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406 lines
15 KiB
406 lines
15 KiB
commit 9637d8a253493be471d9a71640e91349f7a8a050 |
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Author: H.J. Lu <hjl.tools@gmail.com> |
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Date: Wed Jul 29 11:57:54 2015 -0700 |
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Extend local PLT reference check |
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On x86, linker in binutils 2.26 and newer consolidates R_*_JUMP_SLOT with |
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R_*_GLOB_DAT relocation against the same symbol. This patch extends |
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local PLT reference check to support alternate relocations. |
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[BZ #18078] |
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* scripts/check-localplt.awk: Support alternate relocations. |
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* scripts/localplt.awk: Also check relocations in DT_RELA/DT_REL |
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sections. |
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* sysdeps/unix/sysv/linux/i386/localplt.data: Mark free and |
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malloc entries with + REL R_386_GLOB_DAT. |
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* sysdeps/x86_64/localplt.data: New file. |
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commit da53d6dbc28d2a90d6e14dd661e68611c3b741cf |
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Author: Carlos O'Donell <carlos@redhat.com> |
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Date: Thu Nov 6 15:48:44 2014 -0500 |
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Run check-localpltk/textrel/execstack over ld.so. |
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For maximum paranoia we run ld.so through the normal set |
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of tests for all of the shared libraries. This includes |
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running ld.so through check-localplt, check-textrel, and |
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check-execstack. While none of these should trigger any |
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failures given the way ld.so is built, it might possibly |
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fail if a developer does something wrong. This paranoia |
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was triggered by a discussion over the use of __strcpy |
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vs. strcpy [1] and if the symbol could leak and use the |
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libc.so version. |
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The check-localplt test fails right away because localplt.data |
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needs updating for all arches. By default we add 6 new symbols: |
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__tls_get_addr, __libc_memalign, malloc, calloc, realloc and |
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free. Other machines like i386, power, and s390 require some |
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different symbol sets e.g. ___tls_get_addr vs. __tls_get_addr |
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for i386. |
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commit d3d9c95aefded7716d037e241f9d23a1cccab45a |
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Author: H.J. Lu <hjl.tools@gmail.com> |
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Date: Wed Oct 14 05:59:50 2015 -0700 |
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Support PLT and GOT references in local PIC check |
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commit a0af371c25ac1f215cf0db64e54cbb9a1b51f78c |
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Author: Alan Modra <amodra@gmail.com> |
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Date: Fri Feb 20 15:23:28 2015 +1030 |
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Fix localplt test breakage with new readelf |
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Since 2014-11-24 binutils git commit bb4d2ac2, readelf has appended |
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the symbol version to symbols shown in reloc dumps. |
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[BZ #16512] |
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* scripts/localplt.awk: Strip off symbol version. |
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* NEWS: Mention bug fix. |
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diff -Nrup a/elf/Makefile b/elf/Makefile |
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--- a/elf/Makefile 2017-10-22 09:16:02.451399056 -0400 |
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+++ b/elf/Makefile 2017-10-22 09:16:39.217285466 -0400 |
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@@ -915,7 +915,7 @@ $(objpfx)tst-pie1: $(objpfx)tst-piemod1. |
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ifeq (yes,$(build-shared)) |
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tests: $(objpfx)check-textrel.out $(objpfx)check-execstack.out |
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-all-built-dso := $(common-objpfx)libc.so \ |
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+all-built-dso := $(common-objpfx)elf/ld.so $(common-objpfx)libc.so \ |
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$(filter-out $(common-objpfx)linkobj/libc.so, \ |
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$(sort $(wildcard $(addprefix $(common-objpfx), \ |
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*/lib*.so \ |
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@@ -974,6 +974,7 @@ tests: $(objpfx)check-localplt.out |
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localplt-built-dso := $(addprefix $(common-objpfx),\ |
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libc.so \ |
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+ elf/ld.so \ |
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math/libm.so \ |
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rt/librt.so \ |
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dlfcn/libdl.so \ |
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diff -Nrup a/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data b/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data |
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--- a/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data 2017-10-22 09:16:01.379402341 -0400 |
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+++ b/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data 2017-10-22 09:16:39.217285466 -0400 |
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@@ -12,3 +12,15 @@ libm.so: matherr |
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libm.so: __signbit |
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libm.so: __signbitf |
