[PATCH 3/5] exec: Remove recursion from search_binary_handler

Linus Torvalds torvalds at linux-foundation.org
Sun May 10 19:38:20 UTC 2020

On Sat, May 9, 2020 at 9:30 PM Tetsuo Handa
<penguin-kernel at i-love.sakura.ne.jp> wrote:
> Wouldn't this change cause
>         if (fd_binary > 0)
>                 ksys_close(fd_binary);
>         bprm->interp_flags = 0;
>         bprm->interp_data = 0;
> not to be called when "Search for the interpreter" failed?

Good catch. We seem to have some subtle magic wrt the fd_binary file
descriptor, which depends on the recursive behavior.

I'm not seeing how to fix it cleanly with the "turn it into a loop".
Basically, that binfmt_misc use-case isn't really a tail-call.

Eric, ideas?


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