* [PATCH] alternative compat_ioctl table implementation
@ 2003-05-02 17:59 Arnd Bergmann
2003-05-02 18:09 ` Ben Collins
0 siblings, 1 reply; 4+ messages in thread
From: Arnd Bergmann @ 2003-05-02 17:59 UTC (permalink / raw)
To: linux-kernel; +Cc: Pavel Machek
I had some trouble making the 2.5.68bk implementation
for compat_ioctl work on s390x because of a cross-compiling
bug in gcc-2.95.
This patch changes the way that the translation table
is generated and solves the problem by replacing
the assembler magic with linker magic.
As a side effect, it adds type-checking for the handler
functions and makes it possible to put COMPATIBLE_IOCTL()
in places other than arch/*/kernel/ioctl32.c, e.g. next
to the normal ioctl handler.
This needs the compat-ioctl-fix.patch from 2.5.68mm4.
Opinions?
Arnd <><
===== include/asm-generic/vmlinux.lds.h 1.7 vs edited =====
--- 1.7/include/asm-generic/vmlinux.lds.h Mon Feb 3 22:00:30 2003
+++ edited/include/asm-generic/vmlinux.lds.h Fri May 2 16:47:13 2003
@@ -1,3 +1,5 @@
+#include <linux/config.h>
+
#ifndef LOAD_OFFSET
#define LOAD_OFFSET 0
#endif
@@ -45,3 +47,11 @@
*(__ksymtab_strings) \
}
+#ifdef CONFIG_COMPAT \
+#define COMPAT_IOCTL_TABLE \
+ ioctl_start = .; \
+ .data.ioctltrans : { *(.data.ioctltrans) } \
+ ioctl_end = .;
+#else
+#define COMPAT_IOCTL_TABLE
+#endif
===== include/linux/compat.h 1.11 vs edited =====
--- 1.11/include/linux/compat.h Wed Apr 16 07:48:21 2003
+++ edited/include/linux/compat.h Fri May 2 16:47:13 2003
@@ -12,6 +12,14 @@
#include <linux/param.h> /* for HZ */
#include <asm/compat.h>
+#define __IOCTL_HANDLER(name,cmd,handler) \
+ static struct ioctl_trans name \
+ __attribute_used__ \
+ __attribute__((section(".data.ioctltrans"))) = \
+ { cmd, handler, 0 };
+#define HANDLE_IOCTL(cmd,handler) __IOCTL_HANDLER(handle_ioctl_ ## cmd,cmd,handler)
+#define COMPATIBLE_IOCTL(cmd) __IOCTL_HANDLER(compatible_ioctl_ ## cmd,cmd,0)
+
#define compat_jiffies_to_clock_t(x) \
(((unsigned long)(x) * COMPAT_USER_HZ) / HZ)
===== arch/parisc/vmlinux.lds.S 1.13 vs edited =====
--- 1.13/arch/parisc/vmlinux.lds.S Wed Apr 2 10:42:56 2003
+++ edited/arch/parisc/vmlinux.lds.S Fri May 2 16:56:36 2003
@@ -44,6 +44,7 @@
*(.data)
}
+ COMPAT_IOCTL_TABLE
#ifdef CONFIG_PARISC64
. = ALIGN(16); /* Linkage tables */
.opd : { *(.opd) } PROVIDE (__gp = .);
===== arch/parisc/kernel/ioctl32.c 1.8 vs edited =====
--- 1.8/arch/parisc/kernel/ioctl32.c Wed Apr 30 20:03:39 2003
+++ edited/arch/parisc/kernel/ioctl32.c Fri May 2 16:47:13 2003
@@ -2893,13 +2893,6 @@
return err;
}
-#define HANDLE_IOCTL(cmd, handler) { cmd, (ioctl_trans_handler_t)handler, 0 },
-#define COMPATIBLE_IOCTL(cmd) HANDLE_IOCTL(cmd, sys_ioctl)
-
-#define IOCTL_TABLE_START struct ioctl_trans ioctl_start[] = {
-#define IOCTL_TABLE_END }; struct ioctl_trans ioctl_end[0];
-
-IOCTL_TABLE_START
#include <linux/compat_ioctl.h>
/* Might be moved to compat_ioctl.h with some ifdefs... */
@@ -3084,5 +3077,4 @@
HANDLE_IOCTL(DRM32_IOCTL_DMA, drm32_dma);
HANDLE_IOCTL(DRM32_IOCTL_RES_CTX, drm32_res_ctx);
#endif /* DRM */
-IOCTL_TABLE_END
===== arch/ppc64/vmlinux.lds.S 1.14 vs edited =====
--- 1.14/arch/ppc64/vmlinux.lds.S Wed Apr 2 10:42:56 2003
+++ edited/arch/ppc64/vmlinux.lds.S Fri May 2 16:56:48 2003
@@ -57,6 +57,7 @@
*(.dynamic)
CONSTRUCTORS
}
+ COMPAT_IOCTL_TABLE
. = ALIGN(4096);
_edata = .;
PROVIDE (edata = .);
===== arch/ppc64/kernel/ioctl32.c 1.27 vs edited =====
--- 1.27/arch/ppc64/kernel/ioctl32.c Wed Apr 30 17:47:36 2003
+++ edited/arch/ppc64/kernel/ioctl32.c Fri May 2 16:47:14 2003
@@ -3649,14 +3649,9 @@
unsigned long next;
};
-#define COMPATIBLE_IOCTL(cmd) { cmd, (unsigned long)sys_ioctl, 0 },
-
-#define HANDLE_IOCTL(cmd,handler) { cmd, (unsigned long)handler, 0 },
-
#define AUTOFS_IOC_SETTIMEOUT32 _IOWR(0x93,0x64,unsigned int)
#define SMB_IOC_GETMOUNTUID_32 _IOR('u', 1, compat_uid_t)
-static struct ioctl_trans ioctl_translations[] = {
/* List here explicitly which ioctl's need translation,
* all others default to calling sys_ioctl().
