Discussion:
[PATCH] elf: Report property change when merging properties
(too old to reply)
H.J. Lu
2018-11-22 18:48:35 UTC
Permalink
With merging properties, report property change in linker map file, like

Merging property 0xc0000002 in foo.o (0x1) and bar.o (None): removed

bfd/

elf-properties.c (elf_merge_gnu_property_list): Updated. Report
property change in linker map file.
(_bfd_elf_link_setup_gnu_properties): Pass abfd to
elf_merge_gnu_property_list.

ld/

* NEWS: Updated for property change report.
* ld.tex: Document property change report.
* testsuite/ld-x86-64/property-x86-ibt1a-x32.d: Check linker map
file.
* testsuite/ld-x86-64/property-x86-ibt1a.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt1a.map: New file.
---
bfd/elf-properties.c | 95 +++++++++++++++----
ld/NEWS | 2 +
ld/ld.texi | 22 +++++
.../ld-x86-64/property-x86-ibt1a-x32.d | 3 +-
ld/testsuite/ld-x86-64/property-x86-ibt1a.d | 3 +-
ld/testsuite/ld-x86-64/property-x86-ibt1a.map | 5 +
6 files changed, 108 insertions(+), 22 deletions(-)
create mode 100644 ld/testsuite/ld-x86-64/property-x86-ibt1a.map

diff --git a/bfd/elf-properties.c b/bfd/elf-properties.c
index 861db73170..2119170017 100644
--- a/bfd/elf-properties.c
+++ b/bfd/elf-properties.c
@@ -261,47 +261,102 @@ elf_find_and_remove_property (elf_property_list **listp,
return NULL;
}

-/* Merge GNU property list *LISTP with ABFD. */
+/* Merge GNU property list *LISTP in ABFD with FIRST_PBFD. */

static void
-elf_merge_gnu_property_list (struct bfd_link_info *info, bfd *abfd,
- elf_property_list **listp)
+elf_merge_gnu_property_list (struct bfd_link_info *info, bfd *first_pbfd,
+ bfd *abfd, elf_property_list **listp)
{
elf_property_list *p, **lastp;
elf_property *pr;
+ bfd_boolean number_p;
+ bfd_vma number = 0;

- /* Merge each GNU property in ABFD with the one on *LISTP. */
- lastp = &elf_properties (abfd);
+ /* Merge each GNU property in FIRST_PBFD with the one on *LISTP. */
+ lastp = &elf_properties (first_pbfd);
for (p = *lastp; p; p = p->next)
{
+ if (p->property.pr_kind == property_number)
+ {
+ number_p = TRUE;
+ number = p->property.u.number;
+ }
+ else
+ number_p = FALSE;
pr = elf_find_and_remove_property (listp, p->property.pr_type);
/* Pass NULL to elf_merge_gnu_properties for the property which
isn't on *LISTP. */
- elf_merge_gnu_properties (info, abfd, &p->property, pr);
+ elf_merge_gnu_properties (info, first_pbfd, &p->property, pr);
if (p->property.pr_kind == property_remove)
{
/* Remove this property. */
*lastp = p->next;
+ if (number_p)
+ {
+ if (pr != NULL)
+ info->callbacks->minfo
+ (_("Merging property %W in %pB (0x%v) and %pB "
+ "(0x%v): removed\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, number,
+ abfd, pr->u.number);
+ else
+ info->callbacks->minfo
+ (_("Merging property %W in %pB (0x%v) and %pB "
+ "(None): removed\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, number,
+ abfd);
+ }
+ else
+ info->callbacks->minfo
+ (_("Merging property %W in %pB and %pB: removed\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, abfd);
continue;
}
+ if (number_p)
+ {
+ if (pr != NULL)
+ info->callbacks->minfo
+ (_("Merging property %W in %pB (0x%v) and %pB (0x%v): 0x%v\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, number, abfd,
+ pr->u.number, p->property.u.number);
+ else
+ info->callbacks->minfo
+ (_("Merging property %W in %pB (0x%v) and %pB (None): 0x%v\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, number, abfd,
+ p->property.u.number);
+ }
lastp = &p->next;
}

