Currently for the MFS, firmware and VDSO template assembly files we pass
the path to include with .incbin unquoted and use __XSTRING within the
assembly file to stringify it. However, __XSTRING doesn't just perform a
single level of expansion, it performs the normal full expansion of the
macro, and so if the path itself happens to tokenise to something that
includes a defined macro in it that will itself be substituted. For
example, with #define MACRO 1, a path like /path/containing/MACRO/in/it
will expand to /path/containing/1/in/it and then, when stringified, end
up as "/path/containing/1/in/it", not the intended string. Normally,
macros have names that start or end witih underscores and are unlikely
to appear in a tokenised path (even if technically they could), but now
that we've switched to GNU C as of commit ec41a96daa ("sys: Switch the
kernel's C standard from C99 to GNU99.") there are a few new macros
defined which don't start or end with underscores: unix, which is always
defined to 1, and i386, which is defined to 1 on i386. The former
probably doesn't appear in user paths in practice, but the latter has
been seen to and is likely quite common in the wild.
Fix this by defining the macro pre-quoted instead of using __XSTRING.
Note that technically we don't need to do this for vdso_wrap.S today as
all the paths passed to it are safe file names with no user-controlled
prefix but we should do it anyway for consistency and robustness against
future changes.
This allows make tinderbox to pass when built with source and object
directories inside ~/path-with-unix, which would otherwise expand to
~/path-with-1 and break.
PR: 272744
Fixes: ec41a96daa ("sys: Switch the kernel's C standard from C99 to GNU99.")
The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.
Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix
Not doing so results in ctfconvert failing with
ERROR: ctfconvert: elf-vdso.so.o doesn't have type data to convert
On FreeBSD this is non-fatal, since the ctf tools have a hack to make
such errors not fail the build and instead just silently continue
without CTF data (which is a bad idea these days and should probably be
removed; they date back to the original import). However, those are
under #ifdef __FreeBSD__ so do not apply when cross-building from
non-FreeBSD, causing the build to fail.
Fix this by forwarding DEBUG on to the compiler invocation for the VDSO
wrapper. It's assembly so it's not hugely useful, but there is a
non-zero amount of information preserved, and other assembly files are
built with -g by default too so this matches them; the alternative would
be to tag the files.amd64 entries with no-ctfmerge. Note that the VDSO
itself is still compiled without debug info, this only affects the
wrapper linked into the kernel.
Fixes: 98c8b62524 ("vdso for ia32 on amd64"), ab4524b3d7 ("amd64: wrap 64bit sigtramp into vdso")
MFC after: 1 month
