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Diffstat (limited to 'results/classifier/qwen3:32b/reasoning/syscall/1263747')
| -rw-r--r-- | results/classifier/qwen3:32b/reasoning/syscall/1263747 | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/results/classifier/qwen3:32b/reasoning/syscall/1263747 b/results/classifier/qwen3:32b/reasoning/syscall/1263747 new file mode 100644 index 000000000..d2ac396ab --- /dev/null +++ b/results/classifier/qwen3:32b/reasoning/syscall/1263747 @@ -0,0 +1,41 @@ +<think> +Okay, let's try to figure out the category for this bug report. The user says that an ARM64 binary runs fine on real hardware but loops forever in QEMU with 100% CPU usage. The binary is a statically linked OCaml program that should print "hello, world" and exit. + +First, the problem is specific to QEMU, so it's a QEMU bug. The categories given are instruction, syscall, or runtime. + +If the binary is stuck in a loop, maybe there's an issue with how QEMU handles certain instructions. For example, maybe a specific CPU instruction isn't emulated correctly, causing an infinite loop where it should exit. That would be an instruction category issue. + +Alternatively, if the program relies on a syscall that's not properly implemented in QEMU's user-mode emulation, that would be a syscall problem. But the user mentioned it's a statically linked binary, so maybe it's not relying on external libraries. However, even statically linked programs use syscalls for things like printing to stdout. If QEMU's emulation of syscalls like write() or exit() is broken, the program might not behave correctly. However, the program is looping instead of exiting, which might suggest it's not getting a response from a syscall, or perhaps it's stuck in a system call loop. + +Another angle: runtime errors. The OCaml runtime might be doing something that QEMU's user-space emulator isn't handling correctly. For example, thread management, signal handling, or something related to the emulator's runtime support. But the problem is that the binary runs on real hardware, so the runtime on the actual ARM hardware works, but not in QEMU. That suggests QEMU's user-mode emulation isn't handling something the runtime expects. + +But since the binary is stuck in a loop, maybe there's a specific instruction that's causing the loop. For example, if the program uses a certain ARM64 instruction that QEMU's emulator doesn't handle correctly, leading to an infinite loop. The fact that it works on real hardware points to QEMU not emulating that instruction properly. + +Alternatively, maybe the OCaml program uses some low-level features (like specific atomic operations or memory barriers) that QEMU isn't emulating correctly, leading to an infinite loop in the runtime. But again, that could fall under instruction or runtime. + +Wait, the patch mentioned in the source compilation step is from a Caml-list archive. The patch might be related to a specific ARM64 issue. If the original code had a problem with ARM64 that was fixed by the patch, but QEMU isn't handling the corrected code properly, that's possible. However, the user applied the patch, so the code should be correct for real hardware. + +Another thought: if the binary uses syscalls that are supposed to terminate the program (like exit), but QEMU isn't handling that syscall correctly, causing the program to not exit and instead loop. For example, if the exit syscall isn't properly emulated, the program might return to the main loop instead of exiting. That would be a syscall category issue. + +But the symptom is that it's looping with 100% CPU. So maybe the program is stuck in a loop because a certain condition isn't met, which depends on a syscall. For example, maybe the program is waiting for a signal or a resource that isn't available in QEMU's environment. However, the program is supposed to print and exit, so it's more likely that it's getting stuck in a system call that's not returning, or the code isn't reaching the exit call. + +Alternatively, maybe the program uses some hardware-specific features (like CPUID or other cpuid instructions) that QEMU isn't emulating correctly, leading to incorrect behavior. For example, if the OCaml runtime checks for certain CPU features and, in QEMU, it's returning incorrect information, leading to incorrect code paths that loop. + +But without more details on the actual code, it's hard to say. The key is that the binary runs on real hardware but not in QEMU. The problem is in QEMU's user-mode emulation. The fact that it's an infinite loop suggests that either an instruction isn't being emulated correctly, causing the program to not proceed, or a syscall isn't being handled properly, leading to an infinite loop in the program. + +If the program is stuck in a loop that's part of the OCaml runtime, maybe due to incorrect syscall handling (like not being able to allocate memory, or a failed syscall causing a loop), that would be a syscall issue. For example, if the runtime is trying to create threads and the clone() syscall isn't working, leading to an infinite retry loop. + +But given that the user says it's a statically linked binary, maybe it's not using threads. The test program is simple: print_endline "hello, world". So the steps are: initialize OCaml runtime, execute the print, and exit. If during the exit process, the runtime is doing something that's not working in QEMU, perhaps a syscall that's supposed to exit the process isn't working. For example, if the exit_group syscall isn't being emulated, and the program is returning to the runtime, which then loops. + +Alternatively, maybe the program is using some system calls that are architecture-specific, and QEMU's user-mode for ARM64 isn't handling them correctly. For example, maybe the program uses a system call that's available on real ARM64 but QEMU's emulation doesn't support it, leading to an error that's not handled, causing an infinite loop. + +In that case, the problem would be a syscall category issue. However, if the problem is that QEMU is not correctly emulating a specific CPU instruction that the binary uses, leading to incorrect execution flow (like not jumping to the exit code), then it's an instruction issue. + +Given that the problem is that the binary runs on real hardware but not in QEMU, and the binary is using standard OCaml runtime, which is known to work on ARM64 when run natively, the issue is likely in QEMU's emulation of some aspect. The fact that it's looping suggests that a particular instruction or syscall isn't causing the program to exit as expected. + +I think the most likely category here is 'syscall' because the program is probably making a system call (like exit) that isn't being properly handled by QEMU's user-mode emulator, causing it to not exit and instead loop. Alternatively, if the problem is that a specific instruction isn't causing the program to proceed (like a branch or a system call instruction), then it would be 'instruction'. However, without knowing the exact cause, I have to rely on the symptoms. + +But considering that QEMU's user-mode emulation is responsible for translating syscalls between the host and guest architectures. If the binary is making a syscall that QEMU doesn't handle correctly, that's a syscall issue. Since the binary is supposed to exit cleanly, maybe the exit syscall isn't being passed through properly. So the answer might be 'syscall'. +</think> + +syscall \ No newline at end of file |