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[src/trunk]: src/tests/lib/libc/sys Add a test for verifying procinfo note in...



details:   https://anonhg.NetBSD.org/src/rev/76e6d975c49e
branches:  trunk
changeset: 1000027:76e6d975c49e
user:      mgorny <mgorny%NetBSD.org@localhost>
date:      Sun Jun 30 21:20:04 2019 +0000

description:
Add a test for verifying procinfo note inside coredumps.

Add a first test for triggering a core dump in the debugged process
(via PT_DUMPCORE) and verifying it.  The test finds procinfo note
and checks its contents.

The core dump is processed through libelf.  However, it only provides
for finding all note segments (or sections?).  I had to implement
finding and processing individual notes myself.  I've added
a core_find_note() function that will be reused in future tests.

Reviewed by kamil.

diffstat:

 tests/lib/libc/sys/Makefile        |   14 +-
 tests/lib/libc/sys/t_ptrace_wait.c |  185 ++++++++++++++++++++++++++++++++++++-
 2 files changed, 190 insertions(+), 9 deletions(-)

diffs (258 lines):

diff -r 0117171639c8 -r 76e6d975c49e tests/lib/libc/sys/Makefile
--- a/tests/lib/libc/sys/Makefile       Sun Jun 30 19:57:23 2019 +0000
+++ b/tests/lib/libc/sys/Makefile       Sun Jun 30 21:20:04 2019 +0000
@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.56 2019/04/26 20:41:10 maya Exp $
+# $NetBSD: Makefile,v 1.57 2019/06/30 21:20:04 mgorny Exp $
 
 MKMAN= no
 
@@ -88,12 +88,12 @@
 
 LDADD.t_getpid+=        -lpthread
 
-LDADD.t_ptrace_wait+=          -pthread -lm
-LDADD.t_ptrace_wait3+=         -pthread -lm
-LDADD.t_ptrace_wait4+=         -pthread -lm
-LDADD.t_ptrace_wait6+=         -pthread -lm
-LDADD.t_ptrace_waitid+=                -pthread -lm
-LDADD.t_ptrace_waitpid+=       -pthread -lm
+LDADD.t_ptrace_wait+=          -pthread -lm -lelf
+LDADD.t_ptrace_wait3+=         -pthread -lm -lelf
+LDADD.t_ptrace_wait4+=         -pthread -lm -lelf
+LDADD.t_ptrace_wait6+=         -pthread -lm -lelf
+LDADD.t_ptrace_waitid+=                -pthread -lm -lelf
+LDADD.t_ptrace_waitpid+=       -pthread -lm -lelf
 
 .if (${MKRUMP} != "no") && !defined(BSD_MK_COMPAT_FILE)
 CPPFLAGS.t_posix_fadvise.c += -D_KERNTYPES
diff -r 0117171639c8 -r 76e6d975c49e tests/lib/libc/sys/t_ptrace_wait.c
--- a/tests/lib/libc/sys/t_ptrace_wait.c        Sun Jun 30 19:57:23 2019 +0000
+++ b/tests/lib/libc/sys/t_ptrace_wait.c        Sun Jun 30 21:20:04 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: t_ptrace_wait.c,v 1.129 2019/06/26 12:30:13 mgorny Exp $       */
+/*     $NetBSD: t_ptrace_wait.c,v 1.130 2019/06/30 21:20:04 mgorny Exp $       */
 
 /*-
  * Copyright (c) 2016, 2017, 2018, 2019 The NetBSD Foundation, Inc.
@@ -27,10 +27,11 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: t_ptrace_wait.c,v 1.129 2019/06/26 12:30:13 mgorny Exp $");
+__RCSID("$NetBSD: t_ptrace_wait.c,v 1.130 2019/06/30 21:20:04 mgorny Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
+#include <sys/exec_elf.h>
 #include <sys/mman.h>
 #include <sys/ptrace.h>
 #include <sys/resource.h>
@@ -43,6 +44,7 @@
 #include <elf.h>
 #include <err.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <lwp.h>
 #include <pthread.h>
 #include <sched.h>
@@ -66,6 +68,9 @@
 #include <x86/specialreg.h>
 #endif
 
