diff options
Diffstat (limited to 'kernel/extable.c')
| -rw-r--r-- | kernel/extable.c | 98 |
1 files changed, 46 insertions, 52 deletions
diff --git a/kernel/extable.c b/kernel/extable.c index 6a5b61ebc66c..71f482581cab 100644 --- a/kernel/extable.c +++ b/kernel/extable.c @@ -1,20 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* Rewritten by Rusty Russell, on the backs of many others... Copyright (C) 2001 Rusty Russell, 2002 Rusty Russell IBM. - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include <linux/elf.h> #include <linux/ftrace.h> #include <linux/memory.h> #include <linux/extable.h> @@ -46,58 +35,41 @@ u32 __initdata __visible main_extable_sort_needed = 1; /* Sort the kernel's built-in exception table */ void __init sort_main_extable(void) { - if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) { + if (main_extable_sort_needed && + &__stop___ex_table > &__start___ex_table) { pr_notice("Sorting __ex_table...\n"); sort_extable(__start___ex_table, __stop___ex_table); } } +/* Given an address, look for it in the kernel exception table */ +const +struct exception_table_entry *search_kernel_exception_table(unsigned long addr) +{ + return search_extable(__start___ex_table, + __stop___ex_table - __start___ex_table, addr); +} + /* Given an address, look for it in the exception tables. */ const struct exception_table_entry *search_exception_tables(unsigned long addr) { const struct exception_table_entry *e; - e = search_extable(__start___ex_table, - __stop___ex_table - __start___ex_table, addr); + e = search_kernel_exception_table(addr); if (!e) e = search_module_extables(addr); + if (!e) + e = search_bpf_extables(addr); return e; } -int init_kernel_text(unsigned long addr) -{ - if (addr >= (unsigned long)_sinittext && - addr < (unsigned long)_einittext) - return 1; - return 0; -} - int notrace core_kernel_text(unsigned long addr) { - if (addr >= (unsigned long)_stext && - addr < (unsigned long)_etext) + if (is_kernel_text(addr)) return 1; - if (system_state < SYSTEM_RUNNING && - init_kernel_text(addr)) - return 1; - return 0; -} - -/** - * core_kernel_data - tell if addr points to kernel data - * @addr: address to test - * - * Returns true if @addr passed in is from the core kernel data - * section. - * - * Note: On some archs it may return true for core RODATA, and false - * for others. But will always be true for core RW data. - */ -int core_kernel_data(unsigned long addr) -{ - if (addr >= (unsigned long)_sdata && - addr < (unsigned long)_edata) + if (system_state < SYSTEM_FREEING_INITMEM && + is_kernel_inittext(addr)) return 1; return 0; } @@ -114,7 +86,7 @@ int __kernel_text_address(unsigned long addr) * Since we are after the module-symbols check, there's * no danger of address overlap: */ - if (init_kernel_text(addr)) + if (is_kernel_inittext(addr)) return 1; return 0; } @@ -134,14 +106,15 @@ int kernel_text_address(unsigned long addr) * triggers a stack trace, or a WARN() that happens during * coming back from idle, or cpu on or offlining. * - * is_module_text_address() as well as the kprobe slots - * and is_bpf_text_address() require RCU to be watching. + * is_module_text_address() as well as the kprobe slots, + * is_bpf_text_address() and is_bpf_image_address require + * RCU to be watching. */ no_rcu = !rcu_is_watching(); /* Treat this like an NMI as it can happen anywhere */ if (no_rcu) - rcu_nmi_enter(); + ct_nmi_enter(); if (is_module_text_address(addr)) goto out; @@ -154,18 +127,39 @@ int kernel_text_address(unsigned long addr) ret = 0; out: if (no_rcu) - rcu_nmi_exit(); + ct_nmi_exit(); return ret; } /* - * On some architectures (PPC64, IA64) function pointers + * On some architectures (PPC64, IA64, PARISC) function pointers * are actually only tokens to some data that then holds the * real function address. As a result, to find if a function * pointer is part of the kernel text, we need to do some * special dereferencing first. */ +#ifdef CONFIG_HAVE_FUNCTION_DESCRIPTORS +void *dereference_function_descriptor(void *ptr) +{ + func_desc_t *desc = ptr; + void *p; + + if (!get_kernel_nofault(p, (void *)&desc->addr)) + ptr = p; + return ptr; +} +EXPORT_SYMBOL_GPL(dereference_function_descriptor); + +void *dereference_kernel_function_descriptor(void *ptr) +{ + if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd) + return ptr; + + return dereference_function_descriptor(ptr); +} +#endif + int func_ptr_is_kernel_text(void *ptr) { unsigned long addr; |