* [Linux-ia64] [Patch] Fix in process.c
@ 2003-01-18 1:43 Siddha, Suresh B
2003-01-18 1:53 ` David Mosberger
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: Siddha, Suresh B @ 2003-01-18 1:43 UTC (permalink / raw)
To: linux-ia64
[-- Attachment #1: Type: text/plain, Size: 1367 bytes --]
Attached/appended fix for another problem(getting the address of a function), which depends on the compiler behaviour.
thanks,
suresh
diff -Nru linux-2.5.52/arch/ia64/kernel/process.c~ linux-2.5.52/arch/ia64/kernel/process.c
--- linux-2.5.52/arch/ia64/kernel/process.c~ Fri Jan 17 14:53:52 2003
+++ linux-2.5.52/arch/ia64/kernel/process.c Fri Jan 17 15:27:46 2003
@@ -281,7 +281,10 @@
{
unsigned long rbs, child_rbs, rbs_size, stack_offset, stack_top, stack_used;
struct switch_stack *child_stack, *stack;
- extern char ia64_ret_from_clone, ia32_ret_from_clone;
+ extern void ia64_ret_from_clone(void);
+#ifdef CONFIG_IA32_SUPPORT
+ extern void ia32_ret_from_clone(void);
+#endif
struct pt_regs *child_ptregs;
int retval = 0;
@@ -332,10 +335,13 @@
child_ptregs->r12 = (unsigned long) (child_ptregs + 1); /* kernel sp */
child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */
}
+#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(regs))
- child_stack->b0 = (unsigned long) &ia32_ret_from_clone;
+ child_stack->b0 = ((unsigned long *) &ia32_ret_from_clone)[0];
else
- child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
+#else
+ child_stack->b0 = ((unsigned long *) &ia64_ret_from_clone)[0];
+#endif
child_stack->ar_bspstore = child_rbs + rbs_size;
/* copy parts of thread_struct: */
[-- Attachment #2: process.c.diff --]
[-- Type: application/octet-stream, Size: 1226 bytes --]
diff -Nru linux-2.5.52/arch/ia64/kernel/process.c~ linux-2.5.52/arch/ia64/kernel/process.c
--- linux-2.5.52/arch/ia64/kernel/process.c~ Fri Jan 17 14:53:52 2003
+++ linux-2.5.52/arch/ia64/kernel/process.c Fri Jan 17 15:27:46 2003
@@ -281,7 +281,10 @@
{
unsigned long rbs, child_rbs, rbs_size, stack_offset, stack_top, stack_used;
struct switch_stack *child_stack, *stack;
- extern char ia64_ret_from_clone, ia32_ret_from_clone;
+ extern void ia64_ret_from_clone(void);
+#ifdef CONFIG_IA32_SUPPORT
+ extern void ia32_ret_from_clone(void);
+#endif
struct pt_regs *child_ptregs;
int retval = 0;
@@ -332,10 +335,13 @@
child_ptregs->r12 = (unsigned long) (child_ptregs + 1); /* kernel sp */
child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */
}
+#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(regs))
- child_stack->b0 = (unsigned long) &ia32_ret_from_clone;
+ child_stack->b0 = ((unsigned long *) &ia32_ret_from_clone)[0];
else
- child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
+#else
+ child_stack->b0 = ((unsigned long *) &ia64_ret_from_clone)[0];
+#endif
child_stack->ar_bspstore = child_rbs + rbs_size;
/* copy parts of thread_struct: */
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Linux-ia64] [Patch] Fix in process.c
2003-01-18 1:43 [Linux-ia64] [Patch] Fix in process.c Siddha, Suresh B
@ 2003-01-18 1:53 ` David Mosberger
2003-01-18 3:04 ` Siddha, Suresh B
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: David Mosberger @ 2003-01-18 1:53 UTC (permalink / raw)
To: linux-ia64
This one I REALLY don't like:
>>>>> On Fri, 17 Jan 2003 17:43:44 -0800, "Siddha, Suresh B" <suresh.b.siddha@intel.com> said:
Suresh> - extern char ia64_ret_from_clone;
Suresh> + extern void ia64_ret_from_clone(void);
Suresh> - child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
Suresh> + child_stack->b0 = ((unsigned long *) &ia64_ret_from_clone)[0];
Why materialize a function pointer for ABSOLUTELY no reason?
Furthermore, &FUNC can be used as a static initializer, whereas
((long*)&FUNC)[0] cannot.
--david
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [Linux-ia64] [Patch] Fix in process.c
2003-01-18 1:43 [Linux-ia64] [Patch] Fix in process.c Siddha, Suresh B
2003-01-18 1:53 ` David Mosberger
@ 2003-01-18 3:04 ` Siddha, Suresh B
2003-01-18 3:11 ` David Mosberger
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Siddha, Suresh B @ 2003-01-18 3:04 UTC (permalink / raw)
To: linux-ia64
hi David,
Type of "ia64_ret_from_clone" is declared differently here(char as against function) and we end up linking object files with different types for the symbol(which the linker will not like).
