--- /dev/null
+From 5a45a4c5c3f5e36a03770deb102ca6ba256ff3d7 Mon Sep 17 00:00:00 2001
+From: Kees Cook <keescook@chromium.org>
+Date: Fri, 13 Jan 2017 14:09:35 -0800
+Subject: gcc-plugins: consolidate on PASS_INFO macro
+
+From: Kees Cook <keescook@chromium.org>
+
+commit 5a45a4c5c3f5e36a03770deb102ca6ba256ff3d7 upstream.
+
+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 <keescook@chromium.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ scripts/gcc-plugins/cyc_complexity_plugin.c | 6 +-----
+ scripts/gcc-plugins/latent_entropy_plugin.c | 8 ++------
+ scripts/gcc-plugins/sancov_plugin.c | 8 ++------
+ 3 files changed, 5 insertions(+), 17 deletions(-)
+
+--- a/scripts/gcc-plugins/cyc_complexity_plugin.c
++++ b/scripts/gcc-plugins/cyc_complexity_plugin.c
+@@ -52,12 +52,8 @@ static unsigned int cyc_complexity_execu
+ __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
+ {
+ const char * const plugin_name = plugin_info->base_name;
+- struct register_pass_info cyc_complexity_pass_info;
+
+- cyc_complexity_pass_info.pass = make_cyc_complexity_pass();
+- cyc_complexity_pass_info.reference_pass_name = "ssa";
+- cyc_complexity_pass_info.ref_pass_instance_number = 1;
+- cyc_complexity_pass_info.pos_op = PASS_POS_INSERT_AFTER;
++ PASS_INFO(cyc_complexity, "ssa", 1, PASS_POS_INSERT_AFTER);
+
+ if (!plugin_default_version_check(version, &gcc_version)) {
+ error(G_("incompatible gcc/plugin versions"));
+--- a/scripts/gcc-plugins/latent_entropy_plugin.c
++++ b/scripts/gcc-plugins/latent_entropy_plugin.c
+@@ -592,12 +592,6 @@ __visible int plugin_init(struct plugin_
+ const struct plugin_argument * const argv = plugin_info->argv;
+ int i;
+
+- struct register_pass_info latent_entropy_pass_info;
+-
+- latent_entropy_pass_info.pass = make_latent_entropy_pass();
+- latent_entropy_pass_info.reference_pass_name = "optimized";
+- latent_entropy_pass_info.ref_pass_instance_number = 1;
+- latent_entropy_pass_info.pos_op = PASS_POS_INSERT_BEFORE;
+ static const struct ggc_root_tab gt_ggc_r_gt_latent_entropy[] = {
+ {
+ .base = &latent_entropy_decl,
+@@ -609,6 +603,8 @@ __visible int plugin_init(struct plugin_
+ LAST_GGC_ROOT_TAB
+ };
+
++ PASS_INFO(latent_entropy, "optimized", 1, PASS_POS_INSERT_BEFORE);
++
+ if (!plugin_default_version_check(version, &gcc_version)) {
+ error(G_("incompatible gcc/plugin versions"));
+ return 1;
+--- a/scripts/gcc-plugins/sancov_plugin.c
++++ b/scripts/gcc-plugins/sancov_plugin.c
+@@ -89,7 +89,6 @@ static void sancov_start_unit(void __unu
+ __visible int plugin_init(struct plugin_name_args *plugin_info, struct plugin_gcc_version *version)
+ {
+ int i;
+- struct register_pass_info sancov_plugin_pass_info;
+ const char * const plugin_name = plugin_info->base_name;
+ const int argc = plugin_info->argc;
+ const struct plugin_argument * const argv = plugin_info->argv;
+@@ -107,14 +106,11 @@ __visible int plugin_init(struct plugin_
+ };
+
+ /* BBs can be split afterwards?? */
+- sancov_plugin_pass_info.pass = make_sancov_pass();
+ #if BUILDING_GCC_VERSION >= 4009
+- sancov_plugin_pass_info.reference_pass_name = "asan";
++ PASS_INFO(sancov, "asan", 0, PASS_POS_INSERT_BEFORE);
+ #else
+- sancov_plugin_pass_info.reference_pass_name = "nrv";
++ PASS_INFO(sancov, "nrv", 1, PASS_POS_INSERT_BEFORE);
+ #endif
+- sancov_plugin_pass_info.ref_pass_instance_number = 0;
+- sancov_plugin_pass_info.pos_op = PASS_POS_INSERT_BEFORE;
+
+ if (!plugin_default_version_check(version, &gcc_version)) {
+ error(G_("incompatible gcc/plugin versions"));
--- /dev/null
+From c40160f2998c897231f8454bf797558d30a20375 Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Wed, 6 Apr 2022 00:28:15 +0200
+Subject: gcc-plugins: latent_entropy: use /dev/urandom
+
+From: Jason A. Donenfeld <Jason@zx2c4.com>
+
+commit c40160f2998c897231f8454bf797558d30a20375 upstream.
