diff options
| -rw-r--r-- | ChangeLog | 9 | ||||
| -rw-r--r-- | elf/tst-pldd.c | 70 | ||||
| -rw-r--r-- | support/Makefile | 1 | ||||
| -rw-r--r-- | support/support_ptrace.c | 44 | ||||
| -rw-r--r-- | support/xptrace.h | 32 |
5 files changed, 137 insertions, 19 deletions
@@ -1,3 +1,12 @@ +2019-09-18 Stefan Liebler <stli@linux.ibm.com> + + * elf/tst-pldd.c (do_test): Add UNSUPPORTED check. + Rearrange subprocesses. + (pldd_process): New function. + * support/Makefile (libsupport-routines): Add support_ptrace. + * support/xptrace.h: New file. + * support/support_ptrace.c: Likewise. + 2019-09-17 Adhemerval Zanella <adhemerval.zanella@linaro.org> * sysdeps/unix/sysv/linux/sparc/sparc64/time.c: Remove file. diff --git a/elf/tst-pldd.c b/elf/tst-pldd.c index 3f97e27..afe43f9 100644 --- a/elf/tst-pldd.c +++ b/elf/tst-pldd.c @@ -30,6 +30,11 @@ #include <support/capture_subprocess.h> #include <support/check.h> #include <support/support.h> +#include <support/xptrace.h> +#include <support/xunistd.h> +#include <sys/mman.h> +#include <errno.h> +#include <signal.h> static void target_process (void *arg) @@ -37,6 +42,34 @@ target_process (void *arg) pause (); } +static void +pldd_process (void *arg) +{ + pid_t *target_pid_ptr = (pid_t *) arg; + + /* Create a copy of current test to check with pldd. As the + target_process is a child of this pldd_process, pldd is also able + to attach to target_process if YAMA is configured to 1 = + "restricted ptrace". */ + struct support_subprocess target = support_subprocess (target_process, NULL); + + /* Store the pid of target-process as do_test needs it in order to + e.g. terminate it at end of the test. */ + *target_pid_ptr = target.pid; + + /* Three digits per byte plus null terminator. */ + char pid[3 * sizeof (uint32_t) + 1]; + snprintf (pid, array_length (pid), "%d", target.pid); + + char *prog = xasprintf ("%s/pldd", support_bindir_prefix); + + /* Run pldd and use the pid of target_process as argument. */ + execve (prog, (char *const []) { (char *) prog, pid, NULL }, + (char *const []) { NULL }); + + FAIL_EXIT1 ("Returned from execve: errno=%d=%m\n", errno); +} + /* The test runs in a container because pldd does not support tracing a binary started by the loader iself (as with testrun.sh). */ @@ -52,25 +85,22 @@ in_str_list (const char *libname, const char *const strlist[]) static int do_test (void) { - /* Create a copy of current test to check with pldd. */ - struct support_subprocess target = support_subprocess (target_process, NULL); - - /* Run 'pldd' on test subprocess. */ - struct support_capture_subprocess pldd; + /* Check if our subprocess can be debugged with ptrace. */ { - /* Three digits per byte plus null terminator. */ - char pid[3 * sizeof (uint32_t) + 1]; - snprintf (pid, array_length (pid), "%d", target.pid); - - char *prog = xasprintf ("%s/pldd", support_bindir_prefix); - - pldd = support_capture_subprogram (prog, - (char *const []) { (char *) prog, pid, NULL }); + int ptrace_scope = support_ptrace_scope (); + if (ptrace_scope >= 2) + FAIL_UNSUPPORTED ("/proc/sys/kernel/yama/ptrace_scope >= 2"); + } - support_capture_subprocess_check (&pldd, "pldd", 0, sc_allow_stdout); + pid_t *target_pid_ptr = (pid_t *) xmmap (NULL, sizeof (pid_t), + PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, -1); - free (prog); - } + /* Run 'pldd' on test subprocess which will be created in pldd_process. + The pid of the subprocess will be written to target_pid_ptr. */ + struct support_capture_subprocess pldd; + pldd = support_capture_subprocess (pldd_process, target_pid_ptr); + support_capture_subprocess_check (&pldd, "pldd", 0, sc_allow_stdout); /* Check 'pldd' output. The test is expected to be linked against only loader and libc. */ @@ -85,7 +115,7 @@ do_test (void) /* First line is in the form of <pid>: <full path of executable> */ TEST_COMPARE (fscanf (out, "%u: " STRINPUT (512), &pid, buffer), 2); - TEST_COMPARE (pid, target.pid); + TEST_COMPARE (pid, *target_pid_ptr); TEST_COMPARE (strcmp (basename (buffer), "tst-pldd"), 0); /* It expects only one loader and libc loaded by the program. */ @@ -93,7 +123,7 @@ do_test (void) while (fgets (buffer, array_length (buffer), out) != NULL) { /* Ignore vDSO. */ - if (buffer[0] != '/') + if (buffer[0] != '/') continue; /* Remove newline so baseline (buffer) can compare against the @@ -128,7 +158,9 @@ do_test (void) } support_capture_subprocess_free (&pldd); - support_process_terminate (&target); + if (kill (*target_pid_ptr, SIGKILL) != 0) + FAIL_EXIT1 ("Unable to kill target_process: errno=%d=%m\n", errno); + xmunmap (target_pid_ptr, sizeof (pid_t)); return 0; } diff --git a/support/Makefile b/support/Makefile index be90043..ca238ee 100644 --- a/support/Makefile +++ b/support/Makefile @@ -56,6 +56,7 @@ libsupport-routines = \ support_format_hostent \ support_format_netent \ support_isolate_in_subprocess \ + support_ptrace \ support_openpty \ support_paths \ support_quote_blob \ diff --git a/support/support_ptrace.c b/support/support_ptrace.c new file mode 100644 index 0000000..616b08c --- /dev/null +++ b/support/support_ptrace.c @@ -0,0 +1,44 @@ +/* Support functions handling ptrace_scope. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#include <support/check.h> +#include <support/xstdio.h> +#include <support/xptrace.h> +#include <sys/prctl.h> + +int +support_ptrace_scope (void) +{ + int ptrace_scope = -1; + +#ifdef __linux__ + /* YAMA may be not enabled. Otherwise it contains a value from 0 to 3: + - 0 classic ptrace permissions + - 1 restricted ptrace + - 2 admin-only attach + - 3 no attach */ + FILE *f = fopen ("/proc/sys/kernel/yama/ptrace_scope", "r"); + if (f != NULL) + { + TEST_COMPARE (fscanf (f, "%d", &ptrace_scope), 1); + xfclose (f); + } +#endif + + return ptrace_scope; +} diff --git a/support/xptrace.h b/support/xptrace.h new file mode 100644 index 0000000..7af8926 --- /dev/null +++ b/support/xptrace.h @@ -0,0 +1,32 @@ +/* Support functions handling ptrace_scope. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef SUPPORT_PTRACE_H +#define SUPPORT_PTRACE_H + +#include <sys/cdefs.h> + +__BEGIN_DECLS + +/* Return the current YAMA mode set on the machine (0 to 3) or -1 + if YAMA is not supported. */ +int support_ptrace_scope (void); + +__END_DECLS + +#endif |