On Tue, Jan 05, 2010 at 03:15:27AM +0100, Andi Kleen wrote:
>
> Add a variant of kernel_text_address() that includes kernel data.
>
> Assumes kernel is _text ... _end - init section. True everywhere?
Tim Abbott has done a great job lately to unify the various
linker scripts used by the different architectures.
Architectures are supposed to follow the skeleton outlined
in include/asm-generic/vmlinux.lds.h
But I think the skeleton needs a small update.
It describes that we mark start of .text with _stext.
But reality is that we use _text for this.
But you can trust _etext an almost all architectures.
It is a bug if it is missing.
So [_text, _etext] is the text section.
The data section may be placed before or after - it depends on the architecture.
But again - only some architectures define _sdata.
But all? define _edata.
Sam
>
> Cc: linux-arch@xxxxxxxxxxxxxxx
> Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> ---
> include/linux/kernel.h | 1 +
> kernel/extable.c | 18 ++++++++++++++++++
> 2 files changed, 19 insertions(+)
>
> Index: linux-2.6.33-rc2-ak/include/linux/kernel.h
> ===================================================================
> --- linux-2.6.33-rc2-ak.orig/include/linux/kernel.h
> +++ linux-2.6.33-rc2-ak/include/linux/kernel.h
> @@ -205,6 +205,7 @@ extern unsigned long long memparse(const
> extern int core_kernel_text(unsigned long addr);
> extern int __kernel_text_address(unsigned long addr);
> extern int kernel_text_address(unsigned long addr);
> +extern int kernel_address(unsigned long addr);
> extern int func_ptr_is_kernel_text(void *ptr);
>
> struct pid;
> Index: linux-2.6.33-rc2-ak/kernel/extable.c
> ===================================================================
> --- linux-2.6.33-rc2-ak.orig/kernel/extable.c
> +++ linux-2.6.33-rc2-ak/kernel/extable.c
> @@ -72,6 +72,18 @@ int core_kernel_text(unsigned long addr)
> return 0;
> }
>
> +static int core_kernel_address(unsigned long addr)
> +{
> + if ((addr >= (unsigned long)_text &&
> + addr <= (unsigned long)_end)) {
> + if (addr >= (unsigned long)__init_begin &&
> + addr < (unsigned long)__init_end)
> + return system_state == SYSTEM_BOOTING;
> + return 1;
> + }
> + return 0;
> +}
> +
> int __kernel_text_address(unsigned long addr)
> {
> if (core_kernel_text(addr))
> @@ -98,6 +110,12 @@ int kernel_text_address(unsigned long ad
> return is_module_text_address(addr);
> }
>
> +/* text or data in core kernel or module */
> +int kernel_address(unsigned long addr)
> +{
> + return core_kernel_address(addr) || is_module_address(addr);
> +}
> +
> /*
> * On some architectures (PPC64, IA64) function pointers
> * are actually only tokens to some data that then holds the
> --
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