| /* |
| * vma01 - test not merging a VMA which cloned from parent process |
| * |
| * This program is used for testing the following upstream commit: |
| * 965f55dea0e331152fa53941a51e4e16f9f06fae |
| * |
| * The cloned VMA shares the anon_vma lock with the parent process's |
| * VMA. If we do the merge, more vmas (even the new range is only |
| * for current process) use the perent process's anon_vma lock. This |
| * introduces scalability issues. find_mergeable_anon_vma() already |
| * considers this case. |
| * |
| * This test program clones VMA and checks /proc/self/maps file, on |
| * an unpatched kernel, there is a single 6*ps VMA for the child |
| * like this: |
| * |
| * 7fee32989000-7fee3298f000 -w-p 00000000 00:00 0 |
| * |
| * On a patched kernel, there are two 3*ps VMAs like this: |
| * |
| * 7f55bbd47000-7f55bbd4a000 -w-p 00000000 00:00 0 |
| * 7f55bbd4a000-7f55bbd4d000 -w-p 00000000 00:00 0 |
| * |
| * Copyright (C) 2011 Red Hat, Inc. |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of version 2 of the GNU General Public |
| * License as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it would be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| * |
| * Further, this software is distributed without any warranty that it |
| * is free of the rightful claim of any third person regarding |
| * infringement or the like. Any license provided herein, whether |
| * implied or otherwise, applies only to this software file. Patent |
| * licenses, if any, provided herein do not apply to combinations of |
| * this program with other software, or any other product whatsoever. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| * 02110-1301, USA. |
| */ |
| #include <sys/types.h> |
| #include <sys/mman.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "test.h" |
| |
| #define MAPS_FILE "/proc/self/maps" |
| |
| char *TCID = "vma01"; |
| int TST_TOTAL = 1; |
| |
| static void check_vma(void); |
| static void create_bighole(void); |
| static void *get_end_addr(void *addr_s); |
| static void check_status(int status); |
| static void setup(void); |
| static void cleanup(void); |
| |
| static unsigned long ps; |
| static void *p; |
| |
| int main(int argc, char **argv) |
| { |
| const char *msg; |
| int lc; |
| |
| msg = parse_opts(argc, argv, NULL, NULL); |
| if (msg != NULL) |
| tst_brkm(TBROK, NULL, "OPTION PARSING ERROR - %s", msg); |
| |
| ps = sysconf(_SC_PAGE_SIZE); |
| setup(); |
| |
| for (lc = 0; TEST_LOOPING(lc); lc++) { |
| tst_count = 0; |
| |
| check_vma(); |
| } |
| cleanup(); |
| tst_exit(); |
| } |
| |
| static void check_vma(void) |
| { |
| int status; |
| int topdown; |
| void *t, *u, *x; |
| |
| create_bighole(); |
| t = mmap(p, 3 * ps, PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); |
| if (t == MAP_FAILED) |
| tst_brkm(TBROK | TERRNO, cleanup, "mmap"); |
| memset(t, 1, ps); |
| |
| switch (fork()) { |
| case -1: |
| tst_brkm(TBROK | TERRNO, cleanup, "fork"); |
| case 0: |
| memset(t, 2, ps); |
| u = mmap(t + 3 * ps, 3 * ps, PROT_WRITE, |
| MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); |
| if (u == MAP_FAILED) { |
| perror("mmap"); |
| exit(255); |
| } |
| topdown = (u > t) ? 0 : 1; |
| printf("parent: t = %p\n", t); |
| printf("child : u = %p\n", u); |
| memset(u, 2, ps); |
| |
| if (topdown) { |
| x = get_end_addr(u); |
| printf("child : x = %p\n", x); |
| if (x == t + 3 * ps) |
| exit(1); |
| else if (x == t && get_end_addr(x) == t + 3 * ps) |
| exit(0); |
| } else { |
| x = get_end_addr(t); |
| printf("child : x = %p\n", x); |
| if (x == t + 6 * ps) |
| exit(1); |
| else if (x == u && get_end_addr(x) == t + 6 * ps) |
| exit(0); |
| } |
| exit(255); |
| default: |
| if (waitpid(-1, &status, 0) == -1) |
| tst_brkm(TBROK | TERRNO, cleanup, "waitpid"); |
| if (!WIFEXITED(status)) |
| tst_brkm(TBROK, cleanup, "child exited abnormally."); |
| check_status(WEXITSTATUS(status)); |
| break; |
| } |
| } |
| |
| static void create_bighole(void) |
| { |
| void *t; |
| |
| /* |
| * |-3*ps-| |
| * |------|------|------| hole |
| * t p |
| * |======|------| top-down alloc |
| * |------|======| bottom-up alloc |
| */ |
| t = mmap(NULL, 9 * ps, PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); |
| if (t == MAP_FAILED) |
| tst_brkm(TBROK | TERRNO, cleanup, "mmap"); |
| memset(t, 'a', ps); |
| p = t + 3 * ps; |
| if (munmap(t, 9 * ps) == -1) |
| tst_brkm(TBROK | TERRNO, cleanup, "munmap"); |
| } |
| |
| static void *get_end_addr(void *addr_s) |
| { |
| FILE *fp; |
| void *s, *t; |
| char buf[BUFSIZ]; |
| |
| fp = fopen(MAPS_FILE, "r"); |
| if (fp == NULL) |
| tst_brkm(TBROK | TERRNO, cleanup, "fopen"); |
| while (fgets(buf, BUFSIZ, fp) != NULL) { |
| if (sscanf(buf, "%p-%p ", &s, &t) != 2) |
| continue; |
| if (addr_s == s) { |
| tst_resm(TINFO, "s = %p, t = %p", s, t); |
| fclose(fp); |
| return t; |
| } |
| } |
| fclose(fp); |
| tst_brkm(TBROK, cleanup, "no matched s = %p found.", addr_s); |
| } |
| |
| static void check_status(int status) |
| { |
| switch (status) { |
| case 0: |
| tst_resm(TPASS, "two 3*ps VMAs found."); |
| break; |
| case 1: |
| if (tst_kvercmp(3, 0, 0) < 0) { |
| tst_resm(TCONF, "A single 6*ps VMA found. You may need" |
| " to back port kernel commit 965f55d " |
| "to fix this scalability issue."); |
| } else { |
| tst_resm(TFAIL, "A single 6*ps VMA found."); |
| } |
| break; |
| default: |
| tst_brkm(TBROK, cleanup, "unexpected VMA found."); |
| } |
| } |
| |
| static void setup(void) |
| { |
| tst_sig(FORK, DEF_HANDLER, cleanup); |
| |
| TEST_PAUSE; |
| } |
| |
| static void cleanup(void) |
| { |
| } |