Emese Revfy
38addce8b6
gcc-plugins: Add latent_entropy plugin
...
This adds a new gcc plugin named "latent_entropy". It is designed to
extract as much possible uncertainty from a running system at boot time as
possible, hoping to capitalize on any possible variation in CPU operation
(due to runtime data differences, hardware differences, SMP ordering,
thermal timing variation, cache behavior, etc).
At the very least, this plugin is a much more comprehensive example for
how to manipulate kernel code using the gcc plugin internals.
The need for very-early boot entropy tends to be very architecture or
system design specific, so this plugin is more suited for those sorts
of special cases. The existing kernel RNG already attempts to extract
entropy from reliable runtime variation, but this plugin takes the idea to
a logical extreme by permuting a global variable based on any variation
in code execution (e.g. a different value (and permutation function)
is used to permute the global based on loop count, case statement,
if/then/else branching, etc).
To do this, the plugin starts by inserting a local variable in every
marked function. The plugin then adds logic so that the value of this
variable is modified by randomly chosen operations (add, xor and rol) and
random values (gcc generates separate static values for each location at
compile time and also injects the stack pointer at runtime). The resulting
value depends on the control flow path (e.g., loops and branches taken).
Before the function returns, the plugin mixes this local variable into
the latent_entropy global variable. The value of this global variable
is added to the kernel entropy pool in do_one_initcall() and _do_fork(),
though it does not credit any bytes of entropy to the pool; the contents
of the global are just used to mix the pool.
Additionally, the plugin can pre-initialize arrays with build-time
random contents, so that two different kernel builds running on identical
hardware will not have the same starting values.
Signed-off-by: Emese Revfy <re.emese@gmail.com>
[kees: expanded commit message and code comments]
Signed-off-by: Kees Cook <keescook@chromium.org>
2016-10-10 14:51:44 -07:00
..
basic
scripts: Fix size mismatch of kexec_purgatory_size
2016-07-22 14:05:40 +02:00
coccinelle
scripts/coccinelle: require coccinelle >= 1.0.4 on device_node_continue.cocci
2016-07-22 12:13:39 +02:00
dtc
scripts/dtc: dt_to_config - kernel config options for a devicetree
2016-07-22 14:48:16 -05:00
gcc-plugins
gcc-plugins: Add latent_entropy plugin
2016-10-10 14:51:44 -07:00
gdb
Revert "scripts/gdb: add a Radix Tree Parser"
2016-07-15 14:54:27 +09:00
genksyms
scripts: genksyms: fix resource leak
2016-04-20 09:24:49 +02:00
kconfig
Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
2016-05-26 22:27:09 -07:00
ksymoops
mod
staging: fsl-mc: add support for device table matching
2016-06-26 17:14:03 -07:00
package
builddeb: Skip gcc-plugins when not configured
2016-08-16 10:16:38 +02:00
selinux
selinux: explicitly declare the role "base_r"
2015-07-13 13:32:00 -04:00
tracing
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
.gitignore
KEYS: Reserve an extra certificate symbol for inserting without recompiling
2016-02-26 15:30:20 +00:00
adjust_autoksyms.sh
kbuild: fix adjust_autoksyms.sh for modules that need only one symbol
2016-05-10 17:25:29 +02:00
analyze_suspend.py
PM / tools: scripts: AnalyzeSuspend v4.2
2016-07-15 23:34:14 +02:00
asn1_compiler.c
ASN.1: fix open failure check on headername
2016-04-06 14:06:48 +01:00
bloat-o-meter
scripts/bloat-o-meter: fix percent on <1% changes
2016-07-26 16:19:19 -07:00
bootgraph.pl
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
check-lc_ctype.c
DocBook: Use a fixed encoding for output
2015-09-28 01:31:48 -06:00
check_extable.sh
scripts: add check_extable.sh script.
