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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-24 08:46:03 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-24 08:46:03 -0700
commitcf9610f9116d55c5a66ef9f1faecacabd93a9322 (patch)
tree757a3d280760c654767631cab5ad8af2d86d1848 /samples/check-exec/inc.c
downloadlinux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.tar.gz
linux-stable-cf9610f9116d55c5a66ef9f1faecacabd93a9322.zip
Merge tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlgrafted
Pull pin control updates from Linus Walleij: "Core changes: - Use the non-blocking mux_state_try_select() in the generic MUX pin control back-end - Free pin maps on pinctrl_generic_to_map() failure in the core helpers New hardware pin control: - Qualcomm Maili TLMM SoC, PMG1110 PMIC, and Eliza LPASS LPI TLMM SoC (this is for the low power audio, LPASS = Low Power Audio SubSystem portions) - Upboard support on top of the Intel pin controller - Apple T6030 and T6031 support (just compatible strings) - Samsung Exynos 8855 SoC - Mediatek MT6858 SoC - Rockchip RK3308B and RV1106 SoCs - Airoha EN7523 and AN7563 SoCs Improvements: - Qualcomm TLMM GPIOs are unconditionally marked as wakeup capable - Qualcomm improvements on top of the Qualcomm PDC (power domain controller) irqchip improvements from tglx:s tree - Qualcomm IPQ806x and IPQ9650 non-urgent pin grop fixups - The NPCM8xx driver has been put into shape fixing many pin and group definitions - Some non-urgent Tegra 264 pin assignments are fixed up - Some non-urgent fixups to Airoha AN7581 and AN7583 registers and pin assignments, missing features etc" * tag 'pinctrl-v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (130 commits) dt-bindings: pinctrl: Convert TI DA850 pupd to DT schema pinctrl: meson: sync some modify from A4 pinctrl: meson: a4: Add input enable pin configuration pinctrl: realtek: rtd1625: remove unused group name spdif_sel pinctrl: realtek: rtd1625: fix base_bit for VE4 GPIO 13 dt-bindings: pinctrl: microchip,pic32mzda-pinctrl: Convert to DT schema Revert "Merge branch 'ib-rsk7204' into devel" pinctrl: rockchip: Add RV1106 pinctrl support dt-bindings: pinctrl: rockchip: Add RV1106 compatible pinctrl: rockchip: Decode drive strength in the get function pinctrl: fix PINCTRL_GENERIC_MUX not always being selectable pinctrl: airoha: add support of an7563 SoC dt-bindings: pinctrl: airoha: add support of an7563 pin controller pinctrl: airoha: try to find chip scu node by phandle first pinctrl: airoha: add support of en7523 SoC dt-bindings: pinctrl: airoha: add support of en7523 pin controller pinctrl: airoha: an7583: add support for olt pinmux pinctrl: airoha: an7583: add support for pon_alt pinmux pinctrl: airoha: an7583: add support for npu_uart pinmux dt-bindings: pinctrl: airoha: an7583: add missed features ...
Diffstat (limited to 'samples/check-exec/inc.c')
-rw-r--r--samples/check-exec/inc.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/samples/check-exec/inc.c b/samples/check-exec/inc.c
new file mode 100644
index 000000000..7f6ef06a2
--- /dev/null
+++ b/samples/check-exec/inc.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Very simple script interpreter that can evaluate two different commands (one
+ * per line):
+ * - "?" to initialize a counter from user's input;
+ * - "+" to increment the counter (which is set to 0 by default).
+ *
+ * See tools/testing/selftests/exec/check-exec-tests.sh and
+ * Documentation/userspace-api/check_exec.rst
+ *
+ * Copyright © 2024 Microsoft Corporation
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <linux/fcntl.h>
+#include <linux/prctl.h>
+#include <linux/securebits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+static int sys_execveat(int dirfd, const char *pathname, char *const argv[],
+ char *const envp[], int flags)
+{
+ return syscall(__NR_execveat, dirfd, pathname, argv, envp, flags);
+}
+
+/* Returns 1 on error, 0 otherwise. */
+static int interpret_buffer(char *buffer, size_t buffer_size)
+{
+ char *line, *saveptr = NULL;
+ long long number = 0;
+
+ /* Each command is the first character of a line. */
+ saveptr = NULL;
+ line = strtok_r(buffer, "\n", &saveptr);
+ while (line) {
+ if (*line != '#' && strlen(line) != 1) {
+ fprintf(stderr, "# ERROR: Unknown string\n");
+ return 1;
+ }
+ switch (*line) {
+ case '#':
+ /* Skips shebang and comments. */
+ break;
+ case '+':
+ /* Increments and prints the number. */
+ number++;
+ printf("%lld\n", number);
+ break;
+ case '?':
+ /* Reads integer from stdin. */
+ fprintf(stderr, "> Enter new number: \n");
+ if (scanf("%lld", &number) != 1) {
+ fprintf(stderr,
+ "# WARNING: Failed to read number from stdin\n");
+ }
+ break;
+ default:
+ fprintf(stderr, "# ERROR: Unknown character '%c'\n",
+ *line);
+ return 1;
+ }
+ line = strtok_r(NULL, "\n", &saveptr);
+ }
+ return 0;
+}
+
+/* Returns 1 on error, 0 otherwise. */
+static int interpret_stream(FILE *script, char *const script_name,
+ char *const *const envp, const bool restrict_stream)
+{
+ int err;
+ char *const script_argv[] = { script_name, NULL };
+ char buf[128] = {};
+ size_t buf_size = sizeof(buf);
+
+ /*
+ * We pass a valid argv and envp to the kernel to emulate a native
+ * script execution. We must use the script file descriptor instead of
+ * the script path name to avoid race conditions.
