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The current KASLR implementation randomizes the physical and virtual addresses of the kernel together (both are offset by the same amount). It calculates the delta of the physical address where vmlinux was linked to load and where it is finally loaded. If the delta is not equal to 0 (i.e. the kernel was relocated), relocation handling needs be done. On 64-bit, this patch randomizes both the physical address where kernel is decompressed and the virtual address where kernel text is mapped and will execute from. We now have two values being chosen, so the function arguments are reorganized to pass by pointer so they can be directly updated. Since relocation handling only depends on the virtual address, we must check the virtual delta, not the physical delta for processing kernel relocations. This also populates the page table for the new virtual address range. 32-bit does not support a separate virtual address, so it continues to use the physical offset for its virtual offset. Additionally updates the sanity checks done on the resulting kernel addresses since they are potentially separate now. [kees: rewrote changelog, limited virtual split to 64-bit only, update checks] [kees: fix CONFIG_RANDOMIZE_BASE=n boot failure] Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/1464216334-17200-4-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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| .gitignore | ||
| cmdline.c | ||
| cpuflags.c | ||
| early_serial_console.c | ||
| eboot.c | ||
| eboot.h | ||
| efi_stub_32.S | ||
| efi_stub_64.S | ||
| efi_thunk_64.S | ||
| error.c | ||
| error.h | ||
| head_32.S | ||
| head_64.S | ||
| kaslr.c | ||
| Makefile | ||
| misc.c | ||
| misc.h | ||
| mkpiggy.c | ||
| pagetable.c | ||
| string.c | ||
| vmlinux.lds.S | ||