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

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

[Bjorn Helgaas]

From: Bjorn Helgaas <bhelgaas@google.com>

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.

Link: https://lore.kernel.org/r/b5c0a68d-8387-4909-beea-f70ab9e6e3d5@kernel.org
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 include/uapi/linux/types.h  | 5 +++--
 tools/include/linux/types.h | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/uapi/linux/types.h b/include/uapi/linux/types.h
index c4dc597f3dcf..2415d5dcb5d3 100644
--- a/include/uapi/linux/types.h
+++ b/include/uapi/linux/types.h
@@ -21,10 +21,11 @@
 
 /* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */
 #ifdef __CHECKER__
-#define __bitwise	__attribute__((bitwise))
+#define __bitwise__ __attribute__((bitwise))
 #else
-#define __bitwise
+#define __bitwise__
 #endif
+#define __bitwise __bitwise__
 
 typedef __u16 __bitwise __le16;
 typedef __u16 __bitwise __be16;
diff --git a/tools/include/linux/types.h b/tools/include/linux/types.h
index 051fdeaf2670..5908e58c3598 100644
--- a/tools/include/linux/types.h
+++ b/tools/include/linux/types.h
@@ -43,10 +43,11 @@ typedef __u8  u8;
 typedef __s8  s8;
 
 #ifdef __CHECKER__
-#define __bitwise	__attribute__((bitwise))
+#define __bitwise__ __attribute__((bitwise))
 #else
-#define __bitwise
+#define __bitwise__
 #endif
+#define __bitwise __bitwise__
 
 #define __force
 #define __user
-- 
2.25.1

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

[Linus Torvalds]

On Wed, May 25, 2022 at 7:46 AM Bjorn Helgaas <helgaas@kernel.org> 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?

                 Linus

---
 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;

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

[Jiri Slaby]

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