2015-04-13 21:03:02 +09:30
checkincludes.pl
checkincludes: fix perlcritic warnings
2010-03-07 21:19:57 +01:00
checkkconfigsymbols.py
checkkconfigsymbols.py: Fix typo in help message
2016-05-01 14:11:12 -07:00
checkpatch.pl
treewide: remove references to the now unnecessary DEFINE_PCI_DEVICE_TABLE
2016-09-01 17:52:01 -07:00
checkstack.pl
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
2014-10-07 21:16:26 -04:00
checksyscalls.sh
x86/asm/entry: Move the arch/x86/syscalls/ definitions to arch/x86/entry/syscalls/
2015-06-04 07:37:37 +02:00
checkversion.pl
kbuild: don't warn about include/linux/version.h not including itself
2011-04-29 15:38:55 +02:00
cleanfile
cleanpatch
coccicheck
coccicheck: refer to Documentation/coccinelle.txt and wiki
2016-07-22 12:13:39 +02:00
config
kbuild: trivial - remove trailing empty lines
2014-06-10 00:04:06 +02:00
conmakehash.c
kbuild: trivial - remove trailing spaces
2014-04-30 17:34:32 +02:00
decode_stacktrace.sh
scripts/decode_stacktrace.sh: handle symbols in modules
2016-05-19 19:12:14 -07:00
decodecode
scripts/decodecode: make faulting insn ptr more robust
2013-04-29 15:54:27 -07:00
depmod.sh
depmod: pass -P $CONFIG_SYMBOL_PREFIX
2013-02-22 11:52:31 +01:00
diffconfig
vfs,ext2: remove CONFIG_EXT2_FS_XIP and rename CONFIG_FS_XIP to CONFIG_FS_DAX
2015-02-16 17:56:04 -08:00
docproc.c
docproc: print a comment about autogeneration for rst output
2016-05-14 09:56:56 -06:00
export_report.pl
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
extract-cert.c
KEYS: Remove unnecessary header #inclusions from extract-cert.c
2015-09-25 16:31:45 +01:00
extract-ikconfig
scripts/extract-ikconfig: Support LZ4-compressed images.
2015-04-15 14:01:12 +02:00
extract-module-sig.pl
KEYS: Provide a script to extract a module signature
2015-10-21 15:18:36 +01:00
extract-sys-certs.pl
KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert
2016-02-26 15:32:05 +00:00
extract-vmlinux
scripts: add extract-vmlinux
2011-08-31 16:12:17 +02:00
extract_xc3028.pl
[media] extract_xc3028.pl: move it to scripts/dir
2016-07-17 14:08:12 -03:00
faddr2line
scripts/faddr2line: improve on base path filtering a bit
2016-09-19 14:49:08 -07:00
gcc-goto.sh
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
gcc-ld
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
gcc-plugin.sh
gcc-plugins: abort builds cleanly when not supported
2016-08-08 17:49:05 -07:00
gcc-version.sh
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
gcc-x86_32-has-stack-protector.sh
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
gcc-x86_64-has-stack-protector.sh
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
gen_initramfs_list.sh
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
get_dvb_firmware
[media] doc-rst: move DVB avulse docs to Documentation/media
2016-07-17 14:02:45 -03:00
get_maintainer.pl
get_maintainer: quiet noisy implicit -f vcs_file_exists checking
2016-08-26 17:39:34 -07:00
gfp-translate
chmod +x scripts/gfp-translate
2012-06-27 12:44:29 -07:00
headerdep.pl
headerdep: perlcritic warning
2010-03-23 12:26:38 +01:00
headers.sh
CRIS: Fix headers_install
2014-12-20 00:01:12 +01:00
headers_check.pl
headers_check: don't warn about c++ guards
2016-05-24 14:12:48 +10:00
headers_install.sh
Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
2014-10-14 09:22:26 +02:00
insert-sys-cert.c
KEYS: Reserve an extra certificate symbol for inserting without recompiling
2016-02-26 15:30:20 +00:00
kallsyms.c
ARM: 8553/1: kallsyms: remove --page-offset command line option
2016-04-07 21:57:16 +01:00
Kbuild.include
kbuild: no gcc-plugins during cc-option tests
2016-08-08 17:49:05 -07:00
kernel-doc
doc-rst: kernel-doc: fix a change introduced by mistake
2016-07-23 08:04:21 -03:00
kernel-doc-xml-ref
scripts/kernel-doc: Adding cross-reference links to html documentation.
2015-08-16 22:11:16 -06:00
ld-version.sh
ld-version: Drop the 4th and 5th version components
2016-05-13 14:02:05 +02:00
Lindent
scripts/Lindent: handle missing indent gracefully
2015-09-04 16:54:41 -07:00
link-vmlinux.sh
GCC plugin infrastructure
2016-06-07 22:57:10 +02:00
Makefile
GCC plugin infrastructure
2016-06-07 22:57:10 +02:00
Makefile.asm-generic
kbuild: Remove stale asm-generic wrappers
2016-07-07 15:58:45 +02:00
Makefile.build
Shared library support
2016-06-07 22:57:10 +02:00
Makefile.clean
Shared library support
2016-06-07 22:57:10 +02:00
Makefile.dtbinst
dtbsinstall: don't move target directory out of the way
2016-01-28 11:40:32 +01:00
Makefile.extrawarn
kbuild: move -Wunused-const-variable to W=1 warning level
2016-05-11 13:05:40 +02:00
Makefile.fwinst
kbuild: include $(src)/Makefile rather than $(obj)/Makefile
2015-04-02 16:42:08 +02:00
Makefile.gcc-plugins
gcc-plugins: Add latent_entropy plugin
2016-10-10 14:51:44 -07:00
Makefile.headersinst
kbuild: collect shorthands into scripts/Kbuild.include
2014-11-26 14:36:52 +01:00
Makefile.help
Add a target to use the Coccinelle checker
2010-06-12 00:00:29 +02:00
Makefile.host
Shared library support
2016-06-07 22:57:10 +02:00
Makefile.kasan
arm64: add KASAN support
2015-10-12 17:46:36 +01:00
Makefile.lib
Merge branch 'akpm' (patches from Andrew)
2016-08-02 21:08:07 -04:00
Makefile.modbuiltin
kbuild: Create output directory in Makefile.modbuiltin
2010-06-10 12:23:08 +02:00
Makefile.modinst
modsign: Abort modules_install when signing fails
2015-08-07 16:26:13 +01:00
Makefile.modpost
modpost: Add flag -E for making section mismatches fatal
2015-10-06 10:46:21 +10:30
Makefile.modsign
modsign: lookup lines ending in .ko in .mod files
2014-08-27 21:54:11 +09:30
Makefile.ubsan
Disable "maybe-uninitialized" warning globally
2016-07-27 13:17:41 -07:00
makelst
markup_oops.pl
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
mkcompile_h
kbuild: trivial - remove trailing spaces
2014-04-30 17:34:32 +02:00
mkmakefile
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
mksysmap
mksysmap: Add h8300 local symbol pattern
2015-06-23 13:35:47 +09:00
mkuboot.sh
mkuboot.sh: Fail if mkimage is missing
2011-01-07 14:31:01 +01:00
mkversion
module-common.lds
kernel: add support for .init_array.* constructors
2015-02-13 21:21:42 -08:00
namespace.pl
kallsyms: add support for relative offsets in kallsyms address table
2016-03-15 16:55:16 -07:00
objdiff
scripts: objdiff: support directories for the augument of record command
2014-06-10 14:59:33 +02:00
patch-kernel
kbuild: trivial - remove trailing spaces
2014-04-30 17:34:32 +02:00
pnmtologo.c
kbuild: trivial - remove trailing empty lines
2014-06-10 00:04:06 +02:00
profile2linkerlist.pl
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00
prune-kernel
scripts: add "prune-kernel" script to clean up old kernel images
2016-02-09 10:09:52 -08:00
recordmcount.c
scripts/recordmcount.c: account for .softirqentry.text
2016-09-28 16:19:02 -07:00
recordmcount.h
recordmcount: Fix endianness handling bug for nop_mcount
2015-11-03 10:45:26 -05:00
recordmcount.pl
scripts/recordmcount.c: account for .softirqentry.text
2016-09-28 16:19:02 -07:00
setlocalversion
kbuild: setlocalversion: print error to STDERR
2016-06-20 17:37:45 +02:00
show_delta
kbuild: trivial - remove trailing empty lines
2014-06-10 00:04:06 +02:00
sign-file.c
modsign: Make sign-file determine the format of the X.509 cert
2016-06-14 13:18:33 +01:00
sortextable.c
parisc: Use generic extable search and sort routines
2016-03-23 16:00:46 +01:00
sortextable.h
scripts/sortextable: suppress warning: `relocs_size' may be used uninitialized
2014-10-14 02:18:23 +02:00
spelling.txt
scripts/spelling.txt: add "fimware" misspelling
2016-05-19 19:12:14 -07:00
stackdelta
scripts: add stackdelta script
2015-08-28 17:04:40 +02:00
stackusage
scripts: add stackusage script
2015-08-28 17:04:40 +02:00
tags.sh
treewide: remove references to the now unnecessary DEFINE_PCI_DEVICE_TABLE
2016-09-01 17:52:01 -07:00
unifdef.c
unifdef: update to upstream version 2.5
2011-01-22 15:50:59 +01:00
ver_linux
scripts: fix typo in ver_linux
2016-02-07 23:01:45 -08:00
xen-hypercalls.sh
xen: build infrastructure for generating hypercall depending symbols
2015-03-16 14:49:13 +00:00
xz_wrap.sh
kbuild: Make scripts executable
2014-08-20 16:03:45 +02:00