* [PATCH] x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE
2016-09-20 14:46 [GIT PULL] EFI fix for v4.9 queue Matt Fleming
@ 2016-09-20 14:46 ` Matt Fleming
2016-09-20 14:59 ` [GIT PULL] EFI fix for v4.9 queue Ingo Molnar
1 sibling, 0 replies; 3+ messages in thread
From: Matt Fleming @ 2016-09-20 14:46 UTC (permalink / raw)
To: Ingo Molnar, Thomas Gleixner, H . Peter Anvin
Cc: Matt Fleming, Ard Biesheuvel, linux-kernel, linux-efi,
Mark Rutland, Mike Galbraith, Mike Krinkin, Peter Jones,
Taku Izumi
Mike Galbraith reported that his machine started rebooting during boot
after,
commit 8e80632fb23f ("efi/esrt: Use efi_mem_reserve() and avoid a kmalloc()")
The ESRT table on his machine is 56 bytes and at no point in the
efi_arch_mem_reserve() call path is that size rounded up to
EFI_PAGE_SIZE, nor is the start address on an EFI_PAGE_SIZE boundary.
Since the EFI memory map only deals with whole pages, inserting an EFI
memory region with 56 bytes results in a new entry covering zero
pages, and completely screws up the calculations for the old regions
that were trimmed.
Round all sizes upwards, and start addresses downwards, to the nearest
EFI_PAGE_SIZE boundary.
Additionally, efi_memmap_insert() expects the mem::range::end value to
be one less than the end address for the region.
Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Reported-by: Mike Krinkin <krinkin.m.u@gmail.com>
Tested-by: Mike Krinkin <krinkin.m.u@gmail.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
arch/x86/platform/efi/quirks.c | 6 +++++-
drivers/firmware/efi/memmap.c | 11 +++++++++++
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index f14b7a9da24b..10aca63a50d7 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -201,8 +201,12 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
return;
}
+ size += addr % EFI_PAGE_SIZE;
+ size = round_up(size, EFI_PAGE_SIZE);
+ addr = round_down(addr, EFI_PAGE_SIZE);
+
mr.range.start = addr;
- mr.range.end = addr + size;
+ mr.range.end = addr + size - 1;
mr.attribute = md.attribute | EFI_MEMORY_RUNTIME;
num_entries = efi_memmap_split_count(&md, &mr.range);
diff --git a/drivers/firmware/efi/memmap.c b/drivers/firmware/efi/memmap.c
index cd96086fd851..f03ddecd232b 100644
--- a/drivers/firmware/efi/memmap.c
+++ b/drivers/firmware/efi/memmap.c
@@ -225,6 +225,17 @@ void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf,
m_end = mem->range.end;
m_attr = mem->attribute;
+ /*
+ * The EFI memory map deals with regions in EFI_PAGE_SIZE
+ * units. Ensure that the region described by 'mem' is aligned
+ * correctly.
+ */
+ if (!IS_ALIGNED(m_start, EFI_PAGE_SIZE) ||
+ !IS_ALIGNED(m_end + 1, EFI_PAGE_SIZE)) {
+ WARN_ON(1);
+ return;
+ }
+
for (old = old_memmap->map, new = buf;
old < old_memmap->map_end;
old += old_memmap->desc_size, new += old_memmap->desc_size) {
--
2.9.3
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [GIT PULL] EFI fix for v4.9 queue
2016-09-20 14:46 [GIT PULL] EFI fix for v4.9 queue Matt Fleming
2016-09-20 14:46 ` [PATCH] x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE Matt Fleming
@ 2016-09-20 14:59 ` Ingo Molnar
1 sibling, 0 replies; 3+ messages in thread
From: Ingo Molnar @ 2016-09-20 14:59 UTC (permalink / raw)
To: Matt Fleming
Cc: Thomas Gleixner, H . Peter Anvin, Ard Biesheuvel, linux-kernel,
linux-efi, Mark Rutland, Mike Galbraith, Mike Krinkin,
Peter Jones, Taku Izumi
* Matt Fleming <matt@codeblueprint.co.uk> wrote:
> Folks, please pull the following fix for the v4.9 EFI queue sat in
> tip/efi/core.
>
> The following changes since commit 5465fe0fc3316f7cdda66732a7986f4ebe76d949:
>
> Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into efi/core (2016-09-13 20:21:55 +0200)
>
> are available in the git repository at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git tags/efi-next
>
> for you to fetch changes up to 92dc33501bfba74655dbf3ec63ea82d040fd6d58:
>
> x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE (2016-09-20 15:43:31 +0100)
>
> ----------------------------------------------------------------
> * Fix a boot crash reported by Mike Galbraith and Mike Krinkin. The
> new EFI memory map reservation code didn't align reservations to
> EFI_PAGE_SIZE boundaries causing bogus regions to be inserted into
> the global EFI memory map - Matt Fleming
>
> ----------------------------------------------------------------
> Matt Fleming (1):
> x86/efi: Round EFI memmap reservations to EFI_PAGE_SIZE
>
> arch/x86/platform/efi/quirks.c | 6 +++++-
> drivers/firmware/efi/memmap.c | 11 +++++++++++
> 2 files changed, 16 insertions(+), 1 deletion(-)
Pulled into tip:efi/core, thanks a lot Matt!
Ingo
^ permalink raw reply [flat|nested] 3+ messages in thread