2.6.5+BK compile error: binfmt_elf on sparc64

2.6.5+BK compile error: binfmt_elf on sparc64

[Meelis Roos]

Because of -Werror, it bails out:

In file included from arch/sparc64/kernel/binfmt_elf32.c:154:
fs/binfmt_elf.c: In function `load_elf_interp':
fs/binfmt_elf.c:369: warning: comparison is always false due to limited range of data type
fs/binfmt_elf.c: In function `load_elf_binary':
fs/binfmt_elf.c:780: warning: comparison is always false due to limited range of data type

It's the comparision "elf_ppnt->p_memsz > TASK_SIZE".

p_memsz is Elf32_Word, TASK_SIZE is defined as
#define TASK_SIZE       ((unsigned long)-VPTE_SIZE)

At the first glance I can't see what's wrong here.

-- 
Meelis Roos (mroos@linux.ee)

Re: 2.6.5+BK compile error: binfmt_elf on sparc64

[David S. Miller]

On Wed, 14 Apr 2004 11:33:00 +0300 (EEST)
Meelis Roos <mroos@linux.ee> wrote:

> Because of -Werror, it bails out:
> 
> In file included from arch/sparc64/kernel/binfmt_elf32.c:154:
> fs/binfmt_elf.c: In function `load_elf_interp':
> fs/binfmt_elf.c:369: warning: comparison is always false due to limited range of data type
> fs/binfmt_elf.c: In function `load_elf_binary':
> fs/binfmt_elf.c:780: warning: comparison is always false due to limited range of data type
> 
> It's the comparision "elf_ppnt->p_memsz > TASK_SIZE".
> 
> p_memsz is Elf32_Word, TASK_SIZE is defined as
> #define TASK_SIZE       ((unsigned long)-VPTE_SIZE)
> 
> At the first glance I can't see what's wrong here.

The compiler is telling us that the condition is always false because a 32-bit
value can never have the codition being tested against a 64-bit one (TASK_SIZE).
I've tried everything to kill this warning, even casting both sides of the
conparison to 64-bit, but gcc can still see things clearly.

So just comment out the -Werror line in arch/sparc64/kernel/Makefile which is
how I'm (unfortunately) solving this for now.

Re: 2.6.5+BK compile error: binfmt_elf on sparc64

[Herbert Poetzl]

On Wed, Apr 14, 2004 at 11:53:01AM -0700, David S. Miller wrote:
> On Wed, 14 Apr 2004 11:33:00 +0300 (EEST)
> Meelis Roos <mroos@linux.ee> wrote:
> 
> > Because of -Werror, it bails out:
> > 
> > In file included from arch/sparc64/kernel/binfmt_elf32.c:154:
> > fs/binfmt_elf.c: In function `load_elf_interp':
> > fs/binfmt_elf.c:369: warning: comparison is always false due to limited range of data type
> > fs/binfmt_elf.c: In function `load_elf_binary':
> > fs/binfmt_elf.c:780: warning: comparison is always false due to limited range of data type
> > 
> > It's the comparision "elf_ppnt->p_memsz > TASK_SIZE".
> > 
> > p_memsz is Elf32_Word, TASK_SIZE is defined as
> > #define TASK_SIZE       ((unsigned long)-VPTE_SIZE)
> > 
> > At the first glance I can't see what's wrong here.
> 
> The compiler is telling us that the condition is always false because a 32-bit
> value can never have the codition being tested against a 64-bit one (TASK_SIZE).
> I've tried everything to kill this warning, even casting both sides of the
> conparison to 64-bit, but gcc can still see things clearly.
> 
> So just comment out the -Werror line in arch/sparc64/kernel/Makefile which is
> how I'm (unfortunately) solving this for now.

what about the good old

	eppnt->p_memsz - TASK_SIZE > 0

HTH,
Herbert

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