Messages in this thread | | | Date | Tue, 5 Jan 2010 09:58:53 +0100 | From | Sam Ravnborg <> | Subject | Re: [PATCH] [2/9] Add a kernel_address() that works for data too |
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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@vger.kernel.org > Signed-off-by: Andi Kleen <ak@linux.intel.com> > > --- > 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 > -- > To unsubscribe from this list: send the line "unsubscribe linux-arch" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
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