From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e3.ny.us.ibm.com (e3.ny.us.ibm.com [32.97.182.143]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e3.ny.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id B5700DDFB7 for ; Thu, 24 Jul 2008 05:11:02 +1000 (EST) Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e3.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m6NJAnmb011844 for ; Wed, 23 Jul 2008 15:10:49 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v9.0) with ESMTP id m6NJAlnV119300 for ; Wed, 23 Jul 2008 15:10:47 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m6NJAlE5012493 for ; Wed, 23 Jul 2008 15:10:47 -0400 Received: from austin.ibm.com (netmail2.austin.ibm.com [9.41.248.176]) by d01av03.pok.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id m6NJAlbM012438 for ; Wed, 23 Jul 2008 15:10:47 -0400 Received: from [9.65.41.135] (sig-9-65-41-135.mts.ibm.com [9.65.41.135]) by austin.ibm.com (8.13.8/8.12.10) with ESMTP id m6NJAkoX029704 for ; Wed, 23 Jul 2008 14:10:46 -0500 Message-ID: <48878236.9020605@austin.ibm.com> Date: Wed, 23 Jul 2008 14:10:46 -0500 From: Nathan Fontenot MIME-Version: 1.0 To: linuxppc-dev@ozlabs.org Subject: [PATCH] Remove kmalloc call in handling writes to lparcfg Content-Type: text/plain; charset=ISO-8859-1; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , There are only 4 valid name=value pairs for writes to /proc/ppc64/lparcfg. Current code allocates a buffer to copy this information in from the user. Since the longest name=value pair will easily fit into a buffer of 64 characters, simply put the buffer on the stack instead of allocating the buffer. NOTE: This patch applies on top of the CMO patches. Signed-off-by: Nathan Fotenot --- Index: linux-2.6.git/arch/powerpc/kernel/lparcfg.c =================================================================== --- linux-2.6.git.orig/arch/powerpc/kernel/lparcfg.c 2008-07-22 13:17:40.000000000 -0500 +++ linux-2.6.git/arch/powerpc/kernel/lparcfg.c 2008-07-23 13:40:50.000000000 -0500 @@ -573,29 +573,27 @@ static ssize_t lparcfg_write(struct file *file, const char __user * buf, size_t count, loff_t * off) { - char *kbuf; + int kbuf_sz = 64; + char kbuf[kbuf_sz]; char *tmp; u64 new_entitled, *new_entitled_ptr = &new_entitled; u8 new_weight, *new_weight_ptr = &new_weight; - ssize_t retval = -ENOMEM; + ssize_t retval; if (!firmware_has_feature(FW_FEATURE_SPLPAR) || firmware_has_feature(FW_FEATURE_ISERIES)) return -EINVAL; - kbuf = kmalloc(count, GFP_KERNEL); - if (!kbuf) - goto out; + if (count > kbuf_sz) + return -EINVAL; - retval = -EFAULT; if (copy_from_user(kbuf, buf, count)) - goto out; + return -EFAULT; - retval = -EINVAL; kbuf[count - 1] = '\0'; tmp = strchr(kbuf, '='); if (!tmp) - goto out; + return -EINVAL; *tmp++ = '\0'; @@ -603,32 +601,32 @@ char *endp; *new_entitled_ptr = (u64) simple_strtoul(tmp, &endp, 10); if (endp == tmp) - goto out; + return -EINVAL; retval = update_ppp(new_entitled_ptr, NULL); } else if (!strcmp(kbuf, "capacity_weight")) { char *endp; *new_weight_ptr = (u8) simple_strtoul(tmp, &endp, 10); if (endp == tmp) - goto out; + return -EINVAL; retval = update_ppp(NULL, new_weight_ptr); } else if (!strcmp(kbuf, "entitled_memory")) { char *endp; *new_entitled_ptr = (u64) simple_strtoul(tmp, &endp, 10); if (endp == tmp) - goto out; + return -EINVAL; retval = update_mpp(new_entitled_ptr, NULL); } else if (!strcmp(kbuf, "entitled_memory_weight")) { char *endp; *new_weight_ptr = (u8) simple_strtoul(tmp, &endp, 10); if (endp == tmp) - goto out; + return -EINVAL; retval = update_mpp(NULL, new_weight_ptr); } else - goto out; + return -EINVAL; if (retval == H_SUCCESS || retval == H_CONSTRAINED) { retval = count; @@ -644,8 +642,6 @@ retval = -EIO; } -out: - kfree(kbuf); return retval; }