mail archive of the barebox mailing list
 help / color / mirror / Atom feed
* [PATCH] ARM: lib64: Properly handle unaligned addresses in string functions
@ 2018-08-10 18:52 Andrey Smirnov
  2018-08-13  6:41 ` Sascha Hauer
  0 siblings, 1 reply; 3+ messages in thread
From: Andrey Smirnov @ 2018-08-10 18:52 UTC (permalink / raw)
  To: barebox; +Cc: Andrey Smirnov

Together FEC driver and parts of IP stack might end up trying to
memcpy() small chunks of memory from uncached (that is Device memory)
addresses that are not properly aligned, leading to data abort.

To prevent such cases, add code to guard unaligned accesses and
redirect them to byte-wise implementations which do not have the above
problem.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 arch/arm/lib64/string.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/arm/lib64/string.c b/arch/arm/lib64/string.c
index cb2633152..1b04f4487 100644
--- a/arch/arm/lib64/string.c
+++ b/arch/arm/lib64/string.c
@@ -5,9 +5,16 @@
 void *__arch_memset(void *dst, int c, __kernel_size_t size);
 void *__arch_memcpy(void * dest, const void *src, size_t count);
 
+static bool properly_aligned(const void *ptr)
+{
+	const unsigned long address = (unsigned long)ptr;
+
+	return get_cr() & CR_M && IS_ALIGNED(address, 16);
+}
+
 void *memset(void *dst, int c, __kernel_size_t size)
 {
-	if (likely(get_cr() & CR_M))
+	if (likely(properly_aligned(dst)))
 		return __arch_memset(dst, c, size);
 
 	return __default_memset(dst, c, size);
@@ -15,7 +22,7 @@ void *memset(void *dst, int c, __kernel_size_t size)
 
 void *memcpy(void * dest, const void *src, size_t count)
 {
-	if (likely(get_cr() & CR_M))
+	if (likely(properly_aligned(dest) && properly_aligned(src)))
 		return __arch_memcpy(dest, src, count);
 
 	return __default_memcpy(dest, src, count);
-- 
2.17.1


_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2018-08-13 14:17 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-08-10 18:52 [PATCH] ARM: lib64: Properly handle unaligned addresses in string functions Andrey Smirnov
2018-08-13  6:41 ` Sascha Hauer
2018-08-13 14:16   ` Andrey Smirnov

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox