Re: [PATCH] x86: Make protected symbols local for -shared

["H.J. Lu" <hjl.tools@gmail.com>]

On Mon, Jul 18, 2022 at 8:13 PM Fangrui Song <i@maskray.me> wrote:
>
> On 2022-07-18, H.J. Lu wrote:
> >On Mon, Jun 27, 2022 at 09:18:27PM -0700, Fangrui Song wrote:
> >> On 2022-06-27, H.J. Lu wrote:
> >> > On Mon, Jun 27, 2022 at 8:44 PM Fangrui Song <i@maskray.me> wrote:
> >> > >
> >> > > On 2022-06-27, H.J. Lu wrote:
> >> > > >On Mon, Jun 27, 2022 at 8:07 PM Fangrui Song <i@maskray.me> wrote:
> >> > > >>
> >> > > >> On 2022-06-27, H.J. Lu wrote:
> >> > > >> >On Mon, Jun 27, 2022 at 11:46 AM Fangrui Song <i@maskray.me> wrote:
> >> > > >> >>
> >> > > >> >> On 2022-06-27, H.J. Lu wrote:
> >> > > >> >> >On Mon, Jun 27, 2022 at 10:53 AM Fangrui Song <i@maskray.me> wrote:
> >> > > >> >> >>
> >> > > >> >> >> On 2022-06-27, H.J. Lu wrote:
> >> > > >> >> >> >On Mon, Jun 27, 2022 at 10:09 AM Fangrui Song <i@maskray.me> wrote:
> >> > > >> >> >> >>
> >> > > >> >> >> >> On 2022-06-27, H.J. Lu wrote:
> >> > > >> >> >> >> >On Sun, Jun 26, 2022 at 12:03 PM Fangrui Song <i@maskray.me> wrote:
> >> > > >> >> >> >> >>
> >> > > >> >> >> >> >> On 2022-06-26, H.J. Lu wrote:
> >> > > >> >> >> >> >> >On Sat, Jun 25, 2022 at 10:44 AM Fangrui Song <i@maskray.me> wrote:
> >> > > >> >> >> >> >> >>
> >> > > >> >> >> >> >> >> Call _bfd_elf_symbol_refs_local_p with local_protected==true.  This has
> >> > > >> >> >> >> >> >> 2 noticeable effects for -shared:
> >> > > >> >> >> >> >> >>
> >> > > >> >> >> >> >> >> * GOT-generating relocations referencing a protected data symbol no
> >> > > >> >> >> >> >> >>   longer lead to a GLOB_DAT (similar to a hidden symbol).
> >> > > >> >> >> >> >> >> * Direct access relocations (e.g. R_X86_64_PC32) no longer has the
> >> > > >> >> >> >> >> >>   confusing diagnostic below.
> >> > > >> >> >> >> >> >>
> >> > > >> >> >> >> >> >>     __attribute__((visibility("protected"))) void *foo() {
> >> > > >> >> >> >> >> >>       return (void *)foo;
> >> > > >> >> >> >> >> >>     }
> >> > > >> >> >> >> >> >>
> >> > > >> >> >> >> >> >>     // gcc -fpic -shared -fuse-ld=bfd
> >> > > >> >> >> >> >> >>     relocation R_X86_64_PC32 against protected symbol `foo' can not be used when making a shared object
> >> > > >> >> >> >> >> >>
> >> > > >> >> >> >> >> >> The new behavior matches arm, aarch64 (commit
> >> > > >> >> >> >> >> >> 83c325007c5599fa9b60b8d5f7b84842160e1d1b), and powerpc ports, and other
> >> > > >> >> >> >> >> >> linkers: gold and ld.lld.
> >> > > >> >> >> >> >> >>
> >> > > >> >> >> >> >> >> Note: if some code tries to use direct access relocations to take the
> >> > > >> >> >> >> >> >> address of foo, the pointer equality will break, but the error should be
> >> > > >> >> >> >> >> >> reported on the executable link, not on the innocent shared object link.
> >> > > >> >> >> >> >> >> glibc 2.36 will give a warning at relocation resolving time.
