From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 153/155] selftests/vm: fix map_hugetlb length used for testing read and write Date: Wed, 01 Apr 2020 21:11:51 -0700 Message-ID: <20200402041151.Oj5_LzOcN%akpm@linux-foundation.org> References: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:38956 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726136AbgDBELw (ORCPT ); Thu, 2 Apr 2020 00:11:52 -0400 In-Reply-To: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, christophe.leroy@c-s.fr, leonardo@linux.ibm.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, mpe@ellerman.id.au, shuah@kernel.org, stable@vger.kernel.org, torvalds@linux-foundation.org From: Christophe Leroy Subject: selftests/vm: fix map_hugetlb length used for testing read and write Commit fa7b9a805c79 ("tools/selftest/vm: allow choosing mem size and page size in map_hugetlb") added the possibility to change the size of memory mapped for the test, but left the read and write test using the default value. This is unnoticed when mapping a length greater than the default one, but segfaults otherwise. Fix read_bytes() and write_bytes() by giving them the real length. Also fix the call to munmap(). Link: http://lkml.kernel.org/r/9a404a13c871c4bd0ba9ede68f69a1225180dd7e.1580978385.git.christophe.leroy@c-s.fr Fixes: fa7b9a805c79 ("tools/selftest/vm: allow choosing mem size and page size in map_hugetlb") Signed-off-by: Christophe Leroy Reviewed-by: Leonardo Bras Cc: Michael Ellerman Cc: Shuah Khan Cc: Signed-off-by: Andrew Morton --- tools/testing/selftests/vm/map_hugetlb.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- a/tools/testing/selftests/vm/map_hugetlb.c~selftests-vm-fix-map_hugetlb-length-used-for-testing-read-and-write +++ a/tools/testing/selftests/vm/map_hugetlb.c @@ -45,20 +45,20 @@ static void check_bytes(char *addr) printf("First hex is %x\n", *((unsigned int *)addr)); } -static void write_bytes(char *addr) +static void write_bytes(char *addr, size_t length) { unsigned long i; - for (i = 0; i < LENGTH; i++) + for (i = 0; i < length; i++) *(addr + i) = (char)i; } -static int read_bytes(char *addr) +static int read_bytes(char *addr, size_t length) { unsigned long i; check_bytes(addr); - for (i = 0; i < LENGTH; i++) + for (i = 0; i < length; i++) if (*(addr + i) != (char)i) { printf("Mismatch at %lu\n", i); return 1; @@ -96,11 +96,11 @@ int main(int argc, char **argv) printf("Returned address is %p\n", addr); check_bytes(addr); - write_bytes(addr); - ret = read_bytes(addr); + write_bytes(addr, length); + ret = read_bytes(addr, length); /* munmap() length of MAP_HUGETLB memory must be hugepage aligned */ - if (munmap(addr, LENGTH)) { + if (munmap(addr, length)) { perror("munmap"); exit(1); } _