+ */
+ err = sys_execveat(fileno(script), "", script_argv, envp,
+ AT_EMPTY_PATH | AT_EXECVE_CHECK);
+ if (err && restrict_stream) {
+ perror("ERROR: Script execution check");
+ return 1;
+ }
+
+ /* Reads script. */
+ buf_size = fread(buf, 1, buf_size - 1, script);
+ return interpret_buffer(buf, buf_size);
+}
+
+static void print_usage(const char *argv0)
+{
+ fprintf(stderr, "usage: %s <script.inc> | -i | -c <command>\n\n",
+ argv0);
+ fprintf(stderr, "Example:\n");
+ fprintf(stderr, " ./set-exec -fi -- ./inc -i < script-exec.inc\n");
+}
+
+int main(const int argc, char *const argv[], char *const *const envp)
+{
+ int opt;
+ char *cmd = NULL;
+ char *script_name = NULL;
+ bool interpret_stdin = false;
+ FILE *script_file = NULL;
+ int secbits;
+ bool deny_interactive, restrict_file;
+ size_t arg_nb;
+
+ secbits = prctl(PR_GET_SECUREBITS);
+ if (secbits == -1) {
+ /*
+ * This should never happen, except with a buggy seccomp
+ * filter.
+ */
+ perror("ERROR: Failed to get securebits");
+ return 1;
+ }
+
+ deny_interactive = !!(secbits & SECBIT_EXEC_DENY_INTERACTIVE);
+ restrict_file = !!(secbits & SECBIT_EXEC_RESTRICT_FILE);
+
+ while ((opt = getopt(argc, argv, "c:i")) != -1) {
+ switch (opt) {
+ case 'c':
+ if (cmd) {
+ fprintf(stderr, "ERROR: Command already set");
+ return 1;
+ }
+ cmd = optarg;
+ break;
+ case 'i':
+ interpret_stdin = true;
+ break;
+ default:
+ print_usage(argv[0]);
+ return 1;
+ }
+ }
+
+ /* Checks that only one argument is used, or read stdin. */
+ arg_nb = !!cmd + !!interpret_stdin;
+ if (arg_nb == 0 && argc == 2) {
+ script_name = argv[1];
+ } else if (arg_nb != 1) {
+ print_usage(argv[0]);
+ return 1;
+ }
+
+ if (cmd) {
+ /*
+ * Other kind of interactive interpretations should be denied
+ * as well (e.g. CLI arguments passing script snippets,
+ * environment variables interpreted as script). However, any
+ * way to pass script files should only be restricted according
+ * to restrict_file.
+ */
+ if (deny_interactive) {
+ fprintf(stderr,
+ "ERROR: Interactive interpretation denied.\n");
+ return 1;
+ }
+
+ return interpret_buffer(cmd, strlen(cmd));
+ }
+
+ if (interpret_stdin && !script_name) {
+ script_file = stdin;
+ /*
+ * As for any execve(2) call, this path may be logged by the
+ * kernel.
+ */
+ script_name = "/proc/self/fd/0";
+ /*
+ * When stdin is used, it can point to a regular file or a
+ * pipe. Restrict stdin execution according to
+ * SECBIT_EXEC_DENY_INTERACTIVE but always allow executable
+ * files (which are not considered as interactive inputs).
+ */
+ return interpret_stream(script_file, script_name, envp,
+ deny_interactive);
+ } else if (script_name && !interpret_stdin) {
+ /*
+ * In this sample, we don't pass any argument to scripts, but
+ * otherwise we would have to forge an argv with such
+ * arguments.
+ */
+ script_file = fopen(script_name, "r");
+ if (!script_file) {
+ perror("ERROR: Failed to open script");
+ return 1;
+ }
+ /*
+ * Restricts file execution according to
+ * SECBIT_EXEC_RESTRICT_FILE.
+ */
+ return interpret_stream(script_file, script_name, envp,
+ restrict_file);
+ }
+
+ print_usage(argv[0]);
+ return 1;
+}