> >> > > >> >> >> >> >> >
> >> > > >> >> >> >> >> >It should be controlled by -z [no]indirect-extern-access.   Can you enable
> >> > > >> >> >> >> >> >-z  indirect-extern-access with -shared by default instead?
> >> > > >> >> >> >> >>
> >> > > >> >> >> >> >> If I set `link_info.indirect_extern_access = 1;` in ld/ldmain.c,
> >> > > >> >> >> >> >> bfd/elf-properties.c:654 will create a
> >> > > >> >> >> >> >> GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS note.
> >> > > >> >> >> >> >> This will probably be unexpected (and check-ld will have 280+ failures).
> >> > > >> >> >> >> >
> >> > > >> >> >> >> >This is normal when the default behavior is changed.  You can pass
> >> > > >> >> >> >> >-z noindirect-extern-access to these testcases.
> >> > > >> >> >> >>
> >> > > >> >> >> >> Adding GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS will be a
> >> > > >> >> >> >> significant behavior change and may unnecessarily break user programs
> >> > > >> >> >> >> (glibc will report an error instead of a warning).
> >> > > >> >> >> >
> >> > > >> >> >> >If glibc reports an error, it is a real bug with unknown consequences
> >> > > >> >> >> >when the copy in the executable is out of sync with the protected
> >> > > >> >> >> >symbol in the shared library,
> >> > > >> >> >>
> >> > > >> >> >> Not necessary.
> >> > > >> >> >>
> >> > > >> >> >> In glibc, GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS has two effects,
> >> > > >> >> >> 1 (copy relocations) and 2 (non-zero value of an undefined function
> >> > > >> >> >> symbol) on
> >> > > >> >> >> https://sourceware.org/pipermail/libc-alpha/2022-June/139552.html
> >> > > >> >> >>
> >> > > >> >> >> 2 does not necessarily cause a problem. In many cases it doesn't as
> >> > > >> >> >> function pointer equality is not an invariant a program relies upon
> >> > > >> >> >> (at least, for many functions, the property is not used). My previous
> >> > > >> >> >> comment has mentioned two cases.
> >> > > >> >> >>
> >> > > >> >> >> 1 likely causes a problem, but technically the shared object can define
> >> > > >> >> >> a protected data symbol without accessing it..
> >> > > >> >> >
> >> > > >> >> >These are unknown consequences.   We don't know what the worst
> >> > > >> >> >cases are.
> >> > > >> >>
> >> > > >> >> They are, just like when a shared object is linked with -Bsymbolic.
> >> > > >> >
> >> > > >> >They have to deal with it since it is done on purpose.
> >> > > >> >
> >> > > >> >> This patch focuses on changing the x86 default to a sane value (matching
> >> > > >> >> aarch64/arm/powerpc64/riscv/etc) and enabling future removal of
> >> > > >> >> `extern_protected_data`.  If you want to switch to
> >> > > >> >> indirect-extern-access default for x86, while I think unnecessary, I will not object.
> >> > > >> >
> >> > > >> >extern_protected_data can be safely removed only when
> >> > > >> >direct access to external symbols are disallowed.   We can't
> >> > > >> >have both ways.
> >> > > >>
> >> > > >> Just define has_no_copy_on_protected to 1 to catch the usage at link
> >> > > >
> >> > > >This is the same as using -z indirect-extern-access on executable.
> >> > > >
> >> > > >> time.  ld's aarch64 port has such an error by default.  gold and ld.lld
> >> > > >> has such an error for a long time now.
> >> > > >>
> >> > > >> We don't need to worry about whether this stricter behavior breaks user
> >> > > >> programs.  As is, protected symbol using GCC+binutils provides no
> >> > > >> benefit.  Programs just avoid protected data symbols.
> >> > > >
> >> > > >Then there should be no problems with
> >> > > >GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS.
> >> > > >I'd like to disallow copy relocation on protected symbols at run-time
> >> > > >when there are unknown consequences.
> >> > >
> >> > > Enabling GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS for x86 by default
> >> > > has these effects:
> >> > >
> >> > > * 280+ check-ld tests will fail
> >> >
> >> > They should be updated.
> >>
> >> That will be a huge effort and may not be so necessary. See below.
> >>
> >> > > * The GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS note appears
> >> >
> >> > It will disallow copy relocation on protected symbols at run-time.
