- 24 Apr, 2017 4 commits
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Naveen N. Rao authored
KPROBES_ON_FTRACE avoids much of the overhead of regular kprobes as it eliminates the need for a trap, as well as the need to emulate or single-step instructions. Though OPTPROBES provides us with similar performance, we have limited optprobes trampoline slots. As such, when asked to probe at a function entry, default to using the ftrace infrastructure. With: # cd /sys/kernel/debug/tracing # echo 'p _do_fork' > kprobe_events before patch: # cat ../kprobes/list c0000000000daf08 k _do_fork+0x8 [DISABLED] c000000000044fc0 k kretprobe_trampoline+0x0 [OPTIMIZED] and after patch: # cat ../kprobes/list c0000000000d074c k _do_fork+0xc [DISABLED][FTRACE] c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED] Signed-off-by:
Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au>
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Naveen N. Rao authored
kprobe_lookup_name() is specific to the kprobe subsystem and may not always return the function entry point (in a subsequent patch for KPROBES_ON_FTRACE). For looking up function entry points, introduce a separate helper and use it in optprobes.c Signed-off-by:
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Naveen N. Rao authored
Allow kprobes to be placed on ftrace _mcount() call sites. This optimization avoids the use of a trap, by riding on ftrace infrastructure. This depends on HAVE_DYNAMIC_FTRACE_WITH_REGS which depends on MPROFILE_KERNEL, which is only currently enabled on powerpc64le with newer toolchains. Based on the x86 code by Masami. Signed-off-by:
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Naveen N. Rao authored
Pass the real LR to the ftrace handler. This is needed for KPROBES_ON_FTRACE for the pre handlers. Also, with KPROBES_ON_FTRACE, the link register may be updated by the pre handlers or by a registed kretprobe. Honor updated LR by restoring it from pt_regs, rather than from the stack save area. Live patch and function graph continue to work fine with this change. Signed-off-by:
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- 20 Apr, 2017 6 commits
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Naveen N. Rao authored
On kprobe handler re-entry, try to emulate the instruction rather than single stepping always. Acked-by:
Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Signed-off-by:
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Naveen N. Rao authored
Factor out code to emulate instruction into a try_to_emulate() helper function. This makes no functional changes. Acked-by:
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Naveen N. Rao authored
With ABIv2, we offset 8 bytes into a function to get at the local entry point. mpe: NB this function is currently not called, the change to generic code to call it is being merged via the tip tree. Acked-by:
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Naveen N. Rao authored
commit 239aeba7 ("perf powerpc: Fix kprobe and kretprobe handling with kallsyms on ppc64le") changed how we use the offset field in struct kprobe on ABIv2. perf now offsets from the global entry point if an offset is specified and otherwise chooses the local entry point. Fix the same in kernel for kprobe API users. We do this by extending kprobe_lookup_name() to accept an additional parameter to indicate the offset specified with the kprobe registration. If offset is 0, we return the local function entry and return the global entry point otherwise. With: # cd /sys/kernel/debug/tracing/ # echo "p _do_fork" >> kprobe_events # echo "p _do_fork+0x10" >> kprobe_events before this patch: # cat ../kprobes/list c0000000000d0748 k _do_fork+0x8 [DISABLED] c0000000000d0758 k _do_fork+0x18 [DISABLED] c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED] and after: # cat ../kprobes/list c0000000000d04c8 k _do_fork+0x8 [DISABLED] c0000000000d04d0 k _do_fork+0x10 [DISABLED] c0000000000412b0 k kretprobe_trampoline+0x0 [OPTIMIZED] Acked-by:
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Naveen N. Rao authored
The macro is now pretty long and ugly on powerpc. In the light of further changes needed here, convert it to a __weak variant to be over-ridden with a nicer looking function. Suggested-by:
Masami Hiramatsu <mhiramat@kernel.org> Acked-by:
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Masami Hiramatsu authored
Skip preparing optprobe if the probe is ftrace-based, since anyway, it must not be optimized (or already optimized by ftrace). Tested-by:
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- 20 Mar, 2017 5 commits
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Linus Torvalds authored
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Linus Torvalds authored
