit
compare on binutils, so we ignore the top 32 bits.
A simple test case can be created by passing in a bogus pointer with
the bottom 32 bits clear. Using a clk_id that is handled by the VDSO,
then one that is handled by the kernel shows the problem:
The bigger issue is if we pass a valid pointer with the bottom 32 bits
clear, in this case we will return success but won't write any data
to the pointer.
I stumbled across this issue because the LLVM integrated assembler
doesn't accept cmpli with 3 arguments. Fix this by converting them to
cmpldi.
Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel") Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Willy Tarreau <w@1wt.eu>
In commit c60ac5693c47 ("powerpc: Update kernel VSID range", 2013-03-13)
we lost a check on the region number (the top four bits of the effective
address) for addresses below PAGE_OFFSET. That commit replaced a check
that the top 18 bits were all zero with a check that bits 46 - 59 were
zero (performed for all addresses, not just user addresses).
This means that userspace can access an address like 0x1000_0xxx_xxxx_xxxx
and we will insert a valid SLB entry for it. The VSID used will be the
same as if the top 4 bits were 0, but the page size will be some random
value obtained by indexing beyond the end of the mm_ctx_high_slices_psize
array in the paca. If that page size is the same as would be used for
region 0, then userspace just has an alias of the region 0 space. If the
page size is different, then no HPTE will be found for the access, and
the process will get a SIGSEGV (since hash_page_mm() will refuse to create
a HPTE for the bogus address).
The access beyond the end of the mm_ctx_high_slices_psize can be at most
5.5MB past the array, and so will be in RAM somewhere. Since the access
is a load performed in real mode, it won't fault or crash the kernel.
At most this bug could perhaps leak a little bit of information about
blocks of 32 bytes of memory located at offsets of i * 512kB past the
paca->mm_ctx_high_slices_psize array, for 1 <= i <= 11.
Currently regs_return_value always negates reg[2] if it determines
the syscall has failed, but when called in kernel context this check is
invalid and may result in returning a wrong value.
This fixes errors reported by CONFIG_KPROBES_SANITY_TEST
Fixes: d7e7528bcd45 ("Audit: push audit success and retcode into arch ptrace.h") Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14381/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
Malta boards used with CPU emulators feature a switch to disable use of
an IOCU. Software has to check this switch & ignore any present IOCU if
the switch is closed. The read used to do this was unsafe for 64 bit
kernels, as it simply casted the address 0xbf403000 to a pointer &
dereferenced it. Whilst in a 32 bit kernel this would access kseg1, in a
64 bit kernel this attempts to access xuseg & results in an address
error exception.
Fix by accessing a correctly formed ckseg1 address generated using the
CKSEG1ADDR macro.
Whilst modifying this code, define the name of the register and the bit
we care about within it, which indicates whether PCI DMA is routed to
the IOCU or straight to DRAM. The code previously checked that bit 0 was
also set, but the least significant 7 bits of the CONFIG_GEN0 register
contain the value of the MReqInfo signal provided to the IOCU OCP bus,
so singling out bit 0 makes little sense & that part of the check is
dropped.
When TIF_SINGLESTEP is set for a task, the single-step state machine is
enabled and we must take care not to reset it to the active-not-pending
state if it is already in the active-pending state.
Unfortunately, that's exactly what user_enable_single_step does, by
unconditionally setting the SS bit in the SPSR for the current task.
This causes failures in the GDB testsuite, where GDB ends up missing
expected step traps if the instruction being stepped generates another
trap, e.g. PTRACE_EVENT_FORK from an SVC instruction.
This patch fixes the problem by preserving the current state of the
stepping state machine when TIF_SINGLESTEP is set on the current thread.
Cc: <stable@vger.kernel.org> Reported-by: Yao Qi <yao.qi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
smp_mb__before_spinlock() is intended to upgrade a spin_lock() operation
to a full barrier, such that prior stores are ordered with respect to
loads and stores occuring inside the critical section.
Unfortunately, the core code defines the barrier as smp_wmb(), which
is insufficient to provide the required ordering guarantees when used in
conjunction with our load-acquire-based spinlock implementation.