- /* Merge the remaining properties on *LISTP with ABFD. */
+ /* Merge the remaining properties on *LISTP with FIRST_PBFD. */
for (p = *listp; p != NULL; p = p->next)
- if (elf_merge_gnu_properties (info, abfd, NULL, &p->property))
- {
- if (p->property.pr_type == GNU_PROPERTY_NO_COPY_ON_PROTECTED)
- elf_has_no_copy_on_protected (abfd) = TRUE;
+ {
+ if (p->property.pr_kind == property_number)
+ {
+ number_p = TRUE;
+ number = p->property.u.number;
+ }
+ else
+ number_p = FALSE;

- pr = _bfd_elf_get_property (abfd, p->property.pr_type,
- p->property.pr_datasz);
- /* It must be a new property. */
- if (pr->pr_kind != property_unknown)
- abort ();
- /* Add a new property. */
- *pr = p->property;
- }
+ if (elf_merge_gnu_properties (info, first_pbfd, NULL, &p->property))
+ {
+ if (p->property.pr_type == GNU_PROPERTY_NO_COPY_ON_PROTECTED)
+ elf_has_no_copy_on_protected (first_pbfd) = TRUE;
+
+ pr = _bfd_elf_get_property (first_pbfd, p->property.pr_type,
+ p->property.pr_datasz);
+ /* It must be a new property. */
+ if (pr->pr_kind != property_unknown)
+ abort ();
+ /* Add a new property. */
+ *pr = p->property;
+ }
+ else if (number_p)
+ info->callbacks->minfo
+ (_("Merging property %W in %pB (None) and %pB (%0xv): removed\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, abfd, number);
+ }
}

/* Get GNU property section size. */
@@ -470,7 +525,7 @@ _bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
when all properties are from ELF objects with different
machine code or class. */
if (first_pbfd != NULL)
- elf_merge_gnu_property_list (info, first_pbfd, listp);
+ elf_merge_gnu_property_list (info, first_pbfd, abfd, listp);

if (list != NULL)
{
diff --git a/ld/NEWS b/ld/NEWS
index e2e87defee..502966635e 100644
--- a/ld/NEWS
+++ b/ld/NEWS
@@ -1,5 +1,7 @@
-*- text -*-

+* Report property change in linker map file when merging GNU properties.
+
* Add support for the C-SKY processor series.

Changes in 2.31:
diff --git a/ld/ld.texi b/ld/ld.texi
index 985c591d6a..f5d0245dd7 100644
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -759,6 +759,28 @@ option is used:

See @ref{Expressions} for more information about expressions in linker
scripts.
+
+@item How GNU properties are merged.
+
+When linker merges input .note.gnu.property sections into one output
+.note.gnu.property section, some properties are removed or updated,
+which are reported in the link map as
+
+@smallexample
+Merging property 0xc0000002 in foo.o (0x1) and bar.o (None): removed
+@end smallexample
+
+It indicates that property 0xc0000002 is removed from output when
+merging properties in @file{foo.o}, whose property 0xc0000002 value
+is 0x1, and @file{bar.o}, which doesn't have property 0xc0000002.
+
+@smallexample
+Merging property 0xc0010001 in foo.o (0x1) and bar.o (0x1): 0x1
+@end smallexample
+
+It indicates that property 0xc0010001 value is 0x1 in output when
+merging properties in @file{foo.o}, whose 0xc0010001 property value
+is 0x1, and @file{bar.o}, whose 0xc0010001 property value is 0x1.
@end itemize

@kindex -n
diff --git a/ld/testsuite/ld-x86-64/property-x86-ibt1a-x32.d b/ld/testsuite/ld-x86-64/property-x86-ibt1a-x32.d
index 7a95401ac3..d05ab1dce5 100644
--- a/ld/testsuite/ld-x86-64/property-x86-ibt1a-x32.d
+++ b/ld/testsuite/ld-x86-64/property-x86-ibt1a-x32.d
@@ -1,8 +1,9 @@
#source: property-x86-empty.s
#source: property-x86-ibt.s
#as: --x32 -mx86-used-note=yes
-#ld: -r -m elf32_x86_64
+#ld: -r -m elf32_x86_64 -Map tmpdir/property-x86-ibt1a-x32.map
#readelf: -n
+#map: property-x86-ibt1a.map

Displaying notes found in: .note.gnu.property
Owner Data size Description
diff --git a/ld/testsuite/ld-x86-64/property-x86-ibt1a.d b/ld/testsuite/ld-x86-64/property-x86-ibt1a.d
index e989a8a817..f8d6a063b4 100644
--- a/ld/testsuite/ld-x86-64/property-x86-ibt1a.d
+++ b/ld/testsuite/ld-x86-64/property-x86-ibt1a.d
@@ -1,8 +1,9 @@
#source: property-x86-empty.s
#source: property-x86-ibt.s
#as: --64 -defsym __64_bit__=1 -mx86-used-note=yes
-#ld: -r -melf_x86_64
+#ld: -r -melf_x86_64 -Map tmpdir/property-x86-ibt1a.map
#readelf: -n
+#map: property-x86-ibt1a.map

