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vanhauser-thc and others added 30 commits April 26, 2025 15:57
AFLFast power schedules regressed since v4.31c
This enables 64-bit detection for the following additional systems:

- [PowerPC64 (little endian)](https://en.wikipedia.org/wiki/Ppc64)
- [S390x](https://en.wikipedia.org/wiki/S390x)
- [LoongArch64](https://en.wikipedia.org/wiki/LoongArch64)
Define WORD_SIZE_64 for more 64-bit arches
Add missing override directive for CFLAGS+= in libdislocator
Add a test case to `test/test-qemu-mode.sh` and make sure that
AFL_QEMU_PERSISTENT_EXITS loops correctly.

This works only on platforms for which `afl-qemu-trace` detects exit
signals and resets the program counter.

This commit updates `test-instr.c` to optionally call `exit(n)` instead of
returning n to the operating system. This option can be activated using
the `EXIT_AT_END` flag. This way, we can test the
QEMU persistent exit mode without having to add a new test file.

You can compile and run `test-instr.c` with the exit mode like so:

```bash
gcc -o exit -DEXIT_AT_END test-instr.c
AFL_QEMU_DEBUG_MAPS= \
    AFL_DEBUG= \
    AFL_QEMU_PERSISTENT_ADDR=$(readelf -a exit | grep 'main$' | awk '{ printf "0x%s", $2 }') \
    AFL_QEMU_PERSISTENT_GPR=1 \
    AFL_QEMU_PERSISTENT_EXITS=1 \
    ./afl-qemu-trace exit
```

Press enter repeatedly and you will see an output like this:

```
...
Debug: Sending status 0xc201ffff

test-instr:

Neither one or zero? How quaint!

test-instr:

Neither one or zero? How quaint!

test-instr:

Neither one or zero? How quaint!

test-instr:

Neither one or zero? How quaint!

test-instr:

Neither one or zero? How quaint!
```

To make sure that persistent exits are detected correctly on x86_64, I've made
the following changes to qemuafl:

```
 linux-user/i386/cpu_loop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/linux-user/i386/cpu_loop.c b/linux-user/i386/cpu_loop.c
index 4509f46b95..46bdbaf94a 100644
--- a/linux-user/i386/cpu_loop.c
+++ b/linux-user/i386/cpu_loop.c
@@ -235,7 +235,7 @@ void cpu_loop(CPUX86State *env)
 #ifndef TARGET_ABI32
         case EXCP_SYSCALL:
             /* linux syscall from syscall instruction */
-            if (afl_fork_child && persistent_exits &&
+            if (persistent_exits &&
                 env->regs[R_EAX] == TARGET_NR_exit_group) {
               env->eip = afl_persistent_addr;
               continue;
```
Disable GCC instrumentation for AFL_SAN_NO_INST
…ing of the forkserver child process, and unsetting it when the target is launched
"!target_hash" already cover "afl->fsrv.nyx_mode && target_hash == 0"
Add test case for AFL_QEMU_PERSISTENT_EXITS
@vanhauser-thc vanhauser-thc merged commit 64da32a into release Jun 28, 2025
16 checks passed
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