ELF: Don't check relocations in non-loaded, non-alloced sections

Don't do anything special with non-loaded, non-alloced sections.
In particular, any relocs in such sections should not affect GOT
and PLT reference counting (ie. we don't allow them to create GOT
or PLT entries), there's no possibility or desire to optimize TLS
relocs, and there's not much point in propagating relocs to shared
libs that the dynamic linker won't relocate.

Since check_relocs is no longer called on non-loaded, non-alloced
sections, remove SEC_ALLOC check.  Resolve relocation in debug section
against symbol defined in shared library to 0.

bfd/

	PR ld/26080
	* elf-m10300.c (mn10300_elf_relocate_section): Resolve relocation
	in debug section against symbol defined in shared library to 0.
	* elf32-i386.c (elf_i386_check_relocs): Remove SEC_ALLOC check.
	* elf32-lm32.c (lm32_elf_check_relocs): Likewise.
	* elf32-m32r.c (m32r_elf_check_relocs): Likewise.
	* elf32-nds32.c (nds32_elf_check_relocs): Likewise.
	* elf32-nios2.c (nios2_elf32_check_relocs): Likewise.
	* elf32-or1k.c (or1k_elf_check_relocs): Likewise.
	* elf32-ppc.c (ppc_elf_check_relocs): Likewise.
	* elf32-sh.c (sh_elf_check_relocs): Likewise.
	* elf32-xtensa.c (elf_xtensa_check_relocs): Likewise.
	* elf64-alpha.c (elf64_alpha_check_relocs): Likewise.
	* elf64-ppc.c (ppc64_elf_check_relocs): Likewise.
	* elf64-x86-64.c (elf_x86_64_check_relocs): Likewise.
	* elfxx-mips.c (_bfd_mips_elf_check_relocs): Likewise.
	* elf32-vax.c (elf_vax_check_relocs): Set non_got_ref for non-GOT
	reference.
	(elf_vax_adjust_dynamic_symbol): Generate a copy reloc only if
	there is non-GOT reference.
	* elflink.c (_bfd_elf_link_check_relocs): Skip non-loaded,
	non-alloced sections.

ld/

	PR ld/26080
	* testsuite/ld-elf/comm-data.exp: Remove copy_reloc.
	* testsuite/ld-elf/comm-data2r.rd: Removed.
	* testsuite/ld-elf/comm-data2r.sd: Likewise.
	* testsuite/ld-elf/comm-data2r.xd: Likewise.

22 files changed, 62 insertions, 136 deletions

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 785951a..13a3ed1 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,28 @@
+2020-06-04  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/26080
+	* elf-m10300.c (mn10300_elf_relocate_section): Resolve relocation
+	in debug section against symbol defined in shared library to 0.
+	* elf32-i386.c (elf_i386_check_relocs): Remove SEC_ALLOC check.
+	* elf32-lm32.c (lm32_elf_check_relocs): Likewise.
+	* elf32-m32r.c (m32r_elf_check_relocs): Likewise.
+	* elf32-nds32.c (nds32_elf_check_relocs): Likewise.
+	* elf32-nios2.c (nios2_elf32_check_relocs): Likewise.
+	* elf32-or1k.c (or1k_elf_check_relocs): Likewise.
+	* elf32-ppc.c (ppc_elf_check_relocs): Likewise.
+	* elf32-sh.c (sh_elf_check_relocs): Likewise.
+	* elf32-xtensa.c (elf_xtensa_check_relocs): Likewise.
+	* elf64-alpha.c (elf64_alpha_check_relocs): Likewise.
+	* elf64-ppc.c (ppc64_elf_check_relocs): Likewise.
+	* elf64-x86-64.c (elf_x86_64_check_relocs): Likewise.
+	* elfxx-mips.c (_bfd_mips_elf_check_relocs): Likewise.
+	* elf32-vax.c (elf_vax_check_relocs): Set non_got_ref for non-GOT
+	reference.
+	(elf_vax_adjust_dynamic_symbol): Generate a copy reloc only if
+	there is non-GOT reference.
+	* elflink.c (_bfd_elf_link_check_relocs): Skip non-loaded,
+	non-alloced sections.
+
 2020-06-03  Stephen Casner  <casner@acm.org>
 
