kernel/linux.git/scripts/gcc-plugins/latent_entropy_plugin.c, branch v6.6.132

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_385.RULE

2022-06-10T12:51:36+00:00

Based on the normalized pattern: licensed under the gpl v2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference. Reviewed-by: Allison Randal Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

gcc-plugins: use KERNELVERSION for plugin version

2022-05-24T15:25:16+00:00

Commit 61f60bac8c05 ("gcc-plugins: Change all version strings match kernel") broke parallel builds. Instead of adding the dependency between GCC plugins and utsrelease.h, let's use KERNELVERSION, which does not require any build artifact. Another reason why I want to avoid utsrelease.h is because it depends on CONFIG_LOCALVERSION(_AUTO) and localversion* files. (include/generated/utsrelease.h depends on include/config/kernel.release, which is generated by scripts/setlocalversion) I want to keep host tools independent of the kernel configuration. There is no good reason to rebuild GCC plugins just because of CONFIG_LOCALVERSION being changed. We just want to associate the plugin versions with the kernel source version. KERNELVERSION should be enough for our purpose. Fixes: 61f60bac8c05 ("gcc-plugins: Change all version strings match kernel") Reported-by: kernel test robot Link: https://lore.kernel.org/linux-mm/202205230239.EZxeZ3Fv-lkp@intel.com Reported-by: Guenter Roeck Signed-off-by: Masahiro Yamada Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220524135541.1453693-1-masahiroy@kernel.org

gcc-plugins: Change all version strings match kernel

2022-05-10T23:54:33+00:00

It's not meaningful for the GCC plugins to track their versions separately from the rest of the kernel. Switch all versions to the kernel version. Fix mismatched indenting while we're at it. Cc: linux-hardening@vger.kernel.org Signed-off-by: Kees Cook

gcc-plugins: latent_entropy: use /dev/urandom

2022-04-12T18:31:40+00:00

While the latent entropy plugin mostly doesn't derive entropy from get_random_const() for measuring the call graph, when __latent_entropy is applied to a constant, then it's initialized statically to output from get_random_const(). In that case, this data is derived from a 64-bit seed, which means a buffer of 512 bits doesn't really have that amount of compile-time entropy. This patch fixes that shortcoming by just buffering chunks of /dev/urandom output and doling it out as requested. At the same time, it's important that we don't break the use of -frandom-seed, for people who want the runtime benefits of the latent entropy plugin, while still having compile-time determinism. In that case, we detect whether gcc's set_random_seed() has been called by making a call to get_random_seed(noinit=true) in the plugin init function, which is called after set_random_seed() is called but before anything that calls get_random_seed(noinit=false), and seeing if it's zero or not. If it's not zero, we're in deterministic mode, and so we just generate numbers with a basic xorshift prng. Note that we don't detect if -frandom-seed is being used using the documented local_tick variable, because it's assigned via: local_tick = (unsigned) tv.tv_sec * 1000 + tv.tv_usec / 1000; which may well overflow and become -1 on its own, and so isn't reliable: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105171 [kees: The 256 byte rnd_buf size was chosen based on average (250), median (64), and std deviation (575) bytes of used entropy for a defconfig x86_64 build] Fixes: 38addce8b600 ("gcc-plugins: Add latent_entropy plugin") Cc: stable@vger.kernel.org Cc: PaX Team Signed-off-by: Jason A. Donenfeld Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220405222815.21155-1-Jason@zx2c4.com

gcc-plugins: latent_entropy: remove unneeded semicolon

2021-03-02T03:19:50+00:00

Fix the following coccicheck warning: scripts/gcc-plugins/latent_entropy_plugin.c:539:2-3: Unneeded semicolon Reported-by: Hulk Robot Signed-off-by: Jason Yan Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20200418070521.10931-1-yanaijie@huawei.com

gcc-plugins: remove code for GCC versions older than 4.9

2020-12-04T22:09:41+00:00

Documentation/process/changes.rst says the minimal GCC version is 4.9. Hence, BUILDING_GCC_VERSION is greater than or equal to 4009. Signed-off-by: Masahiro Yamada Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201202134929.99883-1-masahiroy@kernel.org

gcc-plugins: Use dynamic initializers

2018-02-06T01:27:46+00:00

GCC 8 changed the order of some fields and is very picky about ordering in static initializers, so instead just move to dynamic initializers, and drop the redundant already-zero field assignments. Suggested-by: Valdis Kletnieks Signed-off-by: Kees Cook

gcc-plugins: consolidate on PASS_INFO macro

2017-01-13T22:20:03+00:00

Now that PASS_INFO() exists, use it in the other existing gcc plugins, instead of always open coding the same thing. Based on updates to the grsecurity/PaX gcc plugins. Signed-off-by: Kees Cook

latent_entropy: fix ARM build error on earlier gcc

2017-01-03T20:08:59+00:00

This fixes build errors seen on gcc-4.9.3 or gcc-5.3.1 for an ARM: arm-soc/init/initramfs.c: In function 'error': arm-soc/init/initramfs.c:50:1: error: unrecognizable insn: } ^ (insn 26 25 27 5 (set (reg:SI 111 [ local_entropy.243 ]) (rotatert:SI (reg:SI 116 [ local_entropy.243 ]) (const_int -30 [0xffffffffffffffe2]))) -1 (nil)) Patch from PaX Team Reported-by: Arnd Bergmann Reported-by: Brad Spengler Cc: stable@vger.kernel.org Signed-off-by: Kees Cook

treewide: Fix printk() message errors

2016-12-14T09:54:27+00:00

This patch fix spelling typos in printk and kconfig. Signed-off-by: Masanari Iida Acked-by: Randy Dunlap Signed-off-by: Jiri Kosina