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Commit 1705bd6a authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Petr Mladek
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parisc64: Add .opd based function descriptor dereference 

We are moving towards separate kernel and module function descriptor
dereference callbacks. This patch enables it for parisc64.

For pointers that belong to the kernel
-  Added __start_opd and __end_opd pointers, to track the kernel
   .opd section address range;

-  Added dereference_kernel_function_descriptor(). Now we
   will dereference only function pointers that are within
   [__start_opd, __end_opd);

For pointers that belong to a module
-  Added dereference_module_function_descriptor() to handle module
   function descriptor dereference. Now we will dereference only
   pointers that are within [module->opd.start, module->opd.end).

Link: http://lkml.kernel.org/r/20171109234830.5067-5-sergey.senozhatsky@gmail.com


To: Tony Luck <tony.luck@intel.com>
To: Fenghua Yu <fenghua.yu@intel.com>
To: Helge Deller <deller@gmx.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Paul Mackerras <paulus@samba.org>
To: Michael Ellerman <mpe@ellerman.id.au>
To: James Bottomley <jejb@parisc-linux.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Helge Deller <deller@gmx.de> #parisc64
Signed-off-by: default avatarPetr Mladek <pmladek@suse.com>
parent 5633e85b

arch/parisc/boot/compressed/vmlinux.lds.S

+2 −0
Original line number Diff line number Diff line
@@ -29,7 +29,9 @@ SECTIONS 
	. = ALIGN(16);

	/* Linkage tables */

	.opd : {

		__start_opd = .;

		*(.opd)

		__end_opd = .;

	} PROVIDE (__gp = .);

	.plt : {

		*(.plt)

arch/parisc/include/asm/sections.h

+6 −0
Original line number Diff line number Diff line
@@ -6,8 +6,14 @@ 
#include <asm-generic/sections.h>



#ifdef CONFIG_64BIT



#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1



#undef dereference_function_descriptor

void *dereference_function_descriptor(void *);



#undef dereference_kernel_function_descriptor

void *dereference_kernel_function_descriptor(void *);

#endif



#endif

arch/parisc/kernel/module.c

+16 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ 


#include <asm/pgtable.h>

#include <asm/unwind.h>

#include <asm/sections.h>



#if 0

#define DEBUGP printk
@@ -954,3 +955,18 @@ void module_arch_cleanup(struct module *mod) 
{

	deregister_unwind_table(mod);

}



#ifdef CONFIG_64BIT

void *dereference_module_function_descriptor(struct module *mod, void *ptr)

{

	unsigned long start_opd = (Elf64_Addr)mod->core_layout.base +

				   mod->arch.fdesc_offset;

	unsigned long end_opd = start_opd +

				mod->arch.fdesc_count * sizeof(Elf64_Fdesc);



	if (ptr < (void *)start_opd || ptr >= (void *)end_opd)

		return ptr;



	return dereference_function_descriptor(ptr);

}

#endif

arch/parisc/kernel/process.c

+9 −0
Original line number Diff line number Diff line
@@ -276,6 +276,15 @@ void *dereference_function_descriptor(void *ptr) 
		ptr = p;

	return ptr;

}



void *dereference_kernel_function_descriptor(void *ptr)

{

	if (ptr < (void *)__start_opd ||

			ptr >= (void *)__end_opd)

		return ptr;



	return dereference_function_descriptor(ptr);

}

#endif



static inline unsigned long brk_rnd(void)

arch/parisc/kernel/vmlinux.lds.S

+2 −0
Original line number Diff line number Diff line
@@ -100,7 +100,9 @@ SECTIONS 
	. = ALIGN(16);

	/* Linkage tables */

	.opd : {

		__start_opd = .;

		*(.opd)

		__end_opd = .;

	} PROVIDE (__gp = .);

	.plt : {

		*(.plt)