* [PATCH] module: set .init_array alignment to 8
@ 2017-03-08 1:31 David Daney
2017-03-08 1:35 ` David Daney
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: David Daney @ 2017-03-08 1:31 UTC (permalink / raw)
To: Jessica Yu, Rusty Russell, Andrey Ryabinin, linux-kernel
Cc: Andrew Morton, David Daney
The proper idiom for aligning linker sections in modules is different
than for built-in sections. ". = ALIGN();" followed by a forced
output address of 0 does nothing, as forcing the address changes the
value of ".".
Use output section alignment specifier instead.
Fixes: 9ddf82521c86 ("kernel: add support for .init_array.* constructors")
Signed-off-by: David Daney <david.daney@cavium.com>
---
I noticed this when doing the __jump_table thing. Doesn't seem to
break a defconfig build, but otherwise untested.
scripts/module-common.lds | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/scripts/module-common.lds b/scripts/module-common.lds
index 9b6e246..d61b9e8 100644
--- a/scripts/module-common.lds
+++ b/scripts/module-common.lds
@@ -20,8 +20,7 @@ SECTIONS {
__kcrctab_unused_gpl 0 : { *(SORT(___kcrctab_unused_gpl+*)) }
__kcrctab_gpl_future 0 : { *(SORT(___kcrctab_gpl_future+*)) }
- . = ALIGN(8);
- .init_array 0 : { *(SORT(.init_array.*)) *(.init_array) }
+ .init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
__jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
}
--
2.9.3
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] module: set .init_array alignment to 8
2017-03-08 1:31 [PATCH] module: set .init_array alignment to 8 David Daney
@ 2017-03-08 1:35 ` David Daney
2017-03-09 14:26 ` Andrey Ryabinin
2017-03-13 18:46 ` Jessica Yu
2 siblings, 0 replies; 4+ messages in thread
From: David Daney @ 2017-03-08 1:35 UTC (permalink / raw)
To: David Daney, Jessica Yu, Rusty Russell, Andrey Ryabinin,
linux-kernel, Andrey Ryabinin
Cc: Andrew Morton
It looks like Andrey's e-mail changed. Replying with what I hope is a
valid e-mail for Andrey.
On 03/07/2017 05:31 PM, David Daney wrote:
> The proper idiom for aligning linker sections in modules is different
> than for built-in sections. ". = ALIGN();" followed by a forced
> output address of 0 does nothing, as forcing the address changes the
> value of ".".
>
> Use output section alignment specifier instead.
>
> Fixes: 9ddf82521c86 ("kernel: add support for .init_array.* constructors")
> Signed-off-by: David Daney <david.daney@cavium.com>
> ---
>
> I noticed this when doing the __jump_table thing. Doesn't seem to
> break a defconfig build, but otherwise untested.
>
> scripts/module-common.lds | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/scripts/module-common.lds b/scripts/module-common.lds
> index 9b6e246..d61b9e8 100644
> --- a/scripts/module-common.lds
> +++ b/scripts/module-common.lds
> @@ -20,8 +20,7 @@ SECTIONS {
> __kcrctab_unused_gpl 0 : { *(SORT(___kcrctab_unused_gpl+*)) }
> __kcrctab_gpl_future 0 : { *(SORT(___kcrctab_gpl_future+*)) }
>
> - . = ALIGN(8);
> - .init_array 0 : { *(SORT(.init_array.*)) *(.init_array) }
> + .init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
>
> __jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
> }
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] module: set .init_array alignment to 8
2017-03-08 1:31 [PATCH] module: set .init_array alignment to 8 David Daney
2017-03-08 1:35 ` David Daney
@ 2017-03-09 14:26 ` Andrey Ryabinin
2017-03-13 18:46 ` Jessica Yu
2 siblings, 0 replies; 4+ messages in thread
From: Andrey Ryabinin @ 2017-03-09 14:26 UTC (permalink / raw)
To: David Daney, Jessica Yu, Rusty Russell, linux-kernel; +Cc: Andrew Morton
On 03/08/2017 04:31 AM, David Daney wrote:
> The proper idiom for aligning linker sections in modules is different
> than for built-in sections. ". = ALIGN();" followed by a forced
> output address of 0 does nothing, as forcing the address changes the
> value of ".".
>
> Use output section alignment specifier instead.
>
> Fixes: 9ddf82521c86 ("kernel: add support for .init_array.* constructors")
> Signed-off-by: David Daney <david.daney@cavium.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
> ---
>
> I noticed this when doing the __jump_table thing. Doesn't seem to
> break a defconfig build, but otherwise untested.
>
> scripts/module-common.lds | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/scripts/module-common.lds b/scripts/module-common.lds
> index 9b6e246..d61b9e8 100644
> --- a/scripts/module-common.lds
> +++ b/scripts/module-common.lds
> @@ -20,8 +20,7 @@ SECTIONS {
> __kcrctab_unused_gpl 0 : { *(SORT(___kcrctab_unused_gpl+*)) }
> __kcrctab_gpl_future 0 : { *(SORT(___kcrctab_gpl_future+*)) }
>
> - . = ALIGN(8);
> - .init_array 0 : { *(SORT(.init_array.*)) *(.init_array) }
> + .init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
>
> __jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
> }
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] module: set .init_array alignment to 8
2017-03-08 1:31 [PATCH] module: set .init_array alignment to 8 David Daney
2017-03-08 1:35 ` David Daney
2017-03-09 14:26 ` Andrey Ryabinin
@ 2017-03-13 18:46 ` Jessica Yu
2 siblings, 0 replies; 4+ messages in thread
From: Jessica Yu @ 2017-03-13 18:46 UTC (permalink / raw)
To: David Daney; +Cc: Rusty Russell, Andrey Ryabinin, linux-kernel, Andrew Morton
+++ David Daney [07/03/17 17:31 -0800]:
>The proper idiom for aligning linker sections in modules is different
>than for built-in sections. ". = ALIGN();" followed by a forced
>output address of 0 does nothing, as forcing the address changes the
>value of ".".
>
>Use output section alignment specifier instead.
>
>Fixes: 9ddf82521c86 ("kernel: add support for .init_array.* constructors")
>Signed-off-by: David Daney <david.daney@cavium.com>
Good catch, thanks. I've applied this to modules-next.
Jessica
>I noticed this when doing the __jump_table thing. Doesn't seem to
>break a defconfig build, but otherwise untested.
>
> scripts/module-common.lds | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
>diff --git a/scripts/module-common.lds b/scripts/module-common.lds
>index 9b6e246..d61b9e8 100644
>--- a/scripts/module-common.lds
>+++ b/scripts/module-common.lds
>@@ -20,8 +20,7 @@ SECTIONS {
> __kcrctab_unused_gpl 0 : { *(SORT(___kcrctab_unused_gpl+*)) }
> __kcrctab_gpl_future 0 : { *(SORT(___kcrctab_gpl_future+*)) }
>
>- . = ALIGN(8);
>- .init_array 0 : { *(SORT(.init_array.*)) *(.init_array) }
>+ .init_array 0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
>
> __jump_table 0 : ALIGN(8) { KEEP(*(__jump_table)) }
> }
>--
>2.9.3
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2017-03-08 1:31 [PATCH] module: set .init_array alignment to 8 David Daney
2017-03-08 1:35 ` David Daney
2017-03-09 14:26 ` Andrey Ryabinin
2017-03-13 18:46 ` Jessica Yu
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