This BUG_ON() triggered for me once at shutdown, and I don't see a reason for the check. The code correctly checks whether the swap slot cache is usable or not, so an uninitialized swap slot cache is not actually problematic afaik. I've temporarily just switched the BUG_ON() to a WARN_ON_ONCE(), since I'm not sure why that seemingly pointless check was there. I suspect the real fix is to just remove it entirely, but for now we'll warn about it but not bring the machine down. Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by:Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull more powerpc fixes from Michael Ellerman: "A couple of minor powerpc fixes for 4.11: - wire up statx() syscall - don't print a warning on memory hotplug when HPT resizing isn't available Thanks to: David Gibson, Chandan Rajendra" * tag 'powerpc-4.11-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/pseries: Don't give a warning when HPT resizing isn't available powerpc: Wire up statx() syscall -
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linuxLinus Torvalds authored
Pull parisc fixes from Helge Deller: - Mikulas Patocka added support for R_PARISC_SECREL32 relocations in modules with CONFIG_MODVERSIONS. - Dave Anglin optimized the cache flushing for vmap ranges. - Arvind Yadav provided a fix for a potential NULL pointer dereference in the parisc perf code (and some code cleanups). - I wired up the new statx system call, fixed some compiler warnings with the access_ok() macro and fixed shutdown code to really halt a system at shutdown instead of crashing & rebooting. * 'parisc-4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Fix system shutdown halt parisc: perf: Fix potential NULL pointer dereference parisc: Avoid compiler warnings with access_ok() parisc: Wire up statx system call parisc: Optimize flush_kernel_vmap_range and invalidate_kernel_vmap_range parisc: support R_PARISC_SECREL32 relocation in modules
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git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pendingLinus Torvalds authored
Pull SCSI target fixes from Nicholas Bellinger: "The bulk of the changes are in qla2xxx target driver code to address various issues found during Cavium/QLogic's internal testing (stable CC's included), along with a few other stability and smaller miscellaneous improvements. There are also a couple of different patch sets from Mike Christie, which have been a result of his work to use target-core ALUA logic together with tcm-user backend driver. Finally, a patch to address some long standing issues with pass-through SCSI export of TYPE_TAPE + TYPE_MEDIUM_CHANGER devices, which will make folks using physical (or virtual) magnetic tape happy" * git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (28 commits) qla2xxx: Update driver version to 9.00.00.00-k qla2xxx: Fix delayed response to command for loop mode/direct connect. qla2xxx: Change scsi host lookup method. qla2xxx: Add DebugFS node to display Port Database qla2xxx: Use IOCB interface to submit non-critical MBX. qla2xxx: Add async new target notification qla2xxx: Export DIF stats via debugfs qla2xxx: Improve T10-DIF/PI handling in driver. qla2xxx: Allow relogin to proceed if remote login did not finish qla2xxx: Fix sess_lock & hardware_lock lock order problem. qla2xxx: Fix inadequate lock protection for ABTS. qla2xxx: Fix request queue corruption. qla2xxx: Fix memory leak for abts processing qla2xxx: Allow vref count to timeout on vport delete. tcmu: Convert cmd_time_out into backend device attribute tcmu: make cmd timeout configurable tcmu: add helper to check if dev was configured target: fix race during implicit transition work flushes target: allow userspace to set state to transitioning target: fix ALUA transition timeout handling ...
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- 19 Mar, 2017 15 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimmLinus Torvalds authored
Pull device-dax fixes from Dan Williams: "The device-dax driver was not being careful to handle falling back to smaller fault-granularity sizes. The driver already fails fault attempts that are smaller than the device's alignment, but it also needs to handle the cases where a larger page mapping could be established. For simplicity of the immediate fix the implementation just signals VM_FAULT_FALLBACK until fault-size == device-alignment. One fix is for -stable to address pmd-to-pte fallback from the original implementation, another fix is for the new (introduced in 4.11-rc1) pud-to-pmd regression, and a typo fix comes along for the ride. These have received a build success notification from the kbuild robot" * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: device-dax: fix debug output typo device-dax: fix pud fault fallback handling device-dax: fix pmd/pte fault fallback handling
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Himanshu Madhani authored
Signed-off-by:
Himanshu Madhani <himanshu.madhani@cavium.com> signed-off-by:
Giridhar Malavali <giridhar.malavali@cavium.com> Signed-off-by:
Nicholas Bellinger <nab@linux-iscsi.org>
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Quinn Tran authored
Current driver wait for FW to be in the ready state before processing in-coming commands. For Arbitrated Loop or Point-to- Point (not switch), FW Ready state can take a while. FW will transition to ready state after all Nports have been logged in. In the mean time, certain initiators have completed the login and starts IO. Driver needs to start processing all queues if FW is already started. Signed-off-by:
Quinn Tran <quinn.tran@cavium.com> Signed-off-by:
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Quinn Tran authored
For target mode, when new scsi command arrive, driver first performs a look up of the SCSI Host. The current look up method is based on the ALPA portion of the NPort ID. For Cisco switch, the ALPA can not be used as the index. Instead, the new search method is based on the full value of the Nport_ID via btree lib. Signed-off-by:
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Himanshu Madhani authored
Signed-off-by:
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Quinn Tran authored
The Mailbox interface is currently over subscribed. We like to reserve the Mailbox interface for the chip managment and link initialization. Any non essential Mailbox command will be routed through the IOCB interface. The IOCB interface is able to absorb more commands. Following commands are being routed through IOCB interface - Get ID List (007Ch) - Get Port DB (0064h) - Get Link Priv Stats (006Dh) Signed-off-by:
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Quinn Tran authored
Signed-off-by:
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Anil Gurumurthy authored
Signed-off-by:
Anil Gurumurthy <anil.gurumurthy@cavium.com> Signed-off-by:
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Quinn Tran authored
Add routines to support T10 DIF tag. Signed-off-by:
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Quinn Tran authored
If the remote port have started the login process, then the PLOGI and PRLI should be back to back. Driver will allow the remote port to complete the process. For the case where the remote port decide to back off from sending PRLI, this local port sets an expiration timer for the PRLI. Once the expiration time passes, the relogin retry logic is allowed to go through and perform login with the remote port. Signed-off-by:
Quinn Tran <quinn.tran@qlogic.com> Signed-off-by:
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Quinn Tran authored
The main lock that needs to be held for CMD or TMR submission to upper layer is the sess_lock. The sess_lock is used to serialize cmd submission and session deletion. The addition of hardware_lock being held is not necessary. This patch removes hardware_lock dependency from CMD/TMR submission. Use hardware_lock only for error response in this case. Path1 CPU0 CPU1 ---- ---- lock(&(&ha->tgt.sess_lock)->rlock); lock(&(&ha->hardware_lock)->rlock); lock(&(&ha->tgt.sess_lock)->rlock); lock(&(&ha->hardware_lock)->rlock); Path2/deadlock *** DEADLOCK *** Call Trace: dump_stack+0x85/0xc2 print_circular_bug+0x1e3/0x250 __lock_acquire+0x1425/0x1620 lock_acquire+0xbf/0x210 _raw_spin_lock_irqsave+0x53/0x70 qlt_sess_work_fn+0x21d/0x480 [qla2xxx] process_one_work+0x1f4/0x6e0 Cc: <stable@vger.kernel.org> Cc: Bart Van Assche <Bart.VanAssche@sandisk.com> Reported-by:Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by:
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Quinn Tran authored
Normally, ABTS is sent to Target Core as Task MGMT command. In the case of error, qla2xxx needs to send response, hardware_lock is required to prevent request queue corruption. Cc: <stable@vger.kernel.org> Signed-off-by:
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Quinn Tran authored
When FW notify driver or driver detects low FW resource, driver tries to send out Busy SCSI Status to tell Initiator side to back off. During the send process, the lock was not held. Cc: <stable@vger.kernel.org> Signed-off-by:
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Quinn Tran authored
Cc: <stable@vger.kernel.org> Signed-off-by:
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Joe Carnuccio authored
Cc: <stable@vger.kernel.org> Signed-off-by:
Joe Carnuccio <joe.carnuccio@cavium.com> Signed-off-by:
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- 18 Mar, 2017 10 commits
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Nicholas Bellinger authored
Instead of putting cmd_time_out under ../target/core/user_0/foo/control, which has historically been used by parameters needed for initial backend device configuration, go ahead and move cmd_time_out into a backend device attribute. In order to do this, tcmu_module_init() has been updated to create a local struct configfs_attribute **tcmu_attrs, that is based upon the existing passthrough_attrib_attrs along with the new cmd_time_out attribute. Once **tcm_attrs has been setup, go ahead and point it at tcmu_ops->tb_dev_attrib_attrs so it's picked up by target-core. Also following MNC's previous change, ->cmd_time_out is stored in milliseconds but exposed via configfs in seconds. Also, note this patch restricts the modification of ->cmd_time_out to before + after the TCMU device has been configured, but not while it has active fabric exports. Cc: Mike Christie <mchristi@redhat.com> Signed-off-by: -
Mike Christie authored
A single daemon could implement multiple types of devices using multuple types of real devices that may not support restarting from crashes and/or handling tcmu timeouts. This makes the cmd timeout configurable, so handlers that do not support it can turn if off for now. Signed-off-by:
