87 lines
1.9 KiB
C
87 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* POWER Data Stream Control Register (DSCR) fork test
|
|
*
|
|
* This testcase modifies the DSCR using mtspr, forks and then
|
|
* verifies that the child process has the correct changed DSCR
|
|
* value using mfspr.
|
|
*
|
|
* When using the privilege state SPR, the instructions such as
|
|
* mfspr or mtspr are priviledged and the kernel emulates them
|
|
* for us. Instructions using problem state SPR can be exuecuted
|
|
* directly without any emulation if the HW supports them. Else
|
|
* they also get emulated by the kernel.
|
|
*
|
|
* Copyright 2012, Anton Blanchard, IBM Corporation.
|
|
* Copyright 2015, Anshuman Khandual, IBM Corporation.
|
|
*/
|
|
#include "dscr.h"
|
|
|
|
int dscr_inherit(void)
|
|
{
|
|
unsigned long i, dscr = 0;
|
|
pid_t pid;
|
|
|
|
SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
|
|
|
|
srand(getpid());
|
|
set_dscr(dscr);
|
|
|
|
for (i = 0; i < COUNT; i++) {
|
|
unsigned long cur_dscr, cur_dscr_usr;
|
|
|
|
dscr++;
|
|
if (dscr > DSCR_MAX)
|
|
dscr = 0;
|
|
|
|
if (i % 2 == 0)
|
|
set_dscr_usr(dscr);
|
|
else
|
|
set_dscr(dscr);
|
|
|
|
pid = fork();
|
|
if (pid == -1) {
|
|
perror("fork() failed");
|
|
exit(1);
|
|
} else if (pid) {
|
|
int status;
|
|
|
|
if (waitpid(pid, &status, 0) == -1) {
|
|
perror("waitpid() failed");
|
|
exit(1);
|
|
}
|
|
|
|
if (!WIFEXITED(status)) {
|
|
fprintf(stderr, "Child didn't exit cleanly\n");
|
|
exit(1);
|
|
}
|
|
|
|
if (WEXITSTATUS(status) != 0) {
|
|
fprintf(stderr, "Child didn't exit cleanly\n");
|
|
return 1;
|
|
}
|
|
} else {
|
|
cur_dscr = get_dscr();
|
|
if (cur_dscr != dscr) {
|
|
fprintf(stderr, "Kernel DSCR should be %ld "
|
|
"but is %ld\n", dscr, cur_dscr);
|
|
exit(1);
|
|
}
|
|
|
|
cur_dscr_usr = get_dscr_usr();
|
|
if (cur_dscr_usr != dscr) {
|
|
fprintf(stderr, "User DSCR should be %ld "
|
|
"but is %ld\n", dscr, cur_dscr_usr);
|
|
exit(1);
|
|
}
|
|
exit(0);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
return test_harness(dscr_inherit, "dscr_inherit_test");
|
|
}
|