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authorThomas Garnier2016-08-09 10:11:04 -0700
committerIngo Molnar2016-08-10 14:45:19 +0200
commitc7d2361f7524f365c1ae42f47880e3fa9efb2c2a (patch)
treee9988e6c1201350cdbe459620a3ac295a7898eb1 /arch
parent469f00231278da68062a809306df0bac95a27507 (diff)
x86/mm/KASLR: Fix physical memory calculation on KASLR memory randomization
Initialize KASLR memory randomization after max_pfn is initialized. Also ensure the size is rounded up. It could create problems on machines with more than 1Tb of memory on certain random addresses. Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Aleksey Makarov <aleksey.makarov@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Young <dyoung@redhat.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Joerg Roedel <jroedel@suse.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Lv Zheng <lv.zheng@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: kernel-hardening@lists.openwall.com Fixes: 021182e52fe0 ("Enable KASLR for physical mapping memory regions") Link: http://lkml.kernel.org/r/1470762665-88032-1-git-send-email-thgarnie@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/setup.c8
-rw-r--r--arch/x86/mm/kaslr.c2
2 files changed, 7 insertions, 3 deletions
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 991b77986d57..95cf31c9f4ec 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -936,8 +936,6 @@ void __init setup_arch(char **cmdline_p)
x86_init.oem.arch_setup();
- kernel_randomize_memory();
-
iomem_resource.end = (1ULL << boot_cpu_data.x86_phys_bits) - 1;
setup_memory_map();
parse_setup_data();
@@ -1055,6 +1053,12 @@ void __init setup_arch(char **cmdline_p)
max_possible_pfn = max_pfn;
+ /*
+ * Define random base addresses for memory sections after max_pfn is
+ * defined and before each memory section base is used.
+ */
+ kernel_randomize_memory();
+
#ifdef CONFIG_X86_32
/* max_low_pfn get updated here */
find_low_pfn_range();
diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
index 26dccd6c0df1..ec8654f117d8 100644
--- a/arch/x86/mm/kaslr.c
+++ b/arch/x86/mm/kaslr.c
@@ -97,7 +97,7 @@ void __init kernel_randomize_memory(void)
* add padding if needed (especially for memory hotplug support).
*/
BUG_ON(kaslr_regions[0].base != &page_offset_base);
- memory_tb = ((max_pfn << PAGE_SHIFT) >> TB_SHIFT) +
+ memory_tb = DIV_ROUND_UP(max_pfn << PAGE_SHIFT, 1UL << TB_SHIFT) +
CONFIG_RANDOMIZE_MEMORY_PHYSICAL_PADDING;
/* Adapt phyiscal memory region size based on available memory */