 	Copy several years of fixes from bfd/aoutx.h to bfd/pdp11.c.
diff --git a/bfd/elf-m10300.c b/bfd/elf-m10300.c
index 696514a..5a0bb9f 100644
--- a/bfd/elf-m10300.c
+++ b/bfd/elf-m10300.c
@@ -2066,12 +2066,12 @@ mn10300_elf_relocate_section (bfd *output_bfd,
 		      && elf_hash_table (info)->dynamic_sections_created
 		      && !SYMBOL_REFERENCES_LOCAL (info, hh))
 		  || (r_type == R_MN10300_32
+		      && !SYMBOL_REFERENCES_LOCAL (info, hh)
 		      /* _32 relocs in executables force _COPY relocs,
 			 such that the address of the symbol ends up
 			 being local.  */
-		      && !bfd_link_executable (info)
-		      && !SYMBOL_REFERENCES_LOCAL (info, hh)
-		      && ((input_section->flags & SEC_ALLOC) != 0
+		      && (((input_section->flags & SEC_ALLOC) != 0
+			   && !bfd_link_executable (info))
 			  /* DWARF will emit R_MN10300_32 relocations
 			     in its sections against symbols defined
 			     externally in shared libraries.  We can't
diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 544b931..f6f6699 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -1487,15 +1487,6 @@ elf_i386_check_relocs (bfd *abfd,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   htab = elf_x86_hash_table (info, I386_ELF_DATA);
   if (htab == NULL)
     {
diff --git a/bfd/elf32-lm32.c b/bfd/elf32-lm32.c
index 3c31dd4..aba821f 100644
--- a/bfd/elf32-lm32.c
+++ b/bfd/elf32-lm32.c
@@ -1128,15 +1128,6 @@ lm32_elf_check_relocs (bfd *abfd,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
   sym_hashes = elf_sym_hashes (abfd);
   sym_hashes_end = sym_hashes + symtab_hdr->sh_size/sizeof (Elf32_External_Sym);
diff --git a/bfd/elf32-m32r.c b/bfd/elf32-m32r.c
index 931e138..740be93 100644
--- a/bfd/elf32-m32r.c
+++ b/bfd/elf32-m32r.c
@@ -3424,15 +3424,6 @@ m32r_elf_check_relocs (bfd *abfd,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   sreloc = NULL;
   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
   sym_hashes = elf_sym_hashes (abfd);
diff --git a/bfd/elf32-nds32.c b/bfd/elf32-nds32.c
index 01ea277..1d3a0f7 100644
--- a/bfd/elf32-nds32.c
+++ b/bfd/elf32-nds32.c
@@ -7055,15 +7055,6 @@ nds32_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
       return TRUE;
     }
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
   sym_hashes = elf_sym_hashes (abfd);
   sym_hashes_end =
diff --git a/bfd/elf32-nios2.c b/bfd/elf32-nios2.c
index 71200da..cdc11f9 100644
--- a/bfd/elf32-nios2.c
+++ b/bfd/elf32-nios2.c
@@ -4689,15 +4689,6 @@ nios2_elf32_check_relocs (bfd *abfd, struct bfd_link_info *info,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
   sym_hashes = elf_sym_hashes (abfd);
   sym_hashes_end = (sym_hashes
diff --git a/bfd/elf32-or1k.c b/bfd/elf32-or1k.c
index ac62d63..b25f96b 100644
--- a/bfd/elf32-or1k.c
+++ b/bfd/elf32-or1k.c
@@ -1880,15 +1880,6 @@ or1k_elf_check_relocs (bfd *abfd,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
   sym_hashes = elf_sym_hashes (abfd);
 
diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index 0cb7f67..995e1a9 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -2888,15 +2888,6 @@ ppc_elf_check_relocs (bfd *abfd,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
 #ifdef DEBUG
   _bfd_error_handler ("ppc_elf_check_relocs called for section %pA in %pB",
 		      sec, abfd);
diff --git a/bfd/elf32-sh.c b/bfd/elf32-sh.c
index 9ec745b..dd67046 100644
--- a/bfd/elf32-sh.c
+++ b/bfd/elf32-sh.c
@@ -5350,15 +5350,6 @@ sh_elf_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   BFD_ASSERT (is_sh_elf (abfd));
 
   symtab_hdr = &elf_symtab_hdr (abfd);
diff --git a/bfd/elf32-vax.c b/bfd/elf32-vax.c
index fa84e0b..b5c3d89 100644
--- a/bfd/elf32-vax.c
+++ b/bfd/elf32-vax.c
@@ -712,6 +712,11 @@ elf_vax_check_relocs (bfd *abfd, struct bfd_link_info *info, asection *sec,
 		h->plt.refcount++;
 	    }
 
