commit 92bfc33db9 ("efi: Free malloc regions on exit")
introduced memory freeing in grub_efi_fini(), which is
used not only by exit path but by halt/reboot one as well.
As result of memory freeing, code and data regions used by
modules, such as halt, reboot, acpi (used by halt) also got
freed. After return to module code, CPU executes, filled
by UEFI firmware (tested with edk2), 0xAFAFAFAF pattern as
a code. Which leads to #UD exception later.
grub> halt
!!!! X64 Exception Type - 06(#UD - Invalid Opcode) CPU Apic ID - 00000000 !!!!
RIP - 0000000003F4EC28, CS - 0000000000000038, RFLAGS - 0000000000200246
RAX - 0000000000000000, RCX - 00000000061DA188, RDX - 0A74C0854DC35D41
RBX - 0000000003E10E08, RSP - 0000000007F0F860, RBP - 0000000000000000
RSI - 00000000064DB768, RDI - 000000000832C5C3
R8 - 0000000000000002, R9 - 0000000000000000, R10 - 00000000061E2E52
R11 - 0000000000000020, R12 - 0000000003EE5C1F, R13 - 00000000061E0FF4
R14 - 0000000003E10D80, R15 - 00000000061E2F60
DS - 0000000000000030, ES - 0000000000000030, FS - 0000000000000030
GS - 0000000000000030, SS - 0000000000000030
CR0 - 0000000080010033, CR2 - 0000000000000000, CR3 - 0000000007C01000
CR4 - 0000000000000668, CR8 - 0000000000000000
DR0 - 0000000000000000, DR1 - 0000000000000000, DR2 - 0000000000000000
DR3 - 0000000000000000, DR6 - 00000000FFFF0FF0, DR7 - 0000000000000400
GDTR - 00000000079EEA98 0000000000000047, LDTR - 0000000000000000
IDTR - 0000000007598018 0000000000000FFF, TR - 0000000000000000
FXSAVE_STATE - 0000000007F0F4C0
Proposal here is to continue to free allocated memory for
exit boot services path but keep it for halt/reboot path
as it won't be much security concern here.
Introduced GRUB_LOADER_FLAG_EFI_KEEP_ALLOCATED_MEMORY
loader flag to be used by efi halt/reboot path.
Signed-off-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When booting on an ARMv8 core that implements either CTR.IDC or CTR.DIC
(indicating that some of the cache maintenance operations can be
removed when dealing with I/D-cache coherency, GRUB dies with a
"Unsupported cache type 0x........" message.
This is pretty likely to happen when running in a virtual machine
hosted on an arm64 machine (I've triggered it on a system built around
a bunch of Cortex-A55 cores, which implements CTR.IDC).
It turns out that the way GRUB deals with the CTR register is a bit
harsh for anything from ARMv7 onwards. The layout of the register is
backward compatible, meaning that nothing that gets added is allowed to
break earlier behaviour. In this case, ignoring IDC is completely fine,
and only results in unnecessary cache maintenance.
We can thus avoid being paranoid, and align the 32bit behaviour with
its 64bit equivalent.
This patch has the added benefit that it gets rid of a (gnu-specific)
case range too.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Leif Lindholm <leif@nuviainc.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The 32-bit arm efi port now shares the 64-bit linux loader, so delete
the now unused bits from the 32-bit linux loader.
This in turn leaves the grub-core/kern/arm/efi/misc.c unused, so
delete that too.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
grub_efi_allocate_pages Essentially does 2 unrelated things:
* Allocate at fixed address.
* Allocate at any address.
To switch between 2 different functions it uses address == 0 as magic
value which is wrong as 0 is a perfectly valid fixed adress to allocate at.
According to EABI only STT_FUNC has convention of lowest bit indicating
execution mode. R_THM_{JUMP,CALL}* relocations are assumed to be pointing
to thumb mode unless they use STT_FUNC.
Timer event to keep grub msec counter was running at 1000HZ. This was too
fast for UEFI timer driver and resulted in a 10x slowdown in grub time
versus wallclock. Reduce the timer event frequency and increase tick
increment accordingly to keep better time.
The current code for EFI grub_exit() calls grub_efi_fini() before
returning to firmware. In the case of ARM, this leaves a timer
event running which could lead to a firmware crash. This patch
changes this so that grub_machine_fini() is called with a NORETURN
flag. This allows machine-specific shutdown to happen as well
as the shutdown done by grub_efi_fini().
Signed-off-by: Mark Salter <msalter@redhat.com>
Use the new thumb_get_instruction_word/thumb_set_instruction_word
helpers throughout.
Style cleanup (missing spaces).
Move Thumb MOVW/MOVT handlers into Thumb relocation section of file.
libgcc for boot environment isn't always present and compatible.
libgcc is often absent if endianness or bit-size at boot is different
from running OS.
libgcc may use optimised opcodes that aren't available on boot time.
So instead of relying on libgcc shipped with the compiler, supply
the functions in GRUB directly.
Tests are present to ensure that those replacement functions behave the
way compiler expects them to.
Previously we supplied only unsigned divisions on platforms that need software
division.
Yet compiler may itself use a signed division. A typical example would be a
difference between 2 pointers which involves division by object size.
GCC 4.9 also generates R_ARM_THM_MOVW_ABS_NC and R_ARM_THM_MOVT_ABS,
as an alternative to ABS32.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
The unaligned local in __aeabi_uidivmod leads to a store to a 64bit
value at an address that is not divisible by 8 (in grub_divmod64).
The compiler most likely generates a STRD instruction to store it and
this causes an exception.
Fixes Savannah bug #43632.
This includes improvements done by Leif Lindholm.
Commit c9cd02c broke the u-boot syscall API for va_args that spill over
to the stack, causing the disk support to stop working. This patch
resolves the problem, while keeping the new, cleaner transition_space
handling.
Alexey Makhalov