5e37661389
Even since a previous patch: Fix race between CONFIG_DEBUG_SLABALLOC and modules Sun, 27 Jun 2004 17:55:19 +0000 (17:55 +0000) http://www.kernel.org/git/?p=linux/kernel/git/torvalds/old-2.6-bkcvs.git;a=commit;h=92b3db26d31cf21b70e3c1eadc56c179506d8fbe The function symbol_put_addr() will deadlock the kernel. symbol_put_addr() would acquire modlist_lock, then while holding the lock call two functions kernel_text_address() and module_text_address() which also try to acquire the same lock. This deadlocks the kernel of course. This patch changes symbol_put_addr() to not acquire the modlist_lock, it doesn't need it since it never looks at the module list directly. Also, it now uses core_kernel_text() instead of kernel_text_address(). The latter has an additional check for addr inside a module, but we don't need to do that since we call module_text_address() (the same function kernel_text_address uses) ourselves. Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Cc: Zwane Mwaikambo <zwane@fsmlabs.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Johannes Stezenbach <js@linuxtv.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
68 lines
2.0 KiB
C
68 lines
2.0 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/module.h>
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#include <linux/init.h>
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#include <asm/uaccess.h>
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#include <asm/sections.h>
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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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/* 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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sort_extable(__start___ex_table, __stop___ex_table);
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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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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 (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 __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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return __module_text_address(addr) != NULL;
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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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return module_text_address(addr) != NULL;
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}
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