Just setup RLIMIT_DATA limit and play with anon memory accounting. CC: Quentin Casasnovas <quentin.casasnovas@xxxxxxxxxx> CC: Vegard Nossum <vegard.nossum@xxxxxxxxxx> CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> CC: Willy Tarreau <w@xxxxxx> CC: Andy Lutomirski <luto@xxxxxxxxxxxxxx> CC: Kees Cook <keescook@xxxxxxxxxx> CC: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> CC: Konstantin Khlebnikov <koct9i@xxxxxxxxx> CC: Pavel Emelyanov <xemul@xxxxxxxxxxxxx> CC: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> CC: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx> --- tools/testing/selftests/vm/Makefile | 1 tools/testing/selftests/vm/rlimit-data.c | 201 +++++++++++++++++++++++++++++++ tools/testing/selftests/vm/run_vmtests | 4 3 files changed, 204 insertions(+), 2 deletions(-) Index: linux-ml.git/tools/testing/selftests/vm/Makefile =================================================================== --- linux-ml.git.orig/tools/testing/selftests/vm/Makefile +++ linux-ml.git/tools/testing/selftests/vm/Makefile @@ -10,6 +10,7 @@ BINARIES += on-fault-limit BINARIES += thuge-gen BINARIES += transhuge-stress BINARIES += userfaultfd +BINARIES += rlimit-data all: $(BINARIES) %: %.c Index: linux-ml.git/tools/testing/selftests/vm/rlimit-data.c =================================================================== --- /dev/null +++ linux-ml.git/tools/testing/selftests/vm/rlimit-data.c @@ -0,0 +1,201 @@ +/* + * rlimit-data: + * + * Test that RLIMIT_DATA accounts anonymous + * memory correctly. + */ + +#define _GNU_SOURCE + +#include <stdlib.h> +#include <stdio.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> +#include <string.h> +#include <stdbool.h> + +#include <sys/resource.h> +#include <sys/syscall.h> +#include <sys/mman.h> + +#define pr_info(fmt, ...) \ + fprintf(stdout, fmt, ##__VA_ARGS__) +#define pr_err(fmt, ...) \ + fprintf(stderr, "ERROR: " fmt, ##__VA_ARGS__) +#define pr_perror(fmt, ...) \ + fprintf(stderr, "ERROR: " fmt ": %s\n", ##__VA_ARGS__, \ + strerror(errno)) + +#define mmap_anon(__addr, __size) \ + mmap(__addr, __size, PROT_READ | PROT_WRITE, \ + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0) + +static const char self_status_path[] = "/proc/self/status"; +static int fd_status = -1; +static size_t page_size; + +static const char tplt[] = "VmAnon:"; +static const size_t tplt_len = sizeof(tplt) - 1; + +static int get_self_anon_vm(int fd, unsigned long *npages) +{ + FILE *f = fdopen(fd, "r"); + bool found = false; + char buf[1024]; + + if (!f) { + pr_perror("Can't open status"); + return -1; + } + + setbuffer(f, NULL, 0); + rewind(f); + while (fgets(buf, sizeof(buf), f)) { + if (strncmp(buf, tplt, tplt_len)) + continue; + *npages = (atol(&buf[tplt_len + 1]) << 10) / page_size; + found = true; + break; + } + + if (!found) + pr_err("No data found in status\n"); + return found ? 0 : -1; +} + +int main(int argc, char *argv[]) +{ + unsigned long npages_cur = 0, npages_new = 0; + unsigned long npages_init = 0; + int ret = 1, match; + struct rlimit lim; + + void *mem, *mem_new; + size_t size; + + size_t shmem_size; + void *shmem; + + page_size = getpagesize(); + + if (getrlimit(RLIMIT_DATA, &lim)) { + pr_perror("Can't get rlimit data"); + return 1; + } + + fd_status = open(self_status_path, O_RDONLY); + if (fd_status < 0) { + pr_perror("Can't open %s", self_status_path); + return 1; + } + + if (get_self_anon_vm(fd_status, &npages_init)) + goto err; + pr_info("Initial anon pages %lu\n", npages_init); + + /* + * Map first chunk. + */ + size = page_size * 10; + mem = mmap_anon(NULL, size); + if (mem == MAP_FAILED) { + pr_perror("Can't map first chunk"); + goto err; + } + if (get_self_anon_vm(fd_status, &npages_cur)) + goto err; + pr_info("Mapped %zu bytes %lu pages, parsed %lu\n", + size, size / page_size, npages_cur); + + if (npages_cur <= (npages_init + 10)) { + pr_err("Parsed number of pages is too small\n"); + goto err; + } + + /* + * Allow up to more 80K of anon data. + */ + lim.rlim_cur = (80 << 10) + npages_init * page_size; + lim.rlim_max = RLIM_INFINITY; + if (setrlimit(RLIMIT_DATA, &lim)) { + pr_perror("Can't setup limit to %lu bytes", + (unsigned long)lim.rlim_cur); + goto err; + } + + /* + * This one should fail. + */ + mem_new = mmap_anon(NULL, lim.rlim_cur); + if (mem_new != MAP_FAILED) { + pr_err("RLIMIT_DATA didn't catch the overrflow\n"); + goto err; + } + + /* + * Shrink it. + */ + mem_new = mremap(mem, size, size / 2, MREMAP_MAYMOVE); + if (!mem_new) { + pr_perror("Can't shrink memory"); + goto err; + } + size /= 2; + mem = mem_new; + + if (get_self_anon_vm(fd_status, &npages_cur)) + goto err; + pr_info("Remapped %zu bytes %lu pages, parsed %lu\n", + size, size / page_size, npages_cur); + + if (npages_cur <= (npages_init + 5)) { + pr_err("Parsed number of pages is too small\n"); + goto err; + } + + /* + * Test via sbrk. + */ + mem_new = sbrk(0); + pr_info("Current brk %p\n", sbrk(0)); + mem_new = sbrk(page_size); + if (mem_new != (void *)-1) { + if (get_self_anon_vm(fd_status, &npages_cur)) + goto err; + + /* + * Allow up to two pages. + */ + lim.rlim_cur = (npages_cur + 3) * page_size; + lim.rlim_max = RLIM_INFINITY; + if (setrlimit(RLIMIT_DATA, &lim)) { + pr_perror("Can't setup limit to %lu bytes", + (unsigned long)lim.rlim_cur); + goto err; + } + + pr_info("Allocating 3 pages, must pass..."); + mem_new = sbrk(page_size * 3); + if (mem_new == (void *)-1) { + pr_err("Can't allocate pages while should\n"); + goto err; + } else + pr_info("OK\n"); + + pr_info("Allocating 1 pages, must fail..."); + mem_new = sbrk(page_size); + if (mem_new != (void *)-1) { + pr_err("Allocated page while should not\n"); + goto err; + } else + pr_info("OK\n"); + } + + ret = 0; +err: + if (mem) + munmap(mem, size); + close(fd_status); + return ret; +} Index: linux-ml.git/tools/testing/selftests/vm/run_vmtests =================================================================== --- linux-ml.git.orig/tools/testing/selftests/vm/run_vmtests +++ linux-ml.git/tools/testing/selftests/vm/run_vmtests @@ -131,9 +131,9 @@ else fi echo "--------------------" -echo "running mlock2-tests" +echo "running rlimit-data" echo "--------------------" -./mlock2-tests +./rlimit-data if [ $? 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