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| author | Kees Cook <keescook@chromium.org> | 2013-10-10 17:18:14 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-10-13 03:12:07 -0700 |
| commit | 8ab3820fd5b2896d66da7bb2a906bc382e63e7bc (patch) | |
| tree | 50f6f4458f86eb66552c13bef81169e44d27dc28 /arch/x86/boot/compressed/misc.c | |
| parent | dd78b97367bd575918204cc89107c1479d3fc1a7 (diff) | |
| download | lwn-8ab3820fd5b2896d66da7bb2a906bc382e63e7bc.tar.gz lwn-8ab3820fd5b2896d66da7bb2a906bc382e63e7bc.zip | |
x86, kaslr: Return location from decompress_kernel
This allows decompress_kernel to return a new location for the kernel to
be relocated to. Additionally, enforces CONFIG_PHYSICAL_START as the
minimum relocation position when building with CONFIG_RELOCATABLE.
With CONFIG_RANDOMIZE_BASE set, the choose_kernel_location routine
will select a new location to decompress the kernel, though here it is
presently a no-op. The kernel command line option "nokaslr" is introduced
to bypass these routines.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-3-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/boot/compressed/misc.c')
| -rw-r--r-- | arch/x86/boot/compressed/misc.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index 434f077d2c4d..71387685dc16 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -395,7 +395,7 @@ static void parse_elf(void *output) free(phdrs); } -asmlinkage void decompress_kernel(void *rmode, memptr heap, +asmlinkage void *decompress_kernel(void *rmode, memptr heap, unsigned char *input_data, unsigned long input_len, unsigned char *output, @@ -422,6 +422,10 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap, free_mem_ptr = heap; /* Heap */ free_mem_end_ptr = heap + BOOT_HEAP_SIZE; + output = choose_kernel_location(input_data, input_len, + output, output_len); + + /* Validate memory location choices. */ if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1)) error("Destination address inappropriately aligned"); #ifdef CONFIG_X86_64 @@ -441,5 +445,5 @@ asmlinkage void decompress_kernel(void *rmode, memptr heap, parse_elf(output); handle_relocations(output, output_len); debug_putstr("done.\nBooting the kernel.\n"); - return; + return output; } |