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Re: [PATCH] elf: Report property change when merging properties
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Cary Coutant <ccoutant at gmail dot com>, Nick Clifton <nickc at redhat dot com>, Alan Modra <amodra at gmail dot com>, Binutils <binutils at sourceware dot org>
- Date: Sun, 2 Dec 2018 15:43:08 -0800
- Subject: Re: [PATCH] elf: Report property change when merging properties
- References: <20181122184835.25437-1-hjl.tools@gmail.com> <20181126001549.GS21617@bubble.grove.modra.org> <CAMe9rOq-x82Eo5J63WGkGpH6ots_6bQvv3U4e5L1Os5+uydyPg@mail.gmail.com> <2c601560-3b6e-1b40-5706-57a15566bc5a@redhat.com> <CAMe9rOqg73Risx1f4WQ6ZyWDSATQ2mjo-P1NGfVURM1WYc5M=g@mail.gmail.com> <CAJimCsFZPadaQOS8r5RfPjs75h7kmR=D_gFUc_1u96MPK7i7hQ@mail.gmail.com> <CAMe9rOo=gYa-ewOO2Gg=Hi__gWiVwO8MRzKBLSP6yQNY=Y1W9Q@mail.gmail.com> <CAJimCsFdeBFYq85vuYcoL3fS7wfiDVHwO83VoO=sf+TW1R9EWg@mail.gmail.com> <CAMe9rOohL_91PBSS++pBEhnJxO8fPDGXkMDx6t=AaU3WUGQL6Q@mail.gmail.com>
On Sun, Dec 02, 2018 at 06:18:06AM -0800, H.J. Lu wrote:
> On Sat, Dec 1, 2018 at 9:52 PM Cary Coutant <ccoutant@gmail.com> wrote:
> >
> > > > 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)
> > >
> > > > 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