forked from Minki/linux
8a293be0d6
These files were including module.h for exception table related functions. We've now separated that content out into its own file "extable.h" so now move over to that and where possible, avoid all the extra header content in module.h that we don't really need to compile these non-modular files. Note: init/main.c still needs module.h for __init_or_module kernel/extable.c still needs module.h for is_module_text_address ...and so we don't get the benefit of removing module.h from the cpp feed for these two files, unlike the almost universal 1:1 exchange of module.h for extable.h we were able to do in the arch dirs. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
145 lines
4.0 KiB
C
145 lines
4.0 KiB
C
/* Rewritten by Rusty Russell, on the backs of many others...
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Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/ftrace.h>
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#include <linux/memory.h>
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#include <linux/extable.h>
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#include <linux/module.h>
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#include <linux/mutex.h>
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#include <linux/init.h>
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#include <asm/sections.h>
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#include <linux/uaccess.h>
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/*
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* mutex protecting text section modification (dynamic code patching).
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* some users need to sleep (allocating memory...) while they hold this lock.
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*
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* NOT exported to modules - patching kernel text is a really delicate matter.
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*/
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DEFINE_MUTEX(text_mutex);
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extern struct exception_table_entry __start___ex_table[];
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extern struct exception_table_entry __stop___ex_table[];
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/* Cleared by build time tools if the table is already sorted. */
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u32 __initdata __visible main_extable_sort_needed = 1;
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/* Sort the kernel's built-in exception table */
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void __init sort_main_extable(void)
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{
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if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) {
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pr_notice("Sorting __ex_table...\n");
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sort_extable(__start___ex_table, __stop___ex_table);
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}
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}
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/* Given an address, look for it in the exception tables. */
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const struct exception_table_entry *search_exception_tables(unsigned long addr)
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{
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const struct exception_table_entry *e;
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e = search_extable(__start___ex_table, __stop___ex_table-1, addr);
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if (!e)
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e = search_module_extables(addr);
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return e;
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}
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static inline int init_kernel_text(unsigned long addr)
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{
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if (addr >= (unsigned long)_sinittext &&
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addr < (unsigned long)_einittext)
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return 1;
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return 0;
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}
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int core_kernel_text(unsigned long addr)
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{
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if (addr >= (unsigned long)_stext &&
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addr < (unsigned long)_etext)
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return 1;
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if (system_state == SYSTEM_BOOTING &&
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init_kernel_text(addr))
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return 1;
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return 0;
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}
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/**
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* core_kernel_data - tell if addr points to kernel data
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* @addr: address to test
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*
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* Returns true if @addr passed in is from the core kernel data
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* section.
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*
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* Note: On some archs it may return true for core RODATA, and false
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* for others. But will always be true for core RW data.
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*/
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int core_kernel_data(unsigned long addr)
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{
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if (addr >= (unsigned long)_sdata &&
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addr < (unsigned long)_edata)
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return 1;
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return 0;
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}
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int __kernel_text_address(unsigned long addr)
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{
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if (core_kernel_text(addr))
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return 1;
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if (is_module_text_address(addr))
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return 1;
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if (is_ftrace_trampoline(addr))
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return 1;
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/*
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* There might be init symbols in saved stacktraces.
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* Give those symbols a chance to be printed in
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* backtraces (such as lockdep traces).
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*
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* Since we are after the module-symbols check, there's
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* no danger of address overlap:
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*/
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if (init_kernel_text(addr))
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return 1;
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return 0;
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}
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int kernel_text_address(unsigned long addr)
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{
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if (core_kernel_text(addr))
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return 1;
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if (is_module_text_address(addr))
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return 1;
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return is_ftrace_trampoline(addr);
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}
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/*
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* On some architectures (PPC64, IA64) function pointers
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* are actually only tokens to some data that then holds the
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* real function address. As a result, to find if a function
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* pointer is part of the kernel text, we need to do some
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* special dereferencing first.
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*/
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int func_ptr_is_kernel_text(void *ptr)
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{
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unsigned long addr;
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addr = (unsigned long) dereference_function_descriptor(ptr);
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if (core_kernel_text(addr))
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return 1;
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return is_module_text_address(addr);
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}
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