1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
|
<think>
Okay, so I'm trying to figure out whether this bug report about qemu-i386 is user-mode or system-mode related. The issue is that when running i386 Linux binaries in qemu-i386, the AT_SYSINFO auxval isn't being defined. This causes segfaults in Android's Bionic libc.
From what I understand, auxvals are auxiliary values passed to a process at startup by the kernel. They include things like system information pointers. The specific one here, AT_SYSINFO, is expected by Bionic libc. If it's not present, Bionic tries to use a null pointer, leading to a crash.
The user provided some code snippets showing how Bioniclibc initializes __libc_sysinfo using getauxval(AT_SYSINFO). Since qemu isn't setting this, the function pointer becomes invalid, causing a segfault when __kernel_syscall tries to call it.
Now, thinking about QEMU's architecture: QEMU can run in user mode or system mode. User-mode emulation focuses on running applications without a full OS stack, handling syscalls directly. System-mode involves emulating the entire hardware and booting an OS.
In this case, the problem arises when executing a binary that expects AT_SYSINFO to be set by the kernel (which isn't happening because QEMU's user-mode setup doesn't provide it). So, this seems like a missing feature in QEMU's user-mode emulation for i386. It should probably set up these auxvals as part of its environment setup when running binaries.
Therefore, the issue is related to how QEMU handles user-space processes and their environment variables/auxiliary values. Since it's about process execution and system call handling without involving full OS booting or hardware emulation, this falls under user-mode.
</think>
user
|