*/
@@ -4473,4 +4468,3 @@
HANDLE_IOCTL(BLKBSZGET_32, do_blkbszget)
HANDLE_IOCTL(BLKBSZSET_32, do_blkbszset)
HANDLE_IOCTL(BLKGETSIZE64_32, do_blkgetsize64)
-};
===== arch/s390/vmlinux.lds.S 1.12 vs edited =====
--- 1.12/arch/s390/vmlinux.lds.S Mon Apr 14 21:11:57 2003
+++ edited/arch/s390/vmlinux.lds.S Fri May 2 19:28:50 2003
@@ -3,7 +3,6 @@
*/
#include <asm-generic/vmlinux.lds.h>
-#include <linux/config.h>
#ifndef CONFIG_ARCH_S390X
OUTPUT_FORMAT("elf32-s390", "elf32-s390", "elf32-s390")
@@ -46,6 +45,7 @@
*(.data)
CONSTRUCTORS
}
+ COMPAT_IOCTL_TABLE
. = ALIGN(4096);
__nosave_begin = .;
===== arch/sparc64/vmlinux.lds.S 1.18 vs edited =====
--- 1.18/arch/sparc64/vmlinux.lds.S Wed Apr 2 10:42:56 2003
+++ edited/arch/sparc64/vmlinux.lds.S Fri May 2 16:47:14 2003
@@ -28,6 +28,7 @@
CONSTRUCTORS
}
.data1 : { *(.data1) }
+ COMPAT_IOCTL_TABLE
. = ALIGN(64);
.data.cacheline_aligned : { *(.data.cacheline_aligned) }
_edata = .;
===== arch/sparc64/kernel/ioctl32.c 1.60 vs edited =====
--- 1.60/arch/sparc64/kernel/ioctl32.c Wed Apr 30 17:56:32 2003
+++ edited/arch/sparc64/kernel/ioctl32.c Fri May 2 16:47:14 2003
@@ -3833,16 +3833,6 @@
#define BNEPGETCONNLIST _IOR('B', 210, int)
#define BNEPGETCONNINFO _IOR('B', 211, int)
-typedef int (* ioctl32_handler_t)(unsigned int, unsigned int, unsigned long, struct file *);
-
-#define COMPATIBLE_IOCTL(cmd) HANDLE_IOCTL((cmd),sys_ioctl)
-#define HANDLE_IOCTL(cmd,handler) { (cmd), (ioctl32_handler_t)(handler), NULL },
-#define IOCTL_TABLE_START \
- struct ioctl_trans ioctl_start[] = {
-#define IOCTL_TABLE_END \
- }; struct ioctl_trans ioctl_end[0];
-
-IOCTL_TABLE_START
#include <linux/compat_ioctl.h>
COMPATIBLE_IOCTL(TCSBRKP)
COMPATIBLE_IOCTL(TIOCSTART)
@@ -4154,4 +4144,3 @@
HANDLE_IOCTL(BLKBSZGET_32, do_blkbszget)
HANDLE_IOCTL(BLKBSZSET_32, do_blkbszset)
HANDLE_IOCTL(BLKGETSIZE64_32, do_blkgetsize64)
-IOCTL_TABLE_END
===== arch/x86_64/vmlinux.lds.S 1.15 vs edited =====
--- 1.15/arch/x86_64/vmlinux.lds.S Wed Apr 2 10:42:56 2003
+++ edited/arch/x86_64/vmlinux.lds.S Fri May 2 16:57:36 2003
@@ -33,6 +33,7 @@
CONSTRUCTORS
}
+ COMPAT_IOCTL_TABLE
_edata = .; /* End of data section */
__bss_start = .; /* BSS */
===== arch/x86_64/ia32/ia32_ioctl.c 1.22 vs edited =====
--- 1.22/arch/x86_64/ia32/ia32_ioctl.c Thu May 1 03:31:08 2003
+++ edited/arch/x86_64/ia32/ia32_ioctl.c Fri May 2 16:47:14 2003
@@ -3136,14 +3136,6 @@
return err;
}
-#define REF_SYMBOL(handler) if (0) (void)handler;
-#define HANDLE_IOCTL2(cmd,handler) REF_SYMBOL(handler); asm volatile(".quad %c0, " #handler ",0"::"i" (cmd));
-#define HANDLE_IOCTL(cmd,handler) HANDLE_IOCTL2(cmd,handler)
-#define COMPATIBLE_IOCTL(cmd) HANDLE_IOCTL(cmd,sys_ioctl)
-#define IOCTL_TABLE_START void ioctl_dummy(void) { asm volatile("\n.global ioctl_start\nioctl_start:\n\t" );
-#define IOCTL_TABLE_END asm volatile("\n.global ioctl_end;\nioctl_end:\n"); }
-
-IOCTL_TABLE_START
#include <linux/compat_ioctl.h>
COMPATIBLE_IOCTL(HDIO_SET_KEEPSETTINGS)
COMPATIBLE_IOCTL(HDIO_SCAN_HWIF)
@@ -3380,5 +3372,4 @@
HANDLE_IOCTL(MTRRIOC32_DEL_PAGE_ENTRY, mtrr_ioctl32)
HANDLE_IOCTL(MTRRIOC32_GET_PAGE_ENTRY, mtrr_ioctl32)
HANDLE_IOCTL(MTRRIOC32_KILL_PAGE_ENTRY, mtrr_ioctl32)
-IOCTL_TABLE_END
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] alternative compat_ioctl table implementation