This patch overrides the arm64 definition of smp_mb__before_spinlock()
to map to a full smp_mb().
Cc: Peter Zijlstra <peterz@infradead.org> Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
AT_VECTOR_SIZE_ARCH should be defined with the maximum number of
NEW_AUX_ENT entries that ARCH_DLINFO can contain, but it wasn't defined
for arm64 at all even though ARCH_DLINFO will contain one NEW_AUX_ENT
for the VDSO address.
This shouldn't be a problem as AT_VECTOR_SIZE_BASE includes space for
AT_BASE_PLATFORM which arm64 doesn't use, but lets define it now and add
the comment above ARCH_DLINFO as found in several other architectures to
remind future modifiers of ARCH_DLINFO to keep AT_VECTOR_SIZE_ARCH up to
date.
Fixes: f668cd1673aa ("arm64: ELF definitions") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
Generally, taking an unexpected exception should be a fatal event, and
bad_mode is intended to cater for this. However, it should be possible
to contain unexpected synchronous exceptions from EL0 without bringing
the kernel down, by sending a SIGILL to the task.
We tried to apply this approach in commit 9955ac47f4ba1c95 ("arm64:
don't kill the kernel on a bad esr from el0"), by sending a signal for
any bad_mode call resulting from an EL0 exception.
However, this also applies to other unexpected exceptions, such as
SError and FIQ. The entry paths for these exceptions branch to bad_mode
without configuring the link register, and have no kernel_exit. Thus, if
we take one of these exceptions from EL0, bad_mode will eventually
return to the original user link register value.
This patch fixes this by introducing a new bad_el0_sync handler to cater
for the recoverable case, and restoring bad_mode to its original state,
whereby it calls panic() and never returns. The recoverable case
branches to bad_el0_sync with a bl, and returns to userspace via the
usual ret_to_user mechanism.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Fixes: 9955ac47f4ba1c95 ("arm64: don't kill the kernel on a bad esr from el0") Reported-by: Mark Salter <msalter@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: stable@vger.kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Willy Tarreau <w@1wt.eu>
SA1111 PCMCIA was broken when PCMCIA switched to using dev_pm_ops for
the PCMCIA socket class. PCMCIA used to handle suspend/resume via the
socket hosting device, which happened at normal device suspend/resume
time.
However, the referenced commit changed this: much of the resume now
happens much earlier, in the noirq resume handler of dev_pm_ops.
However, on SA1111, the PCMCIA device is not accessible as the SA1111
has not been resumed at _noirq time. It's slightly worse than that,
because the SA1111 has already been put to sleep at _noirq time, so
suspend doesn't work properly.
Fix this by converting the core SA1111 code to use dev_pm_ops as well,
and performing its own suspend/resume at noirq time.
This fixes these errors in the kernel log:
pcmcia_socket pcmcia_socket0: time out after reset
pcmcia_socket pcmcia_socket1: time out after reset
and the resulting lack of PCMCIA cards after a S2RAM cycle.
Fixes: d7646f7632549 ("pcmcia: use dev_pm_ops for class pcmcia_socket_class") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Clear the current reset status prior to rebooting the platform. This
adds the bit missing from 04fef228fb00 ("[ARM] pxa: introduce
reset_status and clear_reset_status for driver's usage").
Fixes: 04fef228fb00 ("[ARM] pxa: introduce reset_status and clear_reset_status for driver's usage") Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
If the bootloader uses the long descriptor format and jumps to
kernel decompressor code, TTBCR may not be in a right state.
Before enabling the MMU, it is required to clear the TTBCR.PD0
field to use TTBR0 for translation table walks.
The commit dbece45894d3a ("ARM: 7501/1: decompressor:
reset ttbcr for VMSA ARMv7 cores") does the reset of TTBCR.N, but
doesn't consider all the bits for the size of TTBCR.N.
Clear TTBCR.PD0 field and reset all the three bits of TTBCR.N to
indicate the use of TTBR0 and the correct base address width.
