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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-07-03 07:27:52 +0000 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-07-03 07:27:52 +0000 |
| commit | d0c85e36e4de67af628d54e9ab577cc3fad7796a (patch) | |
| tree | f8f784b0f04343b90516a338d6df81df3a85dfa2 /results/classifier/deepseek-2-tmp/output/debug/654 | |
| parent | 7f4364274750eb8cb39a3e7493132fca1c01232e (diff) | |
| download | emulator-bug-study-d0c85e36e4de67af628d54e9ab577cc3fad7796a.tar.gz emulator-bug-study-d0c85e36e4de67af628d54e9ab577cc3fad7796a.zip | |
add deepseek and gemma results
Diffstat (limited to 'results/classifier/deepseek-2-tmp/output/debug/654')
| -rw-r--r-- | results/classifier/deepseek-2-tmp/output/debug/654 | 24 |
1 files changed, 0 insertions, 24 deletions
diff --git a/results/classifier/deepseek-2-tmp/output/debug/654 b/results/classifier/deepseek-2-tmp/output/debug/654 deleted file mode 100644 index f3d89846..00000000 --- a/results/classifier/deepseek-2-tmp/output/debug/654 +++ /dev/null @@ -1,24 +0,0 @@ - -Strace Log Output Mangled -Description of problem: -The syscall log entries from the strace logging capability can be interrupted by other log messages before the full syscall line is -complete. -This makes parsing the strace syscall lines from the log output difficult. -Steps to reproduce: -1. Run the supplied command with a simple dynamically linked binary, or a binary that performs mmaps -2. Notice that the strace 'mmap' syscall log entries in the trace file are interrupted by the page log output -Additional information: -I have attached an example log from a dynamically linked 'hello world' binary, which demonstrates the bug in the mmap syscall strace entries. [output.trace](/uploads/88c83273582d00241fbf95af735dcc61/output.trace) - - -I believe this bug caused by a couple of things: -Firstly, in the linux-user/syscall.c file: the strace syscall entry is not output atomically, but instead split across two calls: -The first half is at `print_syscall`: https://gitlab.com/qemu-project/qemu/-/blob/master/linux-user/syscall.c#L13153 -And the return value (and new line) is printed in `print_syscall_ret`: https://gitlab.com/qemu-project/qemu/-/blob/master/linux-user/syscall.c#L13160 - -In the case of the mmap syscall, the function `log_page_dump` is called between these two functions resulting in the mangled log output: -https://gitlab.com/qemu-project/qemu/-/blob/master/linux-user/mmap.c#L633 -There may be other syscalls that behave similarly, but this was noticed due to the mmap behavior. - - -Internally to the `print_syscall` and `print_syscall_ret` functions, `qemu_log` is called multiple times to compose the full log entry, and it seems that it is inside `qemu_log` that the logfile lock is obtained and dropped - so theoretically another thread can output to the log during the printing of a single syscall entry between these `qemu_log` calls. I do not know if this actually happens in practice besides the mmap scenario described above. |
