1
0

governors.c 3.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293
  1. /*
  2. Copyright (c) 2017-2018, Feral Interactive
  3. All rights reserved.
  4. Redistribution and use in source and binary forms, with or without
  5. modification, are permitted provided that the following conditions are met:
  6. * Redistributions of source code must retain the above copyright notice,
  7. this list of conditions and the following disclaimer.
  8. * Redistributions in binary form must reproduce the above copyright
  9. notice, this list of conditions and the following disclaimer in the
  10. documentation and/or other materials provided with the distribution.
  11. * Neither the name of Feral Interactive nor the names of its contributors
  12. may be used to endorse or promote products derived from this software
  13. without specific prior written permission.
  14. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  15. AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16. IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17. ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  18. LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  19. CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  20. SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  21. INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  22. CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  23. ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  24. POSSIBILITY OF SUCH DAMAGE.
  25. */
  26. #define _GNU_SOURCE
  27. #include "governors.h"
  28. #include "config.h"
  29. #include "governors-query.h"
  30. #include "logging.h"
  31. #include <linux/limits.h>
  32. #include <stdio.h>
  33. #include <sys/wait.h>
  34. #include <unistd.h>
  35. /**
  36. * Update the governors to the given argument, via pkexec
  37. */
  38. bool set_governors(const char *value)
  39. {
  40. pid_t p;
  41. int status = 0;
  42. int ret = 0;
  43. int r = -1;
  44. const char *const exec_args[] = {
  45. "/usr/bin/pkexec", LIBEXECDIR "/cpugovctl", "set", value, NULL,
  46. };
  47. LOG_MSG("Requesting update of governor policy to %s\n", value);
  48. if ((p = fork()) < 0) {
  49. LOG_ERROR("Failed to fork(): %s\n", strerror(errno));
  50. return false;
  51. } else if (p == 0) {
  52. /* Execute the command */
  53. /* Note about cast:
  54. * The statement about argv[] and envp[] being constants is
  55. * included to make explicit to future writers of language
  56. * bindings that these objects are completely constant.
  57. * http://pubs.opengroup.org/onlinepubs/9699919799/functions/exec.html
  58. */
  59. if ((r = execv(exec_args[0], (char *const *)exec_args)) != 0) {
  60. LOG_ERROR("Failed to execute cpugovctl helper: %s %s\n", exec_args[1], strerror(errno));
  61. exit(EXIT_FAILURE);
  62. }
  63. _exit(EXIT_SUCCESS);
  64. } else {
  65. if (waitpid(p, &status, 0) < 0) {
  66. LOG_ERROR("Failed to waitpid(%d): %s\n", (int)p, strerror(errno));
  67. return false;
  68. }
  69. /* i.e. sigsev */
  70. if (!WIFEXITED(status)) {
  71. LOG_ERROR("Child process '%s' exited abnormally\n", exec_args[0]);
  72. }
  73. }
  74. if ((ret = WEXITSTATUS(status)) != 0) {
  75. LOG_ERROR("Failed to update cpu governor policy\n");
  76. return false;
  77. }
  78. return true;
  79. }