linux-xiaomi-chiron/include
Dan Williams 484a418d07 efi: Fix handling of multiple efi_fake_mem= entries
Dave noticed that when specifying multiple efi_fake_mem= entries only
the last entry was successfully being reflected in the efi memory map.
This is due to the fact that the efi_memmap_insert() is being called
multiple times, but on successive invocations the insertion should be
applied to the last new memmap rather than the original map at
efi_fake_memmap() entry.

Rework efi_fake_memmap() to install the new memory map after each
efi_fake_mem= entry is parsed.

This also fixes an issue in efi_fake_memmap() that caused it to litter
emtpy entries into the end of the efi memory map. An empty entry causes
efi_memmap_insert() to attempt more memmap splits / copies than
efi_memmap_split_count() accounted for when sizing the new map. When
that happens efi_memmap_insert() may overrun its allocation, and if you
are lucky will spill over to an unmapped page leading to crash
signature like the following rather than silent corruption:

    BUG: unable to handle page fault for address: ffffffffff281000
    [..]
    RIP: 0010:efi_memmap_insert+0x11d/0x191
    [..]
    Call Trace:
     ? bgrt_init+0xbe/0xbe
     ? efi_arch_mem_reserve+0x1cb/0x228
     ? acpi_parse_bgrt+0xa/0xd
     ? acpi_table_parse+0x86/0xb8
     ? acpi_boot_init+0x494/0x4e3
     ? acpi_parse_x2apic+0x87/0x87
     ? setup_acpi_sci+0xa2/0xa2
     ? setup_arch+0x8db/0x9e1
     ? start_kernel+0x6a/0x547
     ? secondary_startup_64+0xb6/0xc0

Commit af16489848 "x86/efi: Update e820 with reserved EFI boot
services data to fix kexec breakage" introduced more occurrences where
efi_memmap_insert() is invoked after an efi_fake_mem= configuration has
been parsed. Previously the side effects of vestigial empty entries were
benign, but with commit af16489848 that follow-on efi_memmap_insert()
invocation triggers efi_memmap_insert() overruns.

Reported-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20191231014630.GA24942@dhcp-128-65.nay.redhat.com
Link: https://lore.kernel.org/r/20200113172245.27925-14-ardb@kernel.org
2020-01-20 08:14:29 +01:00
..
acpi Merge branches 'acpi-utils', 'acpi-platform', 'acpi-video' and 'acpi-doc' 2019-11-26 10:30:49 +01:00
asm-generic asm-generic/nds32: don't redefine cacheflush primitives 2019-12-30 11:18:43 +01:00
clocksource x86/hyperv: Initialize clockevents earlier in CPU onlining 2019-11-15 10:33:49 +01:00
crypto crypto: ablkcipher - remove deprecated and unused ablkcipher support 2019-11-17 09:02:49 +08:00
drm drm/dp_mst: Have DP_Tx send one msg at a time 2020-01-15 17:01:21 -05:00
dt-bindings dt-bindings: reset: meson8b: fix duplicate reset IDs 2019-12-09 15:21:20 -08:00
keys powerpc updates for 5.5 2019-11-30 14:35:43 -08:00
kunit
kvm Merge remote-tracking branch 'kvmarm/misc-5.5' into kvmarm/next 2019-11-08 11:27:29 +00:00
linux efi: Fix handling of multiple efi_fake_mem= entries 2020-01-20 08:14:29 +01:00
math-emu
media drm main pull for 5.5-rc1 2019-11-27 17:45:48 -08:00
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2020-01-16 10:04:40 +01:00
pcmcia
ras
rdma IB/core: Introduce rdma_user_mmap_entry_insert_range() API 2019-12-12 16:55:36 -05:00
scsi scsi: target: iscsi: Wait for all commands to finish before freeing a session 2019-11-19 21:37:35 -05:00
soc riscv: move sifive_l2_cache.h to include/soc 2020-01-12 10:12:44 -08:00
sound ASoC: Fixes for v5.5 2019-12-17 14:18:32 +01:00
target
trace Merge branch 'dhowells' (patches from DavidH) 2020-01-14 09:56:31 -08:00
uapi Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2020-01-09 15:37:40 -08:00
vdso
video
xen xen/interface: re-define FRONT/BACK_RING_ATTACH() 2019-12-20 13:44:42 +01:00