From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: + selftest-add-mremap_dontunmap-selftest-fix.patch added to -mm tree Date: Wed, 19 Feb 2020 12:36:12 -0800 Message-ID: <20200219203612.JtjXX%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:54478 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726703AbgBSUgO (ORCPT ); Wed, 19 Feb 2020 15:36:14 -0500 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org, bgeffon@google.com, akpm@linux-foundation.org The patch titled Subject: selftest-add-mremap_dontunmap-selftest-fix has been added to the -mm tree. Its filename is selftest-add-mremap_dontunmap-selftest-fix.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/selftest-add-mremap_dontunmap-selftest-fix.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/selftest-add-mremap_dontunmap-selftest-fix.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Andrew Morton Subject: selftest-add-mremap_dontunmap-selftest-fix convert eight-spaces to hard tabs Cc: Brian Geffon Signed-off-by: Andrew Morton --- tools/testing/selftests/vm/mremap_dontunmap.c | 474 ++++++++-------- 1 file changed, 237 insertions(+), 237 deletions(-) --- a/tools/testing/selftests/vm/mremap_dontunmap.c~selftest-add-mremap_dontunmap-selftest-fix +++ a/tools/testing/selftests/vm/mremap_dontunmap.c @@ -25,10 +25,10 @@ char *page_buffer; static void dump_maps(void) { - char cmd[32]; + char cmd[32]; - snprintf(cmd, sizeof(cmd), "cat /proc/%d/maps", getpid()); - system(cmd); + snprintf(cmd, sizeof(cmd), "cat /proc/%d/maps", getpid()); + system(cmd); } #define BUG_ON(condition, description) \ @@ -36,7 +36,7 @@ static void dump_maps(void) if (condition) { \ fprintf(stderr, "[FAIL]\t%s():%d\t%s:%s\n", __func__, \ __LINE__, (description), strerror(errno)); \ - dump_maps(); \ + dump_maps(); \ exit(1); \ } \ } while (0) @@ -45,87 +45,87 @@ static void dump_maps(void) // reporting tests as failed when it's run on an older kernel. static int kernel_support_for_mremap_dontunmap() { - int ret = 0; - unsigned long num_pages = 1; - void *source_mapping = mmap(NULL, num_pages * page_size, PROT_NONE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - BUG_ON(source_mapping == MAP_FAILED, "mmap"); - - // This simple remap should only fail if MREMAP_DONTUNMAP isn't - // supported. - void *dest_mapping = - mremap(source_mapping, num_pages * page_size, num_pages * page_size, - MREMAP_DONTUNMAP | MREMAP_MAYMOVE, 0); - if (dest_mapping == MAP_FAILED) { - ret = errno; - } else { - BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1, - "unable to unmap destination mapping"); - } - - BUG_ON(munmap(source_mapping, num_pages * page_size) == -1, - "unable to unmap source mapping"); - return ret; + int ret = 0; + unsigned long num_pages = 1; + void *source_mapping = mmap(NULL, num_pages * page_size, PROT_NONE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + BUG_ON(source_mapping == MAP_FAILED, "mmap"); + + // This simple remap should only fail if MREMAP_DONTUNMAP isn't + // supported. + void *dest_mapping = + mremap(source_mapping, num_pages * page_size, num_pages * page_size, + MREMAP_DONTUNMAP | MREMAP_MAYMOVE, 0); + if (dest_mapping == MAP_FAILED) { + ret = errno; + } else { + BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1, + "unable to unmap destination mapping"); + } + + BUG_ON(munmap(source_mapping, num_pages * page_size) == -1, + "unable to unmap source mapping"); + return ret; } // This helper will just validate that an entire mapping contains the expected // byte. static int check_region_contains_byte(void *addr, unsigned long size, char byte) { - BUG_ON(size & (page_size - 1), - "check_region_contains_byte expects page multiples"); - BUG_ON((unsigned long)addr & (page_size - 1), - "check_region_contains_byte expects page alignment"); - - memset(page_buffer, byte, page_size); - - unsigned long num_pages = size / page_size; - unsigned long i; - - // Compare each page checking that it contains our expected byte. - for (i = 0; i < num_pages; ++i) { - int ret = - memcmp(addr + (i * page_size), page_buffer, page_size); - if (ret) { - return ret; - } - } + BUG_ON(size & (page_size - 1), + "check_region_contains_byte expects page multiples"); + BUG_ON((unsigned long)addr & (page_size - 1), + "check_region_contains_byte expects page alignment"); + + memset(page_buffer, byte, page_size); + + unsigned long num_pages = size / page_size; + unsigned long i; + + // Compare each page checking that it contains our expected byte. + for (i = 0; i < num_pages; ++i) { + int ret = + memcmp(addr + (i * page_size), page_buffer, page_size); + if (ret) { + return ret; + } + } - return 0; + return 0; } // this test validates that MREMAP_DONTUNMAP moves the pagetables while leaving // the source mapping mapped. static void mremap_dontunmap_simple() { - unsigned long num_pages = 5; + unsigned long num_pages = 5; - void *source_mapping = - mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - BUG_ON(source_mapping == MAP_FAILED, "mmap"); - - memset(source_mapping, 'a', num_pages * page_size); - - // Try to just move the whole mapping anywhere (not fixed). - void *dest_mapping = - mremap(source_mapping, num_pages * page_size, num_pages * page_size, - MREMAP_DONTUNMAP | MREMAP_MAYMOVE, NULL); - BUG_ON(dest_mapping == MAP_FAILED, "mremap"); - - // Validate that the pages have been moved, we know they were moved if - // the dest_mapping contains a's. - BUG_ON(check_region_contains_byte - (dest_mapping, num_pages * page_size, 'a') != 0, - "pages did not migrate"); - BUG_ON(check_region_contains_byte - (source_mapping, num_pages * page_size, 0) != 0, - "source should have no ptes"); - - BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1, - "unable to unmap destination mapping"); - BUG_ON(munmap(source_mapping, num_pages * page_size) == -1, - "unable to unmap source mapping"); + void *source_mapping = + mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + BUG_ON(source_mapping == MAP_FAILED, "mmap"); + + memset(source_mapping, 'a', num_pages * page_size); + + // Try to just move the whole mapping anywhere (not fixed). + void *dest_mapping = + mremap(source_mapping, num_pages * page_size, num_pages * page_size, + MREMAP_DONTUNMAP | MREMAP_MAYMOVE, NULL); + BUG_ON(dest_mapping == MAP_FAILED, "mremap"); + + // Validate that the pages have been moved, we know they were moved if + // the dest_mapping contains a's. + BUG_ON(check_region_contains_byte + (dest_mapping, num_pages * page_size, 'a') != 0, + "pages did not migrate"); + BUG_ON(check_region_contains_byte + (source_mapping, num_pages * page_size, 0) != 0, + "source should have no ptes"); + + BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1, + "unable to unmap destination mapping"); + BUG_ON(munmap(source_mapping, num_pages * page_size) == -1, + "unable to unmap source mapping"); } // This test validates MREMAP_DONTUNMAP will move page tables to a specific @@ -133,194 +133,194 @@ static void mremap_dontunmap_simple() // remains intact. static void mremap_dontunmap_simple_fixed() { - unsigned long num_pages = 5; + unsigned long num_pages = 5; - // Since we want to guarantee that we can remap to a point, we will - // create a mapping up front. - void *dest_mapping = - mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - BUG_ON(dest_mapping == MAP_FAILED, "mmap"); - memset(dest_mapping, 'X', num_pages * page_size); - - void *source_mapping = - mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - BUG_ON(source_mapping == MAP_FAILED, "mmap"); - memset(source_mapping, 'a', num_pages * page_size); - - void *remapped_mapping = - mremap(source_mapping, num_pages * page_size, num_pages * page_size, - MREMAP_FIXED | MREMAP_DONTUNMAP | MREMAP_MAYMOVE, - dest_mapping); - BUG_ON(remapped_mapping == MAP_FAILED, "mremap"); - BUG_ON(remapped_mapping != dest_mapping, - "mremap should have placed the remapped mapping at dest_mapping"); - - // The dest mapping will have been unmap