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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 <nfont@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Nathan Fontenot 2008-07-24 05:10:46 +10:00 committed by Benjamin Herrenschmidt
parent 8391e42a5c
commit 16c14b4621
1 changed files with 12 additions and 16 deletions
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28
arch/powerpc/kernel/lparcfg.c
View File

@ -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;
}