2003-05-02 17:59 [PATCH] alternative compat_ioctl table implementation Arnd Bergmann
@ 2003-05-02 18:09 ` Ben Collins
0 siblings, 0 replies; 4+ messages in thread
From: Ben Collins @ 2003-05-02 18:09 UTC (permalink / raw)
To: Arnd Bergmann; +Cc: linux-kernel, Pavel Machek
On Fri, May 02, 2003 at 07:59:02PM +0200, Arnd Bergmann wrote:
> I had some trouble making the 2.5.68bk implementation
> for compat_ioctl work on s390x because of a cross-compiling
> bug in gcc-2.95.
>
> This patch changes the way that the translation table
> is generated and solves the problem by replacing
> the assembler magic with linker magic.
>
> As a side effect, it adds type-checking for the handler
> functions and makes it possible to put COMPATIBLE_IOCTL()
> in places other than arch/*/kernel/ioctl32.c, e.g. next
> to the normal ioctl handler.
>
> This needs the compat-ioctl-fix.patch from 2.5.68mm4.
>
You macros don't work for things like this:
COMPATIBLE_IOCTL(_IOW('v', BASE_VIDIOCPRIVATE+0, char [256]))
COMPATIBLE_IOCTL(_IOR('v', BASE_VIDIOCPRIVATE+1, char [256]))
...which are in compat_ioctl.h.
--
Debian - http://www.debian.org/
Linux 1394 - http://www.linux1394.org/
Subversion - http://subversion.tigris.org/
Deqo - http://www.deqo.com/
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] alternative compat_ioctl table implementation
2003-05-02 18:09 ` Andi Kleen
@ 2003-05-02 21:42 ` Arnd Bergmann
0 siblings, 0 replies; 4+ messages in thread
From: Arnd Bergmann @ 2003-05-02 21:42 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel, pavel
On Friday 02 May 2003 20:09, Andi Kleen wrote:
> Rather ugly. In my experience all vmlinux.lds hacks are very fragile
> and they break when you just look at them in the wrong way. Also when
> something goes wrong they are a bitch to debug. And binutils is not
> exactly known for not introducing bugs with new releases.
Ok.
> Can't you work around that gcc 2.95 bug in some other way ?
Yes. I noticed now that only the x86_64 code (from which I copied)
contains the assembly version that breaks on cross-compile
and the sparc64 version works fine.
Arnd <><
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] alternative compat_ioctl table implementation
[not found] <200305021959.02726.arnd@arndb.de.suse.lists.linux.kernel>
@ 2003-05-02 18:09 ` Andi Kleen
2003-05-02 21:42 ` Arnd Bergmann
0 siblings, 1 reply; 4+ messages in thread
From: Andi Kleen @ 2003-05-02 18:09 UTC (permalink / raw)
To: Arnd Bergmann; +Cc: linux-kernel, pavel
Arnd Bergmann <arnd@arndb.de> writes:
>
> Opinions?
Rather ugly. In my experience all vmlinux.lds hacks are very fragile
and they break when you just look at them in the wrong way. Also when
something goes wrong they are a bitch to debug. And binutils is not
exactly known for not introducing bugs with new releases.
Can't you work around that gcc 2.95 bug in some other way ?
-Andi
^ permalink raw reply [flat|nested] 4+ messages in thread
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2003-05-02 17:59 [PATCH] alternative compat_ioctl table implementation Arnd Bergmann
2003-05-02 18:09 ` Ben Collins
[not found] <200305021959.02726.arnd@arndb.de.suse.lists.linux.kernel>
2003-05-02 18:09 ` Andi Kleen
2003-05-02 21:42 ` Arnd Bergmann
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