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* [PATCH] ld: Keep indirect symbol from IR if referenced from shared object
@ 2022-02-11 23:19 H.J. Lu
  2022-02-14  0:16 ` H.J. Lu
  0 siblings, 1 reply; 6+ messages in thread
From: H.J. Lu @ 2022-02-11 23:19 UTC (permalink / raw)
  To: binutils

Don't change indirect symbol defined in IR to undefined if it is
referenced from shared object.

bfd/

	PR ld/28879
	* elflink.c (_bfd_elf_merge_symbol): Don't change indirect
	symbol defined in IR to undefined if it is referenced from
	shared object.

ld/

	PR ld/28879
	* testsuite/ld-plugin/lto.exp: Run PR ld/28879 tests.
	* testsuite/ld-plugin/pr28879a.cc: New file.
	* testsuite/ld-plugin/pr28879b.cc: Likewise.
---
 bfd/elflink.c                      |  5 ++---
 ld/testsuite/ld-plugin/lto.exp     | 26 ++++++++++++++++++++++++++
 ld/testsuite/ld-plugin/pr28879a.cc |  7 +++++++
 ld/testsuite/ld-plugin/pr28879b.cc |  8 ++++++++
 4 files changed, 43 insertions(+), 3 deletions(-)
 create mode 100644 ld/testsuite/ld-plugin/pr28879a.cc
 create mode 100644 ld/testsuite/ld-plugin/pr28879b.cc

diff --git a/bfd/elflink.c b/bfd/elflink.c
index 6fa18d92007..f8521426cad 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -1294,9 +1294,8 @@ _bfd_elf_merge_symbol (bfd *abfd,
 	  h->root.non_ir_ref_dynamic = true;
 	  hi->root.non_ir_ref_dynamic = true;
 	}
-
-      if ((oldbfd->flags & BFD_PLUGIN) != 0
-	  && hi->root.type == bfd_link_hash_indirect)
+      else if ((oldbfd->flags & BFD_PLUGIN) != 0
+	       && hi->root.type == bfd_link_hash_indirect)
 	{
 	  /* Change indirect symbol from IR to undefined.  */
 	  hi->root.type = bfd_link_hash_undefined;
diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp
index a70a84562b8..64b880265ee 100644
--- a/ld/testsuite/ld-plugin/lto.exp
+++ b/ld/testsuite/ld-plugin/lto.exp
@@ -471,6 +471,32 @@ set lto_link_elf_tests [list \
   [list {pr27441c.so} \
    {-shared -fPIC -Wl,--as-needed tmpdir/pr27441c.o tmpdir/pr27441b.so tmpdir/pr27441a.so} {-fPIC} \
    {dummy.c} {{readelf {-dW} pr27441c.d}} {pr27441c.so}] \
+  [list \
+   "Build libpr28879a.so" \
+   "-shared" \
+   "-O0 -fpic" \
+   {pr28879a.cc} \
+   {} \
+   "libpr28879a.so" \
+   "c++" \
+  ] \
+  [list \
+   "Build libpr28879b.so" \
+   "-shared -Wl,--no-as-needed tmpdir/libpr28879a.so" \
+   "-O2 -fpic" \
+   {dummy.c} \
+   {} \
+   "libpr28879b.so" \
+  ] \
+  [list \
+   "Build pr28879" \
+   "-Wl,--no-as-needed tmpdir/libpr28879b.so -Wl,-rpath-link,." \
+   "-O0 -flto -D_GLIBCXX_ASSERTIONS" \
+   {pr28879b.cc} \
+   {} \
+   "pr28879" \
+   "c++" \
+  ] \
 ]
 
