2016-11-30 08:08:53

by Maninder Singh

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Subject: [PATCH 1/2] arm64: Correcting format specifier for printin 64 bit addresses

This patch corrects format specifier for printing 64 bit addresses.

Before Patch
============
[ 68.251603] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 68.251673] pgd = ffffffc013950000
[ 68.251782] [00000000] *pgd=0000000093e19003, *pud=0000000093e19003, *pmd=0000000000000000

After patch
===========
[ 8.565030] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 8.565389] pgd = ffffffc013872000
[ 8.565553] [0000000000000000] *pgd=0000000093874003, *pud=0000000093874003, *pmd=0000000000000000

and same for user space fault.

Signed-off-by: Vaneet Narang <[email protected]>
Signed-off-by: Maninder Singh <[email protected]>
---
arch/arm64/mm/fault.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index a78a5c4..8cb5c93 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -77,7 +77,7 @@ void show_pte(struct mm_struct *mm, unsigned long addr)

pr_alert("pgd = %p\n", mm->pgd);
pgd = pgd_offset(mm, addr);
- pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd));
+ pr_alert("[%016lx] *pgd=%016llx", addr, pgd_val(*pgd));

do {
pud_t *pud;
@@ -177,7 +177,7 @@ static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
* No handler, we'll have to terminate things with extreme prejudice.
*/
bust_spinlocks(1);
- pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
+ pr_alert("Unable to handle kernel %s at virtual address %016lx\n",
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
"paging request", addr);

@@ -198,9 +198,15 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
struct siginfo si;

if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) {
- pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
- tsk->comm, task_pid_nr(tsk), fault_name(esr), sig,
- addr, esr);
+ if (compat_user_mode(regs))
+ pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
+ tsk->comm, task_pid_nr(tsk), fault_name(esr), sig,
+ addr, esr);
+ else
+ pr_info("%s[%d]: unhandled %s (%d) at 0x%016lx, esr 0x%03x\n",
+ tsk->comm, task_pid_nr(tsk), fault_name(esr), sig,
+ addr, esr);
+
show_pte(tsk->mm, addr);
show_regs(regs);
}
--
1.9.1


2016-11-30 10:51:00

by Will Deacon

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Subject: Re: [PATCH 1/2] arm64: Correcting format specifier for printin 64 bit addresses

On Wed, Nov 30, 2016 at 01:33:56PM +0530, Maninder Singh wrote:
> This patch corrects format specifier for printing 64 bit addresses.
>
> Before Patch
> ============
> [ 68.251603] Unable to handle kernel NULL pointer dereference at virtual address 00000000
> [ 68.251673] pgd = ffffffc013950000
> [ 68.251782] [00000000] *pgd=0000000093e19003, *pud=0000000093e19003, *pmd=0000000000000000
>
> After patch
> ===========
> [ 8.565030] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
> [ 8.565389] pgd = ffffffc013872000
> [ 8.565553] [0000000000000000] *pgd=0000000093874003, *pud=0000000093874003, *pmd=0000000000000000
>
> and same for user space fault.
>
> Signed-off-by: Vaneet Narang <[email protected]>
> Signed-off-by: Maninder Singh <[email protected]>
> ---
> arch/arm64/mm/fault.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)

There are a bunch of these you haven't caught:

arch/arm64/kernel/signal.c: pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
arch/arm64/kernel/signal32.c: pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
arch/arm64/kernel/signal32.c: pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
arch/arm64/kvm/sys_regs.c: kvm_err("Unsupported guest CP%d access at: %08lx\n",
arch/arm64/kvm/trace.h: TP_printk("guest executed wf%c at: 0x%08lx",
arch/arm64/kvm/trace.h: TP_printk("HVC at 0x%08lx (r0: 0x%08lx, imm: 0x%lx)",
arch/arm64/kvm/trace.h: TP_printk("%s %s reg %d (0x%08llx)", __entry->fn, __entry->is_write?"write to":"read from", __entry->reg, __entry->write_value)
arch/arm64/mm/fault.c: pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd));
arch/arm64/mm/fault.c: pr_alert("Unable to handle kernel %s at virtual address %08lx\n",
arch/arm64/mm/fault.c: pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
arch/arm64/mm/mmu.c: pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
arch/arm64/mm/mmu.c: pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",

so it would probably make sense to fix these to be consistent.

Will

2016-12-09 05:44:02

by Maninder Singh

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Subject: RE: Re: [PATCH 1/2] arm64: Correcting format specifier for printin 64 bit addresses

 
Hi Will,

>There are a bunch of these you haven't caught:
>
....
>arch/arm64/mm/mmu.c: pr_warn("fix_to_virt(FIX_BTMAP_END): %08lx\n",
>
>so it would probably make sense to fix these to be consistent.
>
>Will

All changes are sent in new patch except kvm changes, because for kvm we don't not much idea.


>arch/arm64/kernel/signal32.c: pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",
>arch/arm64/kernel/signal32.c: pr_info_ratelimited("%s[%d]: bad frame in %s: pc=%08llx sp=%08llx\n",

and signal32 fiel changes are not required, because it meant only for 32 bit.

--------------------
Thanks and Regards,
Maninder Singh