mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2025-01-08 23:04:35 +08:00
744b37fb5a
Guest access functions like copy_to/from_guest() call __guestaddr_to_user() which in turn call gmap_fault() in order to translate a guest address to a user space address. In error case __guest_addr_to_user() returns either -EFAULT or -ENOMEM. The copy_to/from_guest functions just pass these return values down to the callers. The -ENOMEM case however is problematic since there are several places which access guest memory like: rc = copy_to_guest(...); if (rc == -EFAULT) error_handling(); So in case of -ENOMEM the code assumes that the guest memory access succeeded even though it failed. This can cause guest data or state corruption. If __guestaddr_to_user() returns -ENOMEM the meaning is that a valid user space mapping exists, but there was not enough memory available when trying to build the guest mapping. In other words an out-of-memory situation occured. For normal user space accesses an out-of-memory situation causes the page fault handler to map -ENOMEM to -EFAULT (see fixup code in do_no_context()). We need to do exactly the same for the kvm gaccess functions. So __guestaddr_to_user() should just map all error codes to -EFAULT. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> |
||
|---|---|---|
| .. | ||
| alpha | ||
| arc | ||
| arm | ||
| arm64 | ||
| avr32 | ||
| blackfin | ||
| c6x | ||
| cris | ||
| frv | ||
| h8300 | ||
| hexagon | ||
| ia64 | ||
| m32r | ||
| m68k | ||
| metag | ||
| microblaze | ||
| mips | ||
| mn10300 | ||
| openrisc | ||
| parisc | ||
| powerpc | ||
| s390 | ||
| score | ||
| sh | ||
| sparc | ||
| tile | ||
| um | ||
| unicore32 | ||
| x86 | ||
| xtensa | ||
| .gitignore | ||
| Kconfig | ||