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libm.so: __signbitl |
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+# The dynamic loader needs __tls_get_addr for TLS. |
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+ld.so: __tls_get_addr |
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+# The dynamic loader uses __libc_memalign internally to allocate aligned |
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+# TLS storage. The other malloc family of functions are expected to allow |
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+# user symbol interposition. |
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+ld.so: __libc_memalign + RELA R_X86_64_GLOB_DAT |
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+# The main malloc is interposed into the dynamic linker, for |
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+# allocations after the initial link (when dlopen is used). |
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+ld.so: malloc |
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+ld.so: calloc |
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+ld.so: realloc |
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+ld.so: free |
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diff -Nrup a/scripts/check-localplt.awk b/scripts/check-localplt.awk |
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--- a/scripts/check-localplt.awk 2012-12-24 22:02:13.000000000 -0500 |
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+++ b/scripts/check-localplt.awk 2017-10-22 09:16:39.218285463 -0400 |
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@@ -3,9 +3,16 @@ |
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# Each line is either a comment starting with # or it looks like: |
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# libfoo.so: function |
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# or |
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+# libfoo.so: function + {RELA|REL} RELOC |
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+# or |
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# libfoo.so: function ? |
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# The latter means that a PLT entry for function is optional in libfoo.so. |
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# The former means one is required. |
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+# The first entry means that one is required. |
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+# The second entry means that one is required and relocation may also be |
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+# {RELA|REL} RELOC. |
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+# The third entry means that a PLT entry for function is optional in |
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+# libfoo.so. |
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# The second file argument is - and this (stdin) receives the output |
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# of the check-localplt program. |
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@@ -14,7 +21,10 @@ BEGIN { result = 0 } |
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FILENAME != "-" && /^#/ { next } |
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FILENAME != "-" { |
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- if (NF != 2 && !(NF == 3 && $3 == "?")) { |
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+ if (NF == 5 && $3 == "+" && ($4 == "RELA" || $4 == "REL")) { |
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+ accept_type[$1 " " $2] = $4; |
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+ accept_reloc[$1 " " $2] = $5; |
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+ } else if (NF != 2 && !(NF == 3 && $3 == "?")) { |
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printf "%s:%d: bad data line: %s\n", FILENAME, FNR, $0 > "/dev/stderr"; |
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result = 2; |
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} else { |
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@@ -23,7 +33,7 @@ FILENAME != "-" { |
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next; |
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} |
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-NF != 2 { |
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+NF != 2 && !(NF == 4 && ($3 == "RELA" || $3 == "REL")) { |
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print "Unexpected output from check-localplt:", $0 > "/dev/stderr"; |
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result = 2; |
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next |
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@@ -31,7 +41,23 @@ NF != 2 { |
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{ |
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key = $1 " " $2 |
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- if (key in accept) { |
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+ if ($3 == "RELA" || $3 == "REL") { |
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+ # Entries like: |
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+ # libc.so: free + RELA R_X86_64_GLOB_DAT |
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+ # may be ignored. |
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+ if (key in accept_type && accept_type[key] == $3 && accept_reloc[key] == $4) { |
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+ # Match |
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+ # libc.so: free + RELA R_X86_64_GLOB_DAT |
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+ delete accept_type[key] |
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+ } |
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+ } else if (NF == 2 && key in accept_reloc) { |
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+ # Match |
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+ # libc.so: free |
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+ # against |
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+ # libc.so: free + RELA R_X86_64_GLOB_DAT |
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+ if (key in accept_type) |
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+ delete accept_type[key] |
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+ } else if (key in accept) { |
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delete accept[key] |
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} else { |
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print "Extra PLT reference:", $0; |
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@@ -49,5 +75,11 @@ END { |
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} |
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} |
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+ for (key in accept_type) { |
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+ # It's mandatory. |
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+ print "Missing required PLT or " accept_reloc[key] " reference:", key; |
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+ result = 1; |
