With the following commit:
4bc9f92e64 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data")
... efi_bgrt_init() calls into the memblock allocator through
efi_mem_reserve() => efi_arch_mem_reserve() *after* mm_init() has been called.
Indeed, KASAN reports a bad read access later on in efi_free_boot_services():
BUG: KASAN: use-after-free in efi_free_boot_services+0xae/0x24c
at addr ffff88022de12740
Read of size 4 by task swapper/0/0
page:ffffea0008b78480 count:0 mapcount:-127
mapping: (null) index:0x1 flags: 0x5fff8000000000()
[...]
Call Trace:
dump_stack+0x68/0x9f
kasan_report_error+0x4c8/0x500
kasan_report+0x58/0x60
__asan_load4+0x61/0x80
efi_free_boot_services+0xae/0x24c
start_kernel+0x527/0x562
x86_64_start_reservations+0x24/0x26
x86_64_start_kernel+0x157/0x17a
start_cpu+0x5/0x14
The instruction at the given address is the first read from the memmap's
memory, i.e. the read of md->type in efi_free_boot_services().
Note that the writes earlier in efi_arch_mem_reserve() don't splat because
they're done through early_memremap()ed addresses.
So, after memblock is gone, allocations should be done through the "normal"
page allocator. Introduce a helper, efi_memmap_alloc() for this. Use
it from efi_arch_mem_reserve(), efi_free_boot_services() and, for the sake
of consistency, from efi_fake_memmap() as well.
Note that for the latter, the memmap allocations cease to be page aligned.
This isn't needed though.
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: <stable@vger.kernel.org> # v4.9
Cc: Dave Young <dyoung@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Mika Penttilä <mika.penttila@nextfour.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Fixes: 4bc9f92e64 ("x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data")
Link: http://lkml.kernel.org/r/20170105125130.2815-1-nicstange@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While efi_memmap_init_{early,late}() exist for architecture code to
install memory maps from firmware data and for the virtual memory
regions respectively, drivers don't care which stage of the boot we're
at and just want to swap the existing memmap for a modified one.
efi_memmap_install() abstracts the details of how the new memory map
should be mapped and the existing one unmapped.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Also move the functions from the EFI fake mem driver since future
patches will require access to the memmap insertion code even if
CONFIG_EFI_FAKE_MEM isn't enabled.
This will be useful when we need to build custom EFI memory maps to
allow drivers to mark regions as reserved.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
There is a whole load of generic EFI memory map code inside of the
fake_mem driver which is better suited to being grouped with the rest
of the generic EFI code for manipulating EFI memory maps.
In preparation for that, this patch refactors the core code, so that
it's possible to move entire functions later.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Every EFI architecture apart from ia64 needs to setup the EFI memory
map at efi.memmap, and the code for doing that is essentially the same
across all implementations. Therefore, it makes sense to factor this
out into the common code under drivers/firmware/efi/.
The only slight variation is the data structure out of which we pull
the initial memory map information, such as physical address, memory
descriptor size and version, etc. We can address this by passing a
generic data structure (struct efi_memory_map_data) as the argument to
efi_memmap_init_early() which contains the minimum info required for
initialising the memory map.
In the process, this patch also fixes a few undesirable implementation
differences:
- ARM and arm64 were failing to clear the EFI_MEMMAP bit when
unmapping the early EFI memory map. EFI_MEMMAP indicates whether
the EFI memory map is mapped (not the regions contained within) and
can be traversed. It's more correct to set the bit as soon as we
memremap() the passed in EFI memmap.
- Rename efi_unmmap_memmap() to efi_memmap_unmap() to adhere to the
regular naming scheme.
This patch also uses a read-write mapping for the memory map instead
of the read-only mapping currently used on ARM and arm64. x86 needs
the ability to update the memory map in-place when assigning virtual
addresses to regions (efi_map_region()) and tagging regions when
reserving boot services (efi_reserve_boot_services()).
There's no way for the generic fake_mem code to know which mapping to
use without introducing some arch-specific constant/hook, so just use
read-write since read-only is of dubious value for the EFI memory map.
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Peter Jones <pjones@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Both efi_find_mirror() and efi_fake_memmap() really want to know
whether the EFI memory map is available, not just whether the machine
was booted using EFI. efi_fake_memmap() even has a check for
EFI_MEMMAP at the start of the function.
Since we've already got other code that has this dependency, merge
everything under one if() conditional, and remove the now superfluous
check from efi_fake_memmap().
Tested-by: Dave Young <dyoung@redhat.com> [kexec/kdump]
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [arm]
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Abolish the poorly named EFI memory map, 'memmap'. It is shadowed by a
bunch of local definitions in various files and having two ways to
access the EFI memory map ('efi.memmap' vs. 'memmap') is rather
confusing.
Furthermore, IA64 doesn't even provide this global object, which has
caused issues when trying to write generic EFI memmap code.
Replace all occurrences with efi.memmap, and convert the remaining
iterator code to use for_each_efi_mem_desc().
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Luck, Tony <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-8-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Most of the users of for_each_efi_memory_desc() are equally happy
iterating over the EFI memory map in efi.memmap instead of 'memmap',
since the former is usually a pointer to the latter.
For those users that want to specify an EFI memory map other than
efi.memmap, that can be done using for_each_efi_memory_desc_in_map().
One such example is in the libstub code where the firmware is queried
directly for the memory map, it gets iterated over, and then freed.
This change goes part of the way toward deleting the global 'memmap'
variable, which is not universally available on all architectures
(notably IA64) and is rather poorly named.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-7-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
0f96a99dab ("efi: Add "efi_fake_mem" boot option")
introduced the following warning message:
drivers/firmware/efi/fake_mem.c:186:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
new_memmap_phy was defined as a u64 value and cast to void*,
causing a int-to-pointer-cast warning on x86 32-bit builds.
However, since the void* type is inappropriate for a physical
address, the definition of struct efi_memory_map::phys_map has
been changed to phys_addr_t in the previous patch, and so the
cast can be dropped entirely.
This patch also changes the type of the "new_memmap_phy"
variable from "u64" to "phys_addr_t" to align with the types of
memblock_alloc() and struct efi_memory_map::phys_map.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
[ Removed void* cast, updated commit log]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kamezawa.hiroyu@jp.fujitsu.com
Cc: linux-efi@vger.kernel.org
Cc: matt.fleming@intel.com
Link: http://lkml.kernel.org/r/1445593697-1342-2-git-send-email-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch introduces new boot option named "efi_fake_mem".
By specifying this parameter, you can add arbitrary attribute
to specific memory range.
This is useful for debugging of Address Range Mirroring feature.
For example, if "efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000"
is specified, the original (firmware provided) EFI memmap will be
updated so that the specified memory regions have
EFI_MEMORY_MORE_RELIABLE attribute (0x10000):
<original>
efi: mem36: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB)
<updated>
efi: mem36: [Conventional Memory| |MR| | | | |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB)
efi: mem37: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB)
efi: mem38: [Conventional Memory| |MR| | | | |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB)
efi: mem39: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB)
And you will find that the following message is output:
efi: Memory: 4096M/131455M mirrored memory
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
