Commit Graph

6 Commits

Author SHA1 Message Date
Michael Brown
e39cd79a00 [efi] Split out autoexec script portions of efi_autoboot.c
The "autoboot device" and "autoexec script" functionalities in
efi_autoboot.c are unrelated except in that they both need to be
invoked by efiprefix.c before device drivers are loaded.

Split out the autoexec script portions to a separate file to avoid
potential confusion.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2021-02-17 17:14:19 +00:00
Michael Brown
63625b43e9 [efi] Allow vetoing of drivers that cannot be unloaded
Some UEFI drivers (observed with the "Usb Xhci Driver" on an HP
EliteBook) are particularly badly behaved: they cannot be unloaded and
will leave handles opened with BY_DRIVER attributes even after
disconnecting the driver, thereby preventing a replacement iPXE driver
from opening the handle.

Allow such drivers to be vetoed by falling back to a brute-force
mechanism that will disconnect the driver from all handles, uninstall
the driver binding protocol (to prevent it from attaching to any new
handles), and finally close any stray handles that the vetoed driver
has left open.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-11-30 19:34:57 +00:00
Michael Brown
0e26220902 [efi] Rename efi_blacklist to efi_veto
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-11-07 23:30:56 +00:00
Michael Brown
a61b27b97f [efi] Enable stack protection where possible
Enable -fstack-protector for EFI builds, where binary size is less
critical than for BIOS builds.

The stack cookie must be constructed immediately on entry, which
prohibits the use of any viable entropy source.  Construct a cookie by
XORing together various mildly random quantities to produce a value
that will at least not be identical on each run.

On detecting a stack corruption, attempt to call Exit() with an
appropriate error.  If that fails, then lock up the machine since
there is no other safe action that can be taken.

The old conditional check for support of -fno-stack-protector is
omitted since this flag dates back to GCC 4.1.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2020-06-24 16:23:21 +01:00
Michael Brown
64b4452bca [efi] Blacklist the Dell Ip4ConfigDxe driver
On a Dell OptiPlex 7010, calling DisconnectController() on the LOM
device handle will lock up the system.  Debugging shows that execution
is trapped in an infinite loop that is somehow trying to reconnect
drivers (without going via ConnectController()).

The problem can be reproduced in the UEFI shell with no iPXE code
present, by using the "disconnect" command.  Experimentation shows
that the only fix is to unload (rather than just disconnect) the
"Ip4ConfigDxe" driver.

Add the concept of a blacklist of UEFI drivers that will be
automatically unloaded when iPXE runs as an application, and add the
Dell Ip4ConfigDxe driver to this blacklist.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
2019-02-19 19:02:11 +00:00
Michael Brown
04ef198d2f [efi] Move architecture-independent EFI prefixes to interface/efi
Signed-off-by: Michael Brown <mcb30@ipxe.org>
2016-03-17 14:51:14 +00:00