> >> >
> >> > >    redundant. It encodes an intention explicit but the intention is
> >> > >    in ld aarch64, gold (all ports), and lld (all ports) with no extra option.
> >> > >
> >> > > IMO, we should do these:
> >> > >
> >> > > * push this commit
> >> > > * treat elf_has_no_copy_on_protected as always true and remove all GNU_PROPERTY_NO_COPY_ON_PROTECTED
> >> > >
> >> > > Again, I understand that there is concern about protected data symbols
> >> > > in shared object.  But as is, nobody uses protected symbols in shared objects.
> >> > > My
> >> > >
> >> > >    // gcc -fpic -shared -fuse-ld=bfd
> >> > >    __attribute__((visibility("protected"))) void *foo() {
> >> > >      return (void *)foo;
> >> > >    }
> >> > >
> >> > > example indicates that protected future symbol is also broken.
> >> >
> >> > To get protected symbol to work properly on x86-64, copy relocation on protected
> >> > symbols should be disallowed at run-time.
> >>
> >> Yes that GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS will change the
> >> glibc warning to an error, but we don't need to hurry making the cases
> >> an error.  Since protected symbols do not have performance benefits (in
> >> gcc's many ports and GNU ld's x86 port), people avoid using it.  My
> >> advise is to just let ld stop producing executables which will trigger
> >> glibc warning/error (this has precedent in gold and ld.lld and FreeBSD's
> >> adoption of ld.lld means that this goes actually very well).  Projects
> >> will gradually fix their builds to enable indirect external access in
> >> the rare case they encounter protected symbols in shared objects.  Then
> >> in a few years, the glibc warning can naturally upgrade to an error,
> >> with possibly a method (e.g. similar to LD_DYNAMIC_WEAK) to downgrade to
> >> a warning.  Finally, remove the opt-out method.
> >>
> >> With this scheme no GNU property is needed.
> >
> >Then, linker should disallow copy relocation against protected symbols
> >and non-canonical reference to canonical protected functions.
> >
> >Something like this.
> >
> >
> >H.J.
> >----
> >x86: Disallow invalid relocations against protected symbols
> >
> >Since glibc 2.36 will issue warnings for copy relocation against
> >protected symbols and non-canonical reference to canonical protected
> >functions, change the linker to always disallow such relocations.
>
> Thanks.  When reporting relocation diagnostics, making the condition
> stricter by removing elf_has_indirect_extern_access is the right
> direction.
>
>
> Your patch alone isn't sufficient to make -fpic -shared below work:

My patch is on top of yours.

> __attribute__((visibility("protected"))) void *foo() {
>    return (void *)foo;
> }
>
>
> >bfd/
> >
> >       * elf32-i386.c (elf_i386_scan_relocs): Remove check for
> >       elf_has_indirect_extern_access.
> >       * elf64-x86-64.c (elf_x86_64_scan_relocs): Likewise.
> >       (elf_x86_64_relocate_section): Remove check for
> >       elf_has_no_copy_on_protected.
> >       * elfxx-x86.c (elf_x86_allocate_dynrelocs): Check for building
> >       executable instead of elf_has_no_copy_on_protected.
> >       (_bfd_x86_elf_adjust_dynamic_symbol): Disallow copy relocation
> >       against non-copyable protected symbol.
> >       * elfxx-x86.h (SYMBOL_NO_COPYRELOC): Remove check for
> >       elf_has_no_copy_on_protected.
> >
> >ld/
> >
> >       * testsuite/ld-i386/i386.exp: Expect linker error for PR ld/17709
> >       test.
> >       * testsuite/ld-i386/pr17709.rd: Removed.
> >       * testsuite/ld-i386/pr17709.err: New file.
> >       * testsuite/ld-x86-64/pr17709.rd: Removed.
> >       * testsuite/ld-x86-64/pr17709.err: New file.
> >       * testsuite/ld-x86-64/pr28875-func.err: Updated.
> >       * testsuite/ld-x86-64/x86-64.exp: Expect linker error for PR
> >       ld/17709 test.  Add tests for function pointer against protected
> >       function.
