Hi Atsushi,
Thanks for the review.
On Tuesday 01 August 2017 01:11 PM, Atsushi Kumagai wrote:
> Hello Pratyush,
>
> Thanks for your work.
>
>> On 07/30/17 at 10:11pm, Pratyush Anand wrote:
>>> Following commit renamed init_level4_pgt to init_top_pgt in kernel.
>>>
>>> commit 65ade2f872b474fa8a04c2d397783350326634e6
>>> Author: Kirill A. Shutemov <kirill.shutemov at linux.intel.com>
>>> Date: Tue Jun 6 14:31:27 2017 +0300
>>>
>>> x86/boot/64: Rename init_level4_pgt and early_level4_pgt
>>>
>>> This patch takes care of above kernel modification in makedumpfile.
>>>
>>> Signed-off-by: Pratyush Anand <panand at redhat.com>
>>> ---
>>> makedumpfile.c | 9 ++++++++-
>>> 1 file changed, 8 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/makedumpfile.c b/makedumpfile.c
>>> index f85003a33551..e875f4bb539e 100644
>>> --- a/makedumpfile.c
>>> +++ b/makedumpfile.c
>>> @@ -1486,6 +1486,8 @@ get_symbol_info(void)
>>> SYMBOL_INIT(_stext, "_stext");
>>> SYMBOL_INIT(swapper_pg_dir, "swapper_pg_dir");
>>> SYMBOL_INIT(init_level4_pgt, "init_level4_pgt");
>>> + if (SYMBOL(init_level4_pgt) == NOT_FOUND_SYMBOL)
>>> + SYMBOL_INIT(init_level4_pgt, "init_top_pgt");
>>> SYMBOL_INIT(vmlist, "vmlist");
>>> SYMBOL_INIT(vmap_area_list, "vmap_area_list");
>>> SYMBOL_INIT(node_online_map, "node_online_map");
>>> @@ -2104,7 +2106,10 @@ write_vmcoreinfo_data(void)
>>> WRITE_SYMBOL("init_uts_ns", init_uts_ns);
>>> WRITE_SYMBOL("_stext", _stext);
>>> WRITE_SYMBOL("swapper_pg_dir", swapper_pg_dir);
>>> - WRITE_SYMBOL("init_level4_pgt", init_level4_pgt);
>>> + if (SYMBOL(init_level4_pgt) == NOT_FOUND_SYMBOL)
>>> + WRITE_SYMBOL("init_top_pgt", init_level4_pgt);
>>> + else
>>> + WRITE_SYMBOL("init_level4_pgt", init_level4_pgt);
>
> Whether the source is init_level4_pgt or init_top_pgt, the value will
> be kept as SYMBOL(init_level4_pgt), so this conditional judgment is meaningless.
IIUC,we will have above if condition true for v4.13 kernel and false for older
kernel, right? Now, if keep the name "init_level4_pgt" in a vmcore generated
for v4.13, would that be good, even though that would work conceptually?
I thought that generated vmcoreinfo from vmlinux should look like as being
encoded into kernel, so same name of symbol as in kernel.
>
> I think what you want to do is like commit: ed46b6ad9, but I don't want to
> introduce a new flag every time a symbol name is changed. So how about
> unification into "init_level4_pgt" for backward compatibility ?
> The old name can be read in all versions of makedumpfile.
I agree, and so I kept "init_level4_pgt" for internal usage of makedumpfile.
But, IMHO any output file (like generated vmcoreinfo with -g) should have
matching kernel symbol.
--
Regards
Pratyush
