logo

mstrace

Small Linux strace(1) implementationgit clone https://anongit.hacktivis.me/git/mstrace.git/

print_syscall.c (1742B)

    

  1. // SPDX-FileCopyrightText: 2024 Haelwenn (lanodan) Monnier <contact+mstrace@hacktivis.me>
  2. // SPDX-License-Identifier: MPL-2.0
  4. #define _DEFAULT_SOURCE
  6. #include "strsyscall.h"
  8. #include <assert.h>
  9. #include <inttypes.h>     // PRIu64
  10. #include <limits.h>       // PATH_MAX
  11. #include <linux/ptrace.h> // __u64
  12. #include <stdio.h>        // fprintf
  13. #include <string.h>       // memcpy
  14. #include <sys/ptrace.h>   // ptrace()
  15. #include <sys/syscall.h>  // SYS_*
  16. #include <unistd.h>       // pid_t
  18. extern pid_t child;
  20. static char *
  21. read_str(intptr_t addr, size_t len)
  22. {
  23. 	static char str_buf[sizeof(unsigned long) * 128] = "";
  24. 	if(len == 0 || len > sizeof(unsigned long) * 128) len = sizeof(unsigned long) * 128;
  26. 	size_t i = 0;
  27. 	while(i < len)
  28. 	{
  29. 		unsigned long tmp = ptrace(PTRACE_PEEKDATA, child, addr + i);
  31. 		memcpy(str_buf + i, &tmp, sizeof(tmp));
  32. 		i += sizeof(tmp);
  34. 		if(memchr(&tmp, 0, sizeof(tmp)) != NULL) break;
  36. 		if(i > len)
  37. 		{
  38. 			str_buf[len - 1] = '\0';
  39. 			break;
  40. 		}
  41. 	}
  43. 	return str_buf;
  44. }
  46. #define Pri_str "\"%s\""
  47. #define Pri_i "%" PRIi64
  48. #define Pri_u "%" PRIu64
  49. #define Pri_o "0o%" PRIo64
  50. #define Pri_x "0x%" PRIx64
  52. void
  53. print_syscall(__u64 nr, __u64 args[6])
  54. {
  55. 	switch(nr)
  56. 	{
  57. #include "syscalls_cases.h"
  58. 	// fallback
  59. 	default:
  60. 		assert(nr < SYSCALLS_MAX);
  61. 		if(str_syscalls[nr] != NULL)
  62. 		{
  63. 			fprintf(stderr, "%s(", str_syscalls[nr]);
  64. 		}
  65. 		else
  66. 		{
  67. 			fprintf(stderr, "syscall(%" PRIu64 ", ", (uint64_t)nr);
  68. 		}
  70. 		fprintf(stderr,
  71. 		        "0x%" PRIx64 ", 0x%" PRIx64 ", 0x%" PRIx64 ", 0x%" PRIx64 ", 0x%" PRIx64 ", 0x%" PRIx64
  72. 		        ")",
  73. 		        (uint64_t)args[0],
  74. 		        (uint64_t)args[1],
  75. 		        (uint64_t)args[2],
  76. 		        (uint64_t)args[3],
  77. 		        (uint64_t)args[4],
  78. 		        (uint64_t)args[5]);
  79. 	}
  80. }