[PATCH 4.9 011/101] kdb: use memmove instead of overlapping memcpy

From: Greg Kroah-Hartman
Date: Thu Dec 06 2018 - 09:44:14 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Arnd Bergmann <arnd@xxxxxxxx>

commit 2cf2f0d5b91fd1b06a6ae260462fc7945ea84add upstream.

gcc discovered that the memcpy() arguments in kdbnearsym() overlap, so
we should really use memmove(), which is defined to handle that correctly:

In function 'memcpy',
inlined from 'kdbnearsym' at /git/arm-soc/kernel/debug/kdb/kdb_support.c:132:4:
/git/arm-soc/include/linux/string.h:353:9: error: '__builtin_memcpy' accessing 792 bytes at offsets 0 and 8 overlaps 784 bytes at offset 8 [-Werror=restrict]
return __builtin_memcpy(p, q, size);

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
kernel/debug/kdb/kdb_support.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -129,13 +129,13 @@ int kdbnearsym(unsigned long addr, kdb_s
}
if (i >= ARRAY_SIZE(kdb_name_table)) {
debug_kfree(kdb_name_table[0]);
- memcpy(kdb_name_table, kdb_name_table+1,
+ memmove(kdb_name_table, kdb_name_table+1,
sizeof(kdb_name_table[0]) *
(ARRAY_SIZE(kdb_name_table)-1));
} else {
debug_kfree(knt1);
knt1 = kdb_name_table[i];
- memcpy(kdb_name_table+i, kdb_name_table+i+1,
+ memmove(kdb_name_table+i, kdb_name_table+i+1,
sizeof(kdb_name_table[0]) *
(ARRAY_SIZE(kdb_name_table)-i-1));
}