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Message-ID: <5146C343.9070609@huawei.com>
Date: Mon, 18 Mar 2013 15:33:23 +0800
From: Hanjun Guo <guohanjun@huawei.com>
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To: Tony Luck <tony.luck@intel.com>, Fenghua Yu <fenghua.yu@intel.com>
CC: Hanjun Guo <guohanjun@huawei.com>, Toshi Kani <toshi.kani@hp.com>,
        Jiang Liu <jiang.liu@huawei.com>, <linux-ia64@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, Jianguo Wu <wujianguo@huawei.com>
Subject: Re: [PATCH V2 2/2] ia64: iosapic: fix kexec oops when iosapic was
 removed
References: <1362717215-33904-1-git-send-email-guohanjun@huawei.com>
In-Reply-To: <1362717215-33904-1-git-send-email-guohanjun@huawei.com>
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ping...

On 2013/3/8 12:33, Hanjun Guo wrote:
> Ioapic hotplug was supported in IA64 code, but will lead to kexec oops
> when iosapic was removed. here is the code logic:
> 
> iosapic_remove
>   iosapic_free
>     memset(&iosapic_lists[index], 0, sizeof(iosapic_lists[0]))
>       iosapic_lists[index].addr was set to 0;
> 
> and then kexec a new kernel
> kexec_disable_iosapic
>   iosapic_write(rte->iosapic,..)
>     __iosapic_write(iosapic->addr, reg, val);
>       addr was set to 0 when iosapic_remove, and oops happened
> 
> The call trace is:
> Starting new kernel
> kexec[11336]: Oops 8804682956800 [1]
> Modules linked in: raw(N) ipv6(N) acpi_cpufreq(N) binfmt_misc(N) fuse(N) nls_iso
> 8859_1(N) loop(N) ipmi_si(N) ipmi_devintf(N) ipmi_msghandler(N) mca_ereport(N) s
> csi_ereport(N) nic_ereport(N) pcie_ereport(N) err_transport(N) nvlist(PN) dm_mod
> (N) tpm_tis(N) tpm(N) ppdev(N) tpm_bios(N) serio_raw(N) i2c_i801(N) iTCO_wdt(N)
> i2c_core(N) iTCO_vendor_support(N) sg(N) ioatdma(N) igb(N) mptctl(N) dca(N) parp
> ort_pc(N) parport(N) container(N) button(N) usbhid(N) hid(N) uhci_hcd(N) ehci_hc
> d(N) usbcore(N) sd_mod(N) crc_t10dif(N) ext3(N) mbcache(N) jbd(N) fan(N) process
> or(N) ide_pci_generic(N) ide_core(N) ata_piix(N) libata(N) mptsas(N) mptscsih(N)
>  mptbase(N) scsi_transport_sas(N) scsi_mod(N) thermal(N) thermal_sys(N) hwmon(N)
> 
> Supported: Yes, External
> 
> Pid: 11336, CPU 0, comm:                kexec
> psr : 0000101009522030 ifs : 8000000000000791 ip  : [<a00000010004c160>]    Tain
> ted: P          N  (2.6.32.12_RAS_V1R3C00B011)
> ip is at kexec_disable_iosapic+0x120/0x1e0
> unat: 0000000000000000 pfs : 0000000000000791 rsc : 0000000000000003
> rnat: 0000000000000000 bsps: 0000000000000000 pr  : 65519aa6a555a659
> ldrs: 0000000000000000 ccv : 00000000ea3cf51e fpsr: 0009804c8a70033f
> csd : 0000000000000000 ssd : 0000000000000000
> b0  : a00000010004c150 b6  : a000000100012620 b7  : a00000010000cda0
> f6  : 000000000000000000000 f7  : 1003e0000000002000000
> f8  : 1003e0000000050000003 f9  : 1003e0000028fb97183cd
> f10 : 1003ee9f380df3c548b67 f11 : 1003e00000000000000cc
> r1  : a0000001016cf660 r2  : 0000000000000000 r3  : 0000000000000000
> r8  : 0000001009526030 r9  : a000000100012620 r10 : e00000010053f600
> r11 : c0000000fec34040 r12 : e00000078f76fd30 r13 : e00000078f760000
> r14 : 0000000000000000 r15 : 0000000000000000 r16 : 0000000000000000
> r17 : 0000000000000000 r18 : 0000000000007fff r19 : 0000000000000000
> r20 : 0000000000000000 r21 : e00000010053f590 r22 : a000000100cf0000
> r23 : 0000000000000036 r24 : e0000007002f8a84 r25 : 0000000000000022
> r26 : e0000007002f8a88 r27 : 0000000000000020 r28 : 0000000000000002
