501348 2025-03-11 11:22:56 +0000 glibc built with -march=x86-64-v3 does not work due to ld.so memcmp 2025-03-12 13:59:56 +0000 1 1 6 Developer tools valgrind memcheck unspecified Other Linux RESOLVED FIXED https://bugs.kde.org/show_bug.cgi?id=485487 NOR normal --- 1 fweimer jseward mark pjfloyd 0 oldest_to_newest 2406660 0 179295 fweimer 2025-03-11 11:22:56 +0000 Created attachment 179295 Proposed memcmp interceptor Same issue as bug 485487, but this time for `memcmp` instead of `strcmp`. 2406993 1 mark 2025-03-12 13:05:45 +0000 Replicated with a dlopen of a library using RPATH. # Invalid read of size 32 # at 0x40242D9: bcmp (memcmp-avx2-movbe.S:415) # by 0x40069BD: fillin_rpath.isra.0 (dl-load.c:510) # by 0x4006C6A: decompose_rpath (dl-load.c:654) # by 0x4009375: _dl_map_object (dl-load.c:2040) # by 0x4002934: openaux (dl-deps.c:64) # by 0x40014E0: _dl_catch_exception (dl-catch.c:237) # by 0x4002D97: _dl_map_object_deps (dl-deps.c:232) # by 0x400CB70: dl_open_worker_begin (dl-open.c:613) # by 0x40014E0: _dl_catch_exception (dl-catch.c:237) # by 0x400C256: dl_open_worker (dl-open.c:778) # by 0x40014E0: _dl_catch_exception (dl-catch.c:237) # by 0x400C6B0: _dl_open (dl-open.c:880) The string being compared is just 11 chars long. It is pretty hard to replicate though any change in environment seems to hide it again. But the patch does look correct and does resolve the issue by always using a simpler memcmp implementation. 2407011 2 mark 2025-03-12 13:59:56 +0000 commit 9ffdeb4927b8505cc5a9ea54f608f4972166bb0e Author: Mark Wielaard <mark@klomp.org> Date: Wed Mar 12 13:57:19 2025 +0100 add_hardwired_spec for ld-linux-x86-64.so.2 memcmp With RPATH processing ld.so compiled for x86-64-v3 uses an optimized avx2 memcmp (bcmp) which causes (false postive) memcheck invalid reads of size 32 warnings. Fix this my adding a hardwire spec with a simpler memcmp for ld-linux-x86-64.so.2. https://bugs.kde.org/show_bug.cgi?id=501348 Authored-by: Florian Weimer <fweimer@redhat.com> And also on the VALGRIND_3_24_0_BRANCH as commit 2c17a8a3e865816ee48e7f78148bbc7240c2a38c Author: Mark Wielaard <mark@klomp.org> Date: Wed Mar 12 13:57:19 2025 +0100 add_hardwired_spec for ld-linux-x86-64.so.2 memcmp With RPATH processing ld.so compiled for x86-64-v3 uses an optimized avx2 memcmp (bcmp) which causes (false postive) memcheck invalid reads of size 32 warnings. Fix this my adding a hardwire spec with a simpler memcmp for ld-linux-x86-64.so.2. https://bugs.kde.org/show_bug.cgi?id=501348 Authored-by: Florian Weimer <fweimer@redhat.com> (cherry picked from commit 9ffdeb4927b8505cc5a9ea54f608f4972166bb0e) 179295 2025-03-11 11:22:56 +0000 2025-03-11 11:22:56 +0000 Proposed memcmp interceptor valgrind-RHEL-82799.patch text/plain 2028 fweimer ZGlmZiAtLWdpdCBhL2NvcmVncmluZC9tX3JlZGlyLmMgYi9jb3JlZ3JpbmQvbV9yZWRpci5jCmlu ZGV4IGY5ZThkODgwMWExOTJlODkuLjY0ZWJlYTNiNjMwNGMyZDYgMTAwNjQ0Ci0tLSBhL2NvcmVn cmluZC9tX3JlZGlyLmMKKysrIGIvY29yZWdyaW5kL21fcmVkaXIuYwpAQCAtMTQyNSw2ICsxNDI1 LDE1IEBAIHZvaWQgVkdfKHJlZGlyX2luaXRpYWxpc2UpICggdm9pZCApCiAgICAgICAgICBOVUxM CiAjICAgICAgICBlbHNlCiAgICAgICAgICBjb21wbGFpbl9hYm91dF9zdHJpcHBlZF9nbGliY19s ZHNvCisjICAgICAgICBlbmRpZgorICAgICAgKTsKKyAgICAgIGFkZF9oYXJkd2lyZWRfc3BlYygK KyAgICAgICAgICJsZC1saW51eC14ODYtNjQuc28uMiIsICJtZW1jbXAiLAorICAgICAgICAgKEFk ZHIpJlZHXyhhbWQ2NF9saW51eF9SRURJUl9GT1JfbWVtY21wKSwKKyMgICAgICAgIGlmbmRlZiBH TElCQ19NQU5EQVRPUllfU1RSTEVOX1JFRElSRUNUCisgICAgICAgICBOVUxMCisjICAgICAgICBl bHNlCisgICAgICAgICBjb21wbGFpbl9hYm91dF9zdHJpcHBlZF9nbGliY19sZHNvCiAjICAgICAg ICBlbmRpZgogICAgICAgKTsKICAgIH0KZGlmZiAtLWdpdCBhL2NvcmVncmluZC9tX3RyYW1wb2xp bmUuUyBiL2NvcmVncmluZC9tX3RyYW1wb2xpbmUuUwppbmRleCBlODk3OTYzYmUyMWE0NmFlLi4y N2YxYjM1ZDJiMDg3NTUxIDEwMDY0NAotLS0gYS9jb3JlZ3JpbmQvbV90cmFtcG9saW5lLlMKKysr IGIvY29yZWdyaW5kL21fdHJhbXBvbGluZS5TCkBAIC0yNDEsNiArMjQxLDI1IEBAIFZHXyhhbWQ2 NF