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+ } |
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+ |
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exit(result); |
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} |
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diff -Nrup a/scripts/localplt.awk b/scripts/localplt.awk |
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--- a/scripts/localplt.awk 2012-12-24 22:02:13.000000000 -0500 |
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+++ b/scripts/localplt.awk 2017-10-22 09:16:39.218285463 -0400 |
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@@ -7,12 +7,14 @@ |
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BEGIN { result = 0 } |
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FILENAME != lastfile { |
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- if (lastfile && jmprel_offset == 0) { |
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+ if (lastfile && jmprel_offset == 0 && rela_offset == 0 && rel_offset == 0) { |
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print FILENAME ": *** failed to find expected output (readelf -WSdr)"; |
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result = 2; |
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} |
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lastfile = FILENAME; |
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jmprel_offset = 0; |
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+ rela_offset = 0; |
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+ rel_offset = 0; |
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delete section_offset_by_address; |
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} |
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@@ -32,9 +34,39 @@ $1 == "Offset" && $2 == "Info" { in_relo |
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NF == 0 { in_relocs = 0 } |
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in_relocs && relocs_offset == jmprel_offset && NF >= 5 { |
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- symval = strtonum("0x" $4); |
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- if (symval != 0) |
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- print whatfile, $5 |
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+ # Relocations against GNU_IFUNC symbols are not shown as an hexadecimal |
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+ # value, but rather as the resolver symbol followed by (). |
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+ if ($4 ~ /\(\)/) { |
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+ print whatfile, gensub(/@.*/, "", "g", $5) |
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+ } else { |
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+ symval = strtonum("0x" $4); |
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+ if (symval != 0) |
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+ print whatfile, gensub(/@.*/, "", "g", $5) |
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+ } |
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+} |
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+ |
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+in_relocs && relocs_offset == rela_offset && NF >= 5 { |
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+ # Relocations against GNU_IFUNC symbols are not shown as an hexadecimal |
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+ # value, but rather as the resolver symbol followed by (). |
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+ if ($4 ~ /\(\)/) { |
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+ print whatfile, gensub(/@.*/, "", "g", $5), "RELA", $3 |
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+ } else { |
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+ symval = strtonum("0x" $4); |
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+ if (symval != 0) |
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+ print whatfile, gensub(/@.*/, "", "g", $5), "RELA", $3 |
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+ } |
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+} |
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+ |
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+in_relocs && relocs_offset == rel_offset && NF >= 5 { |
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+ # Relocations against GNU_IFUNC symbols are not shown as an hexadecimal |
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+ # value, but rather as the resolver symbol followed by (). |
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+ if ($4 ~ /\(\)/) { |
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+ print whatfile, gensub(/@.*/, "", "g", $5), "REL", $3 |
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+ } else { |
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+ symval = strtonum("0x" $4); |
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+ if (symval != 0) |
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+ print whatfile, gensub(/@.*/, "", "g", $5), "REL", $3 |
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+ } |
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} |
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in_relocs { next } |
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@@ -56,4 +88,25 @@ $2 == "(JMPREL)" { |
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next |
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} |
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+$2 == "(RELA)" { |
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+ rela_addr = strtonum($3); |
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+ if (rela_addr in section_offset_by_address) { |
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+ rela_offset = section_offset_by_address[rela_addr]; |
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+ } else { |
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+ print FILENAME ": *** DT_RELA does not match any section's address"; |
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+ result = 2; |
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+ } |
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+ next |
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+} |
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+ |
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+$2 == "(REL)" { |
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+ rel_addr = strtonum($3); |
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+ if (rel_addr in section_offset_by_address) { |
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+ rel_offset = section_offset_by_address[rel_addr]; |
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+ } else { |
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+ print FILENAME ": *** DT_REL does not match any section's address"; |
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+ result = 2; |
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+ } |
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+ next |
