Re: [PATCH] image: check if the file is core dump

[Jan Kiszka <jan.kiszka@siemens.com>]

On 17.04.24 08:46, Zhibin Dong wrote:
> The previous code does a wrong judgement in two cases:
> 1. a file is suffixed by .core but is not a core dump file
> 2. a file is a core dump file but is not suffixed by .core
> 
> The new code uses `file` to determine the type of files, which is more
> accurate.
> 
> Signed-off-by: Zhibin Dong <zhibin.dong@siemens.com>
> ---
>  meta/classes/image.bbclass | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
> index 98741da0..2b0995d2 100644
> --- a/meta/classes/image.bbclass
> +++ b/meta/classes/image.bbclass
> @@ -444,7 +444,7 @@ EOSUDO
>  
>      # Sometimes qemu-user-static generates coredumps in chroot, move them
>      # to work temporary directory and inform user about it.
> -    for f in $(sudo find ${ROOTFSDIR} -type f -name *.core); do
> +    for f in $(sudo find ${ROOTFSDIR} -type f -exec file --mime-type {} \; | grep 'application/x-coredump' | cut -d: -f1); do
>          sudo mv "${f}" "${WORKDIR}/temp/"
>          bbwarn "found core dump in rootfs, check it in ${WORKDIR}/temp/${f##*/}"
>      done

Unfortunately, this turns out to be extreeemly costly: For every file in
the rootfs, we now call 'file' which opens and reads its header to
determine whether it is a coredump. I suspect this was never really
tested against some non-trivial rootfs.

I agree that we would avoid false positives, thus should check for the
mime-type before deleting. But is there really a case for coredumps not
ending on .core?

Jan

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