> >---
> > bfd/elf32-i386.c                        |  3 +--
> > bfd/elf64-x86-64.c                      | 10 +++-------
> > bfd/elfxx-x86.c                         | 21 +++++++++++++++++++--
> > bfd/elfxx-x86.h                         |  3 +--
> > ld/testsuite/ld-i386/i386.exp           |  2 +-
> > ld/testsuite/ld-i386/pr17709.err        |  2 ++
> > ld/testsuite/ld-i386/pr17709.rd         |  4 ----
> > ld/testsuite/ld-x86-64/pr17709.err      |  2 ++
> > ld/testsuite/ld-x86-64/pr17709.rd       |  4 ----
> > ld/testsuite/ld-x86-64/pr28875-func.err |  2 +-
> > ld/testsuite/ld-x86-64/x86-64.exp       | 18 +++++++++++++++++-
> > 11 files changed, 47 insertions(+), 24 deletions(-)
> > create mode 100644 ld/testsuite/ld-i386/pr17709.err
> > delete mode 100644 ld/testsuite/ld-i386/pr17709.rd
> > create mode 100644 ld/testsuite/ld-x86-64/pr17709.err
> > delete mode 100644 ld/testsuite/ld-x86-64/pr17709.rd
> >
> >diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
> >index 04a972e646d..cfb0085b245 100644
> >--- a/bfd/elf32-i386.c
> >+++ b/bfd/elf32-i386.c
> >@@ -1812,8 +1812,7 @@ elf_i386_scan_relocs (bfd *abfd,
> >                     && h->type == STT_FUNC
> >                     && eh->def_protected
> >                     && !SYMBOL_DEFINED_NON_SHARED_P (h)
> >-                    && h->def_dynamic
> >-                    && elf_has_indirect_extern_access (h->root.u.def.section->owner))
> >+                    && h->def_dynamic)
> >                   {
> >                     /* Disallow non-canonical reference to canonical
> >                        protected function.  */
> >diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
> >index 3abc68a4127..62a9a22317a 100644
> >--- a/bfd/elf64-x86-64.c
> >+++ b/bfd/elf64-x86-64.c
> >@@ -2255,8 +2255,7 @@ elf_x86_64_scan_relocs (bfd *abfd, struct bfd_link_info *info,
> >                     && h->type == STT_FUNC
> >                     && eh->def_protected
> >                     && !SYMBOL_DEFINED_NON_SHARED_P (h)
> >-                    && h->def_dynamic
> >-                    && elf_has_indirect_extern_access (h->root.u.def.section->owner))
> >+                    && h->def_dynamic)
> >                   {
> >                     /* Disallow non-canonical reference to canonical
> >                        protected function.  */
> >@@ -3156,8 +3155,7 @@ elf_x86_64_relocate_section (bfd *output_bfd,
> >              || (h != NULL
> >                  && !h->root.linker_def
> >                  && !h->root.ldscript_def
> >-                 && eh->def_protected
> >-                 && elf_has_no_copy_on_protected (h->root.u.def.section->owner)));
> >+                 && eh->def_protected));
> >
> >         if ((input_section->flags & SEC_ALLOC) != 0
> >             && (input_section->flags & SEC_READONLY) != 0
> >@@ -4097,9 +4095,7 @@ elf_x86_64_relocate_section (bfd *output_bfd,
> >           {
> >           case R_X86_64_32S:
> >             sec = h->root.u.def.section;
> >-            if ((info->nocopyreloc
> >-                 || (eh->def_protected
> >-                     && elf_has_no_copy_on_protected (h->root.u.def.section->owner)))
> >+            if ((info->nocopyreloc || eh->def_protected)
> >                 && !(h->root.u.def.section->flags & SEC_CODE))
> >               return elf_x86_64_need_pic (info, input_bfd, input_section,
> >                                           h, NULL, NULL, howto);
