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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Sasha Levin <sashal@kernel.org>
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	Scott Wood <swood@redhat.com>, Wu Hao <hao.wu@intel.com>,
	Alan Tull <atull@kernel.org>,
	linux-fpga@vger.kernel.org
Subject: Re: [PATCH AUTOSEL 5.1 16/59] fpga: dfl: Add lockdep classes for pdata->lock
Date: Sun, 16 Jun 2019 09:09:14 +0200
Message-ID: <20190616070914.GA4464@kroah.com> (raw)
In-Reply-To: <20190615224159.GU1513@sasha-vm>

On Sat, Jun 15, 2019 at 06:41:59PM -0400, Sasha Levin wrote:
> On Sat, Jun 15, 2019 at 07:47:39AM +0200, Greg Kroah-Hartman wrote:
> > On Fri, Jun 14, 2019 at 04:28:00PM -0400, Sasha Levin wrote:
> > > From: Scott Wood <swood@redhat.com>
> > > 
> > > [ Upstream commit dfe3de8d397bf878b31864d4e489d41118ec475f ]
> > > 
> > > struct dfl_feature_platform_data (and it's mutex) is used
> > > by both fme and port devices, and when lockdep is enabled it
> > > complains about nesting between these locks.  Tell lockdep about
> > > the difference so it can track each class separately.
> > > 
> > > Here's the lockdep complaint:
> > > [  409.680668] WARNING: possible recursive locking detected
> > > [  409.685983] 5.1.0-rc3.fpga+ #1 Tainted: G            E
> > > [  409.691469] --------------------------------------------
> > > [  409.696779] fpgaconf/9348 is trying to acquire lock:
> > > [  409.701746] 00000000a443fe2e (&pdata->lock){+.+.}, at: port_enable_set+0x24/0x60 [dfl_afu]
> > > [  409.710006]
> > > [  409.710006] but task is already holding lock:
> > > [  409.715837] 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme]
> > > [  409.724012]
> > > [  409.724012] other info that might help us debug this:
> > > [  409.730535]  Possible unsafe locking scenario:
> > > [  409.730535]
> > > [  409.736457]        CPU0
> > > [  409.738910]        ----
> > > [  409.741360]   lock(&pdata->lock);
> > > [  409.744679]   lock(&pdata->lock);
> > > [  409.747999]
> > > [  409.747999]  *** DEADLOCK ***
> > > [  409.747999]
> > > [  409.753920]  May be due to missing lock nesting notation
> > > [  409.753920]
> > > [  409.760704] 4 locks held by fpgaconf/9348:
> > > [  409.764805]  #0: 0000000063b78782 (&pdata->lock){+.+.}, at: fme_pr_ioctl+0x21d/0x330 [dfl_fme]
> > > [  409.773408]  #1: 00000000213c8a66 (&region->mutex){+.+.}, at: fpga_region_program_fpga+0x24/0x200 [fpga_region]
> > > [  409.783489]  #2: 00000000fe63afb9 (&mgr->ref_mutex){+.+.}, at: fpga_mgr_lock+0x15/0x40 [fpga_mgr]
> > > [  409.792354]  #3: 000000000b2285c5 (&bridge->mutex){+.+.}, at: __fpga_bridge_get+0x26/0xa0 [fpga_bridge]
> > > [  409.801740]
> > > [  409.801740] stack backtrace:
> > > [  409.806102] CPU: 45 PID: 9348 Comm: fpgaconf Kdump: loaded Tainted: G            E     5.1.0-rc3.fpga+ #1
> > > [  409.815658] Hardware name: Intel Corporation S2600BT/S2600BT, BIOS SE5C620.86B.01.00.0763.022420181017 02/24/2018
> > > [  409.825911] Call Trace:
> > > [  409.828369]  dump_stack+0x5e/0x8b
> > > [  409.831686]  __lock_acquire+0xf3d/0x10e0
> > > [  409.835612]  ? find_held_lock+0x3c/0xa0
> > > [  409.839451]  lock_acquire+0xbc/0x1d0
> > > [  409.843030]  ? port_enable_set+0x24/0x60 [dfl_afu]
> > > [  409.847823]  ? port_enable_set+0x24/0x60 [dfl_afu]
> > > [  409.852616]  __mutex_lock+0x86/0x970
> > > [  409.856195]  ? port_enable_set+0x24/0x60 [dfl_afu]
> > > [  409.860989]  ? port_enable_set+0x24/0x60 [dfl_afu]
> > > [  409.865777]  ? __mutex_unlock_slowpath+0x4b/0x290
> > > [  409.870486]  port_enable_set+0x24/0x60 [dfl_afu]
> > > [  409.875106]  fpga_bridges_disable+0x36/0x50 [fpga_bridge]
> > > [  409.880502]  fpga_region_program_fpga+0xea/0x200 [fpga_region]
> > > [  409.886338]  fme_pr_ioctl+0x13e/0x330 [dfl_fme]
> > > [  409.890870]  fme_ioctl+0x66/0xe0 [dfl_fme]
> > > [  409.894973]  do_vfs_ioctl+0xa9/0x720
> > > [  409.898548]  ? lockdep_hardirqs_on+0xf0/0x1a0
> > > [  409.902907]  ksys_ioctl+0x60/0x90
> > > [  409.906225]  __x64_sys_ioctl+0x16/0x20
> > > [  409.909981]  do_syscall_64+0x5a/0x220
> > > [  409.913644]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > > [  409.918698] RIP: 0033:0x7f9d31b9b8d7
> > > [  409.922276] Code: 44 00 00 48 8b 05 b9 15 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 89 15 2d 00 f7 d8 64 89 01 48
> > > [  409.941020] RSP: 002b:00007ffe4cae0d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
> > > [  409.948588] RAX: ffffffffffffffda RBX: 00007f9d32ade6a0 RCX: 00007f9d31b9b8d7
> > > [  409.955719] RDX: 00007ffe4cae0df0 RSI: 000000000000b680 RDI: 0000000000000003
> > > [  409.962852] RBP: 0000000000000003 R08: 00007f9d2b70a177 R09: 00007ffe4cae0e40
> > > [  409.969984] R10: 00007ffe4cae0160 R11: 0000000000000202 R12: 00007ffe4cae0df0
> > > [  409.977115] R13: 000000000000b680 R14: 0000000000000000 R15: 00007ffe4cae0f60
> > > 
> > > Signed-off-by: Scott Wood <swood@redhat.com>
> > > Acked-by: Wu Hao <hao.wu@intel.com>
> > > Acked-by: Alan Tull <atull@kernel.org>
> > > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > > ---
> > >  drivers/fpga/dfl.c | 16 +++++++++++++++-
> > >  1 file changed, 15 insertions(+), 1 deletion(-)
> > 
> > Adding lockdep stuff is not really needed for stable kernels, please
> > drop this from all trees.
> 
> For actual splats? Why? I treat them as compiler warnings. Keeping these
> around will just make them show up over and over in testing (at least
> until we unify our testing story...).