+#include <libelf.h>
+#include <gelf.h>
+
 #include <atf-c.h>
 
 #include "h_macros.h"
@@ -7639,6 +7644,180 @@
 
 /// ----------------------------------------------------------------------------
 
+/*
+ * Parse the core file and find the requested note.  If the reading or parsing
+ * fails, the test is failed.  If the note is found, it is read onto buf, up to
+ * buf_len.  The actual length of the note is returned (which can be greater
+ * than buf_len, indicating that it has been truncated).  If the note is not
+ * found, -1 is returned.
+ */
+static ssize_t core_find_note(const char *core_path,
+    const char *note_name, uint64_t note_type, void *buf, size_t buf_len)
+{
+       int core_fd;
+       Elf *core_elf;
+       size_t core_numhdr, i;
+       ssize_t ret = -1;
+       /* note: we assume note name will be null-terminated */
+       size_t name_len = strlen(note_name) + 1;
+
+       SYSCALL_REQUIRE((core_fd = open(core_path, O_RDONLY)) != -1);
+       SYSCALL_REQUIRE(elf_version(EV_CURRENT) != EV_NONE);
+       SYSCALL_REQUIRE((core_elf = elf_begin(core_fd, ELF_C_READ, NULL)));
+
+       SYSCALL_REQUIRE(elf_getphnum(core_elf, &core_numhdr) != 0);
+       for (i = 0; i < core_numhdr && ret == -1; i++) {
+               GElf_Phdr core_hdr;
+               size_t offset;
+               SYSCALL_REQUIRE(gelf_getphdr(core_elf, i, &core_hdr));
+               if (core_hdr.p_type != PT_NOTE)
+                   continue;
+
+               for (offset = core_hdr.p_offset;
+                   offset < core_hdr.p_offset + core_hdr.p_filesz;) {
+                       Elf64_Nhdr note_hdr;
+                       char name_buf[64];
+
+                       switch (gelf_getclass(core_elf)) {
+                       case ELFCLASS64:
+                               SYSCALL_REQUIRE(pread(core_fd, &note_hdr,
+                                   sizeof(note_hdr), offset)
+                                   == sizeof(note_hdr));
+                               offset += sizeof(note_hdr);
+                               break;
+                       case ELFCLASS32:
+                               {
+                               Elf32_Nhdr tmp_hdr;
+                               SYSCALL_REQUIRE(pread(core_fd, &tmp_hdr,
+                                   sizeof(tmp_hdr), offset)
+                                   == sizeof(tmp_hdr));
+                               offset += sizeof(tmp_hdr);
+                               note_hdr.n_namesz = tmp_hdr.n_namesz;
+                               note_hdr.n_descsz = tmp_hdr.n_descsz;
+                               note_hdr.n_type = tmp_hdr.n_type;
+                               }
+                               break;
+                       }
+
+                       /* indicates end of notes */
+                       if (note_hdr.n_namesz == 0 || note_hdr.n_descsz == 0)
+                               break;
+                       if (note_hdr.n_namesz == name_len &&
+                           note_hdr.n_namesz <= sizeof(name_buf)) {
+                               SYSCALL_REQUIRE(pread(core_fd, name_buf,
+                                   note_hdr.n_namesz, offset)
+                                   == note_hdr.n_namesz);
+
+                               if (!strncmp(note_name, name_buf, name_len) &&
+                                   note_hdr.n_type == note_type)
+                                       ret = note_hdr.n_descsz;
+                       }
+
+                       offset += note_hdr.n_namesz;
+                       /* fix to alignment */
+                       offset = ((offset + core_hdr.p_align - 1)
+                           / core_hdr.p_align) * core_hdr.p_align;
+
+                       /* if name & type matched above */
+                       if (ret != -1) {
+                               ssize_t read_len = MIN(buf_len,
