diff options
Diffstat (limited to 'results/classifier/qwen3:32b/reasoning/syscall/1876373')
| -rw-r--r-- | results/classifier/qwen3:32b/reasoning/syscall/1876373 | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/results/classifier/qwen3:32b/reasoning/syscall/1876373 b/results/classifier/qwen3:32b/reasoning/syscall/1876373 new file mode 100644 index 00000000..f4d45da6 --- /dev/null +++ b/results/classifier/qwen3:32b/reasoning/syscall/1876373 @@ -0,0 +1,13 @@ +<think> +Okay, let's try to figure out what's going on here. The user is reporting a segfault when using mremap in a QEMU-hosted process. The problem occurs when shrinking a buffer to 4096 bytes, but not when using other sizes like 12288. The code works natively on x86_64 but segfaults under qemu-i386 and qemu-arm. The segfault happens during the mremap syscall. + +First, I need to recall what mremap does. It's used to change the size of a memory mapping. The parameters are the old address, old size, new size, and flags. In this case, the program is trying to shrink the mapping from 8192 to 4096. The issue is specific to QEMU emulation, so the problem might be in how QEMU handles the mremap syscall for 32-bit guests. + +The user mentioned that when they change the new_size to 12288, there's no segfault. That's interesting. Maybe there's an alignment or page size issue. Wait, 4096 is exactly one page size on most systems. But mmap and mremap typically deal with page-aligned sizes. However, the code isn't using any flags like MREMAP_FIXED or MREMAP_MAYMOVE. The flags parameter is 0, which means it should just adjust the size if possible. + +But why would QEMU have a problem with this? Maybe QEMU's syscall emulation for mremap on 32-bit targets has a bug when handling the case where the new size is exactly one page. Perhaps the emulator isn't correctly handling the page alignment or the address calculation when reducing the size. The native system works, so the host's mremap implementation is okay. The problem is in QEMU's handling of the syscall for 32-bit processes. + +The categories given are instruction, syscall, or runtime. Since the segfault occurs during the mremap syscall and it's specific to QEMU's emulation of that syscall, this should be classified as a syscall issue. The instruction category would be if there was a wrong instruction being executed, but here the problem is in the syscall handling by QEMU. Runtime errors are more about the program's execution environment, but this seems directly tied to the syscall implementation in QEMU. +</think> + +syscall \ No newline at end of file |