Displaying notes found in: .note.gnu.property
Owner Data size Description
diff --git a/ld/testsuite/ld-x86-64/property-x86-ibt1a.map b/ld/testsuite/ld-x86-64/property-x86-ibt1a.map
new file mode 100644
index 0000000000..43b91abcf5
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/property-x86-ibt1a.map
@@ -0,0 +1,5 @@
+#...
+Merging property 0xc0000002 in tmpdir/property-x86-empty.o \(0x0\) and tmpdir/property-x86-ibt.o \(0x1\): removed
+Merging property 0xc0010000 in tmpdir/property-x86-empty.o \(0x80000000\) and tmpdir/property-x86-ibt.o \(0x80000000\): 0x80000000
+Merging property 0xc0010001 in tmpdir/property-x86-empty.o \(0x1\) and tmpdir/property-x86-ibt.o \(0x1\): 0x1
+#pass
--
2.19.1
Alan Modra
2018-11-26 00:15:49 UTC
Permalink
Post by H.J. Lu
With merging properties, report property change in linker map file, like
Merging property 0xc0000002 in foo.o (0x1) and bar.o (None): removed
To me this is a confusing message. How about simply saying "Removed
property 0xc0000002 in foo.o (0x1)", and similarly for the other
messages where properties are removed. If ld is removing them then it
isn't merging them.
--
Alan Modra
Australia Development Lab, IBM
H.J. Lu
2018-11-26 13:05:50 UTC
Permalink
Post by Alan Modra
Post by H.J. Lu
With merging properties, report property change in linker map file, like
Merging property 0xc0000002 in foo.o (0x1) and bar.o (None): removed
To me this is a confusing message. How about simply saying "Removed
property 0xc0000002 in foo.o (0x1)", and similarly for the other
messages where properties are removed. If ld is removing them then it
isn't merging them.
This misses the crucial info that property 0xc0000002 is removed due to
bar.o (None).
--
H.J.
Nick Clifton
2018-11-27 12:35:29 UTC
Permalink
Hi Guys,
Post by H.J. Lu
Post by Alan Modra
Post by H.J. Lu
Merging property 0xc0000002 in foo.o (0x1) and bar.o (None): removed
To me this is a confusing message. How about simply saying "Removed
property 0xc0000002 in foo.o (0x1)", and similarly for the other
This misses the crucial info that property 0xc0000002 is removed due to
bar.o (None).
Indeed - this was my motivation for requesting the patch in the first place.

How about rewording the message as:

Property 0xc00000002 (0x1) found in foo.o but removed from final link because it is not found in bar.o

A little bit more wordy perhaps, but I think that it explains what is going
on in clearer language.

Cheers
Nick
H.J. Lu
2018-11-29 14:50:26 UTC
Permalink
Post by Nick Clifton
Hi Guys,
Post by H.J. Lu
Post by Alan Modra
Post by H.J. Lu
Merging property 0xc0000002 in foo.o (0x1) and bar.o (None): removed
To me this is a confusing message. How about simply saying "Removed
property 0xc0000002 in foo.o (0x1)", and similarly for the other
This misses the crucial info that property 0xc0000002 is removed due to
bar.o (None).
Indeed - this was my motivation for requesting the patch in the first place.
Property 0xc00000002 (0x1) found in foo.o but removed from final link because it is not found in bar.o
A little bit more wordy perhaps, but I think that it explains what is going
on in clearer language.
How about this?

Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (not found)
--
H.J.
H.J. Lu
2018-11-29 16:05:33 UTC
Permalink
Post by H.J. Lu
Post by Nick Clifton
Hi Guys,
Post by H.J. Lu
Post by Alan Modra
Post by H.J. Lu
Merging property 0xc0000002 in foo.o (0x1) and bar.o (None): removed
To me this is a confusing message. How about simply saying "Removed
property 0xc0000002 in foo.o (0x1)", and similarly for the other
This misses the crucial info that property 0xc0000002 is removed due to
bar.o (None).
Indeed - this was my motivation for requesting the patch in the first place.
Property 0xc00000002 (0x1) found in foo.o but removed from final link because it is not found in bar.o
A little bit more wordy perhaps, but I think that it explains what is going
on in clearer language.
How about this?
Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (not found)
Here is the updated patch with ld.texi change.
--
H.J.
Cary Coutant
2018-12-02 02:10:57 UTC
Permalink
Post by H.J. Lu
How about this?
Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (not found)
What will the message look like if other input files besides foo.o
also contain the property? Isn't the only relevant info here the name
of the file that is missing the property?

