From: Baoquan He <bhe@redhat.com>
To: Jiri Olsa <olsajiri@gmail.com>
Cc: David Hildenbrand <david@redhat.com>,
Lorenzo Stoakes <lstoakes@gmail.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Uladzislau Rezki <urezki@gmail.com>,
Matthew Wilcox <willy@infradead.org>,
Liu Shixin <liushixin2@huawei.com>, Jens Axboe <axboe@kernel.dk>,
Alexander Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH v8 1/4] fs/proc/kcore: avoid bounce buffer for ktext data
Date: Mon, 24 Jul 2023 22:33:43 +0800 [thread overview]
Message-ID: <ZL6Lx6QbLubsj3cg@MiWiFi-R3L-srv> (raw)
In-Reply-To: <ZL4z6LVzrbMvXwyl@krava>
On 07/24/23 at 10:18am, Jiri Olsa wrote:
> On Mon, Jul 24, 2023 at 04:08:41PM +0800, Baoquan He wrote:
> > On 07/24/23 at 08:23am, David Hildenbrand wrote:
> > > Hi,
> > >
> > > >
> > > > I met this too when I executed below command to trigger a kcore reading.
> > > > I wanted to do a simple testing during system running and got this.
> > > >
> > > > makedumpfile --mem-usage /proc/kcore
> > > >
> > > > Later I tried your above objdump testing, it corrupted system too.
> > > >
> > >
> > > What do you mean with "corrupted system too" -- did it not only fail to
> > > dump the system, but also actually harmed the system?
> >
> > From my testing, reading kcore will cause system panic, then reboot. Not
> > sure if Jiri saw the same phenomenon.
>
> it did not crash for me, just the read error
> could you get console output from that?
I got a new arm64 machine, then executing "makedumpfile --mem-usage
/proc/kcore" won't trigger panic, your objdump command can trigger
panic. The call trace is pasted at below. It's the same as the panic and
call trace I met on my last arm64 machine.
[13270.314323] Mem abort info:
[13270.317162] ESR = 0x0000000096000007
[13270.320901] EC = 0x25: DABT (current EL), IL = 32 bits
[13270.326217] SET = 0, FnV = 0
[13270.329261] EA = 0, S1PTW = 0
[13270.332390] FSC = 0x07: level 3 translation fault
[13270.337270] Data abort info:
[13270.340139] ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000
[13270.345626] CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[13270.350666] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[13270.355981] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000400651d64000
[13270.362672] [ffffdc9cf3ea0000] pgd=1000401ffffff003, p4d=1000401ffffff003, pud=1000401fffffe003, pmd=1000401fffffd003, pte=0000000000000000
[13270.375367] Internal error: Oops: 0000000096000007 [#4] SMP
[13270.380934] Modules linked in: mlx5_ib ib_uverbs ib_core rfkill vfat fat joydev cdc_ether usbnet mii mlx5_core acpi_ipmi mlxfw ipmi_ssif psample tls ipmi_devintf pci_hyperv_intf arm_spe_pmu ipmi_msghandler arm_cmn arm_dmc620_pmu arm_dsu_pmu cppc_cpufreq acpi_tad fuse zram xfs crct10dif_ce polyval_ce polyval_generic ghash_ce uas sbsa_gwdt nvme nvme_core ast usb_storage nvme_common i2c_algo_bit xgene_hwmon
[13270.416751] CPU: 15 PID: 8803 Comm: objdump Tainted: G D 6.5.0-rc3 #1
