diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2018-01-04 12:32:03 +0100 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2018-01-05 00:39:57 +0100 |
commit | 1dddd25125112ba49706518ac9077a1026a18f37 (patch) | |
tree | 1a7dbf5aabe4314da221e2323ce66c9d2c4e87c1 /arch/x86/include/asm/pgtable_64_types.h | |
parent | f2078904810373211fb15f91888fba14c01a4acc (diff) |
x86/kaslr: Fix the vaddr_end mess
vaddr_end for KASLR is only documented in the KASLR code itself and is
adjusted depending on config options. So it's not surprising that a change
of the memory layout causes KASLR to have the wrong vaddr_end. This can map
arbitrary stuff into other areas causing hard to understand problems.
Remove the whole ifdef magic and define the start of the cpu_entry_area to
be the end of the KASLR vaddr range.
Add documentation to that effect.
Fixes: 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the fixmap")
Reported-by: Benjamin Gilbert <benjamin.gilbert@coreos.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Benjamin Gilbert <benjamin.gilbert@coreos.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable <stable@vger.kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Garnier <thgarnie@google.com>,
Cc: Alexander Kuleshov <kuleshovmail@gmail.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801041320360.1771@nanos
Diffstat (limited to 'arch/x86/include/asm/pgtable_64_types.h')
-rw-r--r-- | arch/x86/include/asm/pgtable_64_types.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 61b4b60bdc13..6b8f73dcbc2c 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -75,7 +75,13 @@ typedef struct { pteval_t pte; } pte_t; #define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT) #define PGDIR_MASK (~(PGDIR_SIZE - 1)) -/* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */ +/* + * See Documentation/x86/x86_64/mm.txt for a description of the memory map. + * + * 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. + */ #define MAXMEM _AC(__AC(1, UL) << MAX_PHYSMEM_BITS, UL) #ifdef CONFIG_X86_5LEVEL |