-cary
H.J. Lu
2018-12-02 02:56:04 UTC
Permalink
Post by Cary Coutant
Post by H.J. Lu
How about this?
Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (not found)
What will the message look like if other input files besides foo.o
Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (0x20)
Post by Cary Coutant
also contain the property? Isn't the only relevant info here the name
of the file that is missing the property?
It is target specific. A backend may decide to remove a property when
both inputs have the property.
--
H.J.
Cary Coutant
2018-12-02 05:52:27 UTC
Permalink
Post by H.J. Lu
Post by Cary Coutant
What will the message look like if other input files besides foo.o
Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (0x20)
Post by Cary Coutant
also contain the property? Isn't the only relevant info here the name
of the file that is missing the property?
It is target specific. A backend may decide to remove a property when
both inputs have the property.
I'm kind of wondering what it's going to look like when there are more
than two input files.

-cary
H.J. Lu
2018-12-02 14:18:06 UTC
Permalink
Post by Cary Coutant
Post by H.J. Lu
Post by Cary Coutant
What will the message look like if other input files besides foo.o
Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (0x20)
Post by Cary Coutant
also contain the property? Isn't the only relevant info here the name
of the file that is missing the property?
It is target specific. A backend may decide to remove a property when
both inputs have the property.
I'm kind of wondering what it's going to look like when there are more
than two input files.
Updated property 0xc0000002 (0x3) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x3) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o (0x3)
Updated property 0xc0010000 (0x0) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x0) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o (0x0)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o (0x1)
Updated property 0xc0000002 (0x3) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x3) and
/usr/lib/gcc/x86_64-redhat-linux/8/crtbegin.o (0x3)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x0) and
/usr/lib/gcc/x86_64-redhat-linux/8/crtbegin.o (0x80000000)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/usr/lib/gcc/x86_64-redhat-linux/8/crtbegin.o (0x1)
Removed property 0xc0000002 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x3) and
/tmp/ccd2bsvZ.o (not found)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o
(0x80000000) and /tmp/ccd2bsvZ.o (0x0)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/tmp/ccd2bsvZ.o (0x1)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o
(0x80000000) and /tmp/ccYYBqRI.o (0x0)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/tmp/ccYYBqRI.o (0x1)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o
(0x80000000) and /tmp/ccv9JEes.o (0x0)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/tmp/ccv9JEes.o (0x1)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o
(0x80000000) and /usr/lib64/libc_nonshared.a(elf-init.oS) (0x0)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/usr/lib64/libc_nonshared.a(elf-init.oS) (0x1)
Removed property 0xc0000000 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not
found) and /usr/lib64/libc_nonshared.a(elf-init.oS) (0x0)
Removed property 0xc0000001 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not
found) and /usr/lib64/libc_nonshared.a(elf-init.oS) (0x0)
Removed property 0xc0000002 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not
found) and /usr/lib64/libc_nonshared.a(elf-init.oS) (0x3)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o
(0x80000000) and /usr/lib/gcc/x86_64-redhat-linux/8/crtend.o
(0x80000000)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/usr/lib/gcc/x86_64-redhat-linux/8/crtend.o (0x1)
Removed property 0xc0000002 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not
found) and /usr/lib/gcc/x86_64-redhat-linux/8/crtend.o (0x3)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o
(0x80000000) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crtn.o (0x0)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crtn.o (0x1)
Removed property 0xc0000002 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not
found) and /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crtn.o
(0x3)
--
H.J.
H.J. Lu
2018-12-02 23:43:08 UTC
Permalink
Post by H.J. Lu
Post by Cary Coutant
Post by H.J. Lu
Post by Cary Coutant
What will the message look like if other input files besides foo.o
Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (0x20)
Post by Cary Coutant
also contain the property? Isn't the only relevant info here the name
of the file that is missing the property?
It is target specific. A backend may decide to remove a property when
both inputs have the property.
I'm kind of wondering what it's going to look like when there are more
than two input files.
Updated property 0xc0000002 (0x3) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x3) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o (0x3)
Updated property 0xc0010000 (0x0) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x0) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o (0x0)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o (0x1)
Updated property 0xc0000002 (0x3) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x3) and
/usr/lib/gcc/x86_64-redhat-linux/8/crtbegin.o (0x3)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x0) and
/usr/lib/gcc/x86_64-redhat-linux/8/crtbegin.o (0x80000000)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/usr/lib/gcc/x86_64-redhat-linux/8/crtbegin.o (0x1)
Removed property 0xc0000002 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x3) and
/tmp/ccd2bsvZ.o (not found)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o
(0x80000000) and /tmp/ccd2bsvZ.o (0x0)
Updated property 0xc0010001 (0x1) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x1) and
/tmp/ccd2bsvZ.o (0x1)
Updated property 0xc0010000 (0x80000000) to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o
Here is the updated patch to cut down noises. Now it generates:

