commit 9637d8a253493be471d9a71640e91349f7a8a050

Author: H.J. Lu <hjl.tools@gmail.com>

Date:   Wed Jul 29 11:57:54 2015 -0700

    Extend local PLT reference check

    On x86, linker in binutils 2.26 and newer consolidates R_*_JUMP_SLOT with

    R_*_GLOB_DAT relocation against the same symbol.  This patch extends

    local PLT reference check to support alternate relocations.

        [BZ #18078]

        * scripts/check-localplt.awk: Support alternate relocations.

        * scripts/localplt.awk: Also check relocations in DT_RELA/DT_REL

        sections.

        * sysdeps/unix/sysv/linux/i386/localplt.data: Mark free and

        malloc entries with + REL R_386_GLOB_DAT.

        * sysdeps/x86_64/localplt.data: New file.

commit da53d6dbc28d2a90d6e14dd661e68611c3b741cf

Author: Carlos O'Donell <carlos@redhat.com>

Date:   Thu Nov 6 15:48:44 2014 -0500

    Run check-localpltk/textrel/execstack over ld.so.

    For maximum paranoia we run ld.so through the normal set

    of tests for all of the shared libraries. This includes

    running ld.so through check-localplt, check-textrel, and

    check-execstack. While none of these should trigger any

    failures given the way ld.so is built, it might possibly

    fail if a developer does something wrong. This paranoia

    was triggered by a discussion over the use of __strcpy

    vs. strcpy [1] and if the symbol could leak and use the

    libc.so version.

    The check-localplt test fails right away because localplt.data

    needs updating for all arches. By default we add 6 new symbols:

    __tls_get_addr, __libc_memalign, malloc, calloc, realloc and

    free. Other machines like i386, power, and s390 require some

    different symbol sets e.g. ___tls_get_addr vs. __tls_get_addr

    for i386.

commit d3d9c95aefded7716d037e241f9d23a1cccab45a

Author: H.J. Lu <hjl.tools@gmail.com>

Date:   Wed Oct 14 05:59:50 2015 -0700

    Support PLT and GOT references in local PIC check

commit a0af371c25ac1f215cf0db64e54cbb9a1b51f78c

Author: Alan Modra <amodra@gmail.com>

Date:   Fri Feb 20 15:23:28 2015 +1030

    Fix localplt test breakage with new readelf

    Since 2014-11-24 binutils git commit bb4d2ac2, readelf has appended

    the symbol version to symbols shown in reloc dumps.

        [BZ #16512]

        * scripts/localplt.awk: Strip off symbol version.

        * NEWS: Mention bug fix.

diff -Nrup a/elf/Makefile b/elf/Makefile

--- a/elf/Makefile	2017-10-22 09:16:02.451399056 -0400

+++ b/elf/Makefile	2017-10-22 09:16:39.217285466 -0400

@@ -915,7 +915,7 @@ $(objpfx)tst-pie1: $(objpfx)tst-piemod1.

 ifeq (yes,$(build-shared))

 tests: $(objpfx)check-textrel.out $(objpfx)check-execstack.out

-all-built-dso := $(common-objpfx)libc.so \

+all-built-dso := $(common-objpfx)elf/ld.so $(common-objpfx)libc.so \

 		 $(filter-out $(common-objpfx)linkobj/libc.so, \

 			      $(sort $(wildcard $(addprefix $(common-objpfx), \

 							    */lib*.so \

@@ -974,6 +974,7 @@ tests: $(objpfx)check-localplt.out

 localplt-built-dso := $(addprefix $(common-objpfx),\

 				  libc.so \

+                                  elf/ld.so \

 				  math/libm.so \

 				  rt/librt.so \

 				  dlfcn/libdl.so \

diff -Nrup a/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data b/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data

--- a/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data	2017-10-22 09:16:01.379402341 -0400

+++ b/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data	2017-10-22 09:16:39.217285466 -0400

@@ -12,3 +12,15 @@ libm.so: matherr

 libm.so: __signbit

 libm.so: __signbitf

 libm.so: __signbitl

+# The dynamic loader needs __tls_get_addr for TLS.

+ld.so: __tls_get_addr

+# The dynamic loader uses __libc_memalign internally to allocate aligned

+# TLS storage. The other malloc family of functions are expected to allow

+# user symbol interposition.

+ld.so: __libc_memalign + RELA R_X86_64_GLOB_DAT

+# The main malloc is interposed into the dynamic linker, for

+# allocations after the initial link (when dlopen is used).

