From 7f8ec5a4f01aa7d03e94a3d99d7b5f9c02d7fe5a Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 15 May 2018 21:05:35 +0300 Subject: [PATCH] x86/mtrr: Convert to use strncpy_from_user() helper Replace the open coded string fetch from user-space with strncpy_from_user(). Signed-off-by: Andy Shevchenko Cc: Andrew Morton Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Luis R. Rodriguez Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Toshi Kani Link: http://lkml.kernel.org/r/20180515180535.89703-1-andriy.shevchenko@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/mtrr/if.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c index 42b4f2f..c610f47 100644 --- a/arch/x86/kernel/cpu/mtrr/if.c +++ b/arch/x86/kernel/cpu/mtrr/if.c @@ -106,17 +106,9 @@ mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos) memset(line, 0, LINE_SIZE); - length = len; - length--; - - if (length > LINE_SIZE - 1) - length = LINE_SIZE - 1; - + length = strncpy_from_user(line, buf, LINE_SIZE - 1); if (length < 0) - return -EINVAL; - - if (copy_from_user(line, buf, length)) - return -EFAULT; + return length; linelen = strlen(line); ptr = line + linelen - 1; -- 2.7.4