Re: [PATCH] Revert "linux/types.h: remove unnecessary __bitwise__"

From: Jiri Slaby
Date: Thu May 26 2022 - 05:01:02 EST


On 25. 05. 22, 18:02, Linus Torvalds wrote:
On Wed, May 25, 2022 at 7:46 AM Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:

This reverts commit c724c866bb70cb8c607081a26823a1f0ebde4387.

Jiri Slaby reported that c724c866bb70 ("linux/types.h: remove unnecessary
__bitwise__") broke userspace, including open-iscsi, because it uses
__bitwise__.

Restore the __bitwise__ definition.

Hmm.

Presumably it's only the uapi case that actually wants to re-instate it.

And I'd rather make that "__bitwise__" case explicitly special, with a
comment about why it exists when the kernel itself doesn't use it.

IOW, rather than the revert, maybe something like the below
(whitespace-damaged) instead?

Jiri, does something like this work for you?

Yes, thanks.

---
include/uapi/linux/types.h | 3 +++
1 file changed, 3 insertions(+)

diff --git a/include/uapi/linux/types.h b/include/uapi/linux/types.h
index c4dc597f3dcf..308433be33c2 100644
--- a/include/uapi/linux/types.h
+++ b/include/uapi/linux/types.h
@@ -26,6 +26,9 @@
#define __bitwise
#endif

+/* The kernel doesn't use this legacy form, but user space does */
+#define __bitwise__ __bitwise
+
typedef __u16 __bitwise __le16;
typedef __u16 __bitwise __be16;
typedef __u32 __bitwise __le32;


--
js
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