* [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT
@ 2019-08-14 10:44 Andrew Cooper
2019-08-14 12:00 ` Wei Liu
2019-08-27 14:36 ` Jan Beulich
0 siblings, 2 replies; 7+ messages in thread
From: Andrew Cooper @ 2019-08-14 10:44 UTC (permalink / raw)
To: Xen-devel; +Cc: Andrew Cooper, Wei Liu, Jan Beulich, Roger Pau Monné
Introduce a new ENDDATA() helper which sets type and size together.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wl@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
---
xen/arch/x86/boot/x86_64.S | 18 +++++++++---------
xen/include/asm-x86/config.h | 5 +++++
2 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S
index 5ab24d73fc..8a4cc7e747 100644
--- a/xen/arch/x86/boot/x86_64.S
+++ b/xen/arch/x86/boot/x86_64.S
@@ -65,7 +65,7 @@ l1_identmap:
.endif
pfn = pfn + 1
.endr
- .size l1_identmap, . - l1_identmap
+ENDDATA(l1_identmap)
/*
* __page_tables_start does not cover l1_identmap because it (l1_identmap)
@@ -86,7 +86,7 @@ GLOBAL(l2_identmap)
idx = idx + 1
.endr
.fill 4 * L2_PAGETABLE_ENTRIES - 8, 8, 0
- .size l2_identmap, . - l2_identmap
+ENDDATA(l2_identmap)
/*
* L2 mapping the 1GB Xen text/data/bss region. At boot it maps 16MB from
@@ -101,7 +101,7 @@ GLOBAL(l2_xenmap)
idx = idx + 1
.endr
.fill L2_PAGETABLE_ENTRIES - 8, 8, 0
- .size l2_xenmap, . - l2_xenmap
+ENDDATA(l2_xenmap)
/* L2 mapping the fixmap. Uses 1x 4k page. */
l2_fixmap:
@@ -114,7 +114,7 @@ l2_fixmap:
.endif
idx = idx + 1
.endr
- .size l2_fixmap, . - l2_fixmap
+ENDDATA(l2_fixmap)
/* Identity map, covering the 4 l2_identmap tables. Uses 1x 4k page. */
l3_identmap:
@@ -124,7 +124,7 @@ l3_identmap:
idx = idx + 1
.endr
.fill L3_PAGETABLE_ENTRIES - 4, 8, 0
- .size l3_identmap, . - l3_identmap
+ENDDATA(l3_identmap)
/* L3 mapping the fixmap. Uses 1x 4k page. */
l3_xenmap:
@@ -139,7 +139,7 @@ l3_xenmap:
.endif
idx = idx + 1
.endr
- .size l3_xenmap, . - l3_xenmap
+ENDDATA(l3_xenmap)
/* Top-level master (and idle-domain) page directory. */
GLOBAL(idle_pg_table)
@@ -155,7 +155,7 @@ GLOBAL(idle_pg_table)
.endif
idx = idx + 1
.endr
- .size idle_pg_table, . - idle_pg_table
+ENDDATA(idle_pg_table)
GLOBAL(__page_tables_end)
@@ -165,8 +165,8 @@ GLOBAL(__page_tables_end)
GLOBAL(l2_bootmap)
.fill 4 * L2_PAGETABLE_ENTRIES, 8, 0
- .size l2_bootmap, . - l2_bootmap
+ENDDATA(l2_bootmap)
GLOBAL(l3_bootmap)
.fill L3_PAGETABLE_ENTRIES, 8, 0
- .size l3_bootmap, . - l3_bootmap
+ENDDATA(l3_bootmap)
diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
index 22dc795eea..35705441ff 100644
--- a/xen/include/asm-x86/config.h
+++ b/xen/include/asm-x86/config.h
@@ -56,6 +56,11 @@
#define GLOBAL(name) \
.globl name; \
name:
+
+#define ENDDATA(name) \
+ .type name, STT_OBJECT; \
+ .size name, . - name
+
#endif
#define NR_hypercalls 64
--
2.11.0
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT
2019-08-14 10:44 [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT Andrew Cooper
@ 2019-08-14 12:00 ` Wei Liu
2019-08-14 12:06 ` Andrew Cooper
2019-08-27 14:33 ` Jan Beulich
2019-08-27 14:36 ` Jan Beulich
1 sibling, 2 replies; 7+ messages in thread
From: Wei Liu @ 2019-08-14 12:00 UTC (permalink / raw)
To: Andrew Cooper; +Cc: Xen-devel, Wei Liu, Jan Beulich, Roger Pau Monné
On Wed, Aug 14, 2019 at 11:44:04AM +0100, Andrew Cooper wrote:
[...]
> diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
> index 22dc795eea..35705441ff 100644
> --- a/xen/include/asm-x86/config.h
> +++ b/xen/include/asm-x86/config.h
> @@ -56,6 +56,11 @@
> #define GLOBAL(name) \
> .globl name; \
> name:
> +
> +#define ENDDATA(name) \
> + .type name, STT_OBJECT; \
Isn't the correct syntax
.type name STT_OBJECT;
?
The comma shouldn't be there according to as manual.
The rest looks good.
Wei.
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT
2019-08-14 12:00 ` Wei Liu
@ 2019-08-14 12:06 ` Andrew Cooper
2019-08-27 14:33 ` Jan Beulich
1 sibling, 0 replies; 7+ messages in thread
From: Andrew Cooper @ 2019-08-14 12:06 UTC (permalink / raw)
To: Wei Liu; +Cc: Xen-devel, Jan Beulich, Roger Pau Monné
On 14/08/2019 13:00, Wei Liu wrote:
> On Wed, Aug 14, 2019 at 11:44:04AM +0100, Andrew Cooper wrote:
> [...]
>> diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
>> index 22dc795eea..35705441ff 100644
>> --- a/xen/include/asm-x86/config.h
>> +++ b/xen/include/asm-x86/config.h
>> @@ -56,6 +56,11 @@
>> #define GLOBAL(name) \
>> .globl name; \
>> name:
>> +
>> +#define ENDDATA(name) \
>> + .type name, STT_OBJECT; \
> Isn't the correct syntax
>
> .type name STT_OBJECT;
>
> ?
>
> The comma shouldn't be there according to as manual.
Huh. I'd not even noticed that. We use a comma with .type everywhere in
Xen, including when using STT_* notation rather than the @ variants.
~Andrew
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT
2019-08-14 12:00 ` Wei Liu
2019-08-14 12:06 ` Andrew Cooper
@ 2019-08-27 14:33 ` Jan Beulich
1 sibling, 0 replies; 7+ messages in thread
From: Jan Beulich @ 2019-08-27 14:33 UTC (permalink / raw)
To: Wei Liu, Andrew Cooper; +Cc: Xen-devel, Roger Pau Monné
On 14.08.2019 14:00, Wei Liu wrote:
> On Wed, Aug 14, 2019 at 11:44:04AM +0100, Andrew Cooper wrote:
> [...]
>> diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h
>> index 22dc795eea..35705441ff 100644
>> --- a/xen/include/asm-x86/config.h
>> +++ b/xen/include/asm-x86/config.h
>> @@ -56,6 +56,11 @@
>> #define GLOBAL(name) \
>> .globl name; \
>> name:
>> +
>> +#define ENDDATA(name) \
>> + .type name, STT_OBJECT; \
>
> Isn't the correct syntax
>
> .type name STT_OBJECT;
>
> ?
>
> The comma shouldn't be there according to as manual.
Quote 1:
"ELF Version
-----------
For ELF targets, the '.type' directive is used like this:
.type NAME , TYPE DESCRIPTION
"
The comma is definitely here, unconditionally. But yes, quote 2:
' The syntaxes supported are:
.type <name> STT_<TYPE_IN_UPPER_CASE>
.type <name>,#<type>
.type <name>,@<type>
.type <name>,%<type>
.type <name>,"<type>"'
Judging from the sources all forms treat the comma as optional.
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT
2019-08-14 10:44 [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT Andrew Cooper
2019-08-14 12:00 ` Wei Liu
@ 2019-08-27 14:36 ` Jan Beulich
2019-08-28 18:24 ` Andrew Cooper
1 sibling, 1 reply; 7+ messages in thread
From: Jan Beulich @ 2019-08-27 14:36 UTC (permalink / raw)
To: Andrew Cooper; +Cc: Xen-devel, Wei Liu, Roger Pau Monné
On 14.08.2019 12:44, Andrew Cooper wrote:
> Introduce a new ENDDATA() helper which sets type and size together.
Except this isn't very natural: Setting the size late is quite
common, to avoid the need for an "end" label. But the type would
better be set together with the label definition, i.e. by a
GLOBAL() counterpart (e.g. GLOBAL_DATA()). However, if despite
this remark you think your approach is the way to go:
> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT
2019-08-27 14:36 ` Jan Beulich
@ 2019-08-28 18:24 ` Andrew Cooper
2019-08-29 7:12 ` Jan Beulich
0 siblings, 1 reply; 7+ messages in thread
From: Andrew Cooper @ 2019-08-28 18:24 UTC (permalink / raw)
To: Jan Beulich; +Cc: Xen-devel, Wei Liu, Roger Pau Monné
On 27/08/2019 15:36, Jan Beulich wrote:
> On 14.08.2019 12:44, Andrew Cooper wrote:
>> Introduce a new ENDDATA() helper which sets type and size together.
>
> Except this isn't very natural: Setting the size late is quite
> common, to avoid the need for an "end" label. But the type would
> better be set together with the label definition, i.e. by a
> GLOBAL() counterpart (e.g. GLOBAL_DATA()). However, if despite
> this remark you think your approach is the way to go:
Well - this way is fewer moving parts.
GLOBAL and ENTRY are to do with visibility and alignment. While ENTRY
might not typically be used for data, both are commonly used for code.
We can either have a proliferation of {GLOBAL,ENTRY}{,_DATA,_FUNC,etc}
and a single END, or we can have ENDDATA/ENDFUNC and need no changes to
the existing GLOBAL/ENTRY infrastructure.
~Andrew
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT
2019-08-28 18:24 ` Andrew Cooper
@ 2019-08-29 7:12 ` Jan Beulich
0 siblings, 0 replies; 7+ messages in thread
From: Jan Beulich @ 2019-08-29 7:12 UTC (permalink / raw)
To: Andrew Cooper; +Cc: Xen-devel, Wei Liu, Roger Pau Monné
On 28.08.2019 20:24, Andrew Cooper wrote:
> On 27/08/2019 15:36, Jan Beulich wrote:
>> On 14.08.2019 12:44, Andrew Cooper wrote:
>>> Introduce a new ENDDATA() helper which sets type and size together.
>>
>> Except this isn't very natural: Setting the size late is quite
>> common, to avoid the need for an "end" label. But the type would
>> better be set together with the label definition, i.e. by a
>> GLOBAL() counterpart (e.g. GLOBAL_DATA()). However, if despite
>> this remark you think your approach is the way to go:
>
> Well - this way is fewer moving parts.
>
> GLOBAL and ENTRY are to do with visibility and alignment. While ENTRY
> might not typically be used for data, both are commonly used for code.
>
> We can either have a proliferation of {GLOBAL,ENTRY}{,_DATA,_FUNC,etc}
> and a single END, or we can have ENDDATA/ENDFUNC and need no changes to
> the existing GLOBAL/ENTRY infrastructure.
Yes, it's slightly more of a change the way I'd prefer, but as said,
it would (imo) yield a more natural result. Omission of END() would
then mean only the symbol's size to not be set, but all other
attributes to be correct nevertheless.
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2019-08-29 7:12 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-14 10:44 [Xen-devel] [PATCH] x86/boot: Annotate pagetables with STT_OBJECT Andrew Cooper
2019-08-14 12:00 ` Wei Liu
2019-08-14 12:06 ` Andrew Cooper
2019-08-27 14:33 ` Jan Beulich
2019-08-27 14:36 ` Jan Beulich
2019-08-28 18:24 ` Andrew Cooper
2019-08-29 7:12 ` Jan Beulich
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).