From: Ronnie Sahlberg Subject: [PATCH] Fix compiler warning about "cast increases required alignment" Origin: upstream, https://github.com/sahlberg/libsmb2/commit/66b098787213cda14d8fbf6e346517df2bb1fe7e Bug: https://github.com/sahlberg/libsmb2/issues/408 Last-Update: 2024-04-03 Some ISA, like ARMv6, do not support unaligned memory accesses. The cast here technically convert a the pointer target from a char to another pointer. However, as the buf field (char) is laid out after a pointer in the structure definition, the alignment for buf is forced to the same alignment as a pointer. Thus the issue with unaligned access can not happen and the workaround by re-casting the pointer via void * is safe. Signed-off-by: Ronnie Sahlberg --- lib/alloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/alloc.c b/lib/alloc.c index bd5c8aa..2c2b7be 100644 --- a/lib/alloc.c +++ b/lib/alloc.c @@ -113,7 +113,7 @@ smb2_alloc_data(struct smb2_context *smb2, void *memctx, size_t size) } #ifndef _MSC_VER - hdr = container_of(memctx, struct smb2_alloc_header, buf); + hdr = (struct smb2_alloc_header *)(void *)container_of(memctx, struct smb2_alloc_header, buf); #else { const char* __mptr = memctx; @@ -138,7 +138,7 @@ smb2_free_data(struct smb2_context *smb2, void *ptr) } #ifndef _MSC_VER - hdr = container_of(ptr, struct smb2_alloc_header, buf); + hdr = (struct smb2_alloc_header *)(void *)container_of(ptr, struct smb2_alloc_header, buf); #else { const char* __mptr = ptr; -- 2.47.2