Messages in this thread | | | From | "Leizhen (ThunderTown)" <> | Subject | [Question] Can we use SIGRTMIN when vdso disabled on X86? | Date | Tue, 5 Jun 2018 19:24:46 +0800 |
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After I executed "echo 0 > /proc/sys/abi/vsyscall32" to disable vdso, the rt_sigaction01 test case from ltp_2015 failed. The test case source code please refer to the attachment, and the output as blow:
----------------- ./rt_sigaction01 rt_sigaction01 0 TINFO : signal: 34 rt_sigaction01 1 TPASS : rt_sigaction call succeeded: result = 0 rt_sigaction01 0 TINFO : sa.sa_flags = SA_RESETHAND|SA_SIGINFO rt_sigaction01 0 TINFO : Signal Handler Called with signal number 34
Segmentation fault ------------------
Is this the desired result? In function ia32_setup_rt_frame, I found below code:
if (ksig->ka.sa.sa_flags & SA_RESTORER) restorer = ksig->ka.sa.sa_restorer; else restorer = current->mm->context.vdso + vdso_image_32.sym___kernel_rt_sigreturn; put_user_ex(ptr_to_compat(restorer), &frame->pretcode);
Because the vdso is disabled, so current->mm->context.vdso is NULL, which cause the result of frame->pretcode invalid.
I'm not sure whether this is a kernel bug or just an error of test case itself. Can anyone help me?
-- Thanks! BestRegards /******************************************************************************/ /* Copyright (c) Crackerjack Project., 2007 */ /* */ /* This program is free software; you can redistribute it and/or modify */ /* it under the terms of the GNU General Public License as published by */ /* the Free Software Foundation; either version 2 of the License, or */ /* (at your option) any later version. */ /* */ /* This program 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 General Public License for more details. */ /* */ /* You should have received a copy of the GNU General Public License */ /* along with this program; if not, write to the Free Software Foundation, */ /* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /* */ /* History: Porting from Crackerjack to LTP is done by */ /* Manas Kumar Nayak maknayak@in.ibm.com> */ /******************************************************************************/
/******************************************************************************/ /* Description: This tests the rt_sigaction() syscall */ /* rt_sigaction alters an action taken by a process on receipt */ /* of a particular signal. The action is specified by the */ /* sigaction structure. The previous action on the signal is */ /* saved in oact.sigsetsize should indicate the size of a */ /* sigset_t type. */ /******************************************************************************/
#include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <signal.h> #include <errno.h> #include <sys/syscall.h> #include <string.h>
#include "test.h" #include "linux_syscall_numbers.h" #include "lapi/rt_sigaction.h"
char *TCID = "rt_sigaction01"; static int testno; int TST_TOTAL = 1;
static void cleanup(void) { tst_rmdir(); }
static void setup(void) { TEST_PAUSE; tst_tmpdir(); }
static int test_flags[] = { SA_RESETHAND | SA_SIGINFO, SA_RESETHAND, SA_RESETHAND | SA_SIGINFO, SA_RESETHAND | SA_SIGINFO, SA_NOMASK }; char *test_flags_list[] = { "SA_RESETHAND|SA_SIGINFO", "SA_RESETHAND", "SA_RESETHAND|SA_SIGINFO", "SA_RESETHAND|SA_SIGINFO", "SA_NOMASK" };
static void handler(int sig) { tst_resm(TINFO, "Signal Handler Called with signal number %d\n", sig); return; }
static int set_handler(int sig, int sig_to_mask, int mask_flags) { struct sigaction sa, oldaction;
sa.sa_handler = (void *)handler; sa.sa_flags = mask_flags; sigemptyset(&sa.sa_mask); sigaddset(&sa.sa_mask, sig);
return ltp_rt_sigaction(sig, &sa, &oldaction, SIGSETSIZE); }
int main(int ac, char **av) { unsigned int flag; int signal; int lc;
tst_parse_opts(ac, av, NULL, NULL);
setup();
for (lc = 0; TEST_LOOPING(lc); ++lc) {
tst_count = 0;
for (testno = 0; testno < TST_TOTAL; ++testno) {
for (signal = SIGRTMIN; signal <= SIGRTMAX; signal++) { for (flag = 0; flag < (sizeof(test_flags) / sizeof(test_flags[0])); flag++) {
TEST(set_handler (signal, 0, test_flags[flag]));
if (TEST_RETURN == 0) { tst_resm(TINFO, "signal: %d ", signal); tst_resm(TPASS, "rt_sigaction call succeeded: result = %ld ", TEST_RETURN); tst_resm(TINFO, "sa.sa_flags = %s ", test_flags_list[flag]); kill(getpid(), signal); } else { tst_resm(TFAIL | TTERRNO, "rt_sigaction call " "failed"); }
}
}
}
} cleanup(); tst_exit(); }
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