 # PR 14918 checks that libgcc is not spuriously included in a shared link of
diff --git a/ld/testsuite/ld-plugin/pr28879a.cc b/ld/testsuite/ld-plugin/pr28879a.cc
new file mode 100644
index 00000000000..8307a42e2fb
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28879a.cc
@@ -0,0 +1,7 @@
+#include <string>
+
+void
+func (std::string *s)
+{
+  delete s;
+}
diff --git a/ld/testsuite/ld-plugin/pr28879b.cc b/ld/testsuite/ld-plugin/pr28879b.cc
new file mode 100644
index 00000000000..02fc351366c
--- /dev/null
+++ b/ld/testsuite/ld-plugin/pr28879b.cc
@@ -0,0 +1,8 @@
+#include <string>
+
+int
+main (void)
+{
+  std::string header;
+  return 0;
+}
-- 
2.34.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ld: Keep indirect symbol from IR if referenced from shared object
  2022-02-11 23:19 [PATCH] ld: Keep indirect symbol from IR if referenced from shared object H.J. Lu
@ 2022-02-14  0:16 ` H.J. Lu
  2022-02-14  2:47   ` Alan Modra
  0 siblings, 1 reply; 6+ messages in thread
From: H.J. Lu @ 2022-02-14  0:16 UTC (permalink / raw)
  To: Binutils, Nick Clifton, Alan Modra

On Fri, Feb 11, 2022 at 3:19 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> Don't change indirect symbol defined in IR to undefined if it is
> referenced from shared object.
>
> bfd/
>
>         PR ld/28879
>         * elflink.c (_bfd_elf_merge_symbol): Don't change indirect
>         symbol defined in IR to undefined if it is referenced from
>         shared object.
>
> ld/
>
>         PR ld/28879
>         * testsuite/ld-plugin/lto.exp: Run PR ld/28879 tests.
>         * testsuite/ld-plugin/pr28879a.cc: New file.
>         * testsuite/ld-plugin/pr28879b.cc: Likewise.
> ---
>  bfd/elflink.c                      |  5 ++---
>  ld/testsuite/ld-plugin/lto.exp     | 26 ++++++++++++++++++++++++++
>  ld/testsuite/ld-plugin/pr28879a.cc |  7 +++++++
>  ld/testsuite/ld-plugin/pr28879b.cc |  8 ++++++++
>  4 files changed, 43 insertions(+), 3 deletions(-)
>  create mode 100644 ld/testsuite/ld-plugin/pr28879a.cc
>  create mode 100644 ld/testsuite/ld-plugin/pr28879b.cc
>
> diff --git a/bfd/elflink.c b/bfd/elflink.c
> index 6fa18d92007..f8521426cad 100644
> --- a/bfd/elflink.c
> +++ b/bfd/elflink.c
> @@ -1294,9 +1294,8 @@ _bfd_elf_merge_symbol (bfd *abfd,
>           h->root.non_ir_ref_dynamic = true;
>           hi->root.non_ir_ref_dynamic = true;
>         }
> -
> -      if ((oldbfd->flags & BFD_PLUGIN) != 0
> -         && hi->root.type == bfd_link_hash_indirect)
> +      else if ((oldbfd->flags & BFD_PLUGIN) != 0
> +              && hi->root.type == bfd_link_hash_indirect)
>         {
>           /* Change indirect symbol from IR to undefined.  */
>           hi->root.type = bfd_link_hash_undefined;
> diff --git a/ld/testsuite/ld-plugin/lto.exp b/ld/testsuite/ld-plugin/lto.exp
> index a70a84562b8..64b880265ee 100644
> --- a/ld/testsuite/ld-plugin/lto.exp
> +++ b/ld/testsuite/ld-plugin/lto.exp
> @@ -471,6 +471,32 @@ set lto_link_elf_tests [list \
>    [list {pr27441c.so} \
>     {-shared -fPIC -Wl,--as-needed tmpdir/pr27441c.o tmpdir/pr27441b.so tmpdir/pr27441a.so} {-fPIC} \
>     {dummy.c} {{readelf {-dW} pr27441c.d}} {pr27441c.so}] \
> +  [list \
> +   "Build libpr28879a.so" \
> +   "-shared" \
> +   "-O0 -fpic" \
> +   {pr28879a.cc} \
> +   {} \
> +   "libpr28879a.so" \
> +   "c++" \
> +  ] \
> +  [list \
> +   "Build libpr28879b.so" \
> +   "-shared -Wl,--no-as-needed tmpdir/libpr28879a.so" \
> +   "-O2 -fpic" \
> +   {dummy.c} \
> +   {} \
> +   "libpr28879b.so" \
> +  ] \
> +  [list \
> +   "Build pr28879" \
> +   "-Wl,--no-as-needed tmpdir/libpr28879b.so -Wl,-rpath-link,." \
> +   "-O0 -flto -D_GLIBCXX_ASSERTIONS" \
> +   {pr28879b.cc} \
> +   {} \
> +   "pr28879" \
> +   "c++" \
> +  ] \
>  ]
>
>  # PR 14918 checks that libgcc is not spuriously included in a shared link of
> diff --git a/ld/testsuite/ld-plugin/pr28879a.cc b/ld/testsuite/ld-plugin/pr28879a.cc
> new file mode 100644
> index 00000000000..8307a42e2fb
> --- /dev/null
> +++ b/ld/testsuite/ld-plugin/pr28879a.cc
> @@ -0,0 +1,7 @@
> +#include <string>
> +
> +void
> +func (std::string *s)
> +{
> +  delete s;
> +}
> diff --git a/ld/testsuite/ld-plugin/pr28879b.cc b/ld/testsuite/ld-plugin/pr28879b.cc
> new file mode 100644
> index 00000000000..02fc351366c
> --- /dev/null
> +++ b/ld/testsuite/ld-plugin/pr28879b.cc
> @@ -0,0 +1,8 @@
> +#include <string>
> +
> +int
> +main (void)
> +{
> +  std::string header;
> +  return 0;
> +}
> --
> 2.34.1
>