Mike Christie <mchristi@redhat.com> Signed-off-by:
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Mike Christie authored
This adds a helper to check if the dev was configured. It will be used in the next patch to prevent updates to some config settings after the device has been setup. Signed-off-by:
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git://github.com/openrisc/linuxLinus Torvalds authored
Pull OpenRISC fixes from Stafford Horne: "OpenRISC fixes for build issues that were exposed by kbuild robots after 4.11 merge. All from allmodconfig builds. This includes: - bug in the handling of 8-byte get_user() calls - module build failure due to multile missing symbol exports" * tag 'openrisc-for-linus' of git://github.com/openrisc/linux: openrisc: Export symbols needed by modules openrisc: fix issue handling 8 byte get_user calls openrisc: xchg: fix `computed is not used` warning
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Mike Christie authored
This fixes the following races: 1. core_alua_do_transition_tg_pt could have read tg_pt_gp_alua_access_state and gone into this if chunk: if (!explicit && atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) == ALUA_ACCESS_STATE_TRANSITION) { and then core_alua_do_transition_tg_pt_work could update the state. core_alua_do_transition_tg_pt would then only set tg_pt_gp_alua_pending_state and the tg_pt_gp_alua_access_state would not get updated with the second calls state. 2. core_alua_do_transition_tg_pt could be setting tg_pt_gp_transition_complete while the tg_pt_gp_transition_work is already completing. core_alua_do_transition_tg_pt then waits on the completion that will never be called. To handle these issues, we just call flush_work which will return when core_alua_do_transition_tg_pt_work has completed so there is no need to do the complete/wait. And, if core_alua_do_transition_tg_pt_work was running, instead of trying to sneak in the state change, we just schedule up another core_alua_do_transition_tg_pt_work call. Note that this does not handle a possible race where there are multiple threads call core_alua_do_transition_tg_pt at the same time. I think we need a mutex in target_tg_pt_gp_alua_access_state_store. Signed-off-by: -
Mike Christie authored
Userspace target_core_user handlers like tcmu-runner may want to set the ALUA state to transitioning while it does implicit transitions. This patch allows that state when set from configfs. Signed-off-by:
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Mike Christie authored
The implicit transition time tells initiators the min time to wait before timing out a transition. We currently schedule the transition to occur in tg_pt_gp_implicit_trans_secs seconds so there is no room for delays. If core_alua_do_transition_tg_pt_work->core_alua_update_tpg_primary_metadata needs to write out info to a remote file, then the initiator can easily time out the operation. Signed-off-by:
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Mike Christie authored
If tcmu-runner is processing a STPG and needs to change the kernel's ALUA state then we cannot use the same work queue for task management requests and ALUA transitions, because we could deadlock. The problem occurs when a STPG times out before tcmu-runner is able to call into target_tg_pt_gp_alua_access_state_store-> core_alua_do_port_transition -> core_alua_do_transition_tg_pt -> queue_work. In this case, the tmr is on the work queue waiting for the STPG to complete, but the STPG transition is now queued behind the waiting tmr. Note: This bug will also be fixed by this patch: http://www.spinics.net/lists/target-devel/msg14560.html which switches the tmr code to use the system workqueues. For both, I am not sure if we need a dedicated workqueue since it is not a performance path and I do not think we need WQ_MEM_RECLAIM to make forward progress to free up memory like the block layer does. Signed-off-by:
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Mike Christie authored
We do not setup the LU group for pscsi devices, so if you write a state to alua_access_state that will cause a transition you will get a NULL pointer dereference. This patch will fail attempts to try and transition the path for backend devices that set the TRANSPORT_FLAG_PASSTHROUGH_ALUA flag. Signed-off-by:
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Mike Christie authored
This patch allows passthrough backends to use the core/base LIO ALUA setup and state checks, but still handle the execution of commands. This will allow the target_core_user module to execute STPG and RTPG in userspace, and not have to duplicate the ALUA state checks, path information (needed so we can check if command is executable on specific paths) and setup (rtslib sets/updates the configfs ALUA interface like it does for iblock or file). For STPG, the target_core_user userspace daemon, tcmu-runner will still execute the STPG, and to update the core/base LIO state it will use the existing configfs interface. For RTPG, tcmu-runner will loop over configfs and/or cache the state. Signed-off-by:
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