d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix reporting of SS_ONSTACK

Browse Source 
Fix reporting of SS_ONSTACK in nested signal delivery when sigaltstack()
is used on some architectures.

Add a unit test for this.  I tested the test by introducing the bug
on amd64.  I did not test it on other architectures.

Reviewed by:	kib
MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D18347
This commit is contained in:
Eric van Gyzen 2018-11-30 22:44:33 +00:00
parent 09057b2c5c
commit 984969cd96
5 changed files with 122 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
sys/arm/arm/machdep.c
View File

@ -653,9 +653,9 @@ sendsig(catcher, ksi, mask)
#endif
frame.sf_si = ksi->ksi_info;
frame.sf_uc.uc_sigmask = *mask;
frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK )
? ((onstack) ? SS_ONSTACK : 0) : SS_DISABLE;
frame.sf_uc.uc_stack = td->td_sigstk;
frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
(onstack ? SS_ONSTACK : 0) : SS_DISABLE;
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(td->td_proc);

4
sys/arm64/arm64/machdep.c
View File

@ -661,9 +661,9 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
get_fpcontext(td, &frame.sf_uc.uc_mcontext);
frame.sf_si = ksi->ksi_info;
frame.sf_uc.uc_sigmask = *mask;
frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) ?
((onstack) ? SS_ONSTACK : 0) : SS_DISABLE;
frame.sf_uc.uc_stack = td->td_sigstk;
frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
(onstack ? SS_ONSTACK : 0) : SS_DISABLE;
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(td->td_proc);

4
sys/riscv/riscv/machdep.c
View File

@ -587,9 +587,9 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
get_fpcontext(td, &frame.sf_uc.uc_mcontext);
frame.sf_si = ksi->ksi_info;
frame.sf_uc.uc_sigmask = *mask;
frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) ?
((onstack) ? SS_ONSTACK : 0) : SS_DISABLE;
frame.sf_uc.uc_stack = td->td_sigstk;
frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ?
(onstack ? SS_ONSTACK : 0) : SS_DISABLE;
mtx_unlock(&psp->ps_mtx);
PROC_UNLOCK(td->td_proc);

1
tests/sys/kern/Makefile
View File

@ -10,6 +10,7 @@ ATF_TESTS_C+= kern_descrip_test
ATF_TESTS_C+= ptrace_test
TEST_METADATA.ptrace_test+= timeout="15"
ATF_TESTS_C+= reaper
ATF_TESTS_C+= sigaltstack
PLAIN_TESTS_C+= subr_unit_test
ATF_TESTS_C+= sys_getrandom
ATF_TESTS_C+= unix_passfd_test

115
tests/sys/kern/sigaltstack.c Normal file
View File

@ -0,0 +1,115 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2018 Eric van Gyzen
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <atf-c.h>
#include <errno.h>
#include <signal.h>
#include <stdbool.h>
#include <stdlib.h>
/*
* TODO add tests for:
*
* - all error cases
* - SS_DISABLE
* - no effect without SA_ONSTACK
*/
static sig_atomic_t disabled_correct = 1;
static sig_atomic_t level1_correct = -1;
static sig_atomic_t level2_correct = -1;
static void
sig_handler(int signo, siginfo_t *info __unused, void *ucp)
{
ucontext_t *uc = ucp;
// The alternate signal stack is enabled.
disabled_correct = disabled_correct &&
(uc->uc_stack.ss_flags & SS_DISABLE) == 0;
if (signo == SIGUSR1) {
// The thread was NOT running on the alternate signal
// stack when this signal arrived.
level1_correct = (uc->uc_stack.ss_flags & SS_ONSTACK) == 0;
raise(SIGUSR2);
} else {
// The thread WAS running on the alternate signal
// stack when this signal arrived.
level2_correct = (uc->uc_stack.ss_flags & SS_ONSTACK) != 0;
}
}
ATF_TC(ss_onstack);
ATF_TC_HEAD(ss_onstack, tc)
{
atf_tc_set_md_var(tc, "descr", "Test reporting of SS_ONSTACK");
}
ATF_TC_BODY(ss_onstack, tc)
{
stack_t ss = {
.ss_size = SIGSTKSZ,
};
stack_t oss = {0};
ss.ss_sp = malloc(ss.ss_size);
ATF_REQUIRE(ss.ss_sp != NULL);
ATF_REQUIRE(sigaltstack(&ss, &oss) == 0);
// There should be no signal stack currently configured.
ATF_CHECK(oss.ss_sp == NULL);
ATF_CHECK(oss.ss_size == 0);
ATF_CHECK((oss.ss_flags & SS_DISABLE) != 0);
ATF_CHECK((oss.ss_flags & SS_ONSTACK) == 0);
struct sigaction sa = {
.sa_sigaction = sig_handler,
.sa_flags = SA_ONSTACK | SA_SIGINFO,
};
ATF_REQUIRE(sigemptyset(&sa.sa_mask) == 0);
ATF_REQUIRE(sigaction(SIGUSR1, &sa, NULL) == 0);
ATF_REQUIRE(sigaction(SIGUSR2, &sa, NULL) == 0);
ATF_REQUIRE(raise(SIGUSR1) == 0);
ATF_CHECK(level1_correct != -1);
ATF_CHECK(level1_correct == 1);
ATF_CHECK(level2_correct != -1);
ATF_CHECK(level2_correct == 1);
}
ATF_TP_ADD_TCS(tp)
{
ATF_TP_ADD_TC(tp, ss_onstack);
return (atf_no_error());
}