Current C-code is assuming gcc specific behaviour(gcc does not fix the type for extern variables, leaves it to the linker).
thanks,
suresh
> -----Original Message-----
> From: David Mosberger [mailto:davidm@napali.hpl.hp.com]
> Sent: Friday, January 17, 2003 5:53 PM
> To: Siddha, Suresh B
> Cc: linux-ia64@linuxia64.org
> Subject: Re: [Linux-ia64] [Patch] Fix in process.c
>
>
> This one I REALLY don't like:
>
> >>>>> On Fri, 17 Jan 2003 17:43:44 -0800, "Siddha, Suresh B"
> <suresh.b.siddha@intel.com> said:
>
> Suresh> - extern char ia64_ret_from_clone;
> Suresh> + extern void ia64_ret_from_clone(void);
>
> Suresh> - child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
> Suresh> + child_stack->b0 = ((unsigned long *)
> &ia64_ret_from_clone)[0];
>
> Why materialize a function pointer for ABSOLUTELY no reason?
> Furthermore, &FUNC can be used as a static initializer, whereas
> ((long*)&FUNC)[0] cannot.
>
> --david
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [Linux-ia64] [Patch] Fix in process.c
2003-01-18 1:43 [Linux-ia64] [Patch] Fix in process.c Siddha, Suresh B
2003-01-18 1:53 ` David Mosberger
2003-01-18 3:04 ` Siddha, Suresh B
@ 2003-01-18 3:11 ` David Mosberger
2003-01-18 3:39 ` Siddha, Suresh B
2003-01-21 2:41 ` Siddha, Suresh B
4 siblings, 0 replies; 6+ messages in thread
From: David Mosberger @ 2003-01-18 3:11 UTC (permalink / raw)
To: linux-ia64
>>>>> On Fri, 17 Jan 2003 19:04:55 -0800, "Siddha, Suresh B" <suresh.b.siddha@intel.com> said:
Suresh> hi David, Type of "ia64_ret_from_clone" is declared
Suresh> differently here(char as against function) and we end up
Suresh> linking object files with different types for the
Suresh> symbol(which the linker will not like).
Suresh> Current C-code is assuming gcc specific behaviour(gcc does
Suresh> not fix the type for extern variables, leaves it to the
Suresh> linker).
I understand that. What I'm saying is that GCC does the sane thing.
There's got to be a way to get the address of a label without having
to materialize a function pointer.
--david
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [Linux-ia64] [Patch] Fix in process.c
2003-01-18 1:43 [Linux-ia64] [Patch] Fix in process.c Siddha, Suresh B
` (2 preceding siblings ...)
2003-01-18 3:11 ` David Mosberger
@ 2003-01-18 3:39 ` Siddha, Suresh B
2003-01-21 2:41 ` Siddha, Suresh B
4 siblings, 0 replies; 6+ messages in thread
From: Siddha, Suresh B @ 2003-01-18 3:39 UTC (permalink / raw)
To: linux-ia64
>
> >>>>> On Fri, 17 Jan 2003 19:04:55 -0800, "Siddha, Suresh B"
> <suresh.b.siddha@intel.com> said:
>
> Suresh> hi David, Type of "ia64_ret_from_clone" is declared
> Suresh> differently here(char as against function) and we end up
> Suresh> linking object files with different types for the
> Suresh> symbol(which the linker will not like).
>
> Suresh> Current C-code is assuming gcc specific behaviour(gcc does
> Suresh> not fix the type for extern variables, leaves it to the
> Suresh> linker).
>
> I understand that. What I'm saying is that GCC does the sane thing.
> There's got to be a way to get the address of a label without having
> to materialize a function pointer.
>
> --david
>
We can do that through the linker script vmlinux.lds.S.
thanks,
suresh
^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [Linux-ia64] [Patch] Fix in process.c
2003-01-18 1:43 [Linux-ia64] [Patch] Fix in process.c Siddha, Suresh B
` (3 preceding siblings ...)
2003-01-18 3:39 ` Siddha, Suresh B
@ 2003-01-21 2:41 ` Siddha, Suresh B
4 siblings, 0 replies; 6+ messages in thread
From: Siddha, Suresh B @ 2003-01-21 2:41 UTC (permalink / raw)
To: linux-ia64
[-- Attachment #1: Type: text/plain, Size: 2161 bytes --]
> >
> > I understand that. What I'm saying is that GCC does the sane thing.
> > There's got to be a way to get the address of a label without having
> > to materialize a function pointer.
> >
> > --david
> >
>
> We can do that through the linker script vmlinux.lds.S.