Hi Nick, Alan,

Is this OK for master and 2.38 branch?

Thanks.

-- 
H.J.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ld: Keep indirect symbol from IR if referenced from shared object
  2022-02-14  0:16 ` H.J. Lu
@ 2022-02-14  2:47   ` Alan Modra
  2022-02-14  2:58     ` H.J. Lu
  0 siblings, 1 reply; 6+ messages in thread
From: Alan Modra @ 2022-02-14  2:47 UTC (permalink / raw)
  To: H.J. Lu; +Cc: Binutils, Nick Clifton

On Sun, Feb 13, 2022 at 04:16:35PM -0800, H.J. Lu wrote:
> On Fri, Feb 11, 2022 at 3:19 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> >
> > Don't change indirect symbol defined in IR to undefined if it is
> > referenced from shared object.

The description above

> > diff --git a/bfd/elflink.c b/bfd/elflink.c
> > index 6fa18d92007..f8521426cad 100644
> > --- a/bfd/elflink.c
> > +++ b/bfd/elflink.c
> > @@ -1294,9 +1294,8 @@ _bfd_elf_merge_symbol (bfd *abfd,
> >           h->root.non_ir_ref_dynamic = true;
> >           hi->root.non_ir_ref_dynamic = true;
> >         }
> > -
> > -      if ((oldbfd->flags & BFD_PLUGIN) != 0
> > -         && hi->root.type == bfd_link_hash_indirect)
> > +      else if ((oldbfd->flags & BFD_PLUGIN) != 0
> > +              && hi->root.type == bfd_link_hash_indirect)
> >         {
> >           /* Change indirect symbol from IR to undefined.  */
> >           hi->root.type = bfd_link_hash_undefined;

and the patch do not exactly match.  The code logic is old sym
indirect in IR, new sym not IR, both in shared library *or both not*.
Is that correct?

-- 
Alan Modra
Australia Development Lab, IBM

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ld: Keep indirect symbol from IR if referenced from shared object
  2022-02-14  2:47   ` Alan Modra
@ 2022-02-14  2:58     ` H.J. Lu
  2022-02-14  4:13       ` Alan Modra
  0 siblings, 1 reply; 6+ messages in thread
From: H.J. Lu @ 2022-02-14  2:58 UTC (permalink / raw)
  To: Alan Modra; +Cc: Binutils, Nick Clifton

On Sun, Feb 13, 2022 at 6:47 PM Alan Modra <amodra@gmail.com> wrote:
>
> On Sun, Feb 13, 2022 at 04:16:35PM -0800, H.J. Lu wrote:
> > On Fri, Feb 11, 2022 at 3:19 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> > >
> > > Don't change indirect symbol defined in IR to undefined if it is
> > > referenced from shared object.
>
> The description above
>
> > > diff --git a/bfd/elflink.c b/bfd/elflink.c
> > > index 6fa18d92007..f8521426cad 100644
> > > --- a/bfd/elflink.c
> > > +++ b/bfd/elflink.c
> > > @@ -1294,9 +1294,8 @@ _bfd_elf_merge_symbol (bfd *abfd,
> > >           h->root.non_ir_ref_dynamic = true;
> > >           hi->root.non_ir_ref_dynamic = true;
> > >         }
> > > -
> > > -      if ((oldbfd->flags & BFD_PLUGIN) != 0
> > > -         && hi->root.type == bfd_link_hash_indirect)
> > > +      else if ((oldbfd->flags & BFD_PLUGIN) != 0
> > > +              && hi->root.type == bfd_link_hash_indirect)
> > >         {
> > >           /* Change indirect symbol from IR to undefined.  */
> > >           hi->root.type = bfd_link_hash_undefined;
>
> and the patch do not exactly match.  The code logic is old sym
> indirect in IR, new sym not IR, both in shared library *or both not*.
> Is that correct?
>

