Messages in this thread | | | Date | Tue, 8 Mar 2016 13:00:41 +0800 | From | Baoquan He <> | Subject | Re: [PATCH v3 06/19] x86, kaslr: Clean up useless code related to run_size. |
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On 03/07/16 at 03:12pm, Kees Cook wrote: > > diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c > > index 42e76c2..069120e 100644 > > --- a/arch/x86/boot/compressed/misc.c > > +++ b/arch/x86/boot/compressed/misc.c > > @@ -393,9 +393,9 @@ asmlinkage __visible void *decompress_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) > > { > > + unsigned long run_size = VO__end - VO__text; > > I think this can be "const" now, yes?
Yes, agree. No one can change it. Will update it.
Thanks
> > > unsigned char *output_orig = output; > > > > real_mode = rmode; > > @@ -416,8 +416,6 @@ asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap, > > lines = real_mode->screen_info.orig_video_lines; > > cols = real_mode->screen_info.orig_video_cols; > > > > - run_size = VO__end - VO__text; > > - > > console_init(); > > debug_putstr("early console in decompress_kernel\n"); > > > > diff --git a/arch/x86/boot/compressed/mkpiggy.c b/arch/x86/boot/compressed/mkpiggy.c > > index a613c84..c5148642 100644 > > --- a/arch/x86/boot/compressed/mkpiggy.c > > +++ b/arch/x86/boot/compressed/mkpiggy.c > > @@ -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"); > > diff --git a/arch/x86/tools/calc_run_size.sh b/arch/x86/tools/calc_run_size.sh > > deleted file mode 100644 > > index 1a4c17b..0000000 > > --- a/arch/x86/tools/calc_run_size.sh > > +++ /dev/null > > @@ -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 > > -- > > 2.5.0 > > > > > > -- > Kees Cook > Chrome OS & Brillo Security
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