Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751179AbWJQTaB (ORCPT ); Tue, 17 Oct 2006 15:30:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751187AbWJQTaB (ORCPT ); Tue, 17 Oct 2006 15:30:01 -0400 Received: from gw.goop.org ([64.81.55.164]:52910 "EHLO mail.goop.org") by vger.kernel.org with ESMTP id S1751179AbWJQT37 (ORCPT ); Tue, 17 Oct 2006 15:29:59 -0400 Message-ID: <4535310C.40708@goop.org> Date: Tue, 17 Oct 2006 12:37:48 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Andrew Morton CC: linux-kernel@vger.kernel.org, Michael Ellerman , Paul Mackerras , Benjamin Herrenschmidt , Rusty Russell Subject: Re: 2.6.19-rc2-mm1 References: <20061016230645.fed53c5b.akpm@osdl.org> In-Reply-To: <20061016230645.fed53c5b.akpm@osdl.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13837 Lines: 477 Andrew Morton wrote: > -generic-implementatation-of-bug.patch > -generic-implementatation-of-bug-fix.patch > +generic-bug-implementation.patch > generic-bug-for-i386.patch > generic-bug-for-x86-64.patch > uml-add-generic-bug-support.patch > use-generic-bug-for-ppc.patch > bug-test-1.patch > > Updated generic-BUG-handling patches > I thought the powerpc patch had been given a clean bill of health? Or was there still a problem with it? J -- From: Jeremy Fitzhardinge Subject: Generic BUG for powerpc This makes powerpc use the generic BUG machinery. The biggest difference from the previous powerpc bug code is that it no longer reports the function name, since it is redundant with kallsyms, and not needed in general. There is an overall reduction of code, since module_32/64 duplicated several functions. Unfortunately there's no way to tell gcc that BUG won't return, so the BUG macro includes a goto loop. This will generate a real jmp instruction, which is never used. BTW, powerpc doesn't seem to be using BUG_OPCODE or BUG_ILLEGAL_INSTRUCTION for actual BUGs any more (I presume they were once used). There are still a couple of uses of those macros elsewhere (kernel/prom_init.c and kernel/head_64.S); should be converted to "twi 31,0,0" as well? Signed-off-by: Jeremy Fitzhardinge Cc: Andi Kleen Cc: Hugh Dickens Cc: Michael Ellerman Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Rusty Russell Signed-off-by: Andrew Morton --- arch/powerpc/Kconfig | 5 ++ arch/powerpc/kernel/module_32.c | 45 +------------------ arch/powerpc/kernel/module_64.c | 45 +------------------ arch/powerpc/kernel/traps.c | 47 +++----------------- arch/powerpc/kernel/vmlinux.lds.S | 6 -- arch/powerpc/xmon/xmon.c | 11 ++-- include/asm-powerpc/bug.h | 84 ++++++++++++++++++------------------- include/asm-powerpc/module.h | 2 8 files changed, 70 insertions(+), 175 deletions(-) diff -r 19fef64d6aef arch/powerpc/Kconfig --- a/arch/powerpc/Kconfig Tue Oct 17 12:26:34 2006 -0700 +++ b/arch/powerpc/Kconfig Tue Oct 17 12:34:09 2006 -0700 @@ -106,6 +106,11 @@ config AUDIT_ARCH config AUDIT_ARCH bool default y + +config GENERIC_BUG + bool + default y + depends on BUG config DEFAULT_UIMAGE bool diff -r 19fef64d6aef arch/powerpc/kernel/module_32.c --- a/arch/powerpc/kernel/module_32.c Tue Oct 17 12:26:34 2006 -0700 +++ b/arch/powerpc/kernel/module_32.c Tue Oct 17 12:34:09 2006 -0700 @@ -23,6 +23,7 @@ #include #include #include +#include #if 0 #define