Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 9 Feb 2002 17:08:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 9 Feb 2002 17:08:16 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:56588 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id ; Sat, 9 Feb 2002 17:07:58 -0500 Message-ID: <3C659D8A.37EA0155@zip.com.au> Date: Sat, 09 Feb 2002 14:07:06 -0800 From: Andrew Morton X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.18-pre9 i686) X-Accept-Language: en MIME-Version: 1.0 To: Linus Torvalds CC: Hugh Dickins , Marcelo Tosatti , "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: [PATCH] BUG preserve registers In-Reply-To: <3C658272.8C517D55@zip.com.au> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > > Yes. Make it so. This works for me, from in-kernel as well as in-module. It'd be good if someone more familiar with x86 could check it over. The ILL_ILLOPN information is not conveniently available within die(), but I think the opcode parsing here is sufficient? (There are no kernel source files >65535 lines. I checked :)) --- linux-2.4.18-pre9/include/asm-i386/page.h Thu Feb 7 13:04:22 2002 +++ linux-akpm/include/asm-i386/page.h Sat Feb 9 13:42:24 2002 @@ -91,17 +91,15 @@ typedef struct { unsigned long pgprot; } /* * Tell the user there is some problem. Beep too, so we can * see^H^H^Hhear bugs in early bootup as well! + * The offending file and line are encoded after the "officially + * undefined" opcode for parsing in the trap handler. */ -#ifdef CONFIG_DEBUG_BUGVERBOSE -extern void do_BUG(const char *file, int line); -#define BUG() do { \ - do_BUG(__FILE__, __LINE__); \ - __asm__ __volatile__("ud2"); \ -} while (0) -#else -#define BUG() __asm__ __volatile__(".byte 0x0f,0x0b") -#endif +#define BUG() \ + __asm__ __volatile__( "ud2\n" \ + "\t.word %c0\n" \ + "\t.long %c1\n" \ + : : "i" (__LINE__), "i" (__FILE__)) #define PAGE_BUG(page) do { \ BUG(); \ --- linux-2.4.18-pre9/arch/i386/kernel/traps.c Sun Sep 30 12:26:08 2001 +++ linux-akpm/arch/i386/kernel/traps.c Sat Feb 9 13:53:47 2002 @@ -237,6 +237,40 @@ bad: printk("\n"); } +static void handle_BUG(struct pt_regs *regs) +{ + unsigned short ud2; + unsigned short line; + char *file; + char c; + unsigned long eip; + + if (regs->xcs & 3) + goto no_bug; /* Not in kernel */ + + eip = regs->eip; + + if (eip < PAGE_OFFSET) + goto no_bug; + if (__get_user(ud2, (unsigned short *)eip)) + goto no_bug; + if (ud2 != 0x0b0f) + goto no_bug; + if (__get_user(line, (unsigned short *)(eip + 2))) + goto no_bug; + if (__get_user(file, (char **)(eip + 4))) + goto no_bug; + if ((unsigned long)file < PAGE_OFFSET) + goto no_bug; + if (__get_user(c, file)) + file = ""; + + printk("Kernel BUG at %s:%d\n", file, line); + +no_bug: + return; +} + spinlock_t die_lock = SPIN_LOCK_UNLOCKED; void die(const char * str, struct pt_regs * regs, long err) @@ -244,6 +278,7 @@ void die(const char * str, struct pt_reg console_verbose(); spin_lock_irq(&die_lock); bust_spinlocks(1); + handle_BUG(regs); printk("%s: %04lx\n", str, err & 0xffff); show_registers(regs); bust_spinlocks(0); --- linux-2.4.18-pre9/arch/i386/kernel/i386_ksyms.c Thu Feb 7 13:04:11 2002 +++ linux-akpm/arch/i386/kernel/i386_ksyms.c Sat Feb 9 13:42:24 2002 @@ -168,9 +168,5 @@ EXPORT_SYMBOL_NOVERS(memset); EXPORT_SYMBOL(atomic_dec_and_lock); #endif -#ifdef CONFIG_DEBUG_BUGVERBOSE -EXPORT_SYMBOL(do_BUG); -#endif - extern int is_sony_vaio_laptop; EXPORT_SYMBOL(is_sony_vaio_laptop); --- linux-2.4.18-pre9/arch/i386/config.in Thu Feb 7 13:04:11 2002 +++ linux-akpm/arch/i386/config.in Sat Feb 9 13:42:24 2002 @@ -421,7 +421,6 @@ if [ "$CONFIG_DEBUG_KERNEL" != "n" ]; th bool ' Memory mapped I/O debugging' CONFIG_DEBUG_IOVIRT bool ' Magic SysRq key' CONFIG_MAGIC_SYSRQ bool ' Spinlock debugging' CONFIG_DEBUG_SPINLOCK - bool ' Verbose BUG() reporting (adds 70K)' CONFIG_DEBUG_BUGVERBOSE fi endmenu --- linux-2.4.18-pre9/arch/i386/mm/fault.c Thu Feb 7 13:04:11 2002 +++ linux-akpm/arch/i386/mm/fault.c Sat Feb 9 13:42:24 2002 @@ -125,12 +125,6 @@ void bust_spinlocks(int yes) } } -void do_BUG(const char *file, int line) -{ - bust_spinlocks(1); - printk("kernel BUG at %s:%d!\n", file, line); -} - asmlinkage void do_invalid_op(struct pt_regs *, unsigned long); extern unsigned long idt; - 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/