+	  /* Non-GOT reference may need a copy reloc in executable or
+	     a dynamic reloc in shared library.  */
+	  if (h != NULL)
+	    h->non_got_ref = 1;
+
 	  /* If we are creating a shared library, we need to copy the
 	     reloc into the shared library.  */
 	  if (bfd_link_pic (info)
@@ -929,6 +934,11 @@ elf_vax_adjust_dynamic_symbol (struct bfd_link_info *info,
   if (bfd_link_pic (info))
     return TRUE;
 
+  /* If there are no references to this symbol that do not use the
+     GOT relocation, we don't need to generate a copy reloc.  */
+  if (!h->non_got_ref)
+    return TRUE;
+
   /* We must allocate the symbol in our .dynbss section, which will
      become part of the .bss section of the executable.  There will be
      an entry for this symbol in the .dynsym section.  The dynamic
diff --git a/bfd/elf32-xtensa.c b/bfd/elf32-xtensa.c
index 05c4f84..9dc815e 100644
--- a/bfd/elf32-xtensa.c
+++ b/bfd/elf32-xtensa.c
@@ -1039,7 +1039,7 @@ elf_xtensa_check_relocs (bfd *abfd,
   const Elf_Internal_Rela *rel;
   const Elf_Internal_Rela *rel_end;
 
-  if (bfd_link_relocatable (info) || (sec->flags & SEC_ALLOC) == 0)
+  if (bfd_link_relocatable (info))
     return TRUE;
 
   BFD_ASSERT (is_xtensa_elf (abfd));
diff --git a/bfd/elf64-alpha.c b/bfd/elf64-alpha.c
index 4e4efae..0b31d45 100644
--- a/bfd/elf64-alpha.c
+++ b/bfd/elf64-alpha.c
@@ -1782,15 +1782,6 @@ elf64_alpha_check_relocs (bfd *abfd, struct bfd_link_info *info,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   BFD_ASSERT (is_alpha_elf (abfd));
 
   dynobj = elf_hash_table (info)->dynobj;
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 5f99d43..769afc5 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -4536,15 +4536,6 @@ ppc64_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   BFD_ASSERT (is_ppc64_elf (abfd));
 
   htab = ppc_hash_table (info);
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 183c808..eada0e5 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -1862,15 +1862,6 @@ elf_x86_64_check_relocs (bfd *abfd, struct bfd_link_info *info,
   if (bfd_link_relocatable (info))
     return TRUE;
 
-  /* Don't do anything special with non-loaded, non-alloced sections.
-     In particular, any relocs in such sections should not affect GOT
-     and PLT reference counting (ie. we don't allow them to create GOT
-     or PLT entries), there's no possibility or desire to optimize TLS
-     relocs, and there's not much point in propagating relocs to shared
-     libs that the dynamic linker won't relocate.  */
-  if ((sec->flags & SEC_ALLOC) == 0)
-    return TRUE;
-
   htab = elf_x86_hash_table (info, X86_64_ELF_DATA);
   if (htab == NULL)
     {
diff --git a/bfd/elflink.c b/bfd/elflink.c
index ce6282a..7e86ade 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -3956,8 +3956,16 @@ _bfd_elf_link_check_relocs (bfd *abfd, struct bfd_link_info *info)
 	  Elf_Internal_Rela *internal_relocs;
 	  bfd_boolean ok;
 
-	  /* Don't check relocations in excluded sections.  */
-	  if ((o->flags & SEC_RELOC) == 0
+	  /* Don't check relocations in excluded sections.  Don't do
+	     anything special with non-loaded, non-alloced sections.
+	     In particular, any relocs in such sections should not
+	     affect GOT and PLT reference counting (ie.  we don't
+	     allow them to create GOT or PLT entries), there's no
+	     possibility or desire to optimize TLS relocs, and
+	     there's not much point in propagating relocs to shared
+	     libs that the dynamic linker won't relocate.  */
+	  if ((o->flags & SEC_ALLOC) == 0
+	      || (o->flags & SEC_RELOC) == 0
 	      || (o->flags & SEC_EXCLUDE) != 0
 	      || o->reloc_count == 0
 	      || ((info->strip == strip_all || info->strip == strip_debugger)
diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c
index e563d56..6c7aaa3 100644
--- a/bfd/elfxx-mips.c
+++ b/bfd/elfxx-mips.c
@@ -8654,10 +8654,8 @@ _bfd_mips_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
       call_reloc_p = FALSE;
 