DEBUGP printk @@ -273,48 +274,10 @@ int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { - char *secstrings; - unsigned int i; - - me->arch.bug_table = NULL; - me->arch.num_bugs = 0; - - /* Find the __bug_table section, if present */ - secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - for (i = 1; i < hdr->e_shnum; i++) { - if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table")) - continue; - me->arch.bug_table = (void *) sechdrs[i].sh_addr; - me->arch.num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry); - break; - } - - /* - * Strictly speaking this should have a spinlock to protect against - * traversals, but since we only traverse on BUG()s, a spinlock - * could potentially lead to deadlock and thus be counter-productive. - */ - list_add(&me->arch.bug_list, &module_bug_list); - - return 0; + return module_bug_finalize(hdr, sechdrs, me); } void module_arch_cleanup(struct module *mod) { - list_del(&mod->arch.bug_list); -} - -struct bug_entry *module_find_bug(unsigned long bugaddr) -{ - struct mod_arch_specific *mod; - unsigned int i; - struct bug_entry *bug; - - list_for_each_entry(mod, &module_bug_list, bug_list) { - bug = mod->bug_table; - for (i = 0; i < mod->num_bugs; ++i, ++bug) - if (bugaddr == bug->bug_addr) - return bug; - } - return NULL; -} + module_bug_cleanup(mod); +} diff -r 19fef64d6aef arch/powerpc/kernel/module_64.c --- a/arch/powerpc/kernel/module_64.c Tue Oct 17 12:26:34 2006 -0700 +++ b/arch/powerpc/kernel/module_64.c Tue Oct 17 12:34:09 2006 -0700 @@ -20,6 +20,7 @@ #include #include #include +#include #include #include @@ -416,48 +417,10 @@ int module_finalize(const Elf_Ehdr *hdr, int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { - char *secstrings; - unsigned int i; - - me->arch.bug_table = NULL; - me->arch.num_bugs = 0; - - /* Find the __bug_table section, if present */ - secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; - for (i = 1; i < hdr->e_shnum; i++) { - if (strcmp(secstrings+sechdrs[i].sh_name, "__bug_table")) - continue; - me->arch.bug_table = (void *) sechdrs[i].sh_addr; - me->arch.num_bugs = sechdrs[i].sh_size / sizeof(struct bug_entry); - break; - } - - /* - * Strictly speaking this should have a spinlock to protect against - * traversals, but since we only traverse on BUG()s, a spinlock - * could potentially lead to deadlock and thus be counter-productive. - */ - list_add(&me->arch.bug_list, &module_bug_list); - - return 0; + return module_bug_finalize(hdr, sechdrs, me); } void module_arch_cleanup(struct module *mod) { - list_del(&mod->arch.bug_list); -} - -struct bug_entry *module_find_bug(unsigned long bugaddr) -{ - struct mod_arch_specific *mod; - unsigned int i; - struct bug_entry *bug; - - list_for_each_entry(mod, &module_bug_list, bug_list) { - bug = mod->bug_table; - for (i = 0; i < mod->num_bugs; ++i, ++bug) - if (bugaddr == bug->bug_addr) - return bug; - } - return NULL; -} + module_bug_cleanup(mod); +} diff -r 19fef64d6aef arch/powerpc/kernel/traps.c --- a/arch/powerpc/kernel/traps.c Tue Oct 17 12:26:34 2006 -0700 +++ b/arch/powerpc/kernel/traps.c Tue Oct 17 12:34:09 2006 -0700 @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -731,54 +732,9 @@ static int emulate_instruction(struct pt return -EINVAL; } -/* - * Look