From 16c14b4621c7b6fc4611abf1f86cd78cdb1b2b03 Mon Sep 17 00:00:00 2001 From: Nathan Fontenot Date: Thu, 24 Jul 2008 05:10:46 +1000 Subject: [PATCH] powerpc/pseries: Remove kmalloc call in handling writes to lparcfg 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. Signed-off-by: Nathan Fotenot Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/lparcfg.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c index 64381a204a5..9f856a0c3e3 100644 --- a/arch/powerpc/kernel/lparcfg.c +++ b/arch/powerpc/kernel/lparcfg.c @@ -573,29 +573,27 @@ static ssize_t update_mpp(u64 *entitlement, u8 *weight) 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 @@ static ssize_t lparcfg_write(struct file *file, const char __user * buf, 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 @@ static ssize_t lparcfg_write(struct file *file, const char __user * buf, retval = -EIO; } -out: - kfree(kbuf); return retval; } -- 2.41.0