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[AVR32] Clean up exception handling code

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* Use generic BUG() handling
  * Remove some useless debug statements
  * Use a common function _exception() to send signals or oops when
    an exception can't be handled. This makes sure init doesn't
    enter an infinite exception loop as well. Borrowed from powerpc.
  * Add some basic exception tracing support to the page fault code.
  * Rework dump_stack(), show_regs() and friends and move everything
    into process.c
  * Print information about configuration options and chip type when
    oopsing

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This commit is contained in:
Haavard Skinnemoen
2007-03-13 17:59:11 +01:00
parent 3b328c9809
commit 623b0355d5
9 changed files with 403 additions and 418 deletions
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116
arch/avr32/mm/fault.c
View File

@@ -16,26 +16,8 @@
#include <asm/kdebug.h>
#include <asm/mmu_context.h>
#include <asm/sysreg.h>
#include <asm/uaccess.h>
#include <asm/tlb.h>
#ifdef DEBUG
static void dump_code(unsigned long pc)
{
char *p = (char *)pc;
char val;
int i;
printk(KERN_DEBUG "Code:");
for (i = 0; i < 16; i++) {
if (__get_user(val, p + i))
break;
printk(" %02x", val);
}
printk("\n");
}
#endif
#include <asm/uaccess.h>
#ifdef CONFIG_KPROBES
ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
@@ -68,17 +50,19 @@ static inline int notify_page_fault(enum die_val val, struct pt_regs *regs,
}
#endif
int exception_trace = 1;
/*
* This routine handles page faults. It determines the address and the
* problem, and then passes it off to one of the appropriate routines.
*
* ecr is the Exception Cause Register. Possible values are:
* 5: Page not found (instruction access)
* 6: Protection fault (instruction access)
* 12: Page not found (read access)
* 13: Page not found (write access)
* 14: Protection fault (read access)
* 15: Protection fault (write access)
* 15: Protection fault (read access)
* 16: Protection fault (write access)
* 20: Page not found (instruction access)
* 24: Page not found (read access)
* 28: Page not found (write access)
*/
asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
{
@@ -88,7 +72,9 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
const struct exception_table_entry *fixup;
unsigned long address;
unsigned long page;
int writeaccess = 0;
int writeaccess;
long signr;
int code;
if (notify_page_fault(DIE_PAGE_FAULT, regs,
ecr, SIGSEGV) == NOTIFY_STOP)
@@ -99,6 +85,9 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
tsk = current;
mm = tsk->mm;
signr = SIGSEGV;
code = SEGV_MAPERR;
/*
* If we're in an interrupt or have no user context, we must
* not take the fault...
@@ -125,7 +114,9 @@ asmlinkage void do_page_fault(unsigned long ecr, struct pt_regs *regs)
* can handle it...
*/
good_area:
//pr_debug("good area: vm_flags = 0x%lx\n", vma->vm_flags);
code = SEGV_ACCERR;
writeaccess = 0;
switch (ecr) {
case ECR_PROTECTION_X:
case ECR_TLB_MISS_X:
@@ -176,46 +167,24 @@ survive:
* map. Fix it, but check if it's kernel or user first...
*/
bad_area:
pr_debug("Bad area [%s:%u]: addr %08lx, ecr %lu\n",
tsk->comm, tsk->pid, address, ecr);
up_read(&mm->mmap_sem);
if (user_mode(regs)) {
/* Hmm...we have to pass address and ecr somehow... */
/* tsk->thread.address = address;
tsk->thread.error_code = ecr; */
#ifdef DEBUG
show_regs(regs);
dump_code(regs->pc);
page = sysreg_read(PTBR);
printk("ptbr = %08lx", page);
if (page) {
page = ((unsigned long *)page)[address >> 22];
printk(" pgd = %08lx", page);
if (page & _PAGE_PRESENT) {
page &= PAGE_MASK;
address &= 0x003ff000;
page = ((unsigned long *)__va(page))[address >> PAGE_SHIFT];
printk(" pte = %08lx\n", page);
}
}
#endif
pr_debug("Sending SIGSEGV to PID %d...\n",
tsk->pid);
force_sig(SIGSEGV, tsk);
if (exception_trace)
printk("%s%s[%d]: segfault at %08lx pc %08lx "
"sp %08lx ecr %lu\n",
is_init(tsk) ? KERN_EMERG : KERN_INFO,
tsk->comm, tsk->pid, address, regs->pc,
regs->sp, ecr);
_exception(SIGSEGV, regs, code, address);
return;
}
no_context:
pr_debug("No context\n");
/* Are we prepared to handle this kernel fault? */
fixup = search_exception_tables(regs->pc);
if (fixup) {
regs->pc = fixup->fixup;
pr_debug("Found fixup at %08lx\n", fixup->fixup);
return;
}
@@ -230,7 +199,6 @@ no_context:
printk(KERN_ALERT
"Unable to handle kernel paging request");
printk(" at virtual address %08lx\n", address);
printk(KERN_ALERT "pc = %08lx\n", regs->pc);
page = sysreg_read(PTBR);
printk(KERN_ALERT "ptbr = %08lx", page);
@@ -241,20 +209,20 @@ no_context:
page &= PAGE_MASK;
address &= 0x003ff000;
page = ((unsigned long *)__va(page))[address >> PAGE_SHIFT];
printk(" pte = %08lx\n", page);
printk(" pte = %08lx", page);
}
}
die("\nOops", regs, ecr);
do_exit(SIGKILL);
printk("\n");
die("Kernel access of bad area", regs, signr);
return;
/*
* We ran out of memory, or some other thing happened to us
* that made us unable to handle the page fault gracefully.
*/
out_of_memory:
printk("Out of memory\n");
up_read(&mm->mmap_sem);
if (current->pid == 1) {
if (is_init(current)) {
yield();
down_read(&mm->mmap_sem);
goto survive;
@@ -267,21 +235,20 @@ out_of_memory:
do_sigbus:
up_read(&mm->mmap_sem);
/*
* Send a sigbus, regardless of whether we were in kernel or
* user mode.
*/
/* address, error_code, trap_no, ... */
#ifdef DEBUG
show_regs(regs);
dump_code(regs->pc);
#endif
pr_debug("Sending SIGBUS to PID %d...\n", tsk->pid);
force_sig(SIGBUS, tsk);
/* Kernel mode? Handle exceptions or die */
signr = SIGBUS;
code = BUS_ADRERR;
if (!user_mode(regs))
goto no_context;
if (exception_trace)
printk("%s%s[%d]: bus error at %08lx pc %08lx "
"sp %08lx ecr %lu\n",
is_init(tsk) ? KERN_EMERG : KERN_INFO,
tsk->comm, tsk->pid, address, regs->pc,
regs->sp, ecr);
_exception(SIGBUS, regs, BUS_ADRERR, address);
}
asmlinkage void do_bus_error(unsigned long addr, int write_access,
@@ -292,8 +259,7 @@ asmlinkage void do_bus_error(unsigned long addr, int write_access,
addr, write_access ? "write" : "read");
printk(KERN_INFO "DTLB dump:\n");
dump_dtlb();
die("Bus Error", regs, write_access);
do_exit(SIGKILL);
die("Bus Error", regs, SIGKILL);
}
/*