through the list of trap instructions that are used for BUG(), - * BUG_ON() and WARN_ON() and see if we hit one. At this point we know - * that the exception was caused by a trap instruction of some kind. - * Returns 1 if we should continue (i.e. it was a WARN_ON) or 0 - * otherwise. - */ -extern struct bug_entry __start___bug_table[], __stop___bug_table[]; - -#ifndef CONFIG_MODULES -#define module_find_bug(x) NULL -#endif - -struct bug_entry *find_bug(unsigned long bugaddr) -{ - struct bug_entry *bug; - - for (bug = __start___bug_table; bug < __stop___bug_table; ++bug) - if (bugaddr == bug->bug_addr) - return bug; - return module_find_bug(bugaddr); -} - -static int check_bug_trap(struct pt_regs *regs) -{ - struct bug_entry *bug; - unsigned long addr; - - if (regs->msr & MSR_PR) - return 0; /* not in kernel */ - addr = regs->nip; /* address of trap instruction */ - if (addr < PAGE_OFFSET) - return 0; - bug = find_bug(regs->nip); - if (bug == NULL) - return 0; - if (bug->line & BUG_WARNING_TRAP) { - /* this is a WARN_ON rather than BUG/BUG_ON */ - printk(KERN_ERR "Badness in %s at %s:%ld\n", - bug->function, bug->file, - bug->line & ~BUG_WARNING_TRAP); - dump_stack(); - return 1; - } - printk(KERN_CRIT "kernel BUG in %s at %s:%ld!\n", - bug->function, bug->file, bug->line); - - return 0; +int is_valid_bugaddr(unsigned long addr) +{ + return is_kernel_addr(addr); } void __kprobes program_check_exception(struct pt_regs *regs) @@ -812,7 +768,9 @@ void __kprobes program_check_exception(s return; if (debugger_bpt(regs)) return; - if (check_bug_trap(regs)) { + + if (!(regs->msr & MSR_PR) && /* not user-mode */ + report_bug(regs->nip) == BUG_TRAP_TYPE_WARN) { regs->nip += 4; return; } diff -r 19fef64d6aef arch/powerpc/kernel/vmlinux.lds.S --- a/arch/powerpc/kernel/vmlinux.lds.S Tue Oct 17 12:26:34 2006 -0700 +++ b/arch/powerpc/kernel/vmlinux.lds.S Tue Oct 17 12:34:09 2006 -0700 @@ -61,11 +61,7 @@ SECTIONS __stop___ex_table = .; } - __bug_table : { - __start___bug_table = .; - *(__bug_table) - __stop___bug_table = .; - } + BUG_TABLE /* * Init sections discarded at runtime diff -r 19fef64d6aef arch/powerpc/xmon/xmon.c --- a/arch/powerpc/xmon/xmon.c Tue Oct 17 12:26:34 2006 -0700 +++ b/arch/powerpc/xmon/xmon.c Tue Oct 17 12:34:35 2006 -0700 @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -35,7 +36,6 @@ #include #include #include -#include #include #ifdef CONFIG_PPC64 @@ -1332,7 +1332,7 @@ static void backtrace(struct pt_regs *ex static void print_bug_trap(struct pt_regs *regs) { - struct bug_entry *bug; + const struct bug_entry *bug; unsigned long addr; if (regs->msr & MSR_PR) @@ -1343,11 +1343,11 @@ static void print_bug_trap(struct pt_reg bug = find_bug(regs->nip); if (bug == NULL) return; - if (bug->line & BUG_WARNING_TRAP) + if (is_warning_bug(bug)) return; - printf("kernel BUG in %s at %s:%d!\n", - bug->function, bug->file, (unsigned int)bug->line); + printf("kernel BUG at %s:%u!