by mremap so we expect the Xs - // to be gone and replaced with a's. - BUG_ON(check_region_contains_byte - (dest_mapping, num_pages * page_size, 'a') != 0, - "pages did not migrate"); - - // And the source mapping will have had its ptes dropped. - BUG_ON(check_region_contains_byte - (source_mapping, num_pages * page_size, 0) != 0, - "source should have no ptes"); - - BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1, - "unable to unmap destination mapping"); - BUG_ON(munmap(source_mapping, num_pages * page_size) == -1, - "unable to unmap source mapping"); + // Since we want to guarantee that we can remap to a point, we will + // create a mapping up front. + void *dest_mapping = + mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + BUG_ON(dest_mapping == MAP_FAILED, "mmap"); + memset(dest_mapping, 'X', num_pages * page_size); + + void *source_mapping = + mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + BUG_ON(source_mapping == MAP_FAILED, "mmap"); + memset(source_mapping, 'a', num_pages * page_size); + + void *remapped_mapping = + mremap(source_mapping, num_pages * page_size, num_pages * page_size, + MREMAP_FIXED | MREMAP_DONTUNMAP | MREMAP_MAYMOVE, + dest_mapping); + BUG_ON(remapped_mapping == MAP_FAILED, "mremap"); + BUG_ON(remapped_mapping != dest_mapping, + "mremap should have placed the remapped mapping at dest_mapping"); + + // The dest mapping will have been unmap by mremap so we expect the Xs + // to be gone and replaced with a's. + BUG_ON(check_region_contains_byte + (dest_mapping, num_pages * page_size, 'a') != 0, + "pages did not migrate"); + + // And the source mapping will have had its ptes dropped. + BUG_ON(check_region_contains_byte + (source_mapping, num_pages * page_size, 0) != 0, + "source should have no ptes"); + + BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1, + "unable to unmap destination mapping"); + BUG_ON(munmap(source_mapping, num_pages * page_size) == -1, + "unable to unmap source mapping"); } // This test validates that we can MREMAP_DONTUNMAP for a portion of an // existing mapping. static void mremap_dontunmap_partial_mapping() { - /* - * source mapping: - * -------------- - * | aaaaaaaaaa | - * -------------- - * to become: - * -------------- - * | aaaaa00000 | - * -------------- - * With the destination mapping containing 5 pages of As. - * --------- - * | aaaaa | - * --------- - */ - unsigned long num_pages = 10; - void *source_mapping = - mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - BUG_ON(source_mapping == MAP_FAILED, "mmap"); - memset(source_mapping, 'a', num_pages * page_size); - - // We will grab the last 5 pages of the source and move them. - void *dest_mapping = - mremap(source_mapping + (5 * page_size), 5 * page_size, - 5 * page_size, - MREMAP_DONTUNMAP | MREMAP_MAYMOVE, NULL); - BUG_ON(dest_mapping == MAP_FAILED, "mremap"); - - // We expect the first 5 pages of the source to contain a's and the - // final 5 pages to contain zeros. - BUG_ON(check_region_contains_byte(source_mapping, 5 * page_size, 'a') != - 0, "first 5 pages of source should have original pages"); - BUG_ON(check_region_contains_byte - (source_mapping + (5 * page_size), 5 * page_size, 0) != 0, - "final 5 pages of source should have no ptes"); - - // Finally we expect the destination to have 5 pages worth of a's. - BUG_ON(check_region_contains_byte(dest_mapping, 5 * page_size, 'a') != - 0, "dest mapping should contain ptes from the source"); - - BUG_ON(munmap(dest_mapping, 5 * page_size) == -1, - "unable to unmap destination mapping"); - BUG_ON(munmap(source_mapping, num_pages * page_size) == -1, - "unable to unmap source mapping"); + /* + * source mapping: + * -------------- + * | aaaaaaaaaa | + * -------------- + * to become: + * -------------- + * | aaaaa00000 | + * -------------- + * With the destination mapping containing 5 pages of As. + * --------- + * | aaaaa | + * --------- + */ + unsigned long num_pages = 10; + void *source_mapping = + mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + BUG_ON(source_mapping == MAP_FAILED, "mmap"); + memset(source_mapping, 'a', num_pages * page_size); + + // We will grab the last 5 pages of the source and move them. + void *dest_mapping = + mremap(source_mapping + (5 * page_size), 5 * page_size, + 5 * page_size, + MREMAP_DONTUNMAP | MREMAP_MAYMOVE, NULL); + BUG_ON(dest_mapping == MAP_FAILED, "mremap"); + + // We expect the first 5 pages of the source to contain a's and the + // final 5 pages to contain zeros. + BUG_ON(check_region_contains_byte(source_mapping, 5 * page_size, 'a') != + 0, "first 5 pages of source should have original pages"); + BUG_ON(check_region_contains_byte + (source_mapping + (5 * page_size), 5 * page_size, 0) != 0, + "final 5 pages of source should have no ptes"); + + // Finally we expect the destination to have 5 pages worth of a's. + BUG_ON(check_region_contains_byte(dest_mapping, 5 * page_size, 'a') != + 0, "dest mapping should contain ptes from the source"); + + BUG_ON(munmap(dest_mapping, 5 * page_size) == -1, + "unable to unmap destination mapping"); + BUG_ON(munmap(source_mapping, num_pages * page_size) == -1, + "unable to unmap source mapping"); } // This test validates that we can shrink an existing mapping via the normal // mremap behavior along with the MREMAP_DONTUNMAP flag. static void mremap_dontunmap_shrink_mapping() { - /* - * We shrink the source by 5 pages while remapping. - * source mapping: - * -------------- - * | aaaaaaaaaa | - * -------------- - * to become: - * --------- - * | 00000 | - * --------- - * With the destination mapping containing 5 pages of As followed by - * the original pages of Xs. - * -------------- - * | aaaaaXXXXX | - * -------------- - */ - - unsigned long num_pages = 10; - - // We use MREMAP_FIXED because we don't want the mremap to place the - // remapped mapping behind the source, if it did - // we wouldn't be able to validate that the mapping was in fact - // adjusted. - void *dest_mapping = - mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - BUG_ON(dest_mapping == MAP_FAILED, "mmap"); - memset(dest_mapping, 'X', num_pages * page_size); - - void *source_mapping = - mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - BUG_ON(source_mapping == MAP_FAILED, "mmap"); - memset(source_mapping, 'a', num_pages * page_size); - - // We are shrinking the mapping while also using MREMAP_DONTUNMAP - void *remapped_mapping = - mremap(source_mapping, num_pages * page_size, 5 * page_size, - MREMAP_FIXED | MREMAP_DONTUNMAP | MREMAP_MAYMOVE, - dest_mapping); - BUG_ON(remapped_mapping == MAP_FAILED, "mremap"); - BUG_ON(remapped_mapping != dest_mapping, - "expected mremap to place mapping at dest"); - - // The last 5 pages of source should have become unmapped while the - // first 5 remain. - unsigned char buf[5]; - int ret = mincore(source_mapping + (5 * page_size), 5 * page_size, buf); - BUG_ON((ret != -1 || (ret == -1 && errno != ENOMEM)), - "we expect -ENOMEM from mincore."); - - BUG_ON(check_region_contains_byte(source_mapping, 5 * page_size, 0) != - 0, "source should have no ptes"); - BUG_ON(check_region_contains_byte(dest_mapping, 5 * page_size, 'a') != - 0, "dest mapping should contain ptes from the source"); - - // And the second half of the destination should be unchanged. - BUG_ON(check_region_contains_byte(dest_mapping + (5 * page_size), - 5 * page_size, 'X') != 0, - "second half of dest shouldn't be touched"); - - // Cleanup - BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1, - "unable to unmap destination mapping"); - BUG_ON(munmap(source_mapping, 5 * page_size) == -1, - "unable to unmap source mapping"); + /* + * We shrink the source by 5 pages while remapping. + * source mapping: + * -------------- + * | aaaaaaaaaa | + * -------------- + * to become: + * --------- + * | 00000 | + * --------- + * With the destination mapping containing 5 pages of As followed by + * the original pages of Xs. + * -------------- + * | aaaaaXXXXX | + * -------------- + */ + + unsigned long num_pages = 10; + + // We use MREMAP_FIXED because we don't want the mremap to place the + // remapped mapping behind the source, if it did + // we wouldn't be able to validate that the mapping was in fact + // adjusted. + void *dest_mapping = + mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + BUG_ON(dest_mapping == MAP_FAILED, "mmap"); + memset(dest_mapping, 'X', num_pages * page_size); + + void *source_mapping = + mmap(NULL, num_pages * page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + BUG_ON(source_mapping == MAP_FAILED, "mmap"); + memset(source_mapping, 'a', num_pages * page_size); + + // We are shrinking the mapping while also using MREMAP_DONTUNMAP + void *remapped_mapping = + mremap(source_mapping, num_pages * page_size, 5 * page_size, + MREMAP_FIXED | MREMAP_DONTUNMAP | MREMAP_MAYMOVE, + dest_mapping); + BUG_ON(remapped_mapping == MAP_FAILED, "mremap"); + BUG_ON(remapped_mapping != dest_mapping, + "expected mremap to place mapping at dest"); + + // The last 5 pages of source should have become unmapped while the + // first 5 remain. + unsigned char buf[5]; + int ret = mincore(source_mapping + (5 * page_size), 5 * page_size, buf); + BUG_ON((ret != -1 || (ret == -1 && errno != ENOMEM)), + "we expect -ENOMEM from mincore."); + + BUG_ON(check_region_contains_byte(source_mapping, 5 * page_size, 0) != + 0, "source should have no ptes"); + BUG_ON(check_region_contains_byte(dest_mapping, 5 * page_size, 'a') != + 0, "dest mapping should contain ptes from the source"); + + // And the second half of the destination should be unchanged. + BUG_ON(check_region_contains_byte(dest_mapping + (5 * page_size), + 5 * page_size, 'X') != 0, + "second half of dest shouldn't be touched"); + + // Cleanup + BUG_ON(munmap(dest_mapping, num_pages * page_size) == -1, + "unable to unmap destination mapping"); + BUG_ON(munmap(source_mapping, 5 * page_size) == -1, + "unable to unmap source mapping"); } int main(void) { - page_size = sysconf(_SC_PAGE_SIZE); + page_size = sysconf(_SC_PAGE_SIZE); - // test for kernel support for MREMAP_DONTUNMAP skipping the test if - // not. - if (kernel_support_for_mremap_dontunmap() != 0) { + // test for kernel support for MREMAP_DONTUNMAP skipping the test if + // not. + if (kernel_support_for_mremap_dontunmap() != 0) { printf("No kernel support for MREMAP_DONTUNMAP\n"); return KSFT_SKIP; } - // Keep a page sized buffer around for when we need it. - page_buffer = - mmap(NULL, page_size, PROT_READ | PROT_WRITE, - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - BUG_ON(page_buffer == MAP_FAILED, "unable to mmap a page."); - - mremap_dontunmap_simple(); - mremap_dontunmap_simple_fixed(); - mremap_dontunmap_partial_mapping(); - mremap_dontunmap_shrink_mapping(); + // Keep a page sized buffer around for when we need it. + page_buffer = + mmap(NULL, page_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + BUG_ON(page_buffer == MAP_FAILED, "unable to mmap a page."); + + mremap_dontunmap_simple(); + mremap_dontunmap_simple_fixed(); + mremap_dontunmap_partial_mapping(); + mremap_dontunmap_shrink_mapping(); - BUG_ON(munmap(page_buffer, page_size) == -1, - "unable to unmap page buffer"); + BUG_ON(munmap(page_buffer, page_size) == -1, + "unable to unmap page buffer"); - printf("OK\n"); - return 0; + printf("OK\n"); + return 0; } _ Patches currently in -mm which might be from akpm@linux-foundation.org are mm.patch mm-add-vm_insert_pages-fix.patch net-zerocopy-use-vm_insert_pages-for-tcp-rcv-zerocopy-fix.patch selftest-add-mremap_dontunmap-selftest-fix.patch hugetlb_cgroup-add-reservation-accounting-for-private-mappings-fix.patch hugetlb_cgroup-add-accounting-for-shared-mappings-fix.patch mm-migratec-migrate-pg_readahead-flag-fix.patch linux-next-rejects.patch linux-next-git-rejects.patch linux-next-fix.patch drivers-tty-serial-sh-scic-suppress-warning.patch kernel-forkc-export-kernel_thread-to-modules.patch