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Diffstat (limited to 'results/classifier/deepseek-2-tmp/output/mistranslation/1824344')
| -rw-r--r-- | results/classifier/deepseek-2-tmp/output/mistranslation/1824344 | 46 |
1 files changed, 0 insertions, 46 deletions
diff --git a/results/classifier/deepseek-2-tmp/output/mistranslation/1824344 b/results/classifier/deepseek-2-tmp/output/mistranslation/1824344 deleted file mode 100644 index 438a32dd..00000000 --- a/results/classifier/deepseek-2-tmp/output/mistranslation/1824344 +++ /dev/null @@ -1,46 +0,0 @@ - -x86: retf or iret pagefault sets wrong error code - -With a x86_64 or i386 guest, non-KVM, when trying to execute a -"iret/iretq/retf" instruction in userspace with invalid stack pointer -(under a protected mode OS, like Linux), wrong bits are set in the -pushed error code; bit 2 is not set, indicating the error comes from -kernel space. - -If the guest OS is using this flag to decide whether this was a kernel -or user page fault, it will mistakenly decide a kernel has irrecoverably -faulted, possibly causing guest OS panic. - - -How to reproduce the problem a guest (non-KVM) Linux: -Note, on recent Linux kernel version, this needs a CPU with SMAP support -(eg. -cpu max) - -$ cat tst.c -int main() -{ -__asm__ volatile ( -"mov $0,%esp\n" -"retf" -); -return 0; -} - -$ gcc tst.c -$ ./a.out -Killed - - -"dmesg" shows the kernel has in fact triggered a "BUG: unable to handle -kernel NULL pointer dereference...", but it has "recovered" by killing -the faulting process (see attached screenshot). - - -Using self-compiled qemu from git: -commit 532cc6da74ec25b5ba6893b5757c977d54582949 (HEAD -> master, tag: v4.0.0-rc3, origin/master, origin/HEAD) -Author: Peter Maydell <email address hidden> -Date: Wed Apr 10 15:38:59 2019 +0100 - - Update version for v4.0.0-rc3 release - - Signed-off-by: Peter Maydell <email address hidden> \ No newline at end of file |