Ah, good point, ok, leave this in :)

thanks,

greg k-h

  reply index

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-14 20:27 [PATCH AUTOSEL 5.1 01/59] lkdtm/usercopy: Moves the KERNEL_DS test to non-canonical Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 02/59] ARC: fix build warnings Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 03/59] dmaengine: jz4780: Fix transfers being ACKed too soon Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 04/59] dmaengine: dw-axi-dmac: fix null dereference when pointer first is null Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 05/59] dmaengine: mediatek-cqdma: sleeping in atomic context Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 06/59] dmaengine: sprd: Fix the possible crash when getting descriptor status Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 07/59] dmaengine: sprd: Add validation of current descriptor in irq handler Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 08/59] dmaengine: sprd: Fix the incorrect start for 2-stage destination channels Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 09/59] dmaengine: sprd: Fix block length overflow Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 10/59] dmaengine: sprd: Fix the right place to configure 2-stage transfer Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 11/59] ARC: [plat-hsdk]: Add missing multicast filter bins number to GMAC node Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 12/59] ARC: [plat-hsdk]: Add missing FIFO size entry in " Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 13/59] MIPS: mark ginvt() as __always_inline Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 14/59] fpga: stratix10-soc: fix use-after-free on s10_init() Sasha Levin
2019-06-14 20:27 ` [PATCH AUTOSEL 5.1 15/59] fpga: dfl: afu: Pass the correct device to dma_mapping_error() Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 16/59] fpga: dfl: Add lockdep classes for pdata->lock Sasha Levin
2019-06-15  5:47   ` Greg Kroah-Hartman
2019-06-15 22:41     ` Sasha Levin
2019-06-16  7:09       ` Greg Kroah-Hartman [this message]
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 17/59] fpga: dfl: expand minor range when registering chrdev region Sasha Levin
2019-06-15  5:48   ` Greg Kroah-Hartman
2019-06-23 19:26     ` Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 18/59] parport: Fix mem leak in parport_register_dev_model Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 19/59] parisc: Fix compiler warnings in float emulation code Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 20/59] habanalabs: fix bug in checking huge page optimization Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 21/59] IB/rdmavt: Fix alloc_qpn() WARN_ON() Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 22/59] IB/hfi1: Insure freeze_work work_struct is canceled on shutdown Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 23/59] IB/{qib, hfi1, rdmavt}: Correct ibv_devinfo max_mr value Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 24/59] IB/hfi1: Validate page aligned for a given virtual address Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 25/59] MIPS: uprobes: remove set but not used variable 'epc' Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 26/59] crypto: hmac - fix memory leak in hmac_init_tfm() Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 27/59] xtensa: Fix section mismatch between memblock_reserve and mem_reserve Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 28/59] kselftest/cgroup: fix unexpected testing failure on test_memcontrol Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 29/59] kselftest/cgroup: fix unexpected testing failure on test_core Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 30/59] kselftest/cgroup: fix incorrect test_core skip Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 31/59] userfaultfd: selftest: fix compiler warning Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 32/59] selftests: vm: install test_vmalloc.sh for run_vmtests Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 33/59] nds32: Avoid IEX status being incorrectly modified Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 34/59] net: dsa: mv88e6xxx: avoid error message on remove from VLAN 0 Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 35/59] net: hns: Fix loopback test failed at copper ports Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 36/59] mdesc: fix a missing-check bug in get_vdev_port_node_info() Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 37/59] sparc: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 38/59] net: ethernet: mediatek: Use hw_feature to judge if HWLRO is supported Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 39/59] net: ethernet: mediatek: Use NET_IP_ALIGN to judge if HW RX_2BYTE_OFFSET is enabled Sasha Levin
2019-06-14 20:28 ` [PATCH AUTOSEL 5.1 40/59] selftests: set sysctl bc_forwarding properly in router_broadcast.sh Sasha Levin

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