Various features and parameters of a pv-kernel are specified via
elf notes in the kernel image. Those notes are part of the interface
between the Xen hypervisor and the kernel.
Instead of using num,bers in the code when interpreting the elf notes
make use of the header supplied by Xen for that purpose.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The loader for xen paravirtualized environment is using lots of global
variables. Reduce the number by making them either local or by putting
them into a single state structure.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When loading a Xen pv-kernel avoid memory leaks in case of errors.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The loader for xen paravirtualized environment isn't callable multiple
times as it won't free any memory in case of failure.
Call grub_relocator_unload() as other modules do it before allocating
a new relocator or when unloading the module.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Currently multiboot2 protocol loads image exactly at address specified in
ELF or multiboot2 header. This solution works quite well on legacy BIOS
platforms. It is possible because memory regions are placed at predictable
addresses (though I was not able to find any spec which says that it is
strong requirement, so, it looks that it is just a goodwill of hardware
designers). However, EFI platforms are more volatile. Even if required
memory regions live at specific addresses then they are sometimes simply
not free (e.g. used by boot/runtime services on Dell PowerEdge R820 and
OVMF). This means that you are not able to just set up final image
destination on build time. You have to provide method to relocate image
contents to real load address which is usually different than load address
specified in ELF and multiboot2 headers.
This patch provides all needed machinery to do self relocation in image code.
First of all GRUB2 reads min_addr (min. load addr), max_addr (max. load addr),
align (required image alignment), preference (it says which memory regions are
preferred by image, e.g. none, low, high) from multiboot_header_tag_relocatable
header tag contained in binary (at this stage load addresses from multiboot2
and/or ELF headers are ignored). Later loader tries to fulfill request (not only
that one) and if it succeeds then it informs image about real load address via
multiboot_tag_load_base_addr tag. At this stage GRUB2 role is finished. Starting
from now executable must cope with relocations itself using whole static and
dynamic knowledge provided by boot loader.
This patch does not provide functionality which could do relocations using
ELF relocation data. However, I was asked by Konrad Rzeszutek Wilk and Vladimir
'phcoder' Serbinenko to investigate that thing. It looks that relevant machinery
could be added to existing code (including this patch) without huge effort.
Additionally, ELF relocation could live in parallel with self relocation provided
by this patch. However, during research I realized that first of all we should
establish the details how ELF relocatable image should look like and how it should
be build. At least to build proper test/example files.
So, this patch just provides support for self relocatable images. If ELF file
with relocs is loaded then GRUB2 complains loudly and ignores it. Support for
such files will be added later.
This patch was tested with Xen image which uses that functionality. However, this Xen
feature is still under development and new patchset will be released in about 2-3 weeks.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
If image requested EFI boot services then skip multiboot2 memory maps.
Main reason for not providing maps is because they will likely be
invalid. We do a few allocations after filling them, e.g. for relocator
needs. Usually we do not care as we would have finished boot services.
If we keep boot services then it is easier/safer to not provide maps.
However, if image needs memory maps and they are not provided by bootloader
then it should get itself just before ExitBootServices() call.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Add tags used to pass ImageHandle to loaded image if requested.
It is used by at least ExitBootServices() function.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Add grub_relocator64_efi relocator. It will be used on EFI 64-bit platforms
when multiboot2 compatible image requests MULTIBOOT_TAG_TYPE_EFI_BS. Relocator
will set lower parts of %rax and %rbx accordingly to multiboot2 specification.
On the other hand processor mode, just before jumping into loaded image, will
be set accordingly to Unified Extensible Firmware Interface Specification,
Version 2.4 Errata B, section 2.3.4, x64 Platforms, boot services. This way
loaded image will be able to use EFI boot services without any issues.
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Rework TPM measurements to use fewer PCRs. After discussion with upstream,
it's preferable to avoid using so many PCRs. Instead, measure into PCRs 8
and 9 but use a prefix in the event log to indicate which subsystem carried
out the measurements.
We want a single buffer that contains the entire kernel image in order to
perform a TPM measurement. Allocate one and copy the entire kernel int it
before pulling out the individual blocks later on.
We want a single buffer that contains the entire kernel image in order to
perform a TPM measurement. Allocate one and copy the entire kernel into it
before pulling out the individual blocks later on.
The Secure Boot code currently reads the kernel from disk, validates the
signature and then reads it from disk again. A sufficiently exciting storage
device could modify the kernel between these two events and trigger the
execution of an untrusted kernel. Avoid re-reading it in order to ensure
this isn't a problem, and in the process speed up boot by not reading the
kernel twice.
Regression from commit:
loader/linux: do not pad initrd with zeroes at the end
a8c473288d
Wimboot fails since the change above because it expects the "trailer"
initrd element on an aligned address.
This issue shows only when newc_name is used and the last initrd
entry has a not aligned size.
While in theory permitted by the spec, modules rarely fit in low memory
anyway and not every kernel is able to handle modules in low memory anyway.
At least VMWare is known not to be able to handle modules at arbitrary
locations.
Syslinux memdisk is using initrd image and needs to know uncompressed
size in advance. For gzip uncompressed size is at the end of compressed
stream. Grub padded each input file to 4 bytes at the end, which means
syslinux got wrong size.
Linux initramfs loader apparently does not care about trailing alignment.
So change code to align beginning of each file instead which atomatically
gives us the correct size for single file.
Reported-By: David Shaw <dshaw@jabberwocky.com>
If grub is signed with a key that's in the trusted EFI keyring, an attacker
can point a boot entry at grub rather than at shim and grub will fail to
locate the shim verification protocol. This would then allow booting an
arbitrary kernel image. Fail validation if Secure Boot is enabled and we
can't find the shim protocol in order to prevent this.
struct ... foo = { 0, } is valid initializer, but older GCC emits
warning which is fatal error due to -Werror=missing-field-initializer.
So simply use full initializer to avoid these errors. This was fixed
probably in GCC 4.7.
See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36750
Currently, if "linux" fails, the "goto fail;" in grub_cmd_initrd sends us
into grub_initrd_close() without grub_initrd_init() being called, and thus
it never clears initrd_ctx->components. grub_initrd_close() then frees that
address, which is stale data from the stack. If the stack happens to have a
stale *address* there that matches a recent allocation, then you'll get a
double free later.
So initialize the memory up front.
Signed-off-by: Peter Jones <pjones@redhat.com>
In file included from ./include/grub/dl.h:23:0,
from grub-core/lib/libgcrypt-grub/cipher/rfc2268.c:3:
./include/grub/list.h:34:18: warning: conflicting types for 'grub_list_push' [en
abled by default]
void EXPORT_FUNC(grub_list_push) (grub_list_t *head, grub_list_t item);
^
./include/grub/symbol.h:68:25: note: in definition of macro 'EXPORT_FUNC'
# define EXPORT_FUNC(x) x
^
In file included from ./include/grub/fs.h:30:0,
from ./include/grub/file.h:25,
from ./grub-core/lib/posix_wrap/stdio.h:23,
from c:\mingw\include\libintl.h:314,
from ./include/grub/i18n.h:33,
from ./include/grub/misc.h:27,
from ./include/grub/list.h:25,
from ./include/grub/dl.h:28,
from grub-core/lib/libgcrypt-grub/cipher/rfc2268.c:3:
./include/grub/partition.h:106:3: note: previous implicit declaration of 'grub_l
ist_push' was here
grub_list_push (GRUB_AS_LIST_P (&grub_partition_map_list),
^
list.h needs just ATTRIBUTE_ERROR from misc.h; split compiler features
into separate file grub/compiler.h and include it instead.
The length of the Device Path End entry in the grub_linux_boot()
function was incorrectly set to 0. This triggers an assert failure
in debug builds of Tianocore.
Set it to sizeof (grub_efi_device_path_t).
