From: Ben Gras Date: Fri, 22 Jul 2011 10:55:04 +0000 (+0000) Subject: kernel: improve exception debug printing X-Git-Tag: v3.2.0~429 X-Git-Url: http://zhaoyanbai.com/repos/%22/xml/v3/mem/static/tz-link.htm?a=commitdiff_plain;h=7ee78ffb82c2d9810271cf7ba47cbab0c194faf1;p=minix.git kernel: improve exception debug printing . fold 2 exception-in-kernel cases (pagefault and rest) into 1 . for exceptions that occur in kernel, don't just print kernel stacktrace (typically that is just the exception handler) but also the stacktrace of when the exception happened --- diff --git a/kernel/arch/i386/exception.c b/kernel/arch/i386/exception.c index da1e6c8c8..294f0355e 100644 --- a/kernel/arch/i386/exception.c +++ b/kernel/arch/i386/exception.c @@ -12,8 +12,39 @@ #include "kernel/proto.h" #include +struct ex_s { + char *msg; + int signum; + int minprocessor; +}; + +static struct ex_s ex_data[] = { + { "Divide error", SIGFPE, 86 }, + { "Debug exception", SIGTRAP, 86 }, + { "Nonmaskable interrupt", SIGBUS, 86 }, + { "Breakpoint", SIGEMT, 86 }, + { "Overflow", SIGFPE, 86 }, + { "Bounds check", SIGFPE, 186 }, + { "Invalid opcode", SIGILL, 186 }, + { "Coprocessor not available", SIGFPE, 186 }, + { "Double fault", SIGBUS, 286 }, + { "Coprocessor segment overrun", SIGSEGV, 286 }, + { "Invalid TSS", SIGSEGV, 286 }, + { "Segment not present", SIGSEGV, 286 }, + { "Stack exception", SIGSEGV, 286 }, /* STACK_FAULT already used */ + { "General protection", SIGSEGV, 286 }, + { "Page fault", SIGSEGV, 386 }, /* not close */ + { NULL, SIGILL, 0 }, /* probably software trap */ + { "Coprocessor error", SIGFPE, 386 }, + { "Alignment check", SIGBUS, 386 }, + { "Machine check", SIGBUS, 386 }, + { "SIMD exception", SIGFPE, 386 }, +}; + extern int catch_pagefaults; +PRIVATE void proc_stacktrace_execute(struct proc *whichproc, reg_t v_bp, reg_t pc); + PRIVATE void pagefault( struct proc *pr, struct exception_frame * frame, int is_nested) @@ -51,7 +82,9 @@ PRIVATE void pagefault( struct proc *pr, } if(is_nested) { - panic("pagefault in kernel at pc 0x%lx address 0x%lx", frame->eip, pagefaultcr2); + printf("pagefault in kernel at pc 0x%lx address 0x%lx\n", + frame->eip, pagefaultcr2); + inkernel_disaster(pr, frame, NULL, is_nested); } /* System processes that don't have their own page table can't @@ -91,40 +124,59 @@ PRIVATE void pagefault( struct proc *pr, return; } +PRIVATE void inkernel_disaster(struct proc *saved_proc, + struct exception_frame * frame, struct ex_s *ep, + int is_nested) +{ + if(ep) { + if (ep->msg == NULL || machine.processor < ep->minprocessor) + printf("\nIntel-reserved exception %d\n", frame->vector); + else + printf("\n%s\n", ep->msg); + } + + printf("cpu %d is_nested = %d ", cpuid, is_nested); + + printf("vec_nr= %d, trap_errno= 0x%x, eip= 0x%x, " + "cs= 0x%x, eflags= 0x%x trap_esp 0x%08x\n", + frame->vector, frame->errcode, frame->eip, + frame->cs, frame->eflags, frame); + printf("KERNEL registers :\n"); +#define REG(n) (((u32_t *)frame)[-n]) + printf( + "\t%%eax 0x%08x %%ebx 0x%08x %%ecx 0x%08x %%edx 0x%08x\n" + "\t%%esp 0x%08x %%ebp 0x%08x %%esi 0x%08x %%edi 0x%08x\n", + REG(1), REG(2), REG(3), REG(4), + REG(5), REG(6), REG(7), REG(8)); + + { + reg_t k_ebp = REG(6); + printf("KERNEL stacktrace, starting with ebp = 0x%lx:\n", k_ebp); + proc_stacktrace_execute(proc_addr(SYSTEM), k_ebp, frame->eip); + } + + printseg("ker cs: ", 1, NULL, frame->cs); + printseg("ker ds: ", 0, NULL, DS_SELECTOR); + + if (saved_proc) { + printf("scheduled was: process %d (%s), ", saved_proc->p_endpoint, saved_proc->p_name); + printf("pc = %u:0x%x\n", (unsigned) saved_proc->p_reg.cs, + (unsigned) saved_proc->p_reg.pc); + proc_stacktrace(saved_proc); + + panic("Unhandled kernel exception"); + } + + /* in an early stage of boot process we don't have processes yet */ + panic("exception in kernel while booting, no saved_proc yet"); +} + /*===========================================================================* * exception * *===========================================================================*/ PUBLIC void exception_handler(int is_nested, struct exception_frame * frame) { /* An exception or unexpected interrupt has occurred. */ - - struct ex_s { - char *msg; - int signum; - int minprocessor; - }; - static struct ex_s ex_data[] = { - { "Divide error", SIGFPE, 86 }, - { "Debug exception", SIGTRAP, 86 }, - { "Nonmaskable interrupt", SIGBUS, 86 }, - { "Breakpoint", SIGEMT, 86 }, - { "Overflow", SIGFPE, 86 }, - { "Bounds check", SIGFPE, 186 }, - { "Invalid opcode", SIGILL, 186 }, - { "Coprocessor not available", SIGFPE, 186 }, - { "Double fault", SIGBUS, 286 }, - { "Coprocessor segment overrun", SIGSEGV, 286 }, - { "Invalid TSS", SIGSEGV, 286 }, - { "Segment not present", SIGSEGV, 286 }, - { "Stack exception", SIGSEGV, 286 }, /* STACK_FAULT already used */ - { "General protection", SIGSEGV, 286 }, - { "Page fault", SIGSEGV, 386 }, /* not close */ - { NULL, SIGILL, 0 }, /* probably software trap */ - { "Coprocessor error", SIGFPE, 386 }, - { "Alignment check", SIGBUS, 386 }, - { "Machine check", SIGBUS, 386 }, - { "SIMD exception", SIGFPE, 386 }, - }; register struct ex_s *ep; struct proc *saved_proc; @@ -196,63 +248,27 @@ PUBLIC void exception_handler(int is_nested, struct exception_frame * frame) } /* Exception in system code. This is not supposed to happen. */ - if (ep->msg == NULL || machine.processor < ep->minprocessor) - printf("\nIntel-reserved exception %d\n", frame->vector); - else - printf("\n%s\n", ep->msg); - printf("cpu %d is_nested = %d ", cpuid, is_nested); + inkernel_disaster(saved_proc, frame, ep, is_nested); - printf("vec_nr= %d, trap_errno= 0x%x, eip= 0x%x, " - "cs= 0x%x, eflags= 0x%x trap_esp 0x%08x\n", - frame->vector, frame->errcode, frame->eip, - frame->cs, frame->eflags, frame); - printf("KERNEL registers :\n"); - printf( - "\t%%eax 0x%08x %%ebx 0x%08x %%ecx 0x%08x %%edx 0x%08x\n" - "\t%%esp 0x%08x %%ebp 0x%08x %%esi 0x%08x %%edi 0x%08x\n", - ((u32_t *)frame)[-1], - ((u32_t *)frame)[-2], - ((u32_t *)frame)[-3], - ((u32_t *)frame)[-4], - ((u32_t *)frame)[-5], - ((u32_t *)frame)[-6], - ((u32_t *)frame)[-7], - ((u32_t *)frame)[-8] - ); - printseg("ker cs: ", 1, NULL, frame->cs); - printseg("ker ds: ", 0, NULL, DS_SELECTOR); - /* TODO should we enable this only when compiled for some debug mode? */ - if (saved_proc) { - printf("scheduled was: process %d (%s), ", proc_nr(saved_proc), saved_proc->p_name); - printf("pc = %u:0x%x\n", (unsigned) saved_proc->p_reg.cs, - (unsigned) saved_proc->p_reg.pc); - proc_stacktrace(saved_proc); - - panic("Unhandled kernel exception"); - } - else { - /* in an early stage of boot process we don't have processes yet */ - panic("exception in kernel while booting"); - } + panic("return from inkernel_disaster"); } /*===========================================================================* - * stacktrace * + * proc_stacktrace_execute * *===========================================================================*/ -PUBLIC void proc_stacktrace(struct proc *whichproc) +PRIVATE void proc_stacktrace_execute(struct proc *whichproc, reg_t v_bp, reg_t pc) { - reg_t v_bp, v_pc, v_hbp; + reg_t v_hbp; int iskernel; int n = 0; - v_bp = whichproc->p_reg.fp; - iskernel = iskernelp(whichproc); printf("%-8.8s %6d 0x%lx ", - whichproc->p_name, whichproc->p_endpoint, whichproc->p_reg.pc); + whichproc->p_name, whichproc->p_endpoint, pc); while(v_bp) { + reg_t v_pc; #define PRCOPY(pr, pv, v, n) \ (iskernel ? (memcpy((char *) v, (char *) pv, n), OK) : \ @@ -272,12 +288,22 @@ PUBLIC void proc_stacktrace(struct proc *whichproc) break; } v_bp = v_hbp; - if(n++ > 50) + if(n++ > 50) { + printf("(truncated after %d steps) ", n); break; + } } printf("\n"); } +/*===========================================================================* + * proc_stacktrace * + *===========================================================================*/ +PUBLIC void proc_stacktrace(struct proc *whichproc) +{ + proc_stacktrace_execute(whichproc, whichproc->p_reg.fp, whichproc->p_reg.pc); +} + PUBLIC void enable_fpu_exception(void) { u32_t cr0 = read_cr0();