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path: root/arch/x86/kernel/cpu/mtrr/if.c
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Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/if.c')
-rw-r--r--arch/x86/kernel/cpu/mtrr/if.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index 08b6ea4..3c1b12d 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -96,17 +96,24 @@ mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
unsigned long long base, size;
char *ptr;
char line[LINE_SIZE];
+ int length;
size_t linelen;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- if (!len)
- return -EINVAL;
memset(line, 0, LINE_SIZE);
- if (len > LINE_SIZE)
- len = LINE_SIZE;
- if (copy_from_user(line, buf, len - 1))
+
+ length = len;
+ length--;
+
+ if (length > LINE_SIZE - 1)
+ length = LINE_SIZE - 1;
+
+ if (length < 0)
+ return -EINVAL;
+
+ if (copy_from_user(line, buf, length))
return -EFAULT;
linelen = strlen(line);
@@ -126,8 +133,8 @@ mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
return -EINVAL;
base = simple_strtoull(line + 5, &ptr, 0);
- for (; isspace(*ptr); ++ptr)
- ;
+ while (isspace(*ptr))
+ ptr++;
if (strncmp(ptr, "size=", 5))
return -EINVAL;
@@ -135,14 +142,14 @@ mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
size = simple_strtoull(ptr + 5, &ptr, 0);
if ((base & 0xfff) || (size & 0xfff))
return -EINVAL;
- for (; isspace(*ptr); ++ptr)
- ;
+ while (isspace(*ptr))
+ ptr++;
if (strncmp(ptr, "type=", 5))
return -EINVAL;
ptr += 5;
- for (; isspace(*ptr); ++ptr)
- ;
+ while (isspace(*ptr))
+ ptr++;
for (i = 0; i < MTRR_NUM_TYPES; ++i) {
if (strcmp(ptr, mtrr_strings[i]))
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