+ld.so: malloc

+ld.so: calloc

+ld.so: realloc

+ld.so: free

diff -Nrup a/scripts/check-localplt.awk b/scripts/check-localplt.awk

--- a/scripts/check-localplt.awk	2012-12-24 22:02:13.000000000 -0500

+++ b/scripts/check-localplt.awk	2017-10-22 09:16:39.218285463 -0400

@@ -3,9 +3,16 @@

 # Each line is either a comment starting with # or it looks like:

 #	libfoo.so: function

 # or

+#      libfoo.so: function + {RELA|REL} RELOC

+# or

 #	libfoo.so: function ?

 # The latter means that a PLT entry for function is optional in libfoo.so.

 # The former means one is required.

+# The first entry means that one is required.

+# The second entry means that one is required and relocation may also be

+# {RELA|REL} RELOC.

+# The third entry means that a PLT entry for function is optional in

+# libfoo.so.

 # The second file argument is - and this (stdin) receives the output

 # of the check-localplt program.

@@ -14,7 +21,10 @@ BEGIN { result = 0 }

 FILENAME != "-" && /^#/ { next }

 FILENAME != "-" {

-  if (NF != 2 && !(NF == 3 && $3 == "?")) {

+  if (NF == 5 && $3 == "+" && ($4 == "RELA" || $4 == "REL")) {

+    accept_type[$1 " " $2] = $4;

+    accept_reloc[$1 " " $2] = $5;

+  } else if (NF != 2 && !(NF == 3 && $3 == "?")) {

     printf "%s:%d: bad data line: %s\n", FILENAME, FNR, $0 > "/dev/stderr";

     result = 2;

   } else {

@@ -23,7 +33,7 @@ FILENAME != "-" {

   next;

 }

-NF != 2 {

+NF != 2 && !(NF == 4 && ($3 == "RELA" || $3 == "REL")) {

   print "Unexpected output from check-localplt:", $0 > "/dev/stderr";

   result = 2;

   next

@@ -31,7 +41,23 @@ NF != 2 {

 {

   key = $1 " " $2

-  if (key in accept) {

+  if ($3 == "RELA" || $3 == "REL") {

+    # Entries like:

+    # libc.so: free + RELA R_X86_64_GLOB_DAT

+    # may be ignored.

+    if (key in accept_type && accept_type[key] == $3 && accept_reloc[key] == $4) {

+      # Match

+      # libc.so: free + RELA R_X86_64_GLOB_DAT

+      delete accept_type[key]

+    }

+  } else if (NF == 2 && key in accept_reloc) {

+    # Match

+    # libc.so: free

+    # against

+    # libc.so: free + RELA R_X86_64_GLOB_DAT

+    if (key in accept_type)

+      delete accept_type[key]

+  } else if (key in accept) {

     delete accept[key]

   } else {

     print "Extra PLT reference:", $0;

@@ -49,5 +75,11 @@ END {

     }

   }

+  for (key in accept_type) {

+    # It's mandatory.

+    print "Missing required PLT or " accept_reloc[key] " reference:", key;

+    result = 1;

+  }

+

   exit(result);

 }

diff -Nrup a/scripts/localplt.awk b/scripts/localplt.awk

--- a/scripts/localplt.awk	2012-12-24 22:02:13.000000000 -0500

+++ b/scripts/localplt.awk	2017-10-22 09:16:39.218285463 -0400

@@ -7,12 +7,14 @@

 BEGIN { result = 0 }

 FILENAME != lastfile {

-  if (lastfile && jmprel_offset == 0) {

+  if (lastfile && jmprel_offset == 0 && rela_offset == 0 && rel_offset == 0) {

     print FILENAME ": *** failed to find expected output (readelf -WSdr)";

     result = 2;

   }

   lastfile = FILENAME;

   jmprel_offset = 0;

+  rela_offset = 0;

+  rel_offset = 0;

   delete section_offset_by_address;

 }

@@ -32,9 +34,39 @@ $1 == "Offset" && $2 == "Info" { in_relo

 NF == 0 { in_relocs = 0 }

 in_relocs && relocs_offset == jmprel_offset && NF >= 5 {

-  symval = strtonum("0x" $4);

-  if (symval != 0)

-    print whatfile, $5

+  # Relocations against GNU_IFUNC symbols are not shown as an hexadecimal

+  # value, but rather as the resolver symbol followed by ().

+  if ($4 ~ /\(\)/) {

+    print whatfile, gensub(/@.*/, "", "g", $5)

+  } else {

+    symval = strtonum("0x" $4);

+    if (symval != 0)

+      print whatfile, gensub(/@.*/, "", "g", $5)

+  }

+}

+

+in_relocs && relocs_offset == rela_offset && NF >= 5 {

+  # Relocations against GNU_IFUNC symbols are not shown as an hexadecimal

+  # value, but rather as the resolver symbol followed by ().

