> On Mon, 20 Oct 2025, Piyush Raj wrote: > >> Hi Hans, >> >> On 19/10/25 07:46, Hans-Peter Nilsson wrote: >> > On Mon, 13 Oct 2025, Piyush Raj wrote: >> > >> > > This patch adds the bpf-vmtest-tool subdirectory under contrib which >> > > tests >> > > BPF programs under a live kernel using a QEMU VM. It automatically >> > > builds the specified kernel version with eBPF support enabled >> > > and stores it under "~/.bpf-vmtest-tool", which is reused for future >> > > invocations. >> > >> > It wasn't immediately clear to be if it happens as written >> > above, but it sounds like this tool may "helpfully" write to >> > ~/.bpf-vmtest-tool. Could you please make sure that the >> > invocation of this tool, as invoked for testing gcc, does *not* >> > write outside the gcc build directory, specifically not to the >> > user's home directory? >> > >> > That'd be quite rude. It'd be better to write there only when >> > specifically requested (not in any regtest session) and error >> > out if that directory, or one specified by some option, doesn't >> > exist. >> > >> > brgds, H-P >> > PS. otherwise nice hack >> >> This tool is only invoked by runtest if the bpf board is explicitly >> requested. >> >> For example: >> make check-gcc RUNTESTFLAGS="--target_board=bpf bpf-torture.exp" > > Yes, that's a prerequisite, but... > >> In a normal "make check-gcc" invocation, the tool will not be executed, so >> the >> user?s home directory will not be accessed. >> >> Considering this, do you see any other cases where the tool might be invoked >> unintentionally ? > > ...design-wise and user-friendliness-wise, IMHO better to > require explicit initialization (some special option or separate > script), and error-out if files expected from such an > initialization do not exist, than to write in the user's home > directory, or anywhere outside where explicit options and > arguments point, for that matter. But again, that's IMHO.
What about having the script check an environment variable and command-line option, and error out if it is not defined? Something like VMTEST_DIR and --vmtest-dir=DIR.
