1 | /* Testing s390x PTRACE_SINGLEBLOCK ptrace request. |
2 | Copyright (C) 2017-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <stdio.h> |
20 | #include <stdlib.h> |
21 | #include <string.h> |
22 | #include <unistd.h> |
23 | #include <sys/wait.h> |
24 | #include <sys/types.h> |
25 | #include <sys/uio.h> |
26 | #include <elf.h> |
27 | #include <support/xunistd.h> |
28 | #include <support/check.h> |
29 | #include <string.h> |
30 | #include <errno.h> |
31 | |
32 | /* Ensure that we use the PTRACE_SINGLEBLOCK definition from glibc ptrace.h |
33 | in tracer_func. We need the kernel ptrace.h for structs ptrace_area |
34 | and gregset_t. */ |
35 | #include <sys/ptrace.h> |
36 | static const enum __ptrace_request req_singleblock = PTRACE_SINGLEBLOCK; |
37 | #include <asm/ptrace.h> |
38 | |
39 | static void |
40 | tracee_func (int pid) |
41 | { |
42 | /* Dump the mapping information for manual inspection of the printed |
43 | tracee addresses. */ |
44 | char str[80]; |
45 | sprintf (str, "cat /proc/%d/maps" , pid); |
46 | puts (s: str); |
47 | system (command: str); |
48 | fflush (stdout); |
49 | |
50 | TEST_VERIFY_EXIT (ptrace (PTRACE_TRACEME) == 0); |
51 | /* Stop tracee. Afterwards the tracer_func can operate. */ |
52 | kill (pid: pid, SIGSTOP); |
53 | |
54 | puts (s: "The PTRACE_SINGLEBLOCK of the tracer will stop after: " |
55 | "brasl %r14,<puts@plt>!" ); |
56 | } |
57 | |
58 | static void |
59 | tracer_func (int pid) |
60 | { |
61 | unsigned long last_break; |
62 | ptrace_area parea; |
63 | gregset_t regs; |
64 | struct iovec parea2; |
65 | gregset_t regs2; |
66 | |
67 | int status; |
68 | int ret; |
69 | #define MAX_CHARS_IN_BUF 4096 |
70 | char buf[MAX_CHARS_IN_BUF + 1]; |
71 | size_t buf_count; |
72 | |
73 | while (1) |
74 | { |
75 | /* Wait for the tracee to be stopped or exited. */ |
76 | wait (stat_loc: &status); |
77 | if (WIFEXITED (status)) |
78 | break; |
79 | |
80 | /* Get information about tracee: gprs, last breaking address. */ |
81 | parea.len = sizeof (regs); |
82 | parea.process_addr = (unsigned long) ®s; |
83 | parea.kernel_addr = 0; |
84 | TEST_VERIFY_EXIT (ptrace (PTRACE_PEEKUSR_AREA, pid, &parea) == 0); |
85 | TEST_VERIFY_EXIT (ptrace (PTRACE_GET_LAST_BREAK, pid, NULL, &last_break) |
86 | == 0); |
87 | |
88 | parea2.iov_len = sizeof (regs2); |
89 | parea2.iov_base = ®s2; |
90 | TEST_VERIFY_EXIT (ptrace (PTRACE_GETREGSET, pid, NT_PRSTATUS, &parea2) |
91 | == 0); |
92 | TEST_VERIFY_EXIT (parea2.iov_len == sizeof (regs2)); |
93 | |
94 | /* Test if gprs obtained by PTRACE_PEEKUSR_AREA and PTRACE_GETREGESET |
95 | have the same values. */ |
96 | TEST_VERIFY_EXIT (memcmp (®s, ®s2, sizeof (regs)) == 0); |
97 | |
98 | printf (format: "child IA: %p last_break: %p\n" , |
99 | (void *) regs[1], (void *) last_break); |
100 | |
101 | /* Execute tracee until next taken branch. |
102 | |
103 | Note: |
104 | Before the commit which introduced this testcase, |
105 | <glibc>/sysdeps/unix/sysv/linux/s390/sys/ptrace.h |
106 | uses ptrace-request 12 for PTRACE_GETREGS, |
107 | but <kernel>/include/uapi/linux/ptrace.h |
108 | uses 12 for PTRACE_SINGLEBLOCK. |
109 | |
110 | The s390 kernel has no support for PTRACE_GETREGS! |
111 | Thus glibc ptrace.h is adjusted to match kernel ptrace.h. |
112 | |
113 | The glibc sys/ptrace.h header contains the identifier |
114 | PTRACE_SINGLEBLOCK in enum __ptrace_request. In contrast, the kernel |
115 | asm/ptrace.h header defines PTRACE_SINGLEBLOCK. |
116 | |
117 | This test ensures, that PTRACE_SINGLEBLOCK defined in glibc |
118 | works as expected. If the kernel would interpret it as |
119 | PTRACE_GETREGS, then the tracee will not make any progress |
120 | and this testcase will time out or the ptrace call will fail with |
121 | different errors. */ |
122 | |
123 | /* Ptrace request 12 is first done with data argument pointing to |
124 | a buffer: |
125 | -If request 12 is interpreted as PTRACE_GETREGS, it will store the regs |
126 | to buffer without an error. |
127 | |
128 | -If request 12 is interpreted as PTRACE_SINGLEBLOCK, it will fail |
129 | as data argument is used as signal-number and the address of |
130 | buf is no valid signal. |
131 | |
132 | -If request 12 is not implemented, it will also fail. |
133 | |
134 | Here the test expects that the buffer is untouched and an error is |
135 | returned. */ |
136 | memset (buf, 'a', MAX_CHARS_IN_BUF); |
137 | ret = ptrace (request: req_singleblock, pid, NULL, buf); |
138 | buf [MAX_CHARS_IN_BUF] = '\0'; |
139 | buf_count = strspn (buf, "a" ); |
140 | TEST_VERIFY_EXIT (buf_count == MAX_CHARS_IN_BUF); |
141 | TEST_VERIFY_EXIT (ret == -1); |
142 | |
143 | /* If request 12 is interpreted as PTRACE_GETREGS, the first ptrace |
144 | call will touch the buffer which is detected by this test. */ |
145 | errno = 0; |
146 | ret = ptrace (request: req_singleblock, pid, NULL, NULL); |
147 | if (ret == 0) |
148 | { |
149 | /* The kernel has support for PTRACE_SINGLEBLOCK ptrace request. */ |
150 | TEST_VERIFY_EXIT (errno == 0); |
151 | } |
152 | else |
153 | { |
154 | /* The kernel (< 3.15) has no support for PTRACE_SINGLEBLOCK ptrace |
155 | request. */ |
156 | TEST_VERIFY_EXIT (errno == EIO); |
157 | TEST_VERIFY_EXIT (ret == -1); |
158 | |
159 | /* Just continue tracee until it exits normally. */ |
160 | TEST_VERIFY_EXIT (ptrace (PTRACE_CONT, pid, NULL, NULL) == 0); |
161 | } |
162 | } |
163 | } |
164 | |
165 | static int |
166 | do_test (void) |
167 | { |
168 | int pid; |
169 | pid = xfork (); |
170 | if (pid) |
171 | tracer_func (pid); |
172 | else |
173 | tracee_func (pid: getpid ()); |
174 | |
175 | return EXIT_SUCCESS; |
176 | } |
177 | |
178 | #include <support/test-driver.c> |
179 | |