The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: bec500777089b3c96c53681fc0aa6fee59711d4a
Gitweb:
https://git.kernel.org/tip/bec500777089b3c96c53681fc0aa6fee59711d4a
Author: Arvind Sankar <nived...@alum.mit.edu>
AuthorDate: Mon, 07 Oct 2019 18:00:02 -04:00
Committer: Ingo Molnar <mi...@kernel.org>
CommitterDate: Tue, 08 Oct 2019 13:27:05 +02:00
lib/string: Make memzero_explicit() inline instead of external
With the use of the barrier implied by barrier_data(), there is no need
for memzero_explicit() to be extern. Making it inline saves the overhead
of a function call, and allows the code to be reused in arch/*/purgatory
without having to duplicate the implementation.
Tested-by: Hans de Goede <hdego...@redhat.com>
Signed-off-by: Arvind Sankar <nived...@alum.mit.edu>
Reviewed-by: Hans de Goede <hdego...@redhat.com>
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
Cc: Borislav Petkov <b...@alien8.de>
Cc: H . Peter Anvin <h...@zytor.com>
Cc: Herbert Xu <herb...@gondor.apana.org.au>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Stephan Mueller <smuel...@chronox.de>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: linux-cry...@vger.kernel.org
Cc: linux-s...@vger.kernel.org
Fixes: 906a4bb97f5d ("crypto: sha256 - Use get/put_unaligned_be32 to get input,
memzero_explicit")
Link: https://lkml.kernel.org/r/20191007220000.ga408...@rani.riverdale.lan
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
include/linux/string.h | 21 ++++++++++++++++++++-
lib/string.c | 21 ---------------------
2 files changed, 20 insertions(+), 22 deletions(-)
diff --git a/include/linux/string.h b/include/linux/string.h
index b2f9df7..b6ccdc2 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.
diff --git a/lib/string.c b/lib/string.c
index cd7a10c..08ec58c 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -748,27 +748,6 @@ void *memset(void *s, int c, size_t count)
EXPORT_SYMBOL(memset);
#endif
-/**
- * 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.
- */
-void memzero_explicit(void *s, size_t count)
-{
- memset(s, 0, count);
- barrier_data(s);
-}
-EXPORT_SYMBOL(memzero_explicit);
-
#ifndef __HAVE_ARCH_MEMSET16
/**
* memset16() - Fill a memory area with a uint16_t
