x86: Add support for ZSTD compressed kernel
- Add support for zstd compressed kernel - Define __DISABLE_EXPORTS in Makefile - Remove __DISABLE_EXPORTS definition from kaslr.c - Bump the heap size for zstd. - Update the documentation. Integrates the ZSTD decompression code to the x86 pre-boot code. Zstandard requires slightly more memory during the kernel decompression on x86 (192 KB vs 64 KB), and the memory usage is independent of the window size. __DISABLE_EXPORTS is now defined in the Makefile, which covers both the existing use in kaslr.c, and the use needed by the zstd decompressor in misc.c. This patch has been boot tested with both a zstd and gzip compressed kernel on i386 and x86_64 using buildroot and QEMU. Additionally, this has been tested in production on x86_64 devices. We saw a 2 second boot time reduction by switching kernel compression from xz to zstd. Signed-off-by: Nick Terrell <terrelln@fb.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20200730190841.2071656-7-nickrterrell@gmail.com
This commit is contained in:
Nick Terrell
Ingo Molnar
parent
0fe4f4ef8c
commit
fb46d057db
|
|
@ -782,9 +782,9 @@ Protocol: 2.08+
|
|||
uncompressed data should be determined using the standard magic
|
||||
numbers. The currently supported compression formats are gzip
|
||||
(magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A), LZMA
|
||||
(magic number 5D 00), XZ (magic number FD 37), and LZ4 (magic number
|
||||
02 21). The uncompressed payload is currently always ELF (magic
|
||||
number 7F 45 4C 46).
|
||||
(magic number 5D 00), XZ (magic number FD 37), LZ4 (magic number
|
||||
02 21) and ZSTD (magic number 28 B5). The uncompressed payload is
|
||||
currently always ELF (magic number 7F 45 4C 46).
|
||||
|
||||
============ ==============
|
||||
Field name: payload_length
|
||||
|
|
|
|||
|
|
@ -188,6 +188,7 @@ config X86
|
|||
select HAVE_KERNEL_LZMA
|
||||
select HAVE_KERNEL_LZO
|
||||
select HAVE_KERNEL_XZ
|
||||
select HAVE_KERNEL_ZSTD
|
||||
select HAVE_KPROBES
|
||||
select HAVE_KPROBES_ON_FTRACE
|
||||
select HAVE_FUNCTION_ERROR_INJECTION
|
||||
|
|
|
|||
|
|
@ -26,7 +26,7 @@ OBJECT_FILES_NON_STANDARD := y
|
|||
KCOV_INSTRUMENT := n
|
||||
|
||||
targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \
|
||||
vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4
|
||||
vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 vmlinux.bin.zst
|
||||
|
||||
KBUILD_CFLAGS := -m$(BITS) -O2
|
||||
KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC)
|
||||
|
|
@ -42,6 +42,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
|
|||
KBUILD_CFLAGS += -Wno-pointer-sign
|
||||
KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
|
||||
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
|
||||
KBUILD_CFLAGS += -D__DISABLE_EXPORTS
|
||||
|
||||
KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__
|
||||
GCOV_PROFILE := n
|
||||
|
|
@ -145,6 +146,8 @@ $(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE
|
|||
$(call if_changed,lzo)
|
||||
$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE
|
||||
$(call if_changed,lz4)
|
||||
$(obj)/vmlinux.bin.zst: $(vmlinux.bin.all-y) FORCE
|
||||
$(call if_changed,zstd22)
|
||||
|
||||
suffix-$(CONFIG_KERNEL_GZIP) := gz
|
||||
suffix-$(CONFIG_KERNEL_BZIP2) := bz2
|
||||
|
|
@ -152,6 +155,7 @@ suffix-$(CONFIG_KERNEL_LZMA) := lzma
|
|||
suffix-$(CONFIG_KERNEL_XZ) := xz
|
||||
suffix-$(CONFIG_KERNEL_LZO) := lzo
|
||||
suffix-$(CONFIG_KERNEL_LZ4) := lz4
|
||||
suffix-$(CONFIG_KERNEL_ZSTD) := zst
|
||||
|
||||
quiet_cmd_mkpiggy = MKPIGGY $@
|
||||
cmd_mkpiggy = $(obj)/mkpiggy $< > $@
|
||||
|
|
|
|||
|
|
@ -19,13 +19,6 @@
|
|||
*/
|
||||
#define BOOT_CTYPE_H
|
||||
|
||||
/*
|
||||
* _ctype[] in lib/ctype.c is needed by isspace() of linux/ctype.h.
|
||||
* While both lib/ctype.c and lib/cmdline.c will bring EXPORT_SYMBOL
|
||||
* which is meaningless and will cause compiling error in some cases.
|
||||
*/
|
||||
#define __DISABLE_EXPORTS
|
||||
|
||||
#include "misc.h"
|
||||
#include "error.h"
|
||||
#include "../string.h"
|
||||
|
|
|
|||
|
|
@ -77,6 +77,10 @@ static int lines, cols;
|
|||
#ifdef CONFIG_KERNEL_LZ4
|
||||
#include "../../../../lib/decompress_unlz4.c"
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_KERNEL_ZSTD
|
||||
#include "../../../../lib/decompress_unzstd.c"
|
||||
#endif
|
||||
/*
|
||||
* NOTE: When adding a new decompressor, please update the analysis in
|
||||
* ../header.S.
|
||||
|
|
|
|||
|
|
@ -24,9 +24,16 @@
|
|||
# error "Invalid value for CONFIG_PHYSICAL_ALIGN"
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_KERNEL_BZIP2
|
||||
#if defined(CONFIG_KERNEL_BZIP2)
|
||||
# define BOOT_HEAP_SIZE 0x400000
|
||||
#else /* !CONFIG_KERNEL_BZIP2 */
|
||||
#elif defined(CONFIG_KERNEL_ZSTD)
|
||||
/*
|
||||
* Zstd needs to allocate the ZSTD_DCtx in order to decompress the kernel.
|
||||
* The ZSTD_DCtx is ~160KB, so set the heap size to 192KB because it is a
|
||||
* round number and to allow some slack.
|
||||
*/
|
||||
# define BOOT_HEAP_SIZE 0x30000
|
||||
#else
|
||||
# define BOOT_HEAP_SIZE 0x10000
|
||||
#endif
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue