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
scripts: Fix size mismatch of kexec_purgatory_size
2016-07-22 14:05:40 +02:00
scripts/coccinelle: require coccinelle >= 1.0.4 on device_node_continue.cocci
2016-07-22 12:13:39 +02:00
scripts/dtc: dt_to_config - kernel config options for a devicetree
2016-07-22 14:48:16 -05:00
gcc-plugins: Add latent_entropy plugin
2016-10-10 14:51:44 -07:00
Revert "scripts/gdb: add a Radix Tree Parser"
2016-07-15 14:54:27 +09:00
scripts: genksyms: fix resource leak
2016-04-20 09:24:49 +02:00
Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
2016-05-26 22:27:09 -07:00
staging: fsl-mc: add support for device table matching
2016-06-26 17:14:03 -07:00
builddeb: Skip gcc-plugins when not configured
2016-08-16 10:16:38 +02:00
selinux: explicitly declare the role "base_r"
2015-07-13 13:32:00 -04:00
KEYS: Reserve an extra certificate symbol for inserting without recompiling
2016-02-26 15:30:20 +00:00
kbuild: fix adjust_autoksyms.sh for modules that need only one symbol
2016-05-10 17:25:29 +02:00
PM / tools: scripts: AnalyzeSuspend v4.2
2016-07-15 23:34:14 +02:00
ASN.1: fix open failure check on headername
2016-04-06 14:06:48 +01:00
scripts/bloat-o-meter: fix percent on <1% changes
2016-07-26 16:19:19 -07:00
DocBook: Use a fixed encoding for output
2015-09-28 01:31:48 -06:00
checkkconfigsymbols.py: Fix typo in help message
2016-05-01 14:11:12 -07:00
treewide: remove references to the now unnecessary DEFINE_PCI_DEVICE_TABLE
2016-09-01 17:52:01 -07:00
x86/asm/entry: Move the arch/x86/syscalls/ definitions to arch/x86/entry/syscalls/
2015-06-04 07:37:37 +02:00
coccicheck: refer to Documentation/coccinelle.txt and wiki
2016-07-22 12:13:39 +02:00
scripts/decode_stacktrace.sh: handle symbols in modules
2016-05-19 19:12:14 -07:00
docproc: print a comment about autogeneration for rst output
2016-05-14 09:56:56 -06:00
KEYS: Remove unnecessary header #inclusions from extract-cert.c
2015-09-25 16:31:45 +01:00
KEYS: Provide a script to extract a module signature
2015-10-21 15:18:36 +01:00
KEYS: Use the symbol value for list size, updated by scripts/insert-sys-cert
2016-02-26 15:32:05 +00:00
[media] extract_xc3028.pl: move it to scripts/dir
2016-07-17 14:08:12 -03:00
scripts/faddr2line: improve on base path filtering a bit
2016-09-19 14:49:08 -07:00
gcc-plugins: abort builds cleanly when not supported
2016-08-08 17:49:05 -07:00
[media] doc-rst: move DVB avulse docs to Documentation/media
2016-07-17 14:02:45 -03:00
get_maintainer: quiet noisy implicit -f vcs_file_exists checking
2016-08-26 17:39:34 -07:00
headers_check: don't warn about c++ guards
2016-05-24 14:12:48 +10:00
KEYS: Reserve an extra certificate symbol for inserting without recompiling
2016-02-26 15:30:20 +00:00
ARM: 8553/1: kallsyms: remove --page-offset command line option
2016-04-07 21:57:16 +01:00
kbuild: no gcc-plugins during cc-option tests
2016-08-08 17:49:05 -07:00
doc-rst: kernel-doc: fix a change introduced by mistake
2016-07-23 08:04:21 -03:00
scripts/kernel-doc: Adding cross-reference links to html documentation.
2015-08-16 22:11:16 -06:00
ld-version: Drop the 4th and 5th version components
2016-05-13 14:02:05 +02:00
scripts/Lindent: handle missing indent gracefully
2015-09-04 16:54:41 -07:00
GCC plugin infrastructure
2016-06-07 22:57:10 +02:00
GCC plugin infrastructure
2016-06-07 22:57:10 +02:00
kbuild: Remove stale asm-generic wrappers
2016-07-07 15:58:45 +02:00
Shared library support
2016-06-07 22:57:10 +02:00
Shared library support
2016-06-07 22:57:10 +02:00
dtbsinstall: don't move target directory out of the way
2016-01-28 11:40:32 +01:00
kbuild: move -Wunused-const-variable to W=1 warning level
2016-05-11 13:05:40 +02:00
gcc-plugins: Add latent_entropy plugin
2016-10-10 14:51:44 -07:00
Shared library support
2016-06-07 22:57:10 +02:00
arm64: add KASAN support
2015-10-12 17:46:36 +01:00
Merge branch 'akpm' (patches from Andrew)
2016-08-02 21:08:07 -04:00
modsign: Abort modules_install when signing fails
2015-08-07 16:26:13 +01:00
modpost: Add flag -E for making section mismatches fatal
2015-10-06 10:46:21 +10:30
Disable "maybe-uninitialized" warning globally
2016-07-27 13:17:41 -07:00
mksysmap: Add h8300 local symbol pattern
2015-06-23 13:35:47 +09:00
kallsyms: add support for relative offsets in kallsyms address table
2016-03-15 16:55:16 -07:00
scripts: add "prune-kernel" script to clean up old kernel images
2016-02-09 10:09:52 -08:00
scripts/recordmcount.c: account for .softirqentry.text
2016-09-28 16:19:02 -07:00
recordmcount: Fix endianness handling bug for nop_mcount
2015-11-03 10:45:26 -05:00
scripts/recordmcount.c: account for .softirqentry.text
2016-09-28 16:19:02 -07:00
kbuild: setlocalversion: print error to STDERR
2016-06-20 17:37:45 +02:00
modsign: Make sign-file determine the format of the X.509 cert
2016-06-14 13:18:33 +01:00
parisc: Use generic extable search and sort routines
2016-03-23 16:00:46 +01:00
scripts/spelling.txt: add "fimware" misspelling
2016-05-19 19:12:14 -07:00
scripts: add stackdelta script
2015-08-28 17:04:40 +02:00
scripts: add stackusage script
2015-08-28 17:04:40 +02:00
treewide: remove references to the now unnecessary DEFINE_PCI_DEVICE_TABLE
2016-09-01 17:52:01 -07:00
scripts: fix typo in ver_linux
2016-02-07 23:01:45 -08:00
38addce8b6