> r29 : a0000001012c8c60 r30 : 0000000000000000 r31 : 0000000000322e49
> 
> Call Trace:
>  [<a000000100018ca0>] show_stack+0x80/0xa0
>                                 sp=e00000078f76f8f0 bsp=e00000078f761380
>  [<a000000100019300>] show_regs+0x640/0x920
>                                 sp=e00000078f76fac0 bsp=e00000078f761328
>  [<a00000010002a130>] die+0x190/0x2e0
>                                 sp=e00000078f76fad0 bsp=e00000078f7612e8
>  [<a000000100922fa0>] ia64_do_page_fault+0x840/0xb20
>                                 sp=e00000078f76fad0 bsp=e00000078f761288
>  [<a00000010000d5c0>] ia64_native_leave_kernel+0x0/0x270
>                                 sp=e00000078f76fb60 bsp=e00000078f761288
>  [<a00000010004c160>] kexec_disable_iosapic+0x120/0x1e0
>                                 sp=e00000078f76fd30 bsp=e00000078f761200
>  [<a000000100016970>] machine_shutdown+0x110/0x140
>                                 sp=e00000078f76fd30 bsp=e00000078f7611c8
>  [<a000000100133530>] kernel_kexec+0xd0/0x120
>                                 sp=e00000078f76fd30 bsp=e00000078f7611a0
>  [<a0000001000eca40>] sys_reboot+0x480/0x4e0
>                                 sp=e00000078f76fd30 bsp=e00000078f761128
>  [<a00000010000d420>] ia64_ret_from_syscall+0x0/0x20
>                                 sp=e00000078f76fe30 bsp=e00000078f761120
> Kernel panic - not syncing: Fatal exception
> 
> With Tony and Toshi's advice, the patch removes the "rte" from rte_list
> when the iosapic was removed.
> 
> v2:
> function name delete_rte_from_list was changed to iosapic_delete_rte with
> Toshi's advice.
> 
> Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
> Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
> Acked-by: Toshi Kani <toshi.kani@hp.com>
> ---
>  arch/ia64/kernel/iosapic.c |   32 +++++++++++++++++++++++++++++++-
>  1 files changed, 31 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/ia64/kernel/iosapic.c b/arch/ia64/kernel/iosapic.c
> index a6e2f75..19f107b 100644
> --- a/arch/ia64/kernel/iosapic.c
> +++ b/arch/ia64/kernel/iosapic.c
> @@ -1010,6 +1010,26 @@ iosapic_check_gsi_range (unsigned int gsi_base, unsigned int ver)
>  	return 0;
>  }
>  
> +static int
> +iosapic_delete_rte(unsigned int irq, unsigned int gsi)
> +{
> +	struct iosapic_rte_info *rte, *temp;
> +
> +	list_for_each_entry_safe(rte, temp, &iosapic_intr_info[irq].rtes,
> +								rte_list) {
> +		if (rte->iosapic->gsi_base + rte->rte_index == gsi) {
> +			if (rte->refcnt)
> +				return -EBUSY;
> +
> +			list_del(&rte->rte_list);
> +			kfree(rte);
> +			return 0;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +
>  int iosapic_init(unsigned long phys_addr, unsigned int gsi_base)
>  {
>  	int num_rte, err, index;
> @@ -1069,7 +1089,7 @@ int iosapic_init(unsigned long phys_addr, unsigned int gsi_base)
>  
>  int iosapic_remove(unsigned int gsi_base)
>  {
> -	int index, err = 0;
> +	int i, irq, index, err = 0;
>  	unsigned long flags;
>  
>  	spin_lock_irqsave(&iosapic_lock, flags);
> @@ -1087,6 +1107,16 @@ int iosapic_remove(unsigned int gsi_base)
>  		goto out;
>  	}
>  
> +	for (i = gsi_base; i < gsi_base + iosapic_lists[index].num_rte; i++) {
> +		irq = __gsi_to_irq(i);
> +		if (irq < 0)
> +			continue;
> +
> +		err = iosapic_delete_rte(irq, i);
> +		if (err)
> +			goto out;
> +	}
> +
>  	iounmap(iosapic_lists[index].addr);
>  	iosapic_free(index);
>   out:
> 


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