4 ms·

/bin/sh execution is supported at the kernel level iirc? Like, the minimum requirement for a linux distribution is /bin/sh, the rest of the system doesn't have

by fao_ 6y ago

/bin/sh execution is supported at the kernel level iirc? Like, the minimum requirement for a linux distribution is /bin/sh, the rest of the system doesn't have to be there necessarily.

deleted 6y ago
[deleted]
deleted 6y ago
[deleted]
10000truths 6y ago
No, the Linux kernel only requires an init executable to run. It otherwise makes no assumptions about the programs available in userland. Pretty much any sane/usable Linux distribution will package a shell, though.
- saagarjha 6y ago
  It does, however, hardcode /bin/sh as a init of last resort: https://github.com/torvalds/linux/blob/dcc0b49040c70ad827a7f3d58a21b01fdb14e749/init/main.c#L1476 https://github.com/torvalds/linux/blob/dcc0b49040c70ad827a7f...
  - fao_ 6y ago
    Exactly what I was talking about, thank you
saagarjha 6y ago
The behavior your are likely thinking of (execvp on a file without a shebang) is implemented in libc.
- fao_ 6y ago
  No. As someone else mentioned, the kernel hardcodes /bin/sh as a last resort: https://github.com/torvalds/linux/blob/dcc0b49040c70ad827a7f3d58a21b01fdb14e749/init/main.c#L1476 https://github.com/torvalds/linux/blob/dcc0b49040c70ad827a7f...