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+} |
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END { exit(result) } |
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diff -Nrup a/sysdeps/generic/localplt.data b/sysdeps/generic/localplt.data |
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--- a/sysdeps/generic/localplt.data 2012-12-24 22:02:13.000000000 -0500 |
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+++ b/sysdeps/generic/localplt.data 2017-10-22 09:18:03.383023954 -0400 |
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@@ -7,3 +7,9 @@ libc.so: malloc |
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libc.so: memalign |
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libc.so: realloc |
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libm.so: matherr |
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+# The main malloc is interposed into the dynamic linker, for |
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+# allocations after the initial link (when dlopen is used). |
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+ld.so: malloc |
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+ld.so: calloc |
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+ld.so: realloc |
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+ld.so: free |
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diff -Nrup a/sysdeps/unix/sysv/linux/i386/nptl/localplt.data b/sysdeps/unix/sysv/linux/i386/nptl/localplt.data |
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--- a/sysdeps/unix/sysv/linux/i386/nptl/localplt.data 2012-12-24 22:02:13.000000000 -0500 |
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+++ b/sysdeps/unix/sysv/linux/i386/nptl/localplt.data 2017-10-22 09:16:39.218285463 -0400 |
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@@ -1,7 +1,21 @@ |
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-libc.so: _Unwind_Find_FDE |
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-libc.so: calloc |
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-libc.so: free |
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-libc.so: malloc |
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-libc.so: memalign |
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-libc.so: realloc |
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-libm.so: matherr |
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+# Linker in binutils 2.26 and newer consolidates R_X86_64_JUMP_SLOT |
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+# relocation with R_386_GLOB_DAT relocation against the same symbol. |
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+libc.so: _Unwind_Find_FDE + REL R_386_GLOB_DAT |
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+libc.so: calloc + REL R_386_GLOB_DAT |
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+libc.so: free + REL R_386_GLOB_DAT |
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+libc.so: malloc + REL R_386_GLOB_DAT |
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+libc.so: memalign + REL R_386_GLOB_DAT |
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+libc.so: realloc + REL R_386_GLOB_DAT |
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+libm.so: matherr + REL R_386_GLOB_DAT |
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+# The dynamic loader uses __libc_memalign internally to allocate aligned |
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+# TLS storage. The other malloc family of functions are expected to allow |
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+# user symbol interposition. |
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+ld.so: __libc_memalign + REL R_386_GLOB_DAT |
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+# The dynamic loader needs __tls_get_addr for TLS. |
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+ld.so: ___tls_get_addr + REL R_386_GLOB_DAT |
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+# The main malloc is interposed into the dynamic linker, for |
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+# allocations after the initial link (when dlopen is used). |
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+ld.so: malloc + REL R_386_GLOB_DAT |
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+ld.so: calloc + REL R_386_GLOB_DAT |
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+ld.so: realloc + REL R_386_GLOB_DAT |
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+ld.so: free + REL R_386_GLOB_DAT |
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diff -Nrup a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/localplt.data |
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--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/localplt.data 2012-12-24 22:02:13.000000000 -0500 |
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+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/nptl/localplt.data 2017-10-22 09:16:39.218285463 -0400 |
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@@ -5,3 +5,13 @@ libc.so: malloc |
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libc.so: memalign |
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libc.so: realloc |
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libm.so: matherr |
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+# The dynamic loader uses __libc_memalign internally to allocate aligned |
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+# TLS storage. The other malloc family of functions are expected to allow |
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+# user symbol interposition. |
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+ld.so: __libc_memalign |
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+# The main malloc is interposed into the dynamic linker, for |
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+# allocations after the initial link (when dlopen is used). |
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+ld.so: malloc |
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+ld.so: calloc |
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+ld.so: realloc |
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+ld.so: free |
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diff -Nrup a/sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/localplt.data |
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--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/localplt.data 2012-12-24 22:02:13.000000000 -0500 |
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+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/nptl/localplt.data 2017-10-22 09:16:39.218285463 -0400 |
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@@ -4,3 +4,13 @@ libc.so: malloc |
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libc.so: memalign |
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libc.so: realloc |
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libm.so: matherr |
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+# The dynamic loader uses __libc_memalign internally to allocate aligned |
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+# TLS storage. The other malloc family of functions are expected to allow |
