Messages in this thread |  | | Subject | Re: [PATCH] PCI: designware: add a check of msi_desc in irqchip | From | Cao Zou <> | Date | Fri, 22 Dec 2017 11:04:16 +0800 |
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On 12/20/2017 12:20 AM, Lorenzo Pieralisi wrote: > On Mon, Dec 18, 2017 at 10:02:20AM +0800, Cao Zou wrote: >> >> On 12/16/2017 01:20 AM, Marc Zyngier wrote: >>> On 15/12/17 16:17, Lorenzo Pieralisi wrote: >>>> [+Marc] >>>> >>>> On Thu, Dec 14, 2017 at 10:21:23AM +0800, cao.zou@windriver.com wrote: >>>>> From: Zou Cao <cao.zou@windriver.com> >>>>> >>>>> When PCIE host setup, 32 MSI irq descriptions are created, but its >>>>> msi_desc is NULL, msi_desc is bound in MSI irq requested by PCI device, >>>>> normally just part of MSI are used, for others not used MSI irqs, its >>>>> msi_desc is NULL, it is dangerous for MSI irq mask when MSI irq mask use >>>>> the msi_desc to mask irq without checking, normally not used MSI irqs are >>>>> never masked, it looks fine, but in some specified case, such as kdump, >>>>> machine_kexec_mask_interrupts will force to mask these not used MSI irqs, >>>>> than a crash will happen with NULL msi_desc. it is necessary to add check >>>>> of msi_desc in irqchip, if we still bind the msi_desc only in irqs request >>>>> and mask MSI irq by msi_desc. >>>>> >>>>> Add dwc_pci_msi_mask/unmask_irq, so we can get a chance to check the >>>>> msi_desc. >>>>> >>>>> here is reproduced crash log in IMX7-SABER board with Intel 1030 PCI, >>>>> when running kdump by "echo c > /proc/sysrq-trigger": >>>>> >>>>> sysrq: SysRq : Trigger a crash >>>>> Unable to handle kernel NULL pointer dereference at virtual address 00000000 >>>>> pgd = 98ee1839 >>>>> [00000000] *pgd=00000000 >>>>> Internal error: Oops: 805 [#1] SMP ARM >>>>> Modules linked in: >>>>> CPU: 0 PID: 1370 Comm: sh Not tainted 4.15.0-rc3-00033-ga638349 #1 >>>>> Hardware name: Freescale i.MX7 Dual (Device Tree) >>>>> PC is at sysrq_handle_crash+0x50/0x98 >>>>> LR is at sysrq_handle_crash+0x50/0x98 >>>>> <snip> >>>>> Backtrace: >>>>> [<c047a15c>] (msi_set_mask_bit) from [<c047a1f0>] (pci_msi_mask_irq+0x14/0x18) >>>>> [<c047a1dc>] (pci_msi_mask_irq) from [<c011142c>] (machine_crash_shutdown+0xd8/0x190) >>>>> [<c0111354>] (machine_crash_shutdown) from [<c01b2924>] (__crash_kexec+0x5c/0xa0) >>>>> [<c01b28c8>] (__crash_kexec) from [<c01b29dc>] (crash_kexec+0x74/0x80) >>>>> [<c01b2968>] (crash_kexec) from [<c010cfa4>] (die+0x220/0x358) >>>>> [<c010cd84>] (die) from [<c01169f0>] (__do_kernel_fault.part.0+0x5c/0x7c) >>>>> [<c0116994>] (__do_kernel_fault.part.0) from [<c0116784>] (do_page_fault+0x2cc/0x37c) >>>>> [<c01164b8>] (do_page_fault) from [<c0116970>] (do_translation_fault+0xb0/0xbc) >>>>> [<c01168c0>] (do_translation_fault) from [<c010138c>] (do_DataAbort+0x3c/0xbc) >>>>> [<c0101350>] (do_DataAbort) from [<c010d944>] (__dabt_svc+0x64/0xa0) >>>>> Exception stack(0xec08bdf8 to 0xec08be40) >>>>> bde0: 00000000 ec08be10 >>>>> be00: 00000000 00000000 00000000 00000001 00000063 00000000 00000007 ec08a000 >>>>> be20: 00000000 ec08be5c ec08be48 ec08be48 c04c46b8 c04c46b8 60060013 ffffffff >>>>> [<c04c4668>] (sysrq_handle_crash) from [<c04c4900>] (__handle_sysrq+0xe0/0x254) >>>>> [<c04c4820>] (__handle_sysrq) from [<c04c4aec>] (write_sysrq_trigger+0x78/0x90) >>>>> [<c04c4a74>] (write_sysrq_trigger) from [<c029148c>] (proc_reg_write+0x68/0x90) >>>>> [<c0291424>] (proc_reg_write) from [<c0229ef8>] (__vfs_write+0x34/0x12c) >>>>> [<c0229ec4>] (__vfs_write) from [<c022a16c>] (vfs_write+0xa8/0x16c) >>>>> [<c022a0c4>] (vfs_write) from [<c022a340>] (SyS_write+0x44/0x90) >>>>> [<c022a2fc>] (SyS_write) from [<c0108220>] (ret_fast_syscall+0x0/0x28) >>>>> >>>>> Signed-off-by: Zou Cao <cao.zou@windriver.com> >>>>> --- >>>>> drivers/pci/dwc/pcie-designware-host.c | 24 ++++++++++++++++++++---- >>>>> 1 file changed, 20 insertions(+), 4 deletions(-) >>>>> >>>>> diff --git a/drivers/pci/dwc/pcie-designware-host.c b/drivers/pci/dwc/pcie-designware-host.c >>>>> index 81e2157..485c4df 100644 >>>>> --- a/drivers/pci/dwc/pcie-designware-host.c >>>>> +++ b/drivers/pci/dwc/pcie-designware-host.c >>>>> @@ -45,12 +45,28 @@ static int dw_pcie_wr_own_conf(struct pcie_port *pp, int where, int size, >>>>> return dw_pcie_write(pci->dbi_base + where, size, val); >>>>> } >>>>> +static void dwc_pci_msi_mask_irq(struct irq_data *data) >>>>> +{ >>>>> + struct msi_desc *desc = irq_data_get_msi_desc(data); >>>>> + >>>>> + if (desc) >>>>> + pci_msi_mask_irq(data); >>>>> +} >>>>> + >>>>> +static void dwc_pci_msi_unmask_irq(struct irq_data *data) >>>>> +{ >>>>> + struct msi_desc *desc = irq_data_get_msi_desc(data); >>>>> + >>>>> + if (desc) >>>>> + pci_msi_unmask_irq(data); >>>>> +} >>>>> + >>>>> static struct irq_chip dw_msi_irq_chip = { >>>>> .name = "PCI-MSI", >>>>> - .irq_enable = pci_msi_unmask_irq, >>>>> - .irq_disable = pci_msi_mask_irq, >>>>> - .irq_mask = pci_msi_mask_irq, >>>>> - .irq_unmask = pci_msi_unmask_irq, >>>>> + .irq_enable = dwc_pci_msi_unmask_irq, >>>>> + .irq_disable = dwc_pci_msi_mask_irq, >>>>> + .irq_mask = dwc_pci_msi_mask_irq, >>>>> + .irq_unmask = dwc_pci_msi_unmask_irq, >>>>> }; >>>> You have to CC me next time please. >>>> >>>> CC'ed Marc since he knows this code ways better than me and will >>>> help us find the right way of fixing it. >>>> >>>> I do not think that's a DWC-only problem - I see no reason why this >>>> would not affect other host bridges still relying on >>>> struct msi_controller (that we have to remove from the kernel). >>>> >>>> I do not think that this code is an actual fix but a plaster to >>>> paper over the issue - I will have a look into this as soon as >>>> possible to come up with an actual fix. >>> Yeah, this looks mad. The problem is that this seems to allocate >>> interrupts upfront, without being bound to an MSI. What could possibly >>> go wrong? And that's definitely not the only one (pci-tegra.c is one >>> fine example too). >>> >>> Until we take msi_controller and co to the backyard, how about the >>> following: >>> >>> >From b4aa5d20ee7b716795ac875e180f564fe0f52de6 Mon Sep 17 00:00:00 2001 >>> From: Marc Zyngier <marc.zyngier@arm.com> >>> Date: Fri, 15 Dec 2017 17:10:14 +0000 >>> Subject: [PATCH] PCI/MSI: Don't try to mask/unmask an MSI that doesn't have an >>> msi_desc >>> >>> There are a lot of MSI drivers out there that preallocate their >>> interrupts but not the corresponding MSIs. That's a prettty >>> naughty behaviour. On a kexec crash, we try to shut down all >>> the interrupts by calling the disable/mask methods. >>> >>> On these drivers, pci_msi_mask_irq() is unconditionnaly called, >>> leading to a crash. You wanted a crash kernel, right? >>> >>> So let's paper over the issue for the time being by detecting >>> the NULL msi_desc in msi_set_mask_bit(). Eventually, these drivers >>> will have to be fixed... >>> >>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> >>> --- >>> drivers/pci/msi.