/* * Copyright 2015, Cyril Bur, IBM Corp. * * 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 test attempts to see if the VMX registers change across preemption. * Two things should be noted here a) The check_vmx function in asm only checks * the non volatile registers as it is reused from the syscall test b) There is * no way to be sure preemption happened so this test just uses many threads * and a long wait. As such, a successful test doesn't mean much but a failure * is bad. */ #include #include #include #include #include #include #include #include #include "utils.h" /* Time to wait for workers to get preempted (seconds) */ #define PREEMPT_TIME 20 /* * Factor by which to multiply number of online CPUs for total number of * worker threads */ #define THREAD_FACTOR 8 __thread vector int varray[] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12}, {13,14,15,16},{17,18,19,20},{21,22,23,24}, {25,26,27,28},{29,30,31,32},{33,34,35,36}, {37,38,39,40},{41,42,43,44},{45,46,47,48}}; int threads_starting; int running; extern void preempt_vmx(vector int *varray, int *threads_starting, int *running); void *preempt_vmx_c(void *p) { int i, j; srand(pthread_self()); for (i = 0; i < 12; i++) for (j = 0; j < 4; j++) varray[i][j] = rand(); /* Test fails if it ever returns */ preempt_vmx(varray, &threads_starting, &running); return p; } int test_preempt_vmx(void) { int i, rc, threads; pthread_t *tids; threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; tids = malloc(threads * sizeof(pthread_t)); FAIL_IF(!tids); running = true; threads_starting = threads; for (i = 0; i < threads; i++) { rc = pthread_create(&tids[i], NULL, preempt_vmx_c, NULL); FAIL_IF(rc); } setbuf(stdout, NULL); /* Not really nessesary but nice to wait for every thread to start */ printf("\tWaiting for all workers to start..."); while(threads_starting) asm volatile("": : :"memory"); printf("done\n"); printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME); sleep(PREEMPT_TIME); printf("done\n"); printf("\tStopping workers..."); /* * Working are checking this value every loop. In preempt_vmx 'cmpwi r5,0; bne 2b'. * r5 will have loaded the value of running. */ running = 0; for (i = 0; i < threads; i++) { void *rc_p; pthread_join(tids[i], &rc_p); /* * Harness will say the fail was here, look at why preempt_vmx * returned */ if ((long) rc_p) printf("oops\n"); FAIL_IF((long) rc_p); } printf("done\n"); return 0; } int main(int argc, char *argv[]) { return test_harness(test_preempt_vmx, "vmx_preempt"); } ons
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authorDavid S. Miller <davem@davemloft.net>2017-01-30 14:28:22 -0800
committerDavid S. Miller <davem@davemloft.net>2017-01-30 14:28:22 -0800
commit54791b276b4000b307339f269d3bf7db877d536f (patch)
tree1c2616bd373ce5ea28aac2a53e32f5b5834901ce /net/tipc
parent5d0e7705774dd412a465896d08d59a81a345c1e4 (diff)
parent047487241ff59374fded8c477f21453681f5995c (diff)
Merge branch 'sparc64-non-resumable-user-error-recovery'
Liam R. Howlett says: ==================== sparc64: Recover from userspace non-resumable PIO & MEM errors A non-resumable error from userspace is able to cause a kernel panic or trap loop due to the setup and handling of the queued traps once in the kernel. This patch series addresses both of these issues. The queues are fixed by simply zeroing the memory before use. PIO errors from userspace will result in a SIGBUS being sent to the user process. The MEM errors form userspace will result in a SIGKILL and also cause the offending pages to be claimed so they are no longer used in future tasks. SIGKILL is used to ensure that the process does not try to coredump and result in an attempt to read the memory again from within kernel space. Although there is a HV call to scrub the memory (mem_scrub), there is no easy way to guarantee that the real memory address(es) are not used by other tasks. Clearing the error with mem_scrub would zero the memory and cause the other processes to proceed with bad data. The handling of other non-resumable errors remain unchanged and will cause a panic. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/tipc')