From: Baoquan He <bhe@redhat.com>
To: "chenhaixiang (A)" <chenhaixiang3@huawei.com>
Cc: "kexec@lists.infradead.org" <kexec@lists.infradead.org>,
Louhongxiang <louhongxiang@huawei.com>,
"wangbin (A)" <wangbin224@huawei.com>,
"Fangchuangchuang(Fcc,Euler)" <fangchuangchuang@huawei.com>
Subject: Re: Question about Address Range Validation in Crash Kernel Allocation
Date: Tue, 19 Mar 2024 09:38:12 +0800 [thread overview]
Message-ID: <ZfjshNK7Nbdz1de3@MiWiFi-R3L-srv> (raw)
In-Reply-To: <8606fd02d6de4eb3b7c80e4ce3449458@huawei.com>
Hi,
On 03/18/24 at 12:00pm, chenhaixiang (A) wrote:
> Dear kexec Community Members,
>
> I encountered an issue while using kexec-tools on my x86_64 machine.
> When there is a segment marked as 'reserved' within the memory range allocated for the crash kernel in /proc/iomem,the output appears as follows:
> 2d4fd058-60efefff : System RAM
> 2d4fd058-58ffffff : System RAM
> 49000000-58ffffff : Crash kernel
> 53cbd000-53ccffff : Reserved
What kernel are you using? the version of kernel, and kexec-tools?
If you are testing on the latest mainline kernel, you could meet the
issue Dave have met and fixed in below patch:
[PATCH] x86/kexec: do not update E820 kexec table for setup_data
https://lore.kernel.org/all/ZeZ2Kos-OOZNSrmO@darkstar.users.ipa.redhat.com/T/#u
Thanks
Baoquan
>
> The crash_memory_range array will encounter incorrect address ranges:
> CRASH MEMORY RANGES
> 000000002d4fd058-0000000048ffffff (0)
> 0000000053cbd000-0000000048ffffff (1)
> 0000000059000000-0000000053ccffff (0)
>
> Read the code, I noticed that the get_crash_memory_ranges() function invokes exclude_region() to handle the splitting of memory regions, but it seems unable to properly handle the scenario described above.
> The code logic is as follows:
> ...
> if (start < mend && end > mstart) {
> if (start != mstart && end != mend) {
> /* Split memory region */
> crash_memory_range[i].end = start - 1;
> temp_region.start = end + 1;
> temp_region.end = mend;
> temp_region.type = RANGE_RAM;
> tidx = i+1;
> } else if (start != mstart)
> crash_memory_range[i].end = start - 1;
> else
> crash_memory_range[i].start = end + 1;
> }
> ...
> If start < mstart < mend < end, resulting in crash_memory_range[i].end becoming less than crash_memory_range[i].start, leading to incorrect address ranges.
> I would like to know if this behavior is reasonable and whether it is necessary to validate the address ranges for compliance at the end.
>
> Thank you for your time and assistance.
>
> Chen Haixiang
>
> _______________________________________________
> kexec mailing list
> kexec@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
>
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next prev parent reply other threads:[~2024-03-19 1:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-18 12:00 Question about Address Range Validation in Crash Kernel Allocation chenhaixiang (A)
2024-03-19 1:38 ` Baoquan He [this message]
-- strict thread matches above, loose matches on Subject: below --
2024-03-19 7:24 chenhaixiang (A)
2024-03-19 8:21 ` Baoquan He
2024-03-20 13:12 chenhaixiang (A)
2024-03-20 14:08 ` Baoquan He
[not found] <45065451d7d343679e150313c1ee2b62@huawei.com>
2024-03-21 7:09 ` Baoquan He
2024-03-21 9:17 chenhaixiang (A)
2024-03-21 9:48 ` Li Huafei
2024-03-21 10:06 ` Dave Young
2024-03-21 12:37 ` Li Huafei
2024-03-22 1:16 ` Baoquan He
2024-03-22 7:26 ` Dave Young
2024-03-22 7:18 ` Dave Young
2024-03-22 7:58 ` Li Huafei
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