Mering program properties

Removed property 0xc0010000 to merge /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x0) and /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o (0x0)
Removed property 0xc0000002 to merge /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x3) and x.o (not found)
Removed property 0xc0000000 to merge /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not found) and /usr/lib64/libc_nonshared.a(elf-init.oS) (0x0)
Removed property 0xc0000001 to merge /usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not found) and /usr/lib64/libc_nonshared.a(elf-init.oS) (0x0)

OK for trunk?

H.J.
---
bfd/

* elf-properties.c (elf_find_and_remove_property): Add a
bfd_boolean argument to indicate if the property should be
removed.
(elf_merge_gnu_property_list): Updated. Report
property change in linker map file.
(elf_get_gnu_property_section_size): Skip property_remove
properties.
(elf_write_gnu_properties): Likewise.
(_bfd_elf_link_setup_gnu_properties): Report property merge
in linker map file. Pass abfd to elf_merge_gnu_property_list.

include/

* bfdlink.h (bfd_link_info): Add has_map_file.

ld/

* NEWS: Updated for property change report.
* ld.texi: Document property change report.
* ldmain.c (main): Set link_info.has_map_file to TRUE when
linker map file is used.
* testsuite/ld-x86-64/property-x86-ibt1a-x32.d: Check linker map
file.
* testsuite/ld-x86-64/property-x86-ibt1a.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt1a.map: New file.
---
bfd/elf-properties.c | 176 ++++++++++++++----
include/bfdlink.h | 3 +
ld/NEWS | 2 +
ld/ld.texi | 22 +++
ld/ldmain.c | 1 +
.../ld-x86-64/property-x86-ibt1a-x32.d | 3 +-
ld/testsuite/ld-x86-64/property-x86-ibt1a.d | 3 +-
ld/testsuite/ld-x86-64/property-x86-ibt1a.map | 3 +
8 files changed, 177 insertions(+), 36 deletions(-)
create mode 100644 ld/testsuite/ld-x86-64/property-x86-ibt1a.map

diff --git a/bfd/elf-properties.c b/bfd/elf-properties.c
index cd44ed6194..4de49c08b0 100644
--- a/bfd/elf-properties.c
+++ b/bfd/elf-properties.c
@@ -241,7 +241,7 @@ elf_merge_gnu_properties (struct bfd_link_info *info, bfd *abfd,

static elf_property *
elf_find_and_remove_property (elf_property_list **listp,
- unsigned int type)
+ unsigned int type, bfd_boolean remove)
{
elf_property_list *list;

@@ -250,7 +250,8 @@ elf_find_and_remove_property (elf_property_list **listp,
if (type == list->property.pr_type)
{
/* Remove this property. */
- *listp = list->next;
+ if (remove)
+ *listp = list->next;
return &list->property;
}
else if (type < list->property.pr_type)
@@ -261,47 +262,144 @@ elf_find_and_remove_property (elf_property_list **listp,
return NULL;
}

-/* Merge GNU property list *LISTP with ABFD. */
+/* Merge GNU property list *LISTP in ABFD with FIRST_PBFD. */

static void
-elf_merge_gnu_property_list (struct bfd_link_info *info, bfd *abfd,
- elf_property_list **listp)
+elf_merge_gnu_property_list (struct bfd_link_info *info, bfd *first_pbfd,
+ bfd *abfd, elf_property_list **listp)
{
elf_property_list *p, **lastp;
elf_property *pr;
+ bfd_boolean number_p;
+ bfd_vma number = 0;