> >diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
> >index 18f3d335458..7fb972752b3 100644
> >--- a/bfd/elfxx-x86.c
> >+++ b/bfd/elfxx-x86.c
> >@@ -524,8 +524,7 @@ elf_x86_allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
> >     {
> >       asection *sreloc;
> >
> >-      if (eh->def_protected
> >-        && elf_has_no_copy_on_protected (h->root.u.def.section->owner))
> >+      if (eh->def_protected && bfd_link_executable (info))
> >       {
> >         /* Disallow copy relocation against non-copyable protected
> >            symbol.  */
> >@@ -3041,6 +3040,24 @@ _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info,
> >     }
> >   if ((h->root.u.def.section->flags & SEC_ALLOC) != 0 && h->size != 0)
> >     {
> >+      if (eh->def_protected && bfd_link_executable (info))
> >+      for (p = h->dyn_relocs; p != NULL; p = p->next)
> >+        {
> >+          /* Disallow copy relocation against non-copyable protected
> >+             symbol.  */
> >+          s = p->sec->output_section;
> >+          if (s != NULL && (s->flags & SEC_READONLY) != 0)
> >+            {
> >+              info->callbacks->einfo
> >+                /* xgettext:c-format */
> >+                (_("%F%P: %pB: copy relocation against non-copyable "
> >+                   "protected symbol `%s' in %pB\n"),
> >+                 p->sec->owner, h->root.root.string,
> >+                 h->root.u.def.section->owner);
> >+              return false;
> >+            }
> >+        }
> >+
> >       srel->size += htab->sizeof_reloc;
> >       h->needs_copy = 1;
> >     }
> >diff --git a/bfd/elfxx-x86.h b/bfd/elfxx-x86.h
> >index 77fb1ad72bc..7d23893938c 100644
> >--- a/bfd/elfxx-x86.h
> >+++ b/bfd/elfxx-x86.h
> >@@ -135,12 +135,11 @@
> >
> > /* Should copy relocation be generated for a symbol.  Don't generate
> >    copy relocation against a protected symbol defined in a shared
> >-   object with GNU_PROPERTY_NO_COPY_ON_PROTECTED.  */
> >+   object.  */
> > #define SYMBOL_NO_COPYRELOC(INFO, EH) \
> >   ((EH)->def_protected \
> >    && ((EH)->elf.root.type == bfd_link_hash_defined \
> >        || (EH)->elf.root.type == bfd_link_hash_defweak) \
> >-   && elf_has_no_copy_on_protected ((EH)->elf.root.u.def.section->owner) \
> >    && ((EH)->elf.root.u.def.section->owner->flags & DYNAMIC) != 0 \
> >    && ((EH)->elf.root.u.def.section->flags & SEC_CODE) == 0)
> >
> >diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
> >index b4f7de49fd5..0ab9c001336 100644
> >--- a/ld/testsuite/ld-i386/i386.exp
> >+++ b/ld/testsuite/ld-i386/i386.exp
> >@@ -224,7 +224,7 @@ set i386tests {
> >      "--32 -mx86-used-note=yes" {pr17709a.s} {} "libpr17709.so"}
> >     {"PR ld/17709 (2)" "-melf_i386 tmpdir/libpr17709.so" ""
> >      "--32 -mx86-used-note=yes"
> >-     {pr17709b.s} {{readelf -r pr17709.rd}} "pr17709"}
> >+     {pr17709b.s} {{ld "pr17709.err"}} "pr17709"}
> >     {"Build pr19827a.o" "" ""
> >      "--32 -mx86-used-note=yes" { pr19827a.S }}
> >     {"Build pr19827b.so" "-melf_i386 -shared" ""
> >diff --git a/ld/testsuite/ld-i386/pr17709.err b/ld/testsuite/ld-i386/pr17709.err
> >new file mode 100644
> >index 00000000000..fa6a4bacce3
> >--- /dev/null
> >+++ b/ld/testsuite/ld-i386/pr17709.err
> >@@ -0,0 +1,2 @@
> >+.*: tmpdir/pr17709b.o: copy relocation against non-copyable protected symbol `foo' in tmpdir/libpr17709.so
> >+#...