+
+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 <pageexec@freemail.hu>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: Kees Cook <keescook@chromium.org>
+Link: https://lore.kernel.org/r/20220405222815.21155-1-Jason@zx2c4.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ scripts/gcc-plugins/latent_entropy_plugin.c | 44 +++++++++++++++++-----------
+ 1 file changed, 27 insertions(+), 17 deletions(-)
+
+--- a/scripts/gcc-plugins/latent_entropy_plugin.c
++++ b/scripts/gcc-plugins/latent_entropy_plugin.c
+@@ -86,25 +86,31 @@ static struct plugin_info latent_entropy
+ .help = "disable\tturn off latent entropy instrumentation\n",
+ };
+
+-static unsigned HOST_WIDE_INT seed;
+-/*
+- * get_random_seed() (this is a GCC function) generates the seed.
+- * This is a simple random generator without any cryptographic security because
+- * the entropy doesn't come from here.
+- */
++static unsigned HOST_WIDE_INT deterministic_seed;
++static unsigned HOST_WIDE_INT rnd_buf[32];
++static size_t rnd_idx = ARRAY_SIZE(rnd_buf);
++static int urandom_fd = -1;
++
+ static unsigned HOST_WIDE_INT get_random_const(void)
+ {
+- unsigned int i;
+- unsigned HOST_WIDE_INT ret = 0;
+-
+- for (i = 0; i < 8 * sizeof(ret); i++) {
+- ret = (ret << 1) | (seed & 1);
+- seed >>= 1;
+- if (ret & 1)
+- seed ^= 0xD800000000000000ULL;
++ if (deterministic_seed) {
++ unsigned HOST_WIDE_INT w = deterministic_seed;
++ w ^= w << 13;
++ w ^= w >> 7;
++ w ^= w << 17;
++ deterministic_seed = w;
++ return deterministic_seed;
+ }
+
+- return ret;
++ if (urandom_fd < 0) {
++ urandom_fd = open("/dev/urandom", O_RDONLY);
++ gcc_assert(urandom_fd >= 0);
++ }
++ if (rnd_idx >= ARRAY_SIZE(rnd_buf)) {
++ gcc_assert(read(urandom_fd, rnd_buf, sizeof(rnd_buf)) == sizeof(rnd_buf));
++ rnd_idx = 0;
++ }
++ return rnd_buf[rnd_idx++];
+ }
+
+ static tree tree_get_random_const(tree type)
+@@ -556,8 +562,6 @@ static void latent_entropy_start_unit(vo
+ tree type, id;
+ int quals;
+
+- seed = get_random_seed(false);
+-
+ if (in_lto_p)
+ return;
+
+@@ -592,6 +596,12 @@ __visible int plugin_init(struct plugin_
+ const struct plugin_argument * const argv = plugin_info->argv;
+ int i;
+
++ /*
++ * Call get_random_seed() with noinit=true, so that this returns
++ * 0 in the case where no seed has been passed via -frandom-seed.
++ */
++ deterministic_seed = get_random_seed(true);
++
+ static const struct ggc_root_tab gt_ggc_r_gt_latent_entropy[] = {
+ {
+ .base = &latent_entropy_decl,
projects / thirdparty / kernel / stable-queue.git / commitdiff