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> >>> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c >>> index e06607167858..a5042cc8f3fc 100644 >>> --- a/drivers/pci/msi.c >>> +++ b/drivers/pci/msi.c >>> @@ -227,6 +227,9 @@ static void msi_set_mask_bit(struct irq_data *data, u32 flag) >>> { >>> struct msi_desc *desc = irq_data_get_msi_desc(data); >>> + if (WARN_ONCE(!desc, "NULL MSI descriptor!")) >>> + return; >>> + >>> if (desc->msi_attrib.is_msix) { >>> msix_mask_irq(desc, flag); >>> readl(desc->mask_base); /* Flush write to device */ >> For "if (WARN_ONCE(!desc, "NULL MSI descriptor!")", it is a good way, >> just one problem. how to fix the kexec/kdump? this WARN_ONCE can tell >> the pci dirver to fix the MIS bound problem, but in kexec/kdump, it >> will force to mask all MSI, it means that there are a lot of WARNINGS >> when running kexec/kdump. > There will be one warning as Marc said. Mind testing Marc's patch > and reporting the result on the mailing list please if you want > the issue fixed ? > > Thanks, > Lorenzo > Hi Lorenzo: Of course it can fix this issue, but warning will be seen in every time when running kdump
root@nxp-imx7:~# echo c > /proc/sysrandom: crng init done
sys/ sysrq-trigger sysvipc/ root@nxp-imx7:~# echo c > /proc/sysrq-trigger sysrq: SysRq : Trigger a crash Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = a9470000 [00000000] *pgd=a9474835, *pte=00000000, *ppte=00000000 Internal error: Oops: 817 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 369 Comm: sh Not tainted 4.12.14-yocto-standard+ #98 Hardware name: Freescale i.MX7 Dual (Device Tree) task: a86e5400 task.stack: a9438000 PC is at sysrq_handle_crash+0x30/0x3c LR is at sysrq_handle_crash+0x2c/0x3c pc : [<8059576c>] lr : [<80595768>] psr: 600e0013 sp : a9439eb8 ip : a9439eb8 fp : a9439ecc r10: 00000000 r9 : a9438000 r8 : 00000001 r7 : 00000000 r6 : 00000063 r5 : 00000007 r4 : 00000001 r3 : 00000000 r2 : a9439ea0 r1 : ab615434 r0 : 00000063 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: a947006a DAC: 00000051 Process sh (pid: 369, stack limit = 0xa9438210) Stack: (0xa9439eb8 to 0xa943a000) 9ea0: 8059573c 8106f41c 9ec0: a9439eec a9439ed0 80595968 80595748 00000002 a8451444 a8451400 00000000 9ee0: a9439f04 a9439ef0 80595a78 805958c4 a9439f78 a8451444 a9439f2c a9439f08 9f00: 802c570c 80595a1c 802c5698 00000000 00000002 001042a8 a9439f78 001042a8 9f20: a9439f44 a9439f30 80268078 802c56a4 a9439f78 a901d6c0 a9439f74 a9439f48 9f40: 80269598 8026805c 80286cac 80286c1c 00000000 00000000 a901d6c0 a901d6c0 9f60: 00000002 001042a8 a9439fa4 a9439f78 8026982c 802694e4 00000000 00000000 9f80: 00000002 001042a8 76f19da8 00000004 80107f68 00000000 00000000 a9439fa8 9fa0: 80107d60 802697ec 00000002 001042a8 00000001 001042a8 00000002 00000000 9fc0: 00000002 001042a8 76f19da8 00000004 00000002 00000002 00000000 00000000 9fe0: 00000444 7e9d4980 76e466f0 76e9e41c 600e0010 00000001 3dbfa0e8 a39746c6 [<8059576c>] (sysrq_handle_crash) from [<80595968>] (__handle_sysrq+0xb0/0x158) [<80595968>] (__handle_sysrq) from [<80595a78>] (write_sysrq_trigger+0x68/0x78) [<80595a78>] (write_sysrq_trigger) from [<802c570c>] (proc_reg_write+0x74/0xa4) [<802c570c>] (proc_reg_write) from [<80268078>] (__vfs_write+0x28/0x48) [<80268078>] (__vfs_write) from [<80269598>] (vfs_write+0xc0/0x164) [<80269598>] (vfs_write) from [<8026982c>] (SyS_write+0x4c/0x8c) [<8026982c>] (SyS_write) from [<80107d60>] (ret_fast_syscall+0x0/0x3c) Code: e5834000 f57ff04e ebee0bee e3a03000 (e5c34000) ------------[ cut here ]------------ WARNING: CPU: 0 PID: 369 at /export/disk1T/linux-yocto-4.12/drivers/pci/msi.c:230 msi_set_mask_bit+0x50/0xb0 NULL MSI descriptor! Modules linked in: CPU: 0 PID: 369 Comm: sh Not tainted 4.12.14-yocto-standard+ #98 Hardware name: Freescale i.MX7 Dual (Device Tree) [<80111a50>] (unwind_backtrace) from [<8010c110>] (show_stack+0x20/0x24) [<8010c110>] (show_stack) from [<804cb3dc>] (dump_stack+0x80/0xa0) [<804cb3dc>] (dump_stack) from [<8012a2f4>] (__warn+0xe4/0x114) [<8012a2f4>] (__warn) from [<8012a3f4>] (warn_slowpath_fmt+0x48/0x50) [<8012a3f4>] (warn_slowpath_fmt) from [<8052f380>] (msi_set_mask_bit+0x50/0xb0) [<8052f380>] (msi_set_mask_bit) from [<8052f41c>] (pci_msi_mask_irq+0x1c/0x20) [<8052f41c>] (pci_msi_mask_irq) from [<80110224>] (machine_crash_shutdown+0x108/0x174) [<80110224>] (machine_crash_shutdown) from [<801a7244>] (__crash_kexec+0x88/0xac) [<801a7244>] (__crash_kexec) from [<801a72d0>] (crash_kexec+0x68/0x78) [<801a72d0>] (crash_kexec) from [<8010c46c>] (die+0x358/0x47c) [<8010c46c>] (die) from [<8011ccbc>] (__do_kernel_fault.part.0+0x64/0x1f4) [<8011ccbc>] (__do_kernel_fault.part.0) from [<80ade250>] (do_page_fault+0x348/0x3d4) [<80ade250>] (do_page_fault) from [<801011f8>] (do_DataAbort+0x44/0xc4) [<801011f8>] (do_DataAbort) from [<80add5b8>] (__dabt_svc+0x58/0x80) Exception stack(0xa9439e68 to 0xa9439eb0) 9e60: 00000063 ab615434 a9439ea0 00000000 00000001 00000007 9e80: 00000063 00000000 00000001 a9438000 00000000 a9439ecc a9439eb8 a9439eb8 9ea0: 80595768 8059576c 600e0013 ffffffff [<80add5b8>] (__dabt_svc) from [<8059576c>] (sysrq_handle_crash+0x30/0x3c) [<8059576c>] (sysrq_handle_crash) from [<80595968>] (__handle_sysrq+0xb0/0x158) [<80595968>] (__handle_sysrq) from [<80595a78>] (write_sysrq_trigger+0x68/0x78) [<80595a78>] (write_sysrq_trigger) from [<802c570c>] (proc_reg_write+0x74/0xa4) [<802c570c>] (proc_reg_write) from [<80268078>] (__vfs_write+0x28/0x48) [<80268078>] (__vfs_write) from [<80269598>] (vfs_write+0xc0/0x164) [<80269598>] (vfs_write) from [<8026982c>] (SyS_write+0x4c/0x8c) [<8026982c>] (SyS_write) from [<80107d60>] (ret_fast_syscall+0x0/0x3c) ---[ end trace 7a853bb920d02801 ]--- Loading crashdump kernel... Bye! Booting Linux on physical CPU 0x0 Linux version 4.12.14-yocto-standard+ (czou@pek-czou-u14) (gcc version 4.7.3 20130226 (prerelease) (crosstool-NG linaro-1.13.1-4.7-2013.03-20130313 - Linaro GCC 2013.03) ) #98 SMP PREEMPT Fri Dec 22 10:59:43 CST7 CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=10c5387d CPU: div instructions available: patching division code CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache OF: fdt: Machine model: Freescale i.MX7 SabreSD Board OF: fdt: Ignoring memory range 0x80000000 - 0x88000000 Memory policy: Data cache writealloc OF: reserved mem: failed to allocate memory for node 'linux,cma' cma: Failed to reserve 320 MiB percpu: Embedded 17 pages/cpu @8fc75000 s38016 r8192 d23424 u69632 Built 1 zonelists in Zone order, mobility grouping on. Total pages: 64706 Kernel command line: console=ttymxc0,115200 root=/dev/nfs ip=dhcp nfsroot=128.224.162.234:/var/lib/tftp/nfs/rootfs_imx7wrl10,v3 maxcpus=1 elfcorehdr=0x9cf00000 mem=261120K PID hash table entries: 1024 (order: 0, 4096 bytes) Dentry cache hash table entries: 32768 (order: 5, 131072 bytes) Inode-cache hash table entries: 16384 (order: 4, 65536 bytes) Memory: 241716K/261120K available (10240K kernel code, 778K rwdata, 2388K rodata, 1024K init, 364K bss, 19404K reserved, 0K cma-reserved, 0K highmem) Virtual kernel memory layout: vector : 0xffff0000 - 0xffff1000 ( 4 kB) fixmap : 0xffc00000 - 0xfff00000 (3072 kB) vmalloc : 0x90000000 - 0xff800000 (1784 MB) lowmem : 0x80000000 - 0x8ff00000 ( 255 MB) pkmap : 0x7fe00000 - 0x80000000 ( 2 MB)
Regards, czou
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