[13270.424570] Hardware name: WIWYNN Mt.Jade Server System B81.030Z1.0007/Mt.Jade Motherboard, BIOS 2.10.20220531 (SCP: 2.10.20220531) 2022/05/31
[13270.437337] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[13270.444289] pc : __arch_copy_to_user+0x180/0x240
[13270.448910] lr : _copy_to_iter+0x11c/0x5d0
[13270.453002] sp : ffff8000b15a37c0
[13270.456306] x29: ffff8000b15a37c0 x28: ffffdc9cf3ea0000 x27: ffffdc9cf6938158
[13270.463431] x26: ffff8000b15a3ba8 x25: 0000000000000690 x24: ffff8000b15a3b80
[13270.470556] x23: 00000000000038ac x22: ffffdc9cf3ea0000 x21: ffff8000b15a3b80
[13270.477682] x20: ffffdc9cf64fdf00 x19: 0000000000000400 x18: 0000000000000000
[13270.484806] x17: 0000000000000000 x16: 0000000000000000 x15: ffffdc9cf3ea0000
[13270.491931] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
[13270.499056] x11: 0001000000000000 x10: ffffdc9cf64fdf00 x9 : 0000000000000690
[13270.506182] x8 : 000000007c000000 x7 : 0000fd007e000000 x6 : 000000000eee0b60
[13270.513306] x5 : 000000000eee0f60 x4 : 0000000000000000 x3 : 0000000000000400
[13270.520431] x2 : 0000000000000380 x1 : ffffdc9cf3ea0000 x0 : 000000000eee0b60
[13270.527556] Call trace:
[13270.529992] __arch_copy_to_user+0x180/0x240
[13270.534250] read_kcore_iter+0x718/0x878
[13270.538167] proc_reg_read_iter+0x8c/0xe8
[13270.542168] vfs_read+0x214/0x2c0
[13270.545478] ksys_read+0x78/0x118
[13270.548782] __arm64_sys_read+0x24/0x38
[13270.552608] invoke_syscall+0x78/0x108
[13270.556351] el0_svc_common.constprop.0+0x4c/0xf8
[13270.561044] do_el0_svc+0x34/0x50
[13270.564347] el0_svc+0x34/0x108
[13270.567482] el0t_64_sync_handler+0x100/0x130
[13270.571829] el0t_64_sync+0x194/0x198
[13270.575483] Code: d503201f d503201f d503201f d503201f (a8c12027)
[13270.581567] ---[ end trace 0000000000000000 ]---
next prev parent reply other threads:[~2023-07-24 14:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-23 10:15 [PATCH v8 0/4] convert read_kcore(), vread() to use iterators Lorenzo Stoakes
2023-03-23 10:15 ` [PATCH v8 1/4] fs/proc/kcore: avoid bounce buffer for ktext data Lorenzo Stoakes
2023-05-31 11:58 ` Jiri Olsa
2023-07-21 13:48 ` Baoquan He
2023-07-21 14:13 ` Jiri Olsa
2023-07-24 6:23 ` David Hildenbrand
2023-07-24 8:08 ` Baoquan He
2023-07-24 8:18 ` Jiri Olsa
2023-07-24 14:33 ` Baoquan He [this message]
2023-07-31 19:21 ` Lorenzo Stoakes
2023-07-31 19:24 ` David Hildenbrand
2023-07-31 19:40 ` Lorenzo Stoakes
2023-07-31 20:34 ` Jiri Olsa
2023-07-31 21:12 ` Lorenzo Stoakes
2023-07-31 21:50 ` Jiri Olsa
2023-07-31 21:58 ` Lorenzo Stoakes
2023-07-24 9:38 ` Linux regression tracking (Thorsten Leemhuis)
2023-03-23 10:15 ` [PATCH v8 2/4] fs/proc/kcore: convert read_kcore() to read_kcore_iter() Lorenzo Stoakes
2023-03-23 10:15 ` [PATCH v8 3/4] iov_iter: add copy_page_to_iter_nofault() Lorenzo Stoakes
2023-03-23 10:15 ` [PATCH v8 4/4] mm: vmalloc: convert vread() to vread_iter() Lorenzo Stoakes
2023-03-29 4:53 ` [PATCH v8 0/4] convert read_kcore(), vread() to use iterators Baoquan He
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