- /* Merge each GNU property in ABFD with the one on *LISTP. */
- lastp = &elf_properties (abfd);
+ /* Merge each GNU property in FIRST_PBFD with the one on *LISTP. */
+ lastp = &elf_properties (first_pbfd);
for (p = *lastp; p; p = p->next)
+ if (p->property.pr_kind != property_remove)
+ {
+ if (p->property.pr_kind == property_number)
+ {
+ number_p = TRUE;
+ number = p->property.u.number;
+ }
+ else
+ number_p = FALSE;
+ pr = elf_find_and_remove_property (listp, p->property.pr_type,
+ TRUE);
+ /* Pass NULL to elf_merge_gnu_properties for the property which
+ isn't on *LISTP. */
+ elf_merge_gnu_properties (info, first_pbfd, &p->property, pr);
+ if (p->property.pr_kind == property_remove)
+ {
+ if (info->has_map_file)
+ {
+ if (number_p)
+ {
+ if (pr != NULL)
+ info->callbacks->minfo
+ (_("Removed property %W to merge %pB (0x%v) "
+ "and %pB (0x%v)\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd,
+ number, abfd, pr->u.number);
+ else
+ info->callbacks->minfo
+ (_("Removed property %W to merge %pB (0x%v) "
+ "and %pB (not found)\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd,
+ number, abfd);
+ }
+ else
+ {
+ if (pr != NULL)
+ info->callbacks->minfo
+ (_("Removed property %W to merge %pB and %pB\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, abfd);
+ else
+ info->callbacks->minfo
+ (_("Removed property %W to merge %pB and %pB "
+ "(not found)\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, abfd);
+ }
+ }
+ else
+ {
+ /* Remove this property. */
+ *lastp = p->next;
+ continue;
+ }
+ }
+ else if (number_p)
+ {
+ if (pr != NULL)
+ {
+ if (p->property.u.number != number
+ || p->property.u.number != pr->u.number)
+ info->callbacks->minfo
+ (_("Updated property %W (0x%v) to merge %pB (0x%v) "
+ "and %pB (0x%v)\n"),
+ (bfd_vma) p->property.pr_type, p->property.u.number,
+ first_pbfd, number, abfd, pr->u.number);
+ }
+ else
+ {
+ if (p->property.u.number != number)
+ info->callbacks->minfo
+ (_("Updated property %W (%v) to merge %pB (0x%v) "
+ "and %pB (not found)\n"),
+ (bfd_vma) p->property.pr_type, p->property.u.number,
+ first_pbfd, number, abfd);
+ }
+ }
+ lastp = &p->next;
+ }
+
+ /* Merge the remaining properties on *LISTP with FIRST_PBFD. */
+ for (p = *listp; p != NULL; p = p->next)
{
- pr = elf_find_and_remove_property (listp, p->property.pr_type);
- /* Pass NULL to elf_merge_gnu_properties for the property which
- isn't on *LISTP. */
- elf_merge_gnu_properties (info, abfd, &p->property, pr);
- if (p->property.pr_kind == property_remove)
+ if (p->property.pr_kind == property_number)
{
- /* Remove this property. */
- *lastp = p->next;
- continue;
+ number_p = TRUE;
+ number = p->property.u.number;
}
- lastp = &p->next;
- }
-
- /* Merge the remaining properties on *LISTP with ABFD. */
- for (p = *listp; p != NULL; p = p->next)
- if (elf_merge_gnu_properties (info, abfd, NULL, &p->property))
- {
- if (p->property.pr_type == GNU_PROPERTY_NO_COPY_ON_PROTECTED)
- elf_has_no_copy_on_protected (abfd) = TRUE;
+ else
+ number_p = FALSE;

