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Extend ATF tests in t_trapsignal.sh to verify software breakpoint traps

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There are at least four types of SIGTRAP events:
 - software/hardware single step (trace trap)
 - software breakpoint
 - hardware breakpoint/watchpoint
 - kernel event (exec, fork, vfork, vfork-done, lwp-create, lwp-exit)

A program can execute software breakpoint without the context of being
traced and this is a regular crash signal emitting SIGTRAP (TRAP_BRKPT).

Rename original trap_* tests (trap_simple, trap_handle, trap_mask,
trap_handle_recurse and trap_ignore) to segv_* tests and restrict them for
SIGSEGV.

Add new tests: trap_* testing the same scenarios as segv_ ones, however
verifying the software breakpoint trap (SIGTRAP).

Keep the original name of h_segv.c, and extend it for software breakpoint
events.

The purpose of these tests is to verify SIGTRAP kernel paths without the
ptrace(2) context.

All tests pass.

Sponsored by <The NetBSD Foundation>
This commit is contained in:
kamil 2018-05-22 04:32:56 +00:00
parent 33e8159699
commit aaef92583a
2 changed files with 138 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
tests/kernel/h_segv.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: h_segv.c,v 1.3 2018/05/21 08:49:03 kamil Exp $ */
/* $NetBSD: h_segv.c,v 1.4 2018/05/22 04:32:56 kamil Exp $ */
/*-
* Copyright (c) 2017 The NetBSD Foundation, Inc.
@ -29,8 +29,10 @@
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: h_segv.c,v 1.3 2018/05/21 08:49:03 kamil Exp $");
__RCSID("$NetBSD: h_segv.c,v 1.4 2018/05/22 04:32:56 kamil Exp $");
#include <sys/types.h>
#include <sys/ptrace.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
@ -57,21 +59,41 @@ static struct {
{ "ignore", F_IGNORE }
};
static int sig;
static struct {
const char *n;
int v;
} sn[] = {
{ "segv", SIGSEGV },
{ "trap", SIGTRAP }
};
static void
foo(int s)
{
char buf[64];
int i = snprintf(buf, sizeof(buf), "got %d\n", s);
write(2, buf, i);
if (flags & F_RECURSE)
*p = 0;
if (flags & F_RECURSE) {
if (sig == SIGSEGV)
*p = 0;
else if (sig == SIGTRAP) {
#ifdef PTRACE_BREAKPOINT_ASM
PTRACE_BREAKPOINT_ASM;
#else
/* port me */
#endif
}
}
exit(EXIT_SUCCESS);
}
static __dead void
usage(void)
{
fprintf(stderr, "Usage: %s recurse|mask|handle ...\n", getprogname());
const char *pname = getprogname();
fprintf(stderr, "Usage: %s recurse|mask|handle|ignore ...\n", pname);
exit(EXIT_FAILURE);
}
@ -83,16 +105,21 @@ main(int argc, char *argv[])
for (int i = 1; i < argc; i++) {
size_t j;
for (j = 0; j < __arraycount(nv); j++)
for (j = 0; j < __arraycount(nv); j++) {
if (strcmp(nv[j].n, argv[i]) == 0) {
flags |= nv[j].v;
break;
}
if (strcmp(sn[j].n, argv[i]) == 0) {
sig = sn[j].v;
break;
}
}
if (j == __arraycount(nv))
usage();
}
if (flags == 0)
if (flags == 0 || sig == 0)
usage();
if (flags & F_HANDLE) {
@ -101,7 +128,7 @@ main(int argc, char *argv[])
sa.sa_flags = SA_RESTART;
sa.sa_handler = foo;
sigemptyset(&sa.sa_mask);
if (sigaction(SIGSEGV, &sa, NULL) == -1)
if (sigaction(sig, &sa, NULL) == -1)
err(EXIT_FAILURE, "sigaction");
}
@ -109,7 +136,7 @@ main(int argc, char *argv[])
sigset_t set;
sigemptyset(&set);
sigaddset(&set, SIGSEGV);
sigaddset(&set, sig);
if (sigprocmask(SIG_BLOCK, &set, NULL) == -1)
err(EXIT_FAILURE, "sigprocmask");
}
@ -120,10 +147,18 @@ main(int argc, char *argv[])
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_IGN;
sigemptyset(&sa.sa_mask);
if (sigaction(SIGSEGV, &sa, NULL) == -1)
if (sigaction(sig, &sa, NULL) == -1)
err(EXIT_FAILURE, "sigaction");
}
*p = 1;
if (sig == SIGSEGV)
*p = 1;
else if (sig == SIGTRAP) {
#ifdef PTRACE_BREAKPOINT_ASM
PTRACE_BREAKPOINT_ASM;
#else
/* port me */
#endif
}
return EXIT_SUCCESS;
}