\n", + bug->file, bug->line); } void excprint(struct pt_regs *fp) diff -r 19fef64d6aef include/asm-powerpc/bug.h --- a/include/asm-powerpc/bug.h Tue Oct 17 12:26:34 2006 -0700 +++ b/include/asm-powerpc/bug.h Tue Oct 17 12:34:09 2006 -0700 @@ -13,22 +13,25 @@ #ifndef __ASSEMBLY__ -struct bug_entry { - unsigned long bug_addr; - long line; - const char *file; - const char *function; -}; +#ifdef CONFIG_BUG -struct bug_entry *find_bug(unsigned long bugaddr); - -/* - * If this bit is set in the line number it means that the trap - * is for WARN_ON rather than BUG or BUG_ON. - */ -#define BUG_WARNING_TRAP 0x1000000 - -#ifdef CONFIG_BUG +/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags and + sizeof(struct bug_entry), respectively */ +#ifdef CONFIG_DEBUG_BUGVERBOSE +#define _EMIT_BUG_ENTRY \ + ".section __bug_table,\"a\"\n" \ + "2:\t" PPC_LONG "1b, %0\n" \ + "\t.short %1, %2\n" \ + ".org 2b+%3\n" \ + ".previous\n" +#else +#define _EMIT_BUG_ENTRY \ + ".section __bug_table,\"a\"\n" \ + "2:\t" PPC_LONG "1b\n" \ + "\t.short %2\n" \ + ".org 2b+%3\n" \ + ".previous\n" +#endif /* * BUG_ON() and WARN_ON() do their best to cooperate with compile-time @@ -36,14 +39,13 @@ struct bug_entry *find_bug(unsigned long * some compiler versions may not produce optimal results. */ -#define BUG() do { \ - __asm__ __volatile__( \ - "1: twi 31,0,0\n" \ - ".section __bug_table,\"a\"\n" \ - "\t"PPC_LONG" 1b,%0,%1,%2\n" \ - ".previous" \ - : : "i" (__LINE__), "i" (__FILE__), "i" (__FUNCTION__)); \ -} while (0) +#define BUG() do { \ + __asm__ __volatile__( \ + "1: twi 31,0,0\n" \ + _EMIT_BUG_ENTRY \ + : : "i" (__FILE__), "i" (__LINE__), "i" (0)); \ + for(;;) ; \ + } while (0) #define BUG_ON(x) do { \ if (__builtin_constant_p(x)) { \ @@ -51,23 +53,22 @@ struct bug_entry *find_bug(unsigned long BUG(); \ } else { \ __asm__ __volatile__( \ - "1: "PPC_TLNEI" %0,0\n" \ - ".section __bug_table,\"a\"\n" \ - "\t"PPC_LONG" 1b,%1,%2,%3\n" \ - ".previous" \ - : : "r" ((long)(x)), "i" (__LINE__), \ - "i" (__FILE__), "i" (__FUNCTION__)); \ + "1: "PPC_TLNEI" %4,0\n" \ + _EMIT_BUG_ENTRY \ + : : "i" (__FILE__), "i" (__LINE__), "i" (0), \ + "i" (sizeof(struct bug_entry)), \ + "r" ((long)(x))); \ + for(;;) ; \ } \ } while (0) #define __WARN() do { \ __asm__ __volatile__( \ "1: twi 31,0,0\n" \ - ".section __bug_table,\"a\"\n" \ - "\t"PPC_LONG" 1b,%0,%1,%2\n" \ - ".previous" \ - : : "i" (__LINE__ + BUG_WARNING_TRAP), \ - "i" (__FILE__), "i" (__FUNCTION__)); \ + _EMIT_BUG_ENTRY \ + : : "i" (__FILE__), "i" (__LINE__), \ + "i" (BUGFLAG_WARNING), \ + "i" (sizeof(struct bug_entry))); \ } while (0) #define WARN_ON(x) ({ \ @@ -77,13 +78,12 @@ struct bug_entry *find_bug(unsigned long __WARN(); \ } else { \ __asm__ __volatile__( \ - "1: "PPC_TLNEI" %0,0\n" \ - ".section __bug_table,\"a\"\n" \ - "\t"PPC_LONG" 1b,%1,%2,%3\n" \ - ".previous" \ - : : "r" (__ret_warn_on), \ - "i" (__LINE__ + BUG_WARNING_TRAP), \ - "i" (__FILE__), "i" (__FUNCTION__)); \ + "1: "PPC_TLNEI" %4,0\n" \ + _EMIT_BUG_ENTRY \ + : : "i" (__FILE__), "i" (__LINE__), \ + "i" (BUGFLAG_WARNING), \ + "i" (sizeof(struct bug_entry)), \ + "r" (__ret_warn_on)); \ } \ unlikely(__ret_warn_on); \ }) diff -r 19fef64d6aef include/asm-powerpc/module.h --- a/include/asm-powerpc/module.h Tue Oct 17 12:26:34 2006 -0700 +++ b/include/asm-powerpc/module.h Tue Oct 17 12:34:09 2006 -0700 @@ -45,8 +45,6 @@ struct mod_arch_specific { struct bug_entry *bug_table; unsigned int num_bugs; }; - -extern struct bug_entry *module_find_bug(unsigned long bugaddr); /* * Select ELF headers. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/