The existing code is

      if (newdyn != olddyn)
        {
          /* Handle a case where plugin_notice won't be called and thus
             won't set the non_ir_ref flags on the first pass over
             symbols.  */
          h->root.non_ir_ref_dynamic = true;
          hi->root.non_ir_ref_dynamic = true;
        }

If an indirect symbol defined in IR is marked with
non_ir_ref_dynamic, we can't change it to undefined.
That is why I added "else" so that we don't get the
error of undefined reference from shared object.

      if ((oldbfd->flags & BFD_PLUGIN) != 0
          && hi->root.type == bfd_link_hash_indirect)
        {
          /* Change indirect symbol from IR to undefined.  */
          hi->root.type = bfd_link_hash_undefined;
          hi->root.u.undef.abfd = oldbfd;
        }


-- 
H.J.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ld: Keep indirect symbol from IR if referenced from shared object
  2022-02-14  2:58     ` H.J. Lu
@ 2022-02-14  4:13       ` Alan Modra
  2022-02-14 15:28         ` H.J. Lu
  0 siblings, 1 reply; 6+ messages in thread
From: Alan Modra @ 2022-02-14  4:13 UTC (permalink / raw)
  To: H.J. Lu; +Cc: Binutils, Nick Clifton

On Sun, Feb 13, 2022 at 06:58:48PM -0800, H.J. Lu wrote:
> On Sun, Feb 13, 2022 at 6:47 PM Alan Modra <amodra@gmail.com> wrote:
> >
> > On Sun, Feb 13, 2022 at 04:16:35PM -0800, H.J. Lu wrote:
> > > On Fri, Feb 11, 2022 at 3:19 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > >
> > > > Don't change indirect symbol defined in IR to undefined if it is
> > > > referenced from shared object.
> >
> > The description above
> >
> > > > diff --git a/bfd/elflink.c b/bfd/elflink.c
> > > > index 6fa18d92007..f8521426cad 100644
> > > > --- a/bfd/elflink.c
> > > > +++ b/bfd/elflink.c
> > > > @@ -1294,9 +1294,8 @@ _bfd_elf_merge_symbol (bfd *abfd,
> > > >           h->root.non_ir_ref_dynamic = true;
> > > >           hi->root.non_ir_ref_dynamic = true;
> > > >         }
> > > > -
> > > > -      if ((oldbfd->flags & BFD_PLUGIN) != 0
> > > > -         && hi->root.type == bfd_link_hash_indirect)
> > > > +      else if ((oldbfd->flags & BFD_PLUGIN) != 0
> > > > +              && hi->root.type == bfd_link_hash_indirect)
> > > >         {
> > > >           /* Change indirect symbol from IR to undefined.  */
> > > >           hi->root.type = bfd_link_hash_undefined;
> >
> > and the patch do not exactly match.  The code logic is old sym
> > indirect in IR, new sym not IR, both in shared library *or both not*.
> > Is that correct?
> >
> 
> The existing code is
> 
>       if (newdyn != olddyn)
>         {
>           /* Handle a case where plugin_notice won't be called and thus
>              won't set the non_ir_ref flags on the first pass over
>              symbols.  */
>           h->root.non_ir_ref_dynamic = true;
>           hi->root.non_ir_ref_dynamic = true;
>         }
> 
> If an indirect symbol defined in IR is marked with
> non_ir_ref_dynamic, we can't change it to undefined.
> That is why I added "else" so that we don't get the
> error of undefined reference from shared object.

The patch is OK, I wasn't thinking clearly.