       /* Set CONSTRAIN_SYMBOL_P if we need to take the relocation
-	 into account when deciding how to define the symbol.
-	 Relocations in nonallocatable sections such as .pdr and
-	 .debug* should have no effect.  */
-      constrain_symbol_p = ((sec->flags & SEC_ALLOC) != 0);
+	 into account when deciding how to define the symbol.  */
+      constrain_symbol_p = TRUE;
 
       switch (r_type)
 	{
diff --git a/ld/ChangeLog b/ld/ChangeLog
index d8e7e00..00066c5 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,11 @@
+2020-06-04  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/26080
+	* testsuite/ld-elf/comm-data.exp: Remove copy_reloc.
+	* testsuite/ld-elf/comm-data2r.rd: Removed.
+	* testsuite/ld-elf/comm-data2r.sd: Likewise.
+	* testsuite/ld-elf/comm-data2r.xd: Likewise.
+
 2020-06-04  Alan Modra  <amodra@gmail.com>
 
 	* testsuite/config/default.exp: Remove global directive outside
diff --git a/ld/testsuite/ld-elf/comm-data.exp b/ld/testsuite/ld-elf/comm-data.exp
index a53a771..c735fe2 100644
--- a/ld/testsuite/ld-elf/comm-data.exp
+++ b/ld/testsuite/ld-elf/comm-data.exp
@@ -79,12 +79,6 @@ setup_xfail "bfin-*-*"
 
 setup_xfail "arm*-*-*" "ld/13802"
 
-# List targets here that keep copy relocs rather than eliminating
-# them where possible in favour to dynamic relocs in the relevant
-# loadable sections; see also the "-z nocopyreloc" command-line
-# option and the ELIMINATE_COPY_RELOCS macro some backends use.
-set copy_reloc [expr [istarget mn10300-*-*] || [istarget vax-*-*]]
-
 # Verify that a common symbol has been converted to an undefined
 # reference to the global symbol of the same name defined above
 # and that the debug reference has been dropped.
@@ -95,12 +89,9 @@ run_ld_link_tests [list \
 	"$AFLAGS" \
 	{ comm-data2.s } \
 	[list \
-	    [list readelf -s \
-		[expr { $copy_reloc ? "comm-data2r.sd" : "comm-data2.sd"}]] \
-	    [list readelf -r \
-		[expr { $copy_reloc ? "comm-data2r.rd" : "comm-data2.rd"}]] \
-	    [list readelf "-x .debug_foo" \
-		[expr { $copy_reloc ? "comm-data2r.xd" : "comm-data2.xd"}]]] \
+	    [list readelf -s comm-data2.sd] \
+	    [list readelf -r comm-data2.rd] \
+	    [list readelf "-x .debug_foo" comm-data2.xd]] \
 	"comm-data" \
     ] \
     [list \
diff --git a/ld/testsuite/ld-elf/comm-data2r.rd b/ld/testsuite/ld-elf/comm-data2r.rd
deleted file mode 100644
index 64c0396..0000000
--- a/ld/testsuite/ld-elf/comm-data2r.rd
+++ /dev/null
@@ -1,3 +0,0 @@
-Relocation section '\.rela\.dyn' at offset 0x[0-9a-f]+ contains 1 entry:
- +Offset +Info +Type +Sym\.Value +Sym\. Name \+ Addend
-0*12340000 +[0-9a-f]+ +R_.*_COPY +0*12340000 +foo \+ 0
diff --git a/ld/testsuite/ld-elf/comm-data2r.sd b/ld/testsuite/ld-elf/comm-data2r.sd
deleted file mode 100644
index 685b0be..0000000
--- a/ld/testsuite/ld-elf/comm-data2r.sd
+++ /dev/null
@@ -1,10 +0,0 @@
-Symbol table '\.dynsym' contains [0-9]+ entries:
- +Num: +Value +Size +Type +Bind +Vis +Ndx +Name
-#...
- +[0-9]+: +0*12340000 +4 +OBJECT +GLOBAL +DEFAULT +[0-9]+ +foo
-#...
-Symbol table '\.symtab' contains [0-9]+ entries:
- +Num: +Value +Size +Type +Bind +Vis +Ndx +Name
-#...
- +[0-9]+: +0*12340000 +4 +OBJECT +GLOBAL +DEFAULT +[0-9]+ +foo
-#pass
diff --git a/ld/testsuite/ld-elf/comm-data2r.xd b/ld/testsuite/ld-elf/comm-data2r.xd
deleted file mode 100644
index 58f6f2a..0000000
--- a/ld/testsuite/ld-elf/comm-data2r.xd
+++ /dev/null
@@ -1,2 +0,0 @@
-Hex dump of section '\.debug_foo':
- +0x0*76540000 (?:12340000 00000000|00003412 00000000|00000000 00003412) 00000000 00000000 .*