2017-06-01 21:16:34

by Zack Weinberg

[permalink] [raw]
Subject: [PATCH] uapi/linux/a.out.h: don't use deprecated system-specific predefines.

uapi/linux/a.out.h uses a number of predefined macros that are
deprecated because they're in the application namespace
(e.g. '#ifdef linux' instead of '#ifdef __linux__').
This patch corrects all of them.

The primary reason this is worth bothering to fix, considering how
obsolete a.out binary support is, is that the GCC build process
considers this such a severe error that it will copy the header into a
private directory and change the macro names, which causes future
updates to the header to be masked. This header probably doesn't get
updated very often anymore, but it is the _only_ uapi header that gets
this treatment, so IMHO it is worth patching just to drive that number
all the way to zero.

Signed-off-by: Zack Weinberg <[email protected]>
---
include/uapi/linux/a.out.h | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/uapi/linux/a.out.h b/include/uapi/linux/a.out.h
index 7caf44c7fa51..e163133cf1b0 100644
--- a/include/uapi/linux/a.out.h
+++ b/include/uapi/linux/a.out.h
@@ -115,21 +115,21 @@ enum machine_type {
/* Address of data segment in memory after it is loaded.
Note that it is up to you to define SEGMENT_SIZE
on machines not listed here. */
-#if defined(vax) || defined(hp300) || defined(pyr)
+#if defined(__vax__) || defined(__hp300__) || defined(__pyr__)
#define SEGMENT_SIZE page_size
#endif
-#ifdef sony
+#ifdef __sony__
#define SEGMENT_SIZE 0x2000
#endif /* Sony. */
-#ifdef is68k
+#ifdef __is68k__
#define SEGMENT_SIZE 0x20000
#endif
-#if defined(m68k) && defined(PORTAR)
+#if defined(__m68k__) && defined(__PORTAR__)
#define PAGE_SIZE 0x400
#define SEGMENT_SIZE PAGE_SIZE
#endif

-#ifdef linux
+#ifdef __linux__
#ifndef __KERNEL__
#include <unistd.h>
#endif
@@ -260,7 +260,7 @@ struct relocation_info
unsigned int r_extern:1;
/* Four bits that aren't used, but when writing an object file
it is desirable to clear them. */
-#ifdef NS32K
+#ifdef __NS32K__
unsigned r_bsr:1;
unsigned r_disp:1;
unsigned r_pad:2;
--
2.11.0


2017-06-02 07:10:16

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] uapi/linux/a.out.h: don't use deprecated system-specific predefines.

> /* Address of data segment in memory after it is loaded.
> Note that it is up to you to define SEGMENT_SIZE
> on machines not listed here. */
> -#if defined(vax) || defined(hp300) || defined(pyr)
> +#if defined(__vax__) || defined(__hp300__) || defined(__pyr__)
> #define SEGMENT_SIZE page_size
> #endif
> -#ifdef sony
> +#ifdef __sony__
> #define SEGMENT_SIZE 0x2000
> #endif /* Sony. */
> -#ifdef is68k
> +#ifdef __is68k__
> #define SEGMENT_SIZE 0x20000
> #endif
> -#if defined(m68k) && defined(PORTAR)
> +#if defined(__m68k__) && defined(__PORTAR__)
> #define PAGE_SIZE 0x400
> #define SEGMENT_SIZE PAGE_SIZE
> #endif

Can we please fix these conditionals so that only those
relevant to Linux remain? e.g. something like the patch below:


diff --git a/include/uapi/linux/a.out.h b/include/uapi/linux/a.out.h
index 7caf44c7fa51..295cd3ef6330 100644
--- a/include/uapi/linux/a.out.h
+++ b/include/uapi/linux/a.out.h
@@ -112,24 +112,7 @@ enum machine_type {
#define N_TXTADDR(x) (N_MAGIC(x) == QMAGIC ? PAGE_SIZE : 0)
#endif

-/* Address of data segment in memory after it is loaded.
- Note that it is up to you to define SEGMENT_SIZE
- on machines not listed here. */
-#if defined(vax) || defined(hp300) || defined(pyr)
-#define SEGMENT_SIZE page_size
-#endif
-#ifdef sony
-#define SEGMENT_SIZE 0x2000
-#endif /* Sony. */
-#ifdef is68k
-#define SEGMENT_SIZE 0x20000
-#endif
-#if defined(m68k) && defined(PORTAR)
-#define PAGE_SIZE 0x400
-#define SEGMENT_SIZE PAGE_SIZE
-#endif
-
-#ifdef linux
+/* Address of data segment in memory after it is loaded. */
#ifndef __KERNEL__
#include <unistd.h>
#endif
@@ -142,7 +125,6 @@ enum machine_type {
#endif
#endif
#endif
-#endif

#define _N_SEGMENT_ROUND(x) ALIGN(x, SEGMENT_SIZE)

@@ -260,13 +242,7 @@ struct relocation_info
unsigned int r_extern:1;
/* Four bits that aren't used, but when writing an object file
it is desirable to clear them. */
-#ifdef NS32K
- unsigned r_bsr:1;
- unsigned r_disp:1;
- unsigned r_pad:2;
-#else
unsigned int r_pad:4;
-#endif
};
#endif /* no N_RELOCATION_INFO_DECLARED. */


2017-06-02 12:06:50

by Zack Weinberg

[permalink] [raw]
Subject: Re: [PATCH] uapi/linux/a.out.h: don't use deprecated system-specific predefines.