>
hi David,
Here is the patch which does this. Please apply.
thanks,
suresh
diff -Nru linux-2.5.52/arch/ia64/kernel/process.c linux/arch/ia64/kernel/process.c
--- linux-2.5.52/arch/ia64/kernel/process.c Mon Jan 20 13:12:08 2003
+++ linux/arch/ia64/kernel/process.c Mon Jan 20 09:45:21 2003
@@ -281,7 +281,10 @@
{
unsigned long rbs, child_rbs, rbs_size, stack_offset, stack_top, stack_used;
struct switch_stack *child_stack, *stack;
- extern char ia64_ret_from_clone, ia32_ret_from_clone;
+ extern int __ia64_ret_from_clone;
+#ifdef CONFIG_IA32_SUPPORT
+ extern int __ia32_ret_from_clone;
+#endif
struct pt_regs *child_ptregs;
int retval = 0;
@@ -332,10 +335,12 @@
child_ptregs->r12 = (unsigned long) (child_ptregs + 1); /* kernel sp */
child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */
}
+#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(regs))
- child_stack->b0 = (unsigned long) &ia32_ret_from_clone;
+ child_stack->b0 = (unsigned long) &__ia32_ret_from_clone;
else
- child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
+#endif
+ child_stack->b0 = (unsigned long) &__ia64_ret_from_clone;
child_stack->ar_bspstore = child_rbs + rbs_size;
/* copy parts of thread_struct: */
diff -Nru linux-2.5.52/arch/ia64/vmlinux.lds.S linux/arch/ia64/vmlinux.lds.S
--- linux-2.5.52/arch/ia64/vmlinux.lds.S Mon Jan 20 13:12:09 2003
+++ linux/arch/ia64/vmlinux.lds.S Mon Jan 20 18:31:14 2003
@@ -39,6 +39,14 @@
#endif
_etext = .;
+ /* We want to get the address of a label without having
+ to materialize a function pointer. "+0" is for changing
+ the symbol type */
+ __ia64_ret_from_clone = ia64_ret_from_clone + 0;
+#ifdef CONFIG_IA32_SUPPORT
+ __ia32_ret_from_clone = ia32_ret_from_clone + 0;
+#endif
+
/* Read-only data */
/* Global data */
[-- Attachment #2: process.diff --]
[-- Type: application/octet-stream, Size: 1786 bytes --]
diff -Nru linux-2.5.52/arch/ia64/kernel/process.c linux/arch/ia64/kernel/process.c
--- linux-2.5.52/arch/ia64/kernel/process.c Mon Jan 20 13:12:08 2003
+++ linux/arch/ia64/kernel/process.c Mon Jan 20 09:45:21 2003
@@ -281,7 +281,10 @@
{
unsigned long rbs, child_rbs, rbs_size, stack_offset, stack_top, stack_used;
struct switch_stack *child_stack, *stack;
- extern char ia64_ret_from_clone, ia32_ret_from_clone;
+ extern int __ia64_ret_from_clone;
+#ifdef CONFIG_IA32_SUPPORT
+ extern int __ia32_ret_from_clone;
+#endif
struct pt_regs *child_ptregs;
int retval = 0;
@@ -332,10 +335,12 @@
child_ptregs->r12 = (unsigned long) (child_ptregs + 1); /* kernel sp */
child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */
}
+#ifdef CONFIG_IA32_SUPPORT
if (IS_IA32_PROCESS(regs))
- child_stack->b0 = (unsigned long) &ia32_ret_from_clone;
+ child_stack->b0 = (unsigned long) &__ia32_ret_from_clone;
else
- child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
+#endif
+ child_stack->b0 = (unsigned long) &__ia64_ret_from_clone;
child_stack->ar_bspstore = child_rbs + rbs_size;
/* copy parts of thread_struct: */
diff -Nru linux-2.5.52/arch/ia64/vmlinux.lds.S linux/arch/ia64/vmlinux.lds.S
--- linux-2.5.52/arch/ia64/vmlinux.lds.S Mon Jan 20 13:12:09 2003
+++ linux/arch/ia64/vmlinux.lds.S Mon Jan 20 18:31:14 2003
@@ -39,6 +39,14 @@
#endif
_etext = .;
+ /* We want to get the address of a label without having
+ to materialize a function pointer. "+0" is for changing
+ the symbol type */
+ __ia64_ret_from_clone = ia64_ret_from_clone + 0;
+#ifdef CONFIG_IA32_SUPPORT
+ __ia32_ret_from_clone = ia32_ret_from_clone + 0;
+#endif
+
/* Read-only data */
/* Global data */
^ permalink raw reply [flat|nested] 6+ messages in thread
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2003-01-18 1:43 [Linux-ia64] [Patch] Fix in process.c Siddha, Suresh B
2003-01-18 1:53 ` David Mosberger
2003-01-18 3:04 ` Siddha, Suresh B
2003-01-18 3:11 ` David Mosberger
2003-01-18 3:39 ` Siddha, Suresh B
2003-01-21 2:41 ` Siddha, Suresh B
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