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Subject: Re: [PATCH v3 1/1] kdump: append uts_namespace.name offset to
 VMCOREINFO
To:     Alexander Egorenkov <egorenar@linux.ibm.com>, dyoung@redhat.com,
        bhe@redhat.com, vgoyal@redhat.com
Cc:     ebiederm@xmission.com, akpm@linux-foundation.org,
        ktkhai@virtuozzo.com, keescook@chromium.org,
        christian.brauner@ubuntu.com, kexec@lists.infradead.org,
        linux-kernel@vger.kernel.org
References: <20200930102328.396488-1-egorenar@linux.ibm.com>
From:   lijiang <lijiang@redhat.com>
Message-ID: <60526b10-35eb-b6ba-b08d-70ebfe5d07b5@redhat.com>
Date:   Fri, 2 Oct 2020 10:38:22 +0800
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Hi, Alexander

在 2020年09月30日 18:23, Alexander Egorenkov 写道:
> The offset of the field 'init_uts_ns.name' has changed
> since commit 9a56493f6942 ("uts: Use generic ns_common::count").
> 
> Link: https://lore.kernel.org/r/159644978167.604812.1773586504374412107.stgit@localhost.localdomain
> 
> Make the offset of the field 'uts_namespace.name' available
> in VMCOREINFO because tools like 'crash-utility' and
> 'makedumpfile' must be able to read it from crash dumps.
> 
> Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
> ---
> 
> v2 -> v3:
>  * Added documentation to vmcoreinfo.rst
>  * Use the short form of the commit reference
> 
> v1 -> v2:
>  * Improved commit message
>  * Added link to the discussion of the uts namespace changes
> 
>  Documentation/admin-guide/kdump/vmcoreinfo.rst | 6 ++++++
>  kernel/crash_core.c                            | 1 +
>  2 files changed, 7 insertions(+)
> 
> diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst
> index e44a6c01f336..3861a25faae1 100644
> --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst
> +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst
> @@ -39,6 +39,12 @@ call.
>  User-space tools can get the kernel name, host name, kernel release
>  number, kernel version, architecture name and OS type from it.
>  
> +(uts_namespace, name)
> +---------------------
> +
> +Offset of the name's member. Crash Utility and Makedumpfile get
> +the start address of the init_uts_ns.name from this.
> +

Thank you for the update. The v3 looks good to me.

>  node_online_map
>  ---------------
>  
> diff --git a/kernel/crash_core.c b/kernel/crash_core.c
> index 106e4500fd53..173fdc261882 100644
> --- a/kernel/crash_core.c
> +++ b/kernel/crash_core.c
> @@ -447,6 +447,7 @@ static int __init crash_save_vmcoreinfo_init(void)
>  	VMCOREINFO_PAGESIZE(PAGE_SIZE);
>  
>  	VMCOREINFO_SYMBOL(init_uts_ns);
> +	VMCOREINFO_OFFSET(uts_namespace, name);
>  	VMCOREINFO_SYMBOL(node_online_map);
>  #ifdef CONFIG_MMU
>  	VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
>