On 06/02/2017 03:10 AM, Christoph Hellwig wrote:
>
> Can we please fix these conditionals so that only those
> relevant to Linux remain?

I was going for the minimal change since this is dusty-deck code that I
can't practically test, but I have no objection to your more thorough
approach. I don't see anything I would do differently.

zw

2017-06-02 19:12:57

by Linus Torvalds

[permalink] [raw]
Subject: Re: [PATCH] uapi/linux/a.out.h: don't use deprecated system-specific predefines.

On Fri, Jun 2, 2017 at 5:06 AM, Zack Weinberg <[email protected]> wrote:
> On 06/02/2017 03:10 AM, Christoph Hellwig wrote:
>>
>> Can we please fix these conditionals so that only those
>> relevant to Linux remain?
>
> I was going for the minimal change since this is dusty-deck code that I
> can't practically test, but I have no objection to your more thorough
> approach. I don't see anything I would do differently.

Yes, I think I'd just prefer to rip out the stale stuff, and remove
the "#ifdef linux" entirely.

It's not like the kernel wants non-linux headers, and I don't see
non-linux users using the kernel headers either.

Linus

2017-06-14 12:43:17

by Zack Weinberg

[permalink] [raw]
Subject: Re: [PATCH] uapi/linux/a.out.h: don't use deprecated system-specific predefines.

On Fri, Jun 2, 2017 at 3:12 PM, Linus Torvalds
<[email protected]> wrote:
> On Fri, Jun 2, 2017 at 5:06 AM, Zack Weinberg <[email protected]> wrote:
>> On 06/02/2017 03:10 AM, Christoph Hellwig wrote:
>>>
>>> Can we please fix these conditionals so that only those
>>> relevant to Linux remain?
>>
>> I was going for the minimal change since this is dusty-deck code that I
>> can't practically test, but I have no objection to your more thorough
>> approach. I don't see anything I would do differently.
>
> Yes, I think I'd just prefer to rip out the stale stuff, and remove
> the "#ifdef linux" entirely.
>
> It's not like the kernel wants non-linux headers, and I don't see
> non-linux users using the kernel headers either.

Christoph's patch doesn't seem to have been applied yet. Is there
anything I can do to help?

zw

2017-06-14 15:14:38

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] uapi/linux/a.out.h: don't use deprecated system-specific predefines.

On Wed, Jun 14, 2017 at 08:43:08AM -0400, Zack Weinberg wrote:
> Christoph's patch doesn't seem to have been applied yet. Is there
> anything I can do to help?

A formal submission usually helps. I didn't want to post it under
my name as it's mostly your work. How about this:

---
From: Zack Weinberg <[email protected]>
Subject: uapi/linux/a.out.h: don't use deprecated system-specific predefines.

uapi/linux/a.out.h uses a number of predefined macros that are
deprecated because they're in the application namespace
(e.g. '#ifdef linux' instead of '#ifdef __linux__').
This patch either corrects or just removes them if they are not
applicable to Linux.

The primary reason this is worth bothering to fix, considering how
obsolete a.out binary support is, is that the GCC build process
considers this such a severe error that it will copy the header into a
private directory and change the macro names, which causes future
updates to the header to be masked. This header probably doesn't get
updated very often anymore, but it is the _only_ uapi header that gets
this treatment, so IMHO it is worth patching just to drive that number
all the way to zero.

Signed-off-by: Zack Weinberg <[email protected]>
[hch: removed dead conditionals]
Signed-off-by: Christoph Hellwig <[email protected]>

diff --git a/include/uapi/linux/a.out.h b/include/uapi/linux/a.out.h
index 7caf44c7fa51..295cd3ef6330 100644
--- a/include/uapi/linux/a.out.h
+++ b/include/uapi/linux/a.out.h
@@ -112,24 +112,7 @@ enum machine_type {
#define N_TXTADDR(x) (N_MAGIC(x) == QMAGIC ? PAGE_SIZE : 0)
#endif

-/* Address of data segment in memory after it is loaded.
- Note that it is up to you to define SEGMENT_SIZE
- on machines not listed here. */
-#if defined(vax) || defined(hp300) || defined(pyr)
-#define SEGMENT_SIZE page_size
-#endif
-#ifdef sony
-#define SEGMENT_SIZE 0x2000
-#endif /* Sony. */
-#ifdef is68k
-#define SEGMENT_SIZE 0x20000
-#endif
-#if defined(m68k) && defined(PORTAR)
-#define PAGE_SIZE 0x400
-#define SEGMENT_SIZE PAGE_SIZE
-#endif
-
-#ifdef linux
+/* Address of data segment in memory after it is loaded. */
#ifndef __KERNEL__
#include <unistd.h>
#endif
@@ -142,7 +125,6 @@ enum machine_type {
#endif
#endif
#endif
-#endif

#define _N_SEGMENT_ROUND(x) ALIGN(x, SEGMENT_SIZE)

@@ -260,13 +242,7 @@ struct relocation_info
unsigned int r_extern:1;
/* Four bits that aren't used, but when writing an object file
it is desirable to clear them. */
-#ifdef NS32K
- unsigned r_bsr:1;
- unsigned r_disp:1;
- unsigned r_pad:2;
-#else
unsigned int r_pad:4;
-#endif
};
#endif /* no N_RELOCATION_INFO_DECLARED. */