We are moving towards separate kernel and module function descriptor
dereference callbacks. This patch enables it for powerpc64.
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/20171109234830.5067-4-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: Petr Mladek <pmladek@suse.com>
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
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Santosh Sivaraj <santosh@fossix.org> #powerpc
Signed-off-by: Petr Mladek <pmladek@suse.com>
unsigned long tramp;
#endif
+ /* For module function descriptor dereference */
+ unsigned long start_opd;
+ unsigned long end_opd;
#else /* powerpc64 */
/* Indices of PLT sections within module. */
unsigned int core_plt_section;
}
#ifdef PPC64_ELF_ABI_v1
+
+#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1
+
#undef dereference_function_descriptor
static inline void *dereference_function_descriptor(void *ptr)
{
ptr = p;
return ptr;
}
+
+#undef dereference_kernel_function_descriptor
+static inline void *dereference_kernel_function_descriptor(void *ptr)
+{
+ if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd)
+ return ptr;
+
+ return dereference_function_descriptor(ptr);
+}
#endif /* PPC64_ELF_ABI_v1 */
#endif
{
return 0;
}
+
+void *dereference_module_function_descriptor(struct module *mod, void *ptr)
+{
+ if (ptr < (void *)mod->arch.start_opd ||
+ ptr >= (void *)mod->arch.end_opd)
+ return ptr;
+
+ return dereference_function_descriptor(ptr);
+}
#endif
#define STUB_MAGIC 0x73747562 /* stub */
else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0)
dedotify_versions((void *)hdr + sechdrs[i].sh_offset,
sechdrs[i].sh_size);
+ else if (!strcmp(secstrings + sechdrs[i].sh_name, ".opd")) {
+ me->arch.start_opd = sechdrs[i].sh_addr;
+ me->arch.end_opd = sechdrs[i].sh_addr +
+ sechdrs[i].sh_size;
+ }
/* We don't handle .init for the moment: rename to _init */
while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init")))
}
.opd : AT(ADDR(.opd) - LOAD_OFFSET) {
+ __start_opd = .;
*(.opd)
+ __end_opd = .;
}
. = ALIGN(256);