RE: [PATCH] makedumpfile: fix free partial_bitmap2 error

[Atsushi Kumagai <kumagai-atsushi@mxc.nes.nec.co.jp>]

>Description:
>In create_dump_bitmap, after prepare_bitmap2_buffer_cyclic was invoked,
>info->partial_bitmap2 will pointed to a block of contiguous memory. But
>free it in a wrong way because what free_bitmap2_buffer() free is
>info->bitmap2 not info->partial_bitmap2.
>
>Signed-off-by: Arthur Zou <zzou@redhat.com>

Good catch, Thanks!

>---
> makedumpfile.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
>diff --git a/makedumpfile.c b/makedumpfile.c
>index ce4a866..f0d2997 100644
>--- a/makedumpfile.c
>+++ b/makedumpfile.c
>@@ -5143,7 +5143,8 @@ create_dump_bitmap(void)
>
> 			info->num_dumpable = get_num_dumpable_cyclic();
>
>-			free_bitmap2_buffer();
>+			if (info->partial_bitmap2 != NULL)
>+				free(info->partial_bitmap2);

I think it's better to create free_bitmap2_buffer_cyclic() for this.

BTW, write_kdump_pages_and_bitmap_cyclic() also have the same mistake:

        struct cycle cycle = {0};
        for_each_cycle(0, info->max_mapnr, &cycle)
        {
                if (!create_1st_bitmap_cyclic(&cycle))
                        return FALSE;
                if (!write_kdump_bitmap1_cyclic(&cycle))
                        return FALSE;
        }


        free_bitmap1_buffer();

What we should do here is to free partial_bitmap1, so we should
create free_bitmap1_buffer_cyclic() and call it here instead.
Luckily, this mistake is harmless due to the free() at the end
of main():

                if (info->partial_bitmap1 != NULL)
                        free(info->partial_bitmap1);
                if (info->partial_bitmap2 != NULL)
                        free(info->partial_bitmap2);

Now, I think it's better to remove these free(), it's possible
if partial_bitmap1 and partial_bitmap2 are freed in
write_kdump_pages_and_bitmap_cyclic() or write_elf_pages_cyclic().

So could you fix your patch based on my comments?


Thanks
Atsushi Kumagai

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