+  if ($4 ~ /\(\)/) {

+    print whatfile, gensub(/@.*/, "", "g", $5), "RELA", $3

+  } else {

+    symval = strtonum("0x" $4);

+    if (symval != 0)

+      print whatfile, gensub(/@.*/, "", "g", $5), "RELA", $3

+  }

+}

+

+in_relocs && relocs_offset == rel_offset && NF >= 5 {

+  # Relocations against GNU_IFUNC symbols are not shown as an hexadecimal

+  # value, but rather as the resolver symbol followed by ().

+  if ($4 ~ /\(\)/) {

+    print whatfile, gensub(/@.*/, "", "g", $5), "REL", $3

+  } else {

+    symval = strtonum("0x" $4);

+    if (symval != 0)

+      print whatfile, gensub(/@.*/, "", "g", $5), "REL", $3

+  }

 }

 in_relocs { next }

@@ -56,4 +88,25 @@ $2 == "(JMPREL)" {

   next

 }

+$2 == "(RELA)" {

+  rela_addr = strtonum($3);

+  if (rela_addr in section_offset_by_address) {

+    rela_offset = section_offset_by_address[rela_addr];

+  } else {

+    print FILENAME ": *** DT_RELA does not match any section's address";

+    result = 2;

+  }

+  next

+}

+

+$2 == "(REL)" {

+  rel_addr = strtonum($3);

+  if (rel_addr in section_offset_by_address) {

+    rel_offset = section_offset_by_address[rel_addr];

+  } else {

+    print FILENAME ": *** DT_REL does not match any section's address";

+    result = 2;

+  }

+  next

+}

 END { exit(result) }

diff -Nrup a/sysdeps/generic/localplt.data b/sysdeps/generic/localplt.data

--- a/sysdeps/generic/localplt.data	2012-12-24 22:02:13.000000000 -0500

+++ b/sysdeps/generic/localplt.data	2017-10-22 09:18:03.383023954 -0400

@@ -7,3 +7,9 @@ libc.so: malloc

 libc.so: memalign

 libc.so: realloc

 libm.so: matherr

+# The main malloc is interposed into the dynamic linker, for

+# allocations after the initial link (when dlopen is used).

+ld.so: malloc

+ld.so: calloc

+ld.so: realloc

+ld.so: free

diff -Nrup a/sysdeps/unix/sysv/linux/i386/nptl/localplt.data b/sysdeps/unix/sysv/linux/i386/nptl/localplt.data

--- a/sysdeps/unix/sysv/linux/i386/nptl/localplt.data	2012-12-24 22:02:13.000000000 -0500

+++ b/sysdeps/unix/sysv/linux/i386/nptl/localplt.data	2017-10-22 09:16:39.218285463 -0400

@@ -1,7 +1,21 @@

-libc.so: _Unwind_Find_FDE

-libc.so: calloc

-libc.so: free

-libc.so: malloc

-libc.so: memalign

-libc.so: realloc

-libm.so: matherr

+# Linker in binutils 2.26 and newer consolidates R_X86_64_JUMP_SLOT

+# relocation with R_386_GLOB_DAT relocation against the same symbol.

+libc.so: _Unwind_Find_FDE + REL R_386_GLOB_DAT

+libc.so: calloc + REL R_386_GLOB_DAT

+libc.so: free + REL R_386_GLOB_DAT

+libc.so: malloc + REL R_386_GLOB_DAT

+libc.so: memalign + REL R_386_GLOB_DAT

+libc.so: realloc + REL R_386_GLOB_DAT

+libm.so: matherr + REL R_386_GLOB_DAT

+# The dynamic loader uses __libc_memalign internally to allocate aligned

+# TLS storage. The other malloc family of functions are expected to allow

+# user symbol interposition.

+ld.so: __libc_memalign + REL R_386_GLOB_DAT

+# The dynamic loader needs __tls_get_addr for TLS.

+ld.so: ___tls_get_addr + REL R_386_GLOB_DAT

+# The main malloc is interposed into the dynamic linker, for

+# allocations after the initial link (when dlopen is used).

+ld.so: malloc + REL R_386_GLOB_DAT

+ld.so: calloc + REL R_386_GLOB_DAT

+ld.so: realloc + REL R_386_GLOB_DAT

+ld.so: free + REL R_386_GLOB_DAT

diff -Nrup a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/localplt.data

--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/localplt.data	2012-12-24 22:02:13.000000000 -0500

+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/localplt.data	2017-10-22 09:16:39.218285463 -0400

@@ -5,3 +5,13 @@ libc.so: malloc

 libc.so: memalign

 libc.so: realloc

 libm.so: matherr

+# The dynamic loader uses __libc_memalign internally to allocate aligned

+# TLS storage. The other malloc family of functions are expected to allow

+# user symbol interposition.

+ld.so: __libc_memalign

+# The main malloc is interposed into the dynamic linker, for

+# allocations after the initial link (when dlopen is used).

