[PATCH] Cleanup oops/bug reports on i386

From: Pavel Emelyanov
Date: Wed Aug 08 2007 - 10:20:17 EST


Typically the oops first lines look like this:

BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
printing eip:
c049dfbd
*pde = 00000000
Oops: 0002 [#1]
PREEMPT SMP ...

Such output is gained with some ugly if (!nl) printk("\n"); code and
besides being a waste of lines, this is also annoying to read. The
following output looks better (and it is how it looks on x86_64):

BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
printing eip: c049dfbd *pde = 00000000
Oops: 0002 [#1] PREEMPT SMP ...

Signed-off-by: Pavel Emelyanov <xemul@xxxxxxxxxx>

---

arch/i386/kernel/traps.c | 16 ++++------------
arch/i386/mm/fault.c | 13 +++++++------
2 files changed, 11 insertions(+), 18 deletions(-)

diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c
index a20c7ad..f469d20 100644
--- a/arch/i386/kernel/traps.c
+++ b/arch/i386/kernel/traps.c
@@ -368,31 +368,23 @@ void die(const char * str, struct pt_reg
local_save_flags(flags);

if (++die.lock_owner_depth < 3) {
- int nl = 0;
unsigned long esp;
unsigned short ss;

report_bug(regs->eip, regs);

- printk(KERN_EMERG "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
+ printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
#ifdef CONFIG_PREEMPT
- printk(KERN_EMERG "PREEMPT ");
- nl = 1;
+ printk("PREEMPT ");
#endif
#ifdef CONFIG_SMP
- if (!nl)
- printk(KERN_EMERG);
printk("SMP ");
- nl = 1;
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
- if (!nl)
- printk(KERN_EMERG);
printk("DEBUG_PAGEALLOC");
- nl = 1;
#endif
- if (nl)
- printk("\n");
+ printk("\n");
+
if (notify_die(DIE_OOPS, str, regs, err,
current->thread.trap_no, SIGSEGV) !=
NOTIFY_STOP) {
diff --git a/arch/i386/mm/fault.c b/arch/i386/mm/fault.c
index fece684..93263aa 100644
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -537,23 +537,22 @@ no_context:
printk(KERN_ALERT "BUG: unable to handle kernel paging"
" request");
printk(" at virtual address %08lx\n",address);
- printk(KERN_ALERT " printing eip:\n");
- printk("%08lx\n", regs->eip);
+ printk(KERN_ALERT "printing eip: %08lx ", regs->eip);

page = read_cr3();
page = ((__typeof__(page) *) __va(page))[address >> PGDIR_SHIFT];
#ifdef CONFIG_X86_PAE
- printk(KERN_ALERT "*pdpt = %016Lx\n", page);
+ printk("*pdpt = %016Lx ", page);
if ((page >> PAGE_SHIFT) < max_low_pfn
&& page & _PAGE_PRESENT) {
page &= PAGE_MASK;
page = ((__typeof__(page) *) __va(page))[(address >> PMD_SHIFT)
& (PTRS_PER_PMD - 1)];
- printk(KERN_ALERT "*pde = %016Lx\n", page);
+ printk(KERN_ALERT "*pde = %016Lx ", page);
page &= ~_PAGE_NX;
}
#else
- printk(KERN_ALERT "*pde = %08lx\n", page);
+ printk("*pde = %08lx ", page);
#endif

/*
@@ -567,8 +566,10 @@ no_context:
page &= PAGE_MASK;
page = ((__typeof__(page) *) __va(page))[(address >> PAGE_SHIFT)
& (PTRS_PER_PTE - 1)];
- printk(KERN_ALERT "*pte = %0*Lx\n", sizeof(page)*2, (u64)page);
+ printk("*pte = %0*Lx ", sizeof(page)*2, (u64)page);
}
+
+ printk("\n");
}

tsk->thread.cr2 = address;
-
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