- pr = _bfd_elf_get_property (abfd, p->property.pr_type,
- p->property.pr_datasz);
- /* It must be a new property. */
- if (pr->pr_kind != property_unknown)
- abort ();
- /* Add a new property. */
- *pr = p->property;
- }
+ if (elf_merge_gnu_properties (info, first_pbfd, NULL, &p->property))
+ {
+ if (p->property.pr_type == GNU_PROPERTY_NO_COPY_ON_PROTECTED)
+ elf_has_no_copy_on_protected (first_pbfd) = TRUE;
+
+ pr = _bfd_elf_get_property (first_pbfd, p->property.pr_type,
+ p->property.pr_datasz);
+ /* It must be a new property. */
+ if (pr->pr_kind != property_unknown)
+ abort ();
+ /* Add a new property. */
+ *pr = p->property;
+ }
+ else
+ {
+ pr = elf_find_and_remove_property (&elf_properties (first_pbfd),
+ p->property.pr_type,
+ FALSE);
+ if (pr == NULL)
+ {
+ if (number_p)
+ info->callbacks->minfo
+ (_("Removed property %W to merge %pB (not found) and "
+ "%pB (0x%v)\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, abfd,
+ number);
+ else
+ info->callbacks->minfo
+ (_("Removed property %W to merge %pB and %pB\n"),
+ (bfd_vma) p->property.pr_type, first_pbfd, abfd);
+ }
+ else if (pr->pr_kind != property_remove)
+ abort ();
+ }
+ }
}

/* Get GNU property section size. */
@@ -319,8 +417,11 @@ elf_get_gnu_property_section_size (elf_property_list *list,
size = descsz;
for (; list != NULL; list = list->next)
{
- /* There are 4 byte type + 4 byte datasz for each property. */
unsigned int datasz;
+ /* Check if this property should be skipped. */
+ if (list->property.pr_kind == property_remove)
+ continue;
+ /* There are 4 byte type + 4 byte datasz for each property. */
if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
datasz = align_size;
else
@@ -355,6 +456,9 @@ elf_write_gnu_properties (bfd *abfd, bfd_byte *contents,
size = descsz;
for (; list != NULL; list = list->next)
{
+ /* Check if this property should be skipped. */
+ if (list->property.pr_kind == property_remove)
+ continue;
/* There are 4 byte type + 4 byte datasz for each property. */
if (list->property.pr_type == GNU_PROPERTY_STACK_SIZE)
datasz = align_size;
@@ -445,6 +549,10 @@ _bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
return NULL;

/* Merge .note.gnu.property sections. */
+ info->callbacks->minfo (_("\n"));
+ info->callbacks->minfo (_("Mering program properties\n"));
+ info->callbacks->minfo (_("\n"));
+
for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link.next)
if (abfd != first_pbfd
&& (abfd->flags & (DYNAMIC | BFD_PLUGIN)) == 0)
@@ -471,7 +579,7 @@ _bfd_elf_link_setup_gnu_properties (struct bfd_link_info *info)
when all properties are from ELF objects with different
machine code or class. */
if (first_pbfd != NULL)
- elf_merge_gnu_property_list (info, first_pbfd, listp);
+ elf_merge_gnu_property_list (info, first_pbfd, abfd, listp);

if (list != NULL)
{
diff --git a/include/bfdlink.h b/include/bfdlink.h
index 630f7342a9..d66188e6ee 100644
--- a/include/bfdlink.h
+++ b/include/bfdlink.h
@@ -506,6 +506,9 @@ struct bfd_link_info
/* TRUE if common symbols should be treated as undefined. */
unsigned int inhibit_common_definition : 1;

+ /* TRUE if "-Map map" is passed to linker. */
+ unsigned int has_map_file : 1;
+
/* The 1-byte NOP for x86 call instruction. */
char call_nop_byte;

diff --git a/ld/NEWS b/ld/NEWS
index e2e87defee..502966635e 100644
--- a/ld/NEWS
+++ b/ld/NEWS
@@ -1,5 +1,7 @@
-*- text -*-

+* Report property change in linker map file when merging GNU properties.
+
* Add support for the C-SKY processor series.

Changes in 2.31:
diff --git a/ld/ld.texi b/ld/ld.texi
index 985c591d6a..83a322c992 100644
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -759,6 +759,28 @@ option is used:

See @ref{Expressions} for more information about expressions in linker
scripts.
+
+@item How GNU properties are merged.
+
+When linker merges input .note.gnu.property sections into one output
+.note.gnu.property section, some properties are removed or updated,
+which are reported in the link map as
+
+@smallexample
+Removed property 0xc0000002 to merge foo.o (0x1) and bar.o (not found)
+@end smallexample
+
+It indicates that property 0xc0000002 is removed from output when
+merging properties in @file{foo.o}, whose property 0xc0000002 value
+is 0x1, and @file{bar.o}, which doesn't have property 0xc0000002.
+
+@smallexample
+Updated property 0xc0000002 (0x1) to merge foo.o (0x1) and bar.o (0x1)
+@end smallexample
+
+It indicates that property 0xc0010001 value is updated to 0x1 in output
+when merging properties in @file{foo.o}, whose 0xc0010001 property value
+is 0x1, and @file{bar.o}, whose 0xc0010001 property value is 0x1.
@end itemize

