2017-12-14 22:39:32

by Laura Abbott

Subject: [RFC][PATCH] arm64: Switch to %px for printing some addresses at bootup

With the move to stricter %p printing, several of the addresses
are no longer printed out. Switch to %px so they always get printed.

Signed-off-by: Laura Abbott <[email protected]>
---
I'll admit to finding the new %p restrictions particularly irritating
here because I like seeing the print out of the virtual addresses for
debugging and checking. It might also be worth discussing whether we
should be printing anything out?
---
arch/arm64/mm/init.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 5960bef0170d..9be53e050f50 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -613,15 +613,15 @@ void __init mem_init(void)
MLM(MODULES_VADDR, MODULES_END));
pr_notice(" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n",
MLG(VMALLOC_START, VMALLOC_END));
- pr_notice(" .text : 0x%p" " - 0x%p" " (%6ld KB)\n",
+ pr_notice(" .text : 0x%px" " - 0x%px" " (%6ld KB)\n",
MLK_ROUNDUP(_text, _etext));
- pr_notice(" .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n",
+ pr_notice(" .rodata : 0x%px" " - 0x%px" " (%6ld KB)\n",
MLK_ROUNDUP(__start_rodata, __init_begin));
- pr_notice(" .init : 0x%p" " - 0x%p" " (%6ld KB)\n",
+ pr_notice(" .init : 0x%px" " - 0x%px" " (%6ld KB)\n",
MLK_ROUNDUP(__init_begin, __init_end));
- pr_notice(" .data : 0x%p" " - 0x%p" " (%6ld KB)\n",
+ pr_notice(" .data : 0x%px" " - 0x%px" " (%6ld KB)\n",
MLK_ROUNDUP(_sdata, _edata));
- pr_notice(" .bss : 0x%p" " - 0x%p" " (%6ld KB)\n",
+ pr_notice(" .bss : 0x%px" " - 0x%px" " (%6ld KB)\n",
MLK_ROUNDUP(__bss_start, __bss_stop));
pr_notice(" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n",
MLK(FIXADDR_START, FIXADDR_TOP));
--
2.14.3

2017-12-14 22:51:45

by Kees Cook

Subject: Re: [RFC][PATCH] arm64: Switch to %px for printing some addresses at bootup

On Thu, Dec 14, 2017 at 2:39 PM, Laura Abbott <[email protected]> wrote:
> With the move to stricter %p printing, several of the addresses
> are no longer printed out. Switch to %px so they always get printed.
>
> Signed-off-by: Laura Abbott <[email protected]>
> ---
> I'll admit to finding the new %p restrictions particularly irritating
> here because I like seeing the print out of the virtual addresses for
> debugging and checking. It might also be worth discussing whether we
> should be printing anything out?

If they're always printed at boot, I think they should likely be removed...

-Kees

> ---
> arch/arm64/mm/init.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 5960bef0170d..9be53e050f50 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -613,15 +613,15 @@ void __init mem_init(void)
> MLM(MODULES_VADDR, MODULES_END));
> pr_notice(" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n",
> MLG(VMALLOC_START, VMALLOC_END));
> - pr_notice(" .text : 0x%p" " - 0x%p" " (%6ld KB)\n",
> + pr_notice(" .text : 0x%px" " - 0x%px" " (%6ld KB)\n",
> MLK_ROUNDUP(_text, _etext));
> - pr_notice(" .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n",
> + pr_notice(" .rodata : 0x%px" " - 0x%px" " (%6ld KB)\n",
> MLK_ROUNDUP(__start_rodata, __init_begin));
> - pr_notice(" .init : 0x%p" " - 0x%p" " (%6ld KB)\n",
> + pr_notice(" .init : 0x%px" " - 0x%px" " (%6ld KB)\n",
> MLK_ROUNDUP(__init_begin, __init_end));
> - pr_notice(" .data : 0x%p" " - 0x%p" " (%6ld KB)\n",
> + pr_notice(" .data : 0x%px" " - 0x%px" " (%6ld KB)\n",
> MLK_ROUNDUP(_sdata, _edata));
> - pr_notice(" .bss : 0x%p" " - 0x%p" " (%6ld KB)\n",
> + pr_notice(" .bss : 0x%px" " - 0x%px" " (%6ld KB)\n",
> MLK_ROUNDUP(__bss_start, __bss_stop));
> pr_notice(" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n",
> MLK(FIXADDR_START, FIXADDR_TOP));
> --
> 2.14.3
>



--
Kees Cook
Pixel Security

2017-12-14 23:30:49

by Laura Abbott

Subject: Re: [RFC][PATCH] arm64: Switch to %px for printing some addresses at bootup

On 12/14/2017 02:51 PM, Kees Cook wrote:
> On Thu, Dec 14, 2017 at 2:39 PM, Laura Abbott <[email protected]> wrote:
>> With the move to stricter %p printing, several of the addresses
>> are no longer printed out. Switch to %px so they always get printed.
>>
>> Signed-off-by: Laura Abbott <[email protected]>
>> ---
>> I'll admit to finding the new %p restrictions particularly irritating
>> here because I like seeing the print out of the virtual addresses for
>> debugging and checking. It might also be worth discussing whether we
>> should be printing anything out?
>
> If they're always printed at boot, I think they should likely be removed...
>
> -Kees
>

Yeah, I suspected as much. I'll submit a patch to just remove it
unless someone has a counter proposal.

Thanks,
Laura

>> ---
>> arch/arm64/mm/init.c | 10 +++++-----
>> 1 file changed, 5 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
>> index 5960bef0170d..9be53e050f50 100644
>> --- a/arch/arm64/mm/init.c
>> +++ b/arch/arm64/mm/init.c
>> @@ -613,15 +613,15 @@ void __init mem_init(void)
>> MLM(MODULES_VADDR, MODULES_END));
>> pr_notice(" vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n",
>> MLG(VMALLOC_START, VMALLOC_END));
>> - pr_notice(" .text : 0x%p" " - 0x%p" " (%6ld KB)\n",
>> + pr_notice(" .text : 0x%px" " - 0x%px" " (%6ld KB)\n",
>> MLK_ROUNDUP(_text, _etext));
>> - pr_notice(" .rodata : 0x%p" " - 0x%p" " (%6ld KB)\n",
>> + pr_notice(" .rodata : 0x%px" " - 0x%px" " (%6ld KB)\n",
>> MLK_ROUNDUP(__start_rodata, __init_begin));
>> - pr_notice(" .init : 0x%p" " - 0x%p" " (%6ld KB)\n",
>> + pr_notice(" .init : 0x%px" " - 0x%px" " (%6ld KB)\n",
>> MLK_ROUNDUP(__init_begin, __init_end));
>> - pr_notice(" .data : 0x%p" " - 0x%p" " (%6ld KB)\n",
>> + pr_notice(" .data : 0x%px" " - 0x%px" " (%6ld KB)\n",
>> MLK_ROUNDUP(_sdata, _edata));
>> - pr_notice(" .bss : 0x%p" " - 0x%p" " (%6ld KB)\n",
>> + pr_notice(" .bss : 0x%px" " - 0x%px" " (%6ld KB)\n",
>> MLK_ROUNDUP(__bss_start, __bss_stop));
>> pr_notice(" fixed : 0x%16lx - 0x%16lx (%6ld KB)\n",
>> MLK(FIXADDR_START, FIXADDR_TOP));
>> --
>> 2.14.3
>>
>
>
>