Xen project Mailing List

Re: [Xen-devel] Dom0 kernel panic when porting xen to new arm soc

To: Peng Fan <van.freenix@xxxxxxxxx>, Ian Campbell <ian.campbell@xxxxxxxxxx>

From: Julien Grall <julien.grall@xxxxxxxxxx>

Date: Mon, 22 Jun 2015 11:20:37 +0100

Cc: julien.grall@xxxxxxxxxx, Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>, xen-devel@xxxxxxxxxxxxx

Delivery-date: Mon, 22 Jun 2015 10:21:28 +0000

List-id: Xen developer discussion <xen-devel.lists.xen.org>

On 20/06/15 15:47, Peng Fan wrote: > On 6/20/2015 10:08 PM, Peng Fan wrote: >> Hi Julien, >> >> On 6/20/2015 6:19 PM, Julien Grall wrote: >>> Hi, >>> >>> On 19/06/2015 14:22, Peng Fan wrote: >>>> diff --git a/kernel/timer.c b/kernel/timer.c >>>> index 38f0d40..4a025cc 100644 >>>> --- a/kernel/timer.c >>>> +++ b/kernel/timer.c >>>> @@ -1175,6 +1175,10 @@ static inline void __run_timers(struct tvec_base >>>> *base) >>>> >>>> base->running_timer = timer; >>>> detach_expired_timer(timer, base); >>>> + if (!fn) { >>>> + printk("fn is null why????\n"); ----> >>>> This log only shows once. Not sure why fn is null and only once. >>>> + continue; >>>> + } >>>> >>>> if (irqsafe) { >>>> spin_unlock(&base->lock); >>> >>> By any chance, does your board has a another timer (i.e other than the >>> generic timer)? >> >> Yeah. There is a another timer whose rating is lower that generic timer. >>> >>> I would also track down to see who is adding this timer. >>> >>>> But after apply the above kernel patch, Dom0 Linux can handle shell >>>> input. >>>> Just have another question, How can Dom0 handle DMA for arm. >>> >>> When Xen is allocating the RAM bank for DOM0 we use a direct mapping >>> (i.e the Physical Address = Intermediate Address for the RAM). So DOM0 >>> can perform DMA as on baremetal. >> Thanks. Current, without using rootfs in sd card, my Dom0 kernel can >> boot using ramfs. But if with sdhc which use ADMA, Dom0 kernel will >> panic. Below is the log: >> >> sdhci: Secure Digital Host Controller Interface driver >> sdhci: Copyright(c) Pierre Ossman >> sdhci-pltfm: SDHCI platform and OF driver helper >> Unable to handle kernel NULL pointer dereference at virtual address 00000000 >> pgd = 80004000 >> [00000000] *pgd=00000000 >> Internal error: Oops: 5 [#1] PREEMPT SMP ARM >> Modules linked in: >> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.38-02383-g5ccf32b-dirty #22 >> task: 84074000 ti: 84078000 task.ti: 84078000 >> PC is at bitmap_clear+0xc0/0xdc >> LR is at bitmap_clear+0x54/0xdc >> pc : [<8029deb8>] lr : [<8029de4c>] psr: 20000193 >> sp : 84079d80 ip : 00000001 fp : 00000000 >> r10: 00077fff r9 : 00000404 r8 : 00000001 >> r7 : 00000001 r6 : 00000001 r5 : 00000000 r4 : ffffffff >> r3 : 00000001 r2 : 00000001 r1 : 20000193 r0 : 00000015 >> Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel >> Control: 10c53c7d Table: 8800406a DAC: 00000015 >> Process swapper/0 (pid: 1, stack limit = 0x84078238) >> Stack: (0x84079d80 to 0x8407a000) >> 9d80: 80000113 00000000 87efa000 81109918 00001000 800197f8 84128558 >> 00080008 >> 9da0: 84079dec 000000d0 84bfeac0 84126c10 84126c10 ffffffff 00000404 >> ffffffff >> 9dc0: 00000000 00000402 00000000 00000000 84126c10 80310ba8 ffffffff >> 00000000 >> 9de0: 00000000 00000524 84078000 00000000 00000000 ffffffff ffffffff >> 84bfeac0 >> 9e00: 84bfe800 8000b407 07eb0000 8116e0f8 00000000 804ee81c ffffffff >> ffffffff >> 9e20: 00000000 84126c10 84c92010 84bfeac0 00000000 84126c10 84126c00 >> 84bfeac0 >> 9e40: 84078030 804f08e4 804f03d8 84126c10 fffffdfb 8115401c 8115401c >> 00000000 >> 9e60: 0000010f 80362330 803622ec 84126c10 811c8098 00000000 8115401c >> 80360b1c >> 9e80: 84126c10 8115401c 84126c44 00000000 80de1888 80360d28 00000000 >> 8115401c >> 9ea0: 80360c9c 8035f10c 8406965c 84123634 