[coreboot-gerrit] Change in coreboot[master]: libpayload: Clean up unaligned memset() support

[Nico Huber (Code Review)]

Nico Huber has uploaded this change for review. ( https://review.coreboot.org/20750


Change subject: libpayload: Clean up unaligned memset() support
......................................................................

libpayload: Clean up unaligned memset() support

Use a `for` instead of a `while` loop and use meaningful identifiers.
Also, don't use more than one variable for one and the same purpose,
don't use more (non-const) variables than necessary, don't alter more
than one variable per statement, don't compare pointers of different
types and don't do pointer arithmetic on `void *`.

This was meant as a fix up to a regression but that has already been
fixed.

Change-Id: I0c8fd118d127a26cfcf68bfb0bf681495821e80a
Signed-off-by: Nico Huber <nico.huber at secunet.com>
---
M payloads/libpayload/libc/memory.c
1 file changed, 10 insertions(+), 12 deletions(-)



  git pull ssh://review.coreboot.org:29418/coreboot refs/changes/50/20750/1

diff --git a/payloads/libpayload/libc/memory.c b/payloads/libpayload/libc/memory.c
index 8d0172c..25c2b3a 100644
--- a/payloads/libpayload/libc/memory.c
+++ b/payloads/libpayload/libc/memory.c
@@ -33,31 +33,29 @@
 
 #include <libpayload.h>
 
-static void *default_memset(void *s, int c, size_t n)
+static void *default_memset(void *const s, const int c, size_t n)
 {
 	size_t i;
-	void *ret = s;
+	u8 *dst = s;
 	unsigned long w = c & 0xff;
-	u8 *p = s;
 
-	s = (void *)ALIGN_UP((uintptr_t)s, sizeof(unsigned long));
-	while (p != (u8 *)s && n) {
-		*p++ = c;
-		n--;
-	}
+	const u8 *const aligned_start =
+		(const u8 *)ALIGN_UP((uintptr_t)dst, sizeof(unsigned long));
+	for (; n > 0 && dst != aligned_start; --n, ++dst)
+		*dst = (u8)c;
 
 	for (i = 1; i < sizeof(unsigned long); i <<= 1)
 		w = (w << (i * 8)) | w;
 
 	for (i = 0; i < n / sizeof(unsigned long); i++)
-		((unsigned long *)s)[i] = w;
+		((unsigned long *)dst)[i] = w;
 
-	s += i * sizeof(unsigned long);
+	dst += i * sizeof(unsigned long);
 
 	for (i = 0; i < n % sizeof(unsigned long); i++)
-		((u8 *)s)[i] = (u8)c;
+		dst[i] = (u8)c;
 
-	return ret;
+	return s;
 }
 
 void *memset(void *s, int c, size_t n)

-- 
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Gerrit-Project: coreboot
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: I0c8fd118d127a26cfcf68bfb0bf681495821e80a
Gerrit-Change-Number: 20750
Gerrit-PatchSet: 1
Gerrit-Owner: Nico Huber <nico.h at gmx.de>
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