> >diff --git a/ld/testsuite/ld-i386/pr17709.rd b/ld/testsuite/ld-i386/pr17709.rd
> >deleted file mode 100644
> >index 8414784b736..00000000000
> >--- a/ld/testsuite/ld-i386/pr17709.rd
> >+++ /dev/null
> >@@ -1,4 +0,0 @@
> >-
> >-Relocation section '.rel\..*' at offset .* contains 1 entry:
> >- Offset     Info    Type            Sym\.Value  Sym\. Name
> >-[0-9a-f ]+R_386_COPY +[0-9a-f]+ +foo
> >diff --git a/ld/testsuite/ld-x86-64/pr17709.err b/ld/testsuite/ld-x86-64/pr17709.err
> >new file mode 100644
> >index 00000000000..fa6a4bacce3
> >--- /dev/null
> >+++ b/ld/testsuite/ld-x86-64/pr17709.err
> >@@ -0,0 +1,2 @@
> >+.*: tmpdir/pr17709b.o: copy relocation against non-copyable protected symbol `foo' in tmpdir/libpr17709.so
> >+#...
> >diff --git a/ld/testsuite/ld-x86-64/pr17709.rd b/ld/testsuite/ld-x86-64/pr17709.rd
> >deleted file mode 100644
> >index beffd3cb34c..00000000000
> >--- a/ld/testsuite/ld-x86-64/pr17709.rd
> >+++ /dev/null
> >@@ -1,4 +0,0 @@
> >-
> >-Relocation section '.rela\..*' at offset .* contains 1 entry:
> >- +Offset +Info +Type +Symbol's Value +Symbol's Name \+ Addend
> >-[0-9a-f ]+R_X86_64_COPY+[0-9a-f ]+ +foo \+ 0
> >diff --git a/ld/testsuite/ld-x86-64/pr28875-func.err b/ld/testsuite/ld-x86-64/pr28875-func.err
> >index 64e961cb3d4..f6f4658deaf 100644
> >--- a/ld/testsuite/ld-x86-64/pr28875-func.err
> >+++ b/ld/testsuite/ld-x86-64/pr28875-func.err
> >@@ -1,2 +1,2 @@
> >-.*: tmpdir/protected-func-1b.o: non-canonical reference to canonical protected function `protected_func_1a' in tmpdir/libprotected-func-2b.so
> >+.*: tmpdir/protected-func-1b.o: non-canonical reference to canonical protected function `protected_func_1a' in tmpdir/libprotected-func-2..so
> > #...
> >diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
> >index a096c0b9d0f..e6a834a2a61 100644
> >--- a/ld/testsuite/ld-x86-64/x86-64.exp
> >+++ b/ld/testsuite/ld-x86-64/x86-64.exp
> >@@ -177,7 +177,7 @@ set x86_64tests {
> >     {"PR ld/17709 (1)" "-melf_x86_64 -shared" ""
> >      "--64" {pr17709a.s} {} "libpr17709.so"}
> >     {"PR ld/17709 (2)" "-melf_x86_64 tmpdir/libpr17709.so" ""
> >-     "--64" {pr17709b.s} {{readelf -rW pr17709.rd}} "pr17709"}
> >+     "--64" {pr17709b.s} {{ld "pr17709.err"}} "pr17709"}
> >     {"Build pr19827a.o" "" ""
> >      "--64" { pr19827a.S }}
> >     {"Build pr19827b.so" "-melf_x86_64 -shared" ""
> >@@ -1383,6 +1383,22 @@ if { [isnative] && [check_compiler_available] } {
> >           {{error_output "pr28875-func.err"}} \
> >           "protected-func-2" \
> >       ] \
> >+      [list \
> >+          "Build libprotected-func-2c.so" \
> >+          "-shared" \
> >+          "-fPIC -Wa,-mx86-used-note=yes" \
> >+          { protected-func-2c.c } \
> >+          {}  \
> >+          "libprotected-func-2c.so" \
> >+      ] \
> >+      [list \
> >+          "Build protected-func-2a without PIE" \
> >+          "$NOPIE_LDFLAGS -Wl,--no-as-needed tmpdir/libprotected-func-2c.so" \
> >+          "$NOPIE_CFLAGS -Wa,-mx86-used-note=yes" \
> >+          { protected-func-1b.c } \
> >+          {{error_output "pr28875-func.err"}} \
> >+          "protected-func-2a" \
> >+      ] \
> >       [list \
> >           "Build libprotected-data-1a.so" \
> >           "-shared -z noindirect-extern-access" \
> >--
> >2.36.1
> >



-- 
H.J.