+ld.so: malloc

+ld.so: calloc

+ld.so: realloc

+ld.so: free

diff -Nrup a/sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/localplt.data

--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/localplt.data	2012-12-24 22:02:13.000000000 -0500

+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/localplt.data	2017-10-22 09:16:39.218285463 -0400

@@ -4,3 +4,13 @@ libc.so: malloc

 libc.so: memalign

 libc.so: realloc

 libm.so: matherr

+# The dynamic loader uses __libc_memalign internally to allocate aligned

+# TLS storage. The other malloc family of functions are expected to allow

+# user symbol interposition.

+ld.so: __libc_memalign

+# The main malloc is interposed into the dynamic linker, for

+# allocations after the initial link (when dlopen is used).

+ld.so: malloc

+ld.so: calloc

+ld.so: realloc

+ld.so: free

diff -Nrup a/sysdeps/unix/sysv/linux/s390/s390-32/nptl/localplt.data b/sysdeps/unix/sysv/linux/s390/s390-32/nptl/localplt.data

--- a/sysdeps/unix/sysv/linux/s390/s390-32/nptl/localplt.data	2012-12-24 22:02:13.000000000 -0500

+++ b/sysdeps/unix/sysv/linux/s390/s390-32/nptl/localplt.data	2017-10-22 09:16:39.219285460 -0400

@@ -5,3 +5,13 @@ libc.so: malloc

 libc.so: memalign

 libc.so: realloc

 libm.so: matherr

+# The dynamic loader uses __libc_memalign internally to allocate aligned

+# TLS storage. The other malloc family of functions are expected to allow

+# user symbol interposition.

+ld.so: __libc_memalign

+# The main malloc is interposed into the dynamic linker, for

+# allocations after the initial link (when dlopen is used).

+ld.so: malloc

+ld.so: calloc

+ld.so: realloc

+ld.so: free

diff -Nrup a/sysdeps/unix/sysv/linux/s390/s390-64/nptl/localplt.data b/sysdeps/unix/sysv/linux/s390/s390-64/nptl/localplt.data

--- a/sysdeps/unix/sysv/linux/s390/s390-64/nptl/localplt.data	2012-12-24 22:02:13.000000000 -0500

+++ b/sysdeps/unix/sysv/linux/s390/s390-64/nptl/localplt.data	2017-10-22 09:16:39.219285460 -0400

@@ -5,3 +5,13 @@ libc.so: malloc

 libc.so: memalign

 libc.so: realloc

 libm.so: matherr

+# The dynamic loader uses __libc_memalign internally to allocate aligned

+# TLS storage. The other malloc family of functions are expected to allow

+# user symbol interposition.

+ld.so: __libc_memalign

+# The main malloc is interposed into the dynamic linker, for

+# allocations after the initial link (when dlopen is used).

+ld.so: malloc

+ld.so: calloc

+ld.so: realloc

+ld.so: free

diff -Nrup a/sysdeps/x86_64/nptl/localplt.data b/sysdeps/x86_64/nptl/localplt.data

--- a/sysdeps/x86_64/nptl/localplt.data	1969-12-31 19:00:00.000000000 -0500

+++ b/sysdeps/x86_64/nptl/localplt.data	2017-10-22 09:16:39.219285460 -0400

@@ -0,0 +1,23 @@

+# See scripts/check-localplt.awk for how this file is processed.

+# PLT use is required for the malloc family and for matherr because

+# users can define their own functions and have library internals call them.

+# Linker in binutils 2.26 and newer consolidates R_X86_64_JUMP_SLOT

+# relocation with R_X86_64_GLOB_DAT relocation against the same symbol.

+libc.so: calloc + RELA R_X86_64_GLOB_DAT

+libc.so: free + RELA R_X86_64_GLOB_DAT

+libc.so: malloc + RELA R_X86_64_GLOB_DAT

+libc.so: memalign + RELA R_X86_64_GLOB_DAT

+libc.so: realloc + RELA R_X86_64_GLOB_DAT

+libm.so: matherr + RELA R_X86_64_GLOB_DAT

+# The dynamic loader uses __libc_memalign internally to allocate aligned

+# TLS storage. The other malloc family of functions are expected to allow

+# user symbol interposition.

+ld.so: __libc_memalign + RELA R_X86_64_GLOB_DAT

+# The dynamic loader needs __tls_get_addr for TLS.

+ld.so: __tls_get_addr + RELA R_X86_64_GLOB_DAT

+# The main malloc is interposed into the dynamic linker, for

+# allocations after the initial link (when dlopen is used).

+ld.so: malloc + RELA R_X86_64_GLOB_DAT

+ld.so: calloc + RELA R_X86_64_GLOB_DAT

+ld.so: realloc + RELA R_X86_64_GLOB_DAT

+ld.so: free + RELA R_X86_64_GLOB_DAT