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Jan Beulich
6fba45ca3b
Our present approach is working fully behind the compiler's back. This
was found to not work with LTO. Employ ld's --wrap= option instead. Note
that while this makes the build work at least with new enough gcc (it
doesn't with gcc7, for example, due to tool chain side issues afaict),
according to my testing things still won't work when building the
fuzzing harness with afl-cc: While with the gcc7 tool chain I see afl-as
getting invoked, this does not happen with gcc13. Yet without using that
assembler wrapper the resulting binary will look uninstrumented to
afl-fuzz.
While checking the resulting binaries I noticed that we've gained uses
of snprintf() and strstr(), which only just so happen to not cause any
problems. Add a wrappers for them as well.
Since we don't have any actual uses of v{,sn}printf(), no definitions of
their wrappers appear (just yet). But I think we want
__wrap_{,sn}printf() to properly use __real_v{,sn}printf() right away,
which means we need delarations of the latter.
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Suggested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>