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x86/KASLR: Clean up unused code from old 'run_size' and rename it to 'kernel_total_size'

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Since 'run_size' is now calculated in misc.c, the old script and associated
argument passing is no longer needed. This patch removes them, and renames
'run_size' to the more descriptive 'kernel_total_size'.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Baoquan He <bhe@redhat.com>
[ Rewrote the changelog, renamed 'run_size' to 'kernel_total_size' ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Junjie Mao <eternal.n08@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1461888548-32439-6-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Yinghai Lu 2016-04-28 17:09:07 -07:00 committed by Ingo Molnar
parent 67b6662559
commit 4d2d542482
6 changed files with 8 additions and 65 deletions
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4
arch/x86/boot/compressed/Makefile
View File

@ -121,10 +121,8 @@ suffix-$(CONFIG_KERNEL_XZ) := xz
suffix-$(CONFIG_KERNEL_LZO) := lzo
suffix-$(CONFIG_KERNEL_LZ4) := lz4
RUN_SIZE = $(shell $(OBJDUMP) -h vmlinux | \
$(CONFIG_SHELL) $(srctree)/arch/x86/tools/calc_run_size.sh)
quiet_cmd_mkpiggy = MKPIGGY $@
cmd_mkpiggy = $(obj)/mkpiggy $< $(RUN_SIZE) > $@ || ( rm -f $@ ; false )
cmd_mkpiggy = $(obj)/mkpiggy $< > $@ || ( rm -f $@ ; false )
targets += piggy.S
$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE

3
arch/x86/boot/compressed/head_32.S
View File

@ -238,7 +238,6 @@ relocated:
* Do the extraction, and jump to the new kernel..
*/
/* push arguments for extract_kernel: */
pushl $z_run_size /* size of kernel with .bss and .brk */
pushl $z_output_len /* decompressed length, end of relocs */
movl BP_init_size(%esi), %eax
@ -254,7 +253,7 @@ relocated:
pushl %eax /* heap area */
pushl %esi /* real mode pointer */
call extract_kernel /* returns kernel location in %eax */
addl $28, %esp
addl $24, %esp
/*
* Jump to the extracted kernel.

3
arch/x86/boot/compressed/head_64.S
View File

@ -415,8 +415,6 @@ relocated:
* Do the extraction, and jump to the new kernel..
*/
pushq %rsi /* Save the real mode argument */
movq $z_run_size, %r9 /* size of kernel with .bss and .brk */
pushq %r9
movq %rsi, %rdi /* real mode address */
leaq boot_heap(%rip), %rsi /* malloc area for uncompression */
leaq input_data(%rip), %rdx /* input_data */
@ -424,7 +422,6 @@ relocated:
movq %rbp, %r8 /* output target address */
movq $z_output_len, %r9 /* decompressed length, end of relocs */
call extract_kernel /* returns kernel location in %rax */
popq %r9
popq %rsi
/*

11
arch/x86/boot/compressed/misc.c
View File

@ -340,9 +340,9 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
unsigned char *input_data,
unsigned long input_len,
unsigned char *output,
unsigned long output_len,
unsigned long run_size)
unsigned long output_len)
{
const unsigned long kernel_total_size = VO__end - VO__text;
unsigned char *output_orig = output;
/* Retain x86 boot parameters pointer passed from startup_32/64. */
@ -364,8 +364,6 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
lines = boot_params->screen_info.orig_video_lines;
cols = boot_params->screen_info.orig_video_cols;
run_size = VO__end - VO__text;
console_init();
debug_putstr("early console in extract_kernel\n");
@ -377,7 +375,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
debug_putaddr(input_len);
debug_putaddr(output);
debug_putaddr(output_len);
debug_putaddr(run_size);
debug_putaddr(kernel_total_size);
/*
* The memory hole needed for the kernel is the larger of either
@ -385,8 +383,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
* entire decompressed kernel plus .bss and .brk sections.
*/
output = choose_random_location(input_data, input_len, output,
output_len > run_size ? output_len
: run_size);
max(output_len, kernel_total_size));
/* Validate memory location choices. */
if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1))

10
arch/x86/boot/compressed/mkpiggy.c
View File

@ -34,13 +34,11 @@ int main(int argc, char *argv[])
{
uint32_t olen;
long ilen;
unsigned long run_size;
FILE *f = NULL;
int retval = 1;
if (argc < 3) {
fprintf(stderr, "Usage: %s compressed_file run_size\n",
argv[0]);
if (argc < 2) {
fprintf(stderr, "Usage: %s compressed_file\n", argv[0]);
goto bail;
}
@ -65,15 +63,11 @@ int main(int argc, char *argv[])
ilen = ftell(f);
olen = get_unaligned_le32(&olen);
run_size = atoi(argv[2]);
printf(".section \".rodata..compressed\",\"a\",@progbits\n");
printf(".globl z_input_len\n");
printf("z_input_len = %lu\n", ilen);
printf(".globl z_output_len\n");
printf("z_output_len = %lu\n", (unsigned long)olen);
printf(".globl z_run_size\n");
printf("z_run_size = %lu\n", run_size);
printf(".globl input_data, input_data_end\n");
printf("input_data:\n");

42
arch/x86/tools/calc_run_size.sh
View File

@ -1,42 +0,0 @@
#!/bin/sh
#
# Calculate the amount of space needed to run the kernel, including room for
# the .bss and .brk sections.
#
# Usage:
# objdump -h a.out | sh calc_run_size.sh
NUM='\([0-9a-fA-F]*[ \t]*\)'
OUT=$(sed -n 's/^[ \t0-9]*.b[sr][sk][ \t]*'"$NUM$NUM$NUM$NUM"'.*/\1\4/p')
if [ -z "$OUT" ] ; then
echo "Never found .bss or .brk file offset" >&2
exit 1
fi
OUT=$(echo ${OUT# })
sizeA=$(printf "%d" 0x${OUT%% *})
OUT=${OUT#* }
offsetA=$(printf "%d" 0x${OUT%% *})
OUT=${OUT#* }
sizeB=$(printf "%d" 0x${OUT%% *})
OUT=${OUT#* }
offsetB=$(printf "%d" 0x${OUT%% *})
run_size=$(( $offsetA + $sizeA + $sizeB ))
# BFD linker shows the same file offset in ELF.
if [ "$offsetA" -ne "$offsetB" ] ; then
# Gold linker shows them as consecutive.
endB=$(( $offsetB + $sizeB ))
if [ "$endB" != "$run_size" ] ; then
printf "sizeA: 0x%x\n" $sizeA >&2
printf "offsetA: 0x%x\n" $offsetA >&2
printf "sizeB: 0x%x\n" $sizeB >&2
printf "offsetB: 0x%x\n" $offsetB >&2
echo ".bss and .brk are non-contiguous" >&2
exit 1
fi
fi
printf "%d\n" $run_size
exit 0