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+# user symbol interposition. |
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+ld.so: __libc_memalign |
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+# The main malloc is interposed into the dynamic linker, for |
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+# allocations after the initial link (when dlopen is used). |
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+ld.so: malloc |
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+ld.so: calloc |
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+ld.so: realloc |
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+ld.so: free |
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diff -Nrup a/sysdeps/unix/sysv/linux/s390/s390-32/nptl/localplt.data b/sysdeps/unix/sysv/linux/s390/s390-32/nptl/localplt.data |
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--- a/sysdeps/unix/sysv/linux/s390/s390-32/nptl/localplt.data 2012-12-24 22:02:13.000000000 -0500 |
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+++ b/sysdeps/unix/sysv/linux/s390/s390-32/nptl/localplt.data 2017-10-22 09:16:39.219285460 -0400 |
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@@ -5,3 +5,13 @@ libc.so: malloc |
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libc.so: memalign |
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libc.so: realloc |
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libm.so: matherr |
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+# The dynamic loader uses __libc_memalign internally to allocate aligned |
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+# TLS storage. The other malloc family of functions are expected to allow |
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+# user symbol interposition. |
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+ld.so: __libc_memalign |
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+# The main malloc is interposed into the dynamic linker, for |
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+# allocations after the initial link (when dlopen is used). |
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+ld.so: malloc |
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+ld.so: calloc |
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+ld.so: realloc |
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+ld.so: free |
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diff -Nrup a/sysdeps/unix/sysv/linux/s390/s390-64/nptl/localplt.data b/sysdeps/unix/sysv/linux/s390/s390-64/nptl/localplt.data |
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--- a/sysdeps/unix/sysv/linux/s390/s390-64/nptl/localplt.data 2012-12-24 22:02:13.000000000 -0500 |
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+++ b/sysdeps/unix/sysv/linux/s390/s390-64/nptl/localplt.data 2017-10-22 09:16:39.219285460 -0400 |
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@@ -5,3 +5,13 @@ libc.so: malloc |
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libc.so: memalign |
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libc.so: realloc |
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libm.so: matherr |
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+# The dynamic loader uses __libc_memalign internally to allocate aligned |
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+# TLS storage. The other malloc family of functions are expected to allow |
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+# user symbol interposition. |
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+ld.so: __libc_memalign |
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+# The main malloc is interposed into the dynamic linker, for |
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+# allocations after the initial link (when dlopen is used). |
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+ld.so: malloc |
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+ld.so: calloc |
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+ld.so: realloc |
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+ld.so: free |
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diff -Nrup a/sysdeps/x86_64/nptl/localplt.data b/sysdeps/x86_64/nptl/localplt.data |
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--- a/sysdeps/x86_64/nptl/localplt.data 1969-12-31 19:00:00.000000000 -0500 |
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+++ b/sysdeps/x86_64/nptl/localplt.data 2017-10-22 09:16:39.219285460 -0400 |
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@@ -0,0 +1,23 @@ |
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+# See scripts/check-localplt.awk for how this file is processed. |
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+# PLT use is required for the malloc family and for matherr because |
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+# users can define their own functions and have library internals call them. |
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+# Linker in binutils 2.26 and newer consolidates R_X86_64_JUMP_SLOT |
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+# relocation with R_X86_64_GLOB_DAT relocation against the same symbol. |
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+libc.so: calloc + RELA R_X86_64_GLOB_DAT |
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+libc.so: free + RELA R_X86_64_GLOB_DAT |
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+libc.so: malloc + RELA R_X86_64_GLOB_DAT |
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+libc.so: memalign + RELA R_X86_64_GLOB_DAT |
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+libc.so: realloc + RELA R_X86_64_GLOB_DAT |
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+libm.so: matherr + RELA R_X86_64_GLOB_DAT |
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+# The dynamic loader uses __libc_memalign internally to allocate aligned |
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+# TLS storage. The other malloc family of functions are expected to allow |
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+# user symbol interposition. |
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+ld.so: __libc_memalign + RELA R_X86_64_GLOB_DAT |
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+# The dynamic loader needs __tls_get_addr for TLS. |
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+ld.so: __tls_get_addr + RELA R_X86_64_GLOB_DAT |
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+# The main malloc is interposed into the dynamic linker, for |
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+# allocations after the initial link (when dlopen is used). |
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+ld.so: malloc + RELA R_X86_64_GLOB_DAT |
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+ld.so: calloc + RELA R_X86_64_GLOB_DAT |
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+ld.so: realloc + RELA R_X86_64_GLOB_DAT |
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+ld.so: free + RELA R_X86_64_GLOB_DAT
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