8115401c 84c8bf80 8112f3c8 >> 803602bc >> 9ec0: 80d08314 8115401c 00000006 8115401c 00000006 8116e080 8116e080 >> 8036130c >> 9ee0: 00000000 80e00f78 00000006 800088dc 8400f900 80c94fe0 840bd480 >> 80735184 >> 9f00: 00000000 8116e080 0000150c 8012d430 00000000 811105b0 60000113 >> 00000001 >> 9f20: 87ffc576 8075ca38 0000010f 8004b0f0 80d66884 00000006 87ffc583 >> 00000006 >> 9f40: 811105a0 80e00f78 00000006 8116e080 8116e080 80da150c 0000010f >> 80df4154 >> 9f60: 80df4148 80da1c4c 00000006 00000006 80da150c 9355553c 84079f9c >> 80731338 >> 9f80: 00000000 00000000 80727254 00000000 00000000 00000000 00000000 >> 00000000 >> 9fa0: 00000000 8072725c 00000000 8000ecf8 00000000 00000000 00000000 >> 00000000 >> 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 >> 00000000 >> 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 9355553c >> 9355553c >> [<8029deb8>] (bitmap_clear) from [<800197f8>] >> (__arm_dma_free.isra.18+0xe4/0x228) >> [<800197f8>] (__arm_dma_free.isra.18) from [<80310ba8>] >> (xen_swiotlb_free_coherent+0xfc/0x140) >> [<80310ba8>] (xen_swiotlb_free_coherent) from [<804ee81c>] >> (sdhci_add_host+0xb34/0xe64) >> [<804ee81c>] (sdhci_add_host) from [<804f08e4>] >> (sdhci_esdhc_imx_probe+0x50c/0x808) >> [<804f08e4>] (sdhci_esdhc_imx_probe) from [<80362330>] >> (platform_drv_probe+0x44/0xa4) >> [<80362330>] (platform_drv_probe) from [<80360b1c>] >> (driver_probe_device+0x120/0x25c) >> [<80360b1c>] (driver_probe_device) from [<80360d28>] >> (__driver_attach+0x8c/0x90) >> [<80360d28>] (__driver_attach) from [<8035f10c>] >> (bus_for_each_dev+0x60/0x94) >> [<8035f10c>] (bus_for_each_dev) from [<803602bc>] >> (bus_add_driver+0x148/0x1f0) >> [<803602bc>] (bus_add_driver) from [<8036130c>] (driver_register+0x78/0xf8) >> [<8036130c>] (driver_register) from [<800088dc>] >> (do_one_initcall+0xf8/0x144) >> [<800088dc>] (do_one_initcall) from [<80da1c4c>] >> (kernel_init_freeable+0x138/0x1d8) >> [<80da1c4c>] (kernel_init_freeable) from [<8072725c>] (kernel_init+0x8/0xf0) >> [<8072725c>] (kernel_init) from [<8000ecf8>] (ret_from_fork+0x14/0x3c) >> Code: 10866003 1206601f 10633006 11e02312 (e5953000) >> ---[ end trace f6f103bb73cc0503 ]--- >> note: swapper/0[1] exited with preempt_count 1 >> Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b >> >> The piece code is at here: >> if (host->flags & SDHCI_USE_ADMA) { >> /* >> * We need to allocate descriptors for all sg entries >> * (128) and potentially one alignment transfer for >> * each of those entries. >> */ >> host->adma_desc = dma_alloc_coherent(mmc_dev(host->mmc), >> ADMA_SIZE, &host->adma_addr, >> GFP_KERNEL); >> host->align_buffer = kmalloc(128 * 4, GFP_KERNEL); >> printk("%p %p\n", host->adma_desc, host->align_buffer); ---> >> Here host->adma_desc is NULL >> if (!host->adma_desc || !host->align_buffer) { >> dma_free_coherent(mmc_dev(host->mmc), ADMA_SIZE, >> -->Trigger panic >> host->adma_desc, host->adma_addr); >> kfree(host->align_buffer); >> >> So dma_alloc_coherent failed, dma_free_coherent-->bitmap_clear trigger >> Dom0 panic. 128M memory is for Dom0, dma_alloc_coherent should not fail. >> Do you have any suggestions? >> Adding Stefano as he worked on DMA/swiotlb for ARM. > Another problem comes to me, with 128M for Dom0, Dom0 can printk msg to > serial, but with "dom0_mem=1024M", I see nothing from serial for Dom0. Well, the RAM bank will surely be different between the 2 configurations. The DOM0 may have crashed before the console has effectively setup for multiple reason. Can you try this hacky patch [1], it will print everything using the Xen console. [1] http://lists.xen.org/archives/html/xen-devel/2014-10/msg03436.html Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel

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