From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELv5e4RYqnnwiDkZPw1oJLcspTenRxgy07F22MyUPrCako9RSlLaUdUPhHjL4CxHJAmWLtU1 ARC-Seal: i=1; a=rsa-sha256; t=1521215088; cv=none; d=google.com; s=arc-20160816; b=tYT0CiZzZoF2i6ljpbhFxD2RuAfo5QE+bj8suYh+r9YuEy+BbHJZBovAI184kDvYM3 OnlEqoRoG+I3CUnQX+r/ioTKv+PnnrNPsub+/vUHF2MYt312WC8sz58aW8tYs/gCQWwf 19AS+QFKtpxFuDjZSLJ+iT+3hwzGodotirsijW+O05iyl0gc/JRvdIymGjmJjReFsSIP q0kHRc7q3iPGEhIIAYmIKjnY6Pzos2aTOZQsTZlGFrtuQNSJGIdnUDjZ/Jon0ztUYbuN 7SA3Puyh4r87zYK8sxzjhbqwjijnOEaIs7dHSFnRwhjj/EHD0NyByIYQPOikFCkKQ0gF UhCA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=hcZnsrdDq3dWrDVr44dYCMwrN68nTXny5lmf2v5dudA=; b=WXr0Hee5BaaGKOXeEYaAJcUECwc0mh1EG3JzDx8jVd8boCHH7Y6mG4CkGtA094dG2Y lsek5x8/TfBpTc1j5TgC+zdTVJTmKdJ6VMzsVSmqW+xislunU3as6BUi3FcfIQR2fUGi NiVYfDKV5yTzE3ZpcTaUBNfvO4JGIjKyx0LuBvz/RH48U9X+n3GgxM9Xej14qGCSMjOw pvqmecQDS8/uEiQLiWF7GakJlhYdxRqHosbcu8AonMnGDfjEJHrz4hF1813morSa1PEz aN7wV/r73nAZCv4sCSYQNUq4TgmuupoDHBIVGlpXw28WH/aHKVEbZW86uQPjze6PLnzM zJ+g== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jeremy Linton , Davidlohr Bueso , "Paul E. McKenney" , Sasha Levin Subject: [PATCH 4.15 124/128] locking/locktorture: Fix num reader/writer corner cases Date: Fri, 16 Mar 2018 16:24:25 +0100 Message-Id: <20180316152342.593559836@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180316152336.199007505@linuxfoundation.org> References: <20180316152336.199007505@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1595109267893386747?= X-GMAIL-MSGID: =?utf-8?q?1595109632669964203?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Davidlohr Bueso [ Upstream commit 2ce77d16db4240dd2e422fc0a5c26d3e2ec03446 ] Things can explode for locktorture if the user does combinations of nwriters_stress=0 nreaders_stress=0. Fix this by not assuming we always want to torture writer threads. Reported-by: Jeremy Linton Signed-off-by: Davidlohr Bueso Signed-off-by: Paul E. McKenney Reviewed-by: Jeremy Linton Tested-by: Jeremy Linton Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/locking/locktorture.c | 76 ++++++++++++++++++++++++------------------- 1 file changed, 44 insertions(+), 32 deletions(-) --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -715,8 +715,7 @@ static void __torture_print_stats(char * { bool fail = 0; int i, n_stress; - long max = 0; - long min = statp[0].n_lock_acquired; + long max = 0, min = statp ? statp[0].n_lock_acquired : 0; long long sum = 0; n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; @@ -823,7 +822,7 @@ static void lock_torture_cleanup(void) * such, only perform the underlying torture-specific cleanups, * and avoid anything related to locktorture. */ - if (!cxt.lwsa) + if (!cxt.lwsa && !cxt.lrsa) goto end; if (writer_tasks) { @@ -898,6 +897,13 @@ static int __init lock_torture_init(void firsterr = -EINVAL; goto unwind; } + + if (nwriters_stress == 0 && nreaders_stress == 0) { + pr_alert("lock-torture: must run at least one locking thread\n"); + firsterr = -EINVAL; + goto unwind; + } + if (cxt.cur_ops->init) cxt.cur_ops->init(); @@ -921,17 +927,19 @@ static int __init lock_torture_init(void #endif /* Initialize the statistics so that each run gets its own numbers. */ + if (nwriters_stress) { + lock_is_write_held = 0; + cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL); + if (cxt.lwsa == NULL) { + VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); + firsterr = -ENOMEM; + goto unwind; + } - lock_is_write_held = 0; - cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL); - if (cxt.lwsa == NULL) { - VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); - firsterr = -ENOMEM; - goto unwind; - } - for (i = 0; i < cxt.nrealwriters_stress; i++) { - cxt.lwsa[i].n_lock_fail = 0; - cxt.lwsa[i].n_lock_acquired = 0; + for (i = 0; i < cxt.nrealwriters_stress; i++) { + cxt.lwsa[i].n_lock_fail = 0; + cxt.lwsa[i].n_lock_acquired = 0; + } } if (cxt.cur_ops->readlock) { @@ -948,19 +956,21 @@ static int __init lock_torture_init(void cxt.nrealreaders_stress = cxt.nrealwriters_stress; } - lock_is_read_held = 0; - cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL); - if (cxt.lrsa == NULL) { - VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); - firsterr = -ENOMEM; - kfree(cxt.lwsa); - cxt.lwsa = NULL; - goto unwind; - } - - for (i = 0; i < cxt.nrealreaders_stress; i++) { - cxt.lrsa[i].n_lock_fail = 0; - cxt.lrsa[i].n_lock_acquired = 0; + if (nreaders_stress) { + lock_is_read_held = 0; + cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL); + if (cxt.lrsa == NULL) { + VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); + firsterr = -ENOMEM; + kfree(cxt.lwsa); + cxt.lwsa = NULL; + goto unwind; + } + + for (i = 0; i < cxt.nrealreaders_stress; i++) { + cxt.lrsa[i].n_lock_fail = 0; + cxt.lrsa[i].n_lock_acquired = 0; + } } } @@ -990,12 +1000,14 @@ static int __init lock_torture_init(void goto unwind; } - writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]), - GFP_KERNEL); - if (writer_tasks == NULL) { - VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); - firsterr = -ENOMEM; - goto unwind; + if (nwriters_stress) { + writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]), + GFP_KERNEL); + if (writer_tasks == NULL) { + VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); + firsterr = -ENOMEM; + goto unwind; + } } if (cxt.cur_ops->readlock) {