Let user pass their own CPU_TARGET in test-pre.sh

justuswilhelm · justuswilhelm · commit 8618fbc0c267 · 2025-06-04T09:31:13.000+09:00
The target system might be different from the host system. For example,
you can fuzz Linux binaries compiled for *mipsel*, while your host is
*x86_64*.

Some of the tests depend on specific platforms to run correctly.
For example, the afl-fuzz qemu_mode cmplog test only works on Intel or
ARM systems. The `SYS` variable is populated using `uname -m` and the
test cases then consult this variable to decide whether to run the test
or not.

If you want to test afl-fuzz for qemu_mode on mipsel, you might
want to make sure that Intel or ARM tests don't run. With this
patch, you can supply your own `CPU_TARGET` environment variable and skip
platform specific tests. `SYS` then contains the value of `CPU_TARGET`.

This allows you to add tests for *mipsel* or other niche platforms in
the future as well.

Sample usage:

```
$ cd qemu_mode &amp;&amp; env CPU_TARGET=mipsel ./build_qemu_support.sh
$ cd ../test &amp;&amp; env CPU_TARGET=mipsel ./test-qemu-mode.sh
[*] Using environment variable CPU_TARGET=mipsel for SYS
[*] starting AFL++ test framework ...
[*] Testing: qemu_mode
...
```
diff --git a/test/test-pre.sh b/test/test-pre.sh
@@ -113,15 +113,20 @@ test -e /usr/local/bin/opt && {
 }
 AFL_COMPILER=afl-clang-fast
 
-SYS=`uname -m`
-
 GREY="\\033[1;90m"
 BLUE="\\033[1;94m"
 GREEN="\\033[0;32m"
 RED="\\033[0;31m"
 YELLOW="\\033[1;93m"
 RESET="\\033[0m"
 
+if test -n "$CPU_TARGET"; then
+    $ECHO "${RESET}${GREY}[*] Using environment variable CPU_TARGET=$CPU_TARGET for SYS"
+    SYS="$CPU_TARGET"
+else
+    SYS=`uname -m`
+fi
+
 MEM_LIMIT=none
 
 export PATH="${PATH}:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin"