+                                   note_hdr.n_descsz);
+                               SYSCALL_REQUIRE(pread(core_fd, buf,
+                                   read_len, offset) == read_len);
+                               break;
+                       }
+
+                       offset += note_hdr.n_descsz;
+               }
+       }
+
+       elf_end(core_elf);
+       close(core_fd);
+
+       return ret;
+}
+
+ATF_TC(core_dump_procinfo);
+ATF_TC_HEAD(core_dump_procinfo, tc)
+{
+       atf_tc_set_md_var(tc, "descr",
+               "Trigger a core dump and verify its contents.");
+}
+
+ATF_TC_BODY(core_dump_procinfo, tc)
+{
+       const int exitval = 5;
+       pid_t child, wpid;
+#if defined(TWAIT_HAVE_STATUS)
+       const int sigval = SIGTRAP;
+       int status;
+#endif
+       char core_path[] = "/tmp/core.XXXXXX";
+       int core_fd;
+       struct netbsd_elfcore_procinfo procinfo;
+
+       DPRINTF("Before forking process PID=%d\n", getpid());
+       SYSCALL_REQUIRE((child = fork()) != -1);
+       if (child == 0) {
+               DPRINTF("Before calling PT_TRACE_ME from child %d\n", getpid());
+               FORKEE_ASSERT(ptrace(PT_TRACE_ME, 0, NULL, 0) != -1);
+
+               DPRINTF("Before triggering SIGTRAP\n");
+               trigger_trap();
+
+               DPRINTF("Before exiting of the child process\n");
+               _exit(exitval);
+       }
+       DPRINTF("Parent process PID=%d, child's PID=%d\n", getpid(), child);
+
+       DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
+       TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);
+
+       validate_status_stopped(status, sigval);
+
+       SYSCALL_REQUIRE((core_fd = mkstemp(core_path)) != -1);
+       close(core_fd);
+
+       DPRINTF("Call DUMPCORE for the child process\n");
+       SYSCALL_REQUIRE(ptrace(PT_DUMPCORE, child, core_path, strlen(core_path))
+           != -1);
+
+       DPRINTF("Read core file\n");
+       ATF_REQUIRE_EQ(core_find_note(core_path, "NetBSD-CORE",
+           ELF_NOTE_NETBSD_CORE_PROCINFO, &procinfo, sizeof(procinfo)),
+           sizeof(procinfo));
+
+       ATF_CHECK_EQ(procinfo.cpi_version, 1);
+       ATF_CHECK_EQ(procinfo.cpi_cpisize, sizeof(procinfo));
+       ATF_CHECK_EQ(procinfo.cpi_signo, SIGTRAP);
+       ATF_CHECK_EQ(procinfo.cpi_pid, child);
+       ATF_CHECK_EQ(procinfo.cpi_ppid, getpid());
+       ATF_CHECK_EQ(procinfo.cpi_pgrp, getpgid(child));
+       ATF_CHECK_EQ(procinfo.cpi_sid, getsid(child));
+       ATF_CHECK_EQ(procinfo.cpi_ruid, getuid());
+       ATF_CHECK_EQ(procinfo.cpi_euid, geteuid());
+       ATF_CHECK_EQ(procinfo.cpi_rgid, getgid());
+       ATF_CHECK_EQ(procinfo.cpi_egid, getegid());
+       ATF_CHECK_EQ(procinfo.cpi_nlwps, 1);
+       ATF_CHECK_EQ(procinfo.cpi_siglwp, 1);
+
+       unlink(core_path);
+
+       DPRINTF("Before resuming the child process where it left off and "
+           "without signal to be sent\n");
+       SYSCALL_REQUIRE(ptrace(PT_CONTINUE, child, (void *)1, 0) != -1);
+
+       DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
+       TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);
+
+       validate_status_exited(status, exitval);
+
+       DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
+       TWAIT_REQUIRE_FAILURE(ECHILD, wpid = TWAIT_GENERIC(child, &status, 0));
+}
+
+/// ----------------------------------------------------------------------------
+
 #include "t_ptrace_amd64_wait.h"
 #include "t_ptrace_i386_wait.h"
 #include "t_ptrace_x86_wait.h"
@@ -8130,6 +8309,8 @@
        ATF_TP_ADD_TC(tp, user_va0_disable_pt_syscall);
        ATF_TP_ADD_TC(tp, user_va0_disable_pt_detach);
 
+       ATF_TP_ADD_TC(tp, core_dump_procinfo);
+
        ATF_TP_ADD_TCS_PTRACE_WAIT_AMD64();
        ATF_TP_ADD_TCS_PTRACE_WAIT_I386();
        ATF_TP_ADD_TCS_PTRACE_WAIT_X86();



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