110
tests/kernel/t_trapsignal.sh
View File

@ -1,4 +1,4 @@
# $NetBSD: t_trapsignal.sh,v 1.2 2018/05/21 08:49:03 kamil Exp $
# $NetBSD: t_trapsignal.sh,v 1.3 2018/05/22 04:32:56 kamil Exp $
#
# Copyright (c) 2017 The NetBSD Foundation, Inc.
# All rights reserved.
@ -29,60 +29,128 @@
#
HELPER=$(atf_get_srcdir)/h_segv
atf_test_case segv_simple
segv_simple()
{
atf_set "descr" "Test unhandled SIGSEGV with the right exit code"
}
segv_simple_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:" \
${HELPER} segv recurse
}
atf_test_case segv_handle
segv_handle()
{
atf_set "descr" "Test handled SIGSEGV traps call the signal handler"
}
segv_handle_body()
{
atf_check -s exit:0 -o "inline:" -e "inline:got 11\n" \
${HELPER} segv handle
}
atf_test_case segv_mask
segv_mask()
{
atf_set "descr" "Test that masking SIGSEGV get reset"
}
segv_mask_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:" \
${HELPER} segv mask
}
atf_test_case segv_handle_mask
segv_handle_mask()
{
atf_set "descr" "Test handled and masked SIGSEGV traps get reset"
}
segv_handle_mask_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:" \
${HELPER} segv mask handle
}
atf_test_case segv_handle_recurse
segv_handle_recurse()
{
atf_set "descr" "Test that receiving SIGSEGV in the handler resets"
}
segv_handle_recurse_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:got 11\n" \
${HELPER} segv handle recurse
}
atf_test_case segv_ignore
segv_ignore()
{
atf_set "descr" "Test ignored SIGSEGV trap with right exit code"
}
segv_ignore_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:" \
${HELPER} segv ignore
}
atf_test_case trap_simple
trap_simple()
{
atf_set "descr" "Test unhandled traps exit with the right exit code"
atf_set "descr" "Test unhandled SIGTRAP with the right exit code"
}
trap_simple_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:" \
${HELPER} recurse
atf_check -s signal:5 -o "inline:" -e "inline:" \
${HELPER} trap recurse
}
atf_test_case trap_handle
trap_handle()
{
atf_set "descr" "Test handled traps call the signal handler"
atf_set "descr" "Test handled SIGTRAP traps call the signal handler"
}
trap_handle_body()
{
atf_check -s exit:0 -o "inline:" -e "inline:got 11\n" \
${HELPER} handle
atf_check -s exit:0 -o "inline:" -e "inline:got 5\n" \
${HELPER} trap handle
}
atf_test_case trap_mask
trap_mask()
{
atf_set "descr" "Test that masking the trapped signal get reset"
atf_set "descr" "Test that masking the trapped SIGTRAP signal get reset"
}
trap_mask_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:" \
${HELPER} mask
atf_check -s signal:5 -o "inline:" -e "inline:" \
${HELPER} trap mask
}
atf_test_case trap_handle_mask
trap_handle_mask()
{
atf_set "descr" "Test handled and masked traps get reset"
atf_set "descr" "Test handled and masked SIGTRAP traps get reset"
}
trap_handle_mask_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:" \
${HELPER} mask handle
atf_check -s signal:5 -o "inline:" -e "inline:" \
${HELPER} trap mask handle
}
atf_test_case trap_handle_recurse
trap_handle_recurse()
{
atf_set "descr" "Test that receiving the trap in the handler resets"
atf_set "descr" "Test that receiving SIGTRAP in the handler resets"
}
trap_handle_recurse_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:got 11\n" \
${HELPER} handle recurse
atf_check -s signal:5 -o "inline:" -e "inline:got 5\n" \
${HELPER} trap handle recurse
}
atf_test_case trap_ignore
@ -93,12 +161,18 @@ trap_ignore()
trap_ignore_body()
{
atf_check -s signal:11 -o "inline:" -e "inline:" \
${HELPER} ignore
atf_check -s signal:5 -o "inline:" -e "inline:" \
${HELPER} trap ignore
}
atf_init_test_cases()
{
atf_add_test_case segv_simple
atf_add_test_case segv_handle
atf_add_test_case segv_mask
atf_add_test_case segv_handle_recurse
atf_add_test_case segv_ignore
atf_add_test_case trap_simple
atf_add_test_case trap_handle
atf_add_test_case trap_mask