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authorLinus Torvalds <torvalds@linux-foundation.org>2019-10-12 14:46:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-10-12 14:46:14 -0700
commitfcb45a28489c981bcdab510a838fcac5c21c07e2 (patch)
tree773f81c837b86ccaad9333a63ededfc51cd10545 /include
parente9ec3588a9372dfb9b04afcddb199ad9e2be0044 (diff)
parent8d7c6ac3b2371eb1cbc9925a88f4d10efff374de (diff)
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar: "A handful of fixes: a kexec linking fix, an AMD MWAITX fix, a vmware guest support fix when built under Clang, and new CPU model number definitions" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Add Comet Lake to the Intel CPU models header lib/string: Make memzero_explicit() inline instead of external x86/cpu/vmware: Use the full form of INL in VMWARE_PORT x86/asm: Fix MWAITX C-state hint value
Diffstat (limited to 'include')
-rw-r--r--include/linux/string.h21
1 files changed, 20 insertions, 1 deletions
diff --git a/include/linux/string.h b/include/linux/string.h
index b2f9df7f0761..b6ccdc2c7f02 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -227,7 +227,26 @@ static inline bool strstarts(const char *str, const char *prefix)
}
size_t memweight(const void *ptr, size_t bytes);
-void memzero_explicit(void *s, size_t count);
+
+/**
+ * memzero_explicit - Fill a region of memory (e.g. sensitive
+ * keying data) with 0s.
+ * @s: Pointer to the start of the area.
+ * @count: The size of the area.
+ *
+ * Note: usually using memset() is just fine (!), but in cases
+ * where clearing out _local_ data at the end of a scope is
+ * necessary, memzero_explicit() should be used instead in
+ * order to prevent the compiler from optimising away zeroing.
+ *
+ * memzero_explicit() doesn't need an arch-specific version as
+ * it just invokes the one of memset() implicitly.
+ */
+static inline void memzero_explicit(void *s, size_t count)
+{
+ memset(s, 0, count);
+ barrier_data(s);
+}
/**
* kbasename - return the last part of a pathname.