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: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Helge Deller <deller@gmx.de> #parisc64
Signed-off-by: Petr Mladek <pmladek@suse.com>
This commit is contained in:
Sergey Senozhatsky 2017-11-10 08:48:28 +09:00 committed by Petr Mladek
parent 5633e85b2c
commit 1705bd6a68
5 changed files with 35 additions and 0 deletions

View File

@ -29,7 +29,9 @@ SECTIONS
. = ALIGN(16);
/* Linkage tables */
.opd : {
__start_opd = .;
*(.opd)
__end_opd = .;
} PROVIDE (__gp = .);
.plt : {
*(.plt)

View File

@ -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

View File

@ -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

View File

@ -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)

View File

@ -100,7 +100,9 @@ SECTIONS
. = ALIGN(16);
/* Linkage tables */
.opd : {
__start_opd = .;
*(.opd)
__end_opd = .;
} PROVIDE (__gp = .);
.plt : {
*(.plt)