Fixes: dbece45894d3 ("ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores") Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Srinivas Ramana <sramana@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Whilst MPIDR values themselves are less than 32 bits, it is still
perfectly valid for a DT to have #address-cells > 1 in the CPUs node,
resulting in the "reg" property having leading zero cell(s). In that
situation, the big-endian nature of the data conspires with the current
behaviour of only reading the first cell to cause the kernel to think
all CPUs have ID 0, and become resoundingly unhappy as a consequence.
Take the full property length into account when parsing CPUs so as to
be correct under any circumstances.
Cc: Russell King <linux@armlinux.org.uk> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Willy Tarreau <w@1wt.eu>
Not doing so might cause IO-Page-Faults when a device uses
an alias request-id and the alias-dte is left in a lower
page-mode which does not cover the address allocated from
the iova-allocator.
On x86/um CONFIG_SMP is never defined. As a result, several macros
match the asm-generic variant exactly. Drop the local definitions and
pull in asm-generic/barrier.h instead.
This is in preparation to refactoring this code area.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Richard Weinberger <richard@nod.at> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X
relocation to get the symbol address in PIC. When the compressed x86
kernel isn't built as PIC, the linker optimizes R_386_GOT32X relocations
to their fixed symbol addresses. However, when the compressed x86
kernel is loaded at a different address, it leads to the following
load failure:
Failed to allocate space for phdrs
during the decompression stage.
If the compressed x86 kernel is relocatable at run-time, it should be
compiled with -fPIE, instead of -fPIC, if possible and should be built as
Position Independent Executable (PIE) so that linker won't optimize
R_386_GOT32X relocation to its fixed symbol address.
Older linkers generate R_386_32 relocations against locally defined
symbols, _bss, _ebss, _got and _egot, in PIE. It isn't wrong, just less
optimal than R_386_RELATIVE. But the x86 kernel fails to properly handle
R_386_32 relocations when relocating the kernel. To generate
R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as
hidden in both 32-bit and 64-bit x86 kernels.
To build a 64-bit compressed x86 kernel as PIE, we need to disable the
relocation overflow check to avoid relocation overflow errors. We do
this with a new linker command-line option, -z noreloc-overflow, which
got added recently:
Add -z noreloc-overflow command-line option to the x86-64 ELF linker to
disable relocation overflow check. This can be used to avoid relocation
overflow check if there will be no dynamic relocation overflow at
run-time.
The 64-bit compressed x86 kernel is built as PIE only if the linker supports
-z noreloc-overflow. So far 64-bit relocatable compressed x86 kernel
boots fine even when it is built as a normal executable.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org
[ Edited the changelog and comments. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
Å\81ukasz Daniluk reported that on a RHEL kernel that his machine would lock up
after enabling function tracer. I asked him to bisect the functions within
available_filter_functions, which he did and it came down to three:
_paravirt_nop(), _paravirt_ident_32() and _paravirt_ident_64()
It was found that this is only an issue when noreplace-paravirt is added
to the kernel command line.
This means that those functions are most likely called within critical
sections of the funtion tracer, and must not be traced.
In newer kenels _paravirt_nop() is defined within gcc asm(), and is no
longer an issue. But both _paravirt_ident_{32,64}() causes the
following splat when they are traced:
Currently it's possible for broken (or malicious) userspace to flood a
kernel log indefinitely with messages a-la
Program dmidecode tried to access /dev/mem between f0000->100000
because range_is_allowed() is case of CONFIG_STRICT_DEVMEM being turned on
dumps this information each and every time devmem_is_allowed() fails.
Reportedly userspace that is able to trigger contignuous flow of these
messages exists.
It would be possible to rate limit this message, but that'd have a
questionable value; the administrator wouldn't get information about all
the failing accessess, so then the information would be both superfluous
and incomplete at the same time :)
Returning EPERM (which is what is actually happening) is enough indication
for userspace what has happened; no need to log this particular error as
some sort of special condition.
Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1607081137020.24757@cbobk.fhfr.pm Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
projects / thirdparty / kernel / stable.git / log