>       if ((oldbfd->flags & BFD_PLUGIN) != 0
>           && hi->root.type == bfd_link_hash_indirect)
>         {
>           /* Change indirect symbol from IR to undefined.  */
>           hi->root.type = bfd_link_hash_undefined;
>           hi->root.u.undef.abfd = oldbfd;
>         }
> 
> 
> -- 
> H.J.

-- 
Alan Modra
Australia Development Lab, IBM

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] ld: Keep indirect symbol from IR if referenced from shared object
  2022-02-14  4:13       ` Alan Modra
@ 2022-02-14 15:28         ` H.J. Lu
  0 siblings, 0 replies; 6+ messages in thread
From: H.J. Lu @ 2022-02-14 15:28 UTC (permalink / raw)
  To: Alan Modra; +Cc: Binutils, Nick Clifton

On Sun, Feb 13, 2022 at 8:13 PM Alan Modra <amodra@gmail.com> wrote:
>
> On Sun, Feb 13, 2022 at 06:58:48PM -0800, H.J. Lu wrote:
> > On Sun, Feb 13, 2022 at 6:47 PM Alan Modra <amodra@gmail.com> wrote:
> > >
> > > On Sun, Feb 13, 2022 at 04:16:35PM -0800, H.J. Lu wrote:
> > > > On Fri, Feb 11, 2022 at 3:19 PM H.J. Lu <hjl.tools@gmail.com> wrote:
> > > > >
> > > > > Don't change indirect symbol defined in IR to undefined if it is
> > > > > referenced from shared object.
> > >
> > > The description above
> > >
> > > > > diff --git a/bfd/elflink.c b/bfd/elflink.c
> > > > > index 6fa18d92007..f8521426cad 100644
> > > > > --- a/bfd/elflink.c
> > > > > +++ b/bfd/elflink.c
> > > > > @@ -1294,9 +1294,8 @@ _bfd_elf_merge_symbol (bfd *abfd,
> > > > >           h->root.non_ir_ref_dynamic = true;
> > > > >           hi->root.non_ir_ref_dynamic = true;
> > > > >         }
> > > > > -
> > > > > -      if ((oldbfd->flags & BFD_PLUGIN) != 0
> > > > > -         && hi->root.type == bfd_link_hash_indirect)
> > > > > +      else if ((oldbfd->flags & BFD_PLUGIN) != 0
> > > > > +              && hi->root.type == bfd_link_hash_indirect)
> > > > >         {
> > > > >           /* Change indirect symbol from IR to undefined.  */
> > > > >           hi->root.type = bfd_link_hash_undefined;
> > >
> > > and the patch do not exactly match.  The code logic is old sym
> > > indirect in IR, new sym not IR, both in shared library *or both not*.
> > > Is that correct?
> > >
> >
> > The existing code is
> >
> >       if (newdyn != olddyn)
> >         {
> >           /* Handle a case where plugin_notice won't be called and thus
> >              won't set the non_ir_ref flags on the first pass over
> >              symbols.  */
> >           h->root.non_ir_ref_dynamic = true;
> >           hi->root.non_ir_ref_dynamic = true;
> >         }
> >
> > If an indirect symbol defined in IR is marked with
> > non_ir_ref_dynamic, we can't change it to undefined.
> > That is why I added "else" so that we don't get the
> > error of undefined reference from shared object.
>
> The patch is OK, I wasn't thinking clearly.

I checked it into master branch and will backport it to
2.38 branch later this week.

> >       if ((oldbfd->flags & BFD_PLUGIN) != 0
> >           && hi->root.type == bfd_link_hash_indirect)
> >         {
> >           /* Change indirect symbol from IR to undefined.  */
> >           hi->root.type = bfd_link_hash_undefined;
> >           hi->root.u.undef.abfd = oldbfd;
> >         }
> >
> >
> > --
> > H.J.
>
> --
> Alan Modra
> Australia Development Lab, IBM



-- 
H.J.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2022-02-14 15:29 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-02-11 23:19 [PATCH] ld: Keep indirect symbol from IR if referenced from shared object H.J. Lu
2022-02-14  0:16 ` H.J. Lu
2022-02-14  2:47   ` Alan Modra
2022-02-14  2:58     ` H.J. Lu
2022-02-14  4:13       ` Alan Modra
2022-02-14 15:28         ` H.J. Lu

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