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authorLinus Torvalds <torvalds@linux-foundation.org>2018-01-05 12:23:57 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-05 12:23:57 -0800
commitabb7099dbc7a77f8674083050028c493ac601228 (patch)
tree83e2d126a6bca7c0c85d244af44089cc8101cdc8 /Documentation
parentb03acc4cc2c3b2338c6ee760351d010fb4708af3 (diff)
parentde791821c295cc61419a06fe5562288417d1bc58 (diff)
downloadlinux-abb7099dbc7a77f8674083050028c493ac601228.tar.bz2
Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more x86 pti fixes from Thomas Gleixner: "Another small stash of fixes for fallout from the PTI work: - Fix the modules vs. KASAN breakage which was caused by making MODULES_END depend of the fixmap size. That was done when the cpu entry area moved into the fixmap, but now that we have a separate map space for that this is causing more issues than it solves. - Use the proper cache flush methods for the debugstore buffers as they are mapped/unmapped during runtime and not statically mapped at boot time like the rest of the cpu entry area. - Make the map layout of the cpu_entry_area consistent for 4 and 5 level paging and fix the KASLR vaddr_end wreckage. - Use PER_CPU_EXPORT for per cpu variable and while at it unbreak nvidia gfx drivers by dropping the GPL export. The subject line of the commit tells it the other way around, but I noticed that too late. - Fix the ASM alternative macros so they can be used in the middle of an inline asm block. - Rename the BUG_CPU_INSECURE flag to BUG_CPU_MELTDOWN so the attack vector is properly identified. The Spectre mitigations will come with their own bug bits later" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pti: Rename BUG_CPU_INSECURE to BUG_CPU_MELTDOWN x86/alternatives: Add missing '\n' at end of ALTERNATIVE inline asm x86/tlb: Drop the _GPL from the cpu_tlbstate export x86/events/intel/ds: Use the proper cache flush method for mapping ds buffers x86/kaslr: Fix the vaddr_end mess x86/mm: Map cpu_entry_area at the same place on 4/5 level x86/mm: Set MODULES_END to 0xffffffffff000000
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/x86/x86_64/mm.txt18
1 files changed, 11 insertions, 7 deletions
diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt
index ad41b3813f0a..ea91cb61a602 100644
--- a/Documentation/x86/x86_64/mm.txt
+++ b/Documentation/x86/x86_64/mm.txt
@@ -12,8 +12,9 @@ ffffea0000000000 - ffffeaffffffffff (=40 bits) virtual memory map (1TB)
... unused hole ...
ffffec0000000000 - fffffbffffffffff (=44 bits) kasan shadow memory (16TB)
... unused hole ...
-fffffe0000000000 - fffffe7fffffffff (=39 bits) LDT remap for PTI
-fffffe8000000000 - fffffeffffffffff (=39 bits) cpu_entry_area mapping
+ vaddr_end for KASLR
+fffffe0000000000 - fffffe7fffffffff (=39 bits) cpu_entry_area mapping
+fffffe8000000000 - fffffeffffffffff (=39 bits) LDT remap for PTI
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space
@@ -37,13 +38,15 @@ ffd4000000000000 - ffd5ffffffffffff (=49 bits) virtual memory map (512TB)
... unused hole ...
ffdf000000000000 - fffffc0000000000 (=53 bits) kasan shadow memory (8PB)
... unused hole ...
-fffffe8000000000 - fffffeffffffffff (=39 bits) cpu_entry_area mapping
+ vaddr_end for KASLR
+fffffe0000000000 - fffffe7fffffffff (=39 bits) cpu_entry_area mapping
+... unused hole ...
ffffff0000000000 - ffffff7fffffffff (=39 bits) %esp fixup stacks
... unused hole ...
ffffffef00000000 - fffffffeffffffff (=64 GB) EFI region mapping space
... unused hole ...
ffffffff80000000 - ffffffff9fffffff (=512 MB) kernel text mapping, from phys 0
-ffffffffa0000000 - [fixmap start] (~1526 MB) module mapping space
+ffffffffa0000000 - fffffffffeffffff (1520 MB) module mapping space
[fixmap start] - ffffffffff5fffff kernel-internal fixmap range
ffffffffff600000 - ffffffffff600fff (=4 kB) legacy vsyscall ABI
ffffffffffe00000 - ffffffffffffffff (=2 MB) unused hole
@@ -67,9 +70,10 @@ memory window (this size is arbitrary, it can be raised later if needed).
The mappings are not part of any other kernel PGD and are only available
during EFI runtime calls.
-The module mapping space size changes based on the CONFIG requirements for the
-following fixmap section.
-
Note that if CONFIG_RANDOMIZE_MEMORY is enabled, the direct mapping of all
physical memory, vmalloc/ioremap space and virtual memory map are randomized.
Their order is preserved but their base will be offset early at boot time.
+
+Be very careful vs. KASLR when changing anything here. The KASLR address
+range must not overlap with anything except the KASAN shadow area, which is
+correct as KASAN disables KASLR.