@kindex -n
diff --git a/ld/ldmain.c b/ld/ldmain.c
index 24a40aa1ff..b7f51abc75 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -434,6 +434,7 @@ main (int argc, char **argv)
config.map_filename);
}
}
+ link_info.has_map_file = TRUE;
}

lang_process ();
diff --git a/ld/testsuite/ld-x86-64/property-x86-ibt1a-x32.d b/ld/testsuite/ld-x86-64/property-x86-ibt1a-x32.d
index 7a95401ac3..d05ab1dce5 100644
--- a/ld/testsuite/ld-x86-64/property-x86-ibt1a-x32.d
+++ b/ld/testsuite/ld-x86-64/property-x86-ibt1a-x32.d
@@ -1,8 +1,9 @@
#source: property-x86-empty.s
#source: property-x86-ibt.s
#as: --x32 -mx86-used-note=yes
-#ld: -r -m elf32_x86_64
+#ld: -r -m elf32_x86_64 -Map tmpdir/property-x86-ibt1a-x32.map
#readelf: -n
+#map: property-x86-ibt1a.map

Displaying notes found in: .note.gnu.property
Owner Data size Description
diff --git a/ld/testsuite/ld-x86-64/property-x86-ibt1a.d b/ld/testsuite/ld-x86-64/property-x86-ibt1a.d
index e989a8a817..f8d6a063b4 100644
--- a/ld/testsuite/ld-x86-64/property-x86-ibt1a.d
+++ b/ld/testsuite/ld-x86-64/property-x86-ibt1a.d
@@ -1,8 +1,9 @@
#source: property-x86-empty.s
#source: property-x86-ibt.s
#as: --64 -defsym __64_bit__=1 -mx86-used-note=yes
-#ld: -r -melf_x86_64
+#ld: -r -melf_x86_64 -Map tmpdir/property-x86-ibt1a.map
#readelf: -n
+#map: property-x86-ibt1a.map

Displaying notes found in: .note.gnu.property
Owner Data size Description
diff --git a/ld/testsuite/ld-x86-64/property-x86-ibt1a.map b/ld/testsuite/ld-x86-64/property-x86-ibt1a.map
new file mode 100644
index 0000000000..976c835d67
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/property-x86-ibt1a.map
@@ -0,0 +1,3 @@
+#...
+Removed property 0xc0000002 to merge tmpdir/property-x86-empty.o \(0x0\) and tmpdir/property-x86-ibt.o \(0x1\)
+#pass
--
2.19.2
Nick Clifton
2018-12-07 16:23:36 UTC
Permalink
Hi H.J.
Post by H.J. Lu
Mering program properties
Removed property 0xc0010000 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x0) and
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crti.o (0x0)
Removed property 0xc0000002 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (0x3) and
x.o (not found)
Removed property 0xc0000000 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not
found) and /usr/lib64/libc_nonshared.a(elf-init.oS) (0x0)
Removed property 0xc0000001 to merge
/usr/lib/gcc/x86_64-redhat-linux/8/../../../../lib64/crt1.o (not
found) and /usr/lib64/libc_nonshared.a(elf-init.oS) (0x0)
That is much nicer.
Post by H.J. Lu
OK for trunk?
* elf-properties.c (elf_find_and_remove_property): Add a
bfd_boolean argument to indicate if the property should be
removed.
(elf_merge_gnu_property_list): Updated. Report
property change in linker map file.
(elf_get_gnu_property_section_size): Skip property_remove
properties.
(elf_write_gnu_properties): Likewise.
(_bfd_elf_link_setup_gnu_properties): Report property merge
in linker map file. Pass abfd to elf_merge_gnu_property_list.
include/
* bfdlink.h (bfd_link_info): Add has_map_file.
ld/
* NEWS: Updated for property change report.
* ld.texi: Document property change report.
* ldmain.c (main): Set link_info.has_map_file to TRUE when
linker map file is used.
* testsuite/ld-x86-64/property-x86-ibt1a-x32.d: Check linker map
file.
* testsuite/ld-x86-64/property-x86-ibt1a.d: Likewise.
* testsuite/ld-x86-64/property-x86-ibt1a.map: New file.
Approved - please apply.

Cheers
Nick

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