diff options
Diffstat (limited to 'results/classifier/deepseek-r1:32b/reasoning/syscall/1926521')
| -rw-r--r-- | results/classifier/deepseek-r1:32b/reasoning/syscall/1926521 | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/results/classifier/deepseek-r1:32b/reasoning/syscall/1926521 b/results/classifier/deepseek-r1:32b/reasoning/syscall/1926521 new file mode 100644 index 00000000..5a8c91e7 --- /dev/null +++ b/results/classifier/deepseek-r1:32b/reasoning/syscall/1926521 @@ -0,0 +1,17 @@ +<think> +Okay, so I'm trying to classify this bug report for QEMU. The issue is that when an application uses MADV_DONTNEED, QEMU isn't handling it correctly. Let me break down what's happening here. + +The user provided code where they map a page with MAP_PRIVATE | MAP_ANONYMOUS, which means it's private and anonymous—so changes won't be reflected in any file. They write 'A' to the first byte of this mapped area. Then they call madvise with MADV_DONTNEED on that region. + +According to the man pages, after MADV_DONTNEED, accessing those pages should result in either reloading from a file (for shared mappings) or zero-filled pages for private anonymous mappings. In this case, since it's MAP_PRIVATE and anonymous, any access should get zeros because the OS can just drop the pages and refill them on next access with zeros. + +In the code, after calling madvise, they assert that *P is 0. On the host system, this works as expected, but when run under QEMU, it fails, meaning *P isn't zeroed out, causing an assertion failure. + +Looking at the QEMU code, in the syscall.c file, there's a comment saying MADV_DONTNEED is ignored because it's a hint. So QEMU just returns success without doing anything, which explains why the memory isn't cleared as expected. + +So this issue is about how QEMU handles a specific system call—madvise with MADV_DONTNEED. Since it's not correctly implementing the expected behavior of the madvise syscall, it falls under a syscall error category. +</think> + +The bug report pertains to an incorrect handling of the `madvise` system call in QEMU when processing the `MADV_DONTNEED` advice, leading to unexpected memory behavior. + +**Answer:** The given bug is classified as a **syscall** issue. \ No newline at end of file |