From: Yinghai Lu Date: Fri, 29 Apr 2016 00:09:07 +0000 (-0700) Subject: x86/KASLR: Clean up unused code from old 'run_size' and rename it to 'kernel_total_size' X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=4d2d542482205d3df1a0852751f5b004cc6390cc;p=openwrt%2Fstaging%2Fblogic.git x86/KASLR: Clean up unused code from old 'run_size' and rename it to 'kernel_total_size' 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 Signed-off-by: Baoquan He [ Rewrote the changelog, renamed 'run_size' to 'kernel_total_size' ] Signed-off-by: Kees Cook Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Young Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Triplett Cc: Junjie Mao Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vivek Goyal 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 --- diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 45997805adad..adef26d22224 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -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 diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 8a95e2f845aa..1038524270e7 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -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. diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S index 09cdc0c3ee7e..7c047002950c 100644 --- a/arch/x86/boot/compressed/head_64.S +++ b/arch/x86/boot/compressed/head_64.S @@ -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 /* diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index cda93d16ad4d..bee6238e7cfc 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -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)) diff --git a/arch/x86/boot/compressed/mkpiggy.c b/arch/x86/boot/compressed/mkpiggy.c index f095ed9e7d3c..72bad2c8debe 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 1a4c17bb3910..000000000000 --- 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