How to generate Fixes: <commit> ("<text>") things

[wuzhouhui]

Hi,

Stupid question, maybe. But I just could find the answer vi Bing or Google.

How to generate
    Fixes: <commit> ("<text>")
E.g.
    Fixes: 298a32b13208 ("kmemleak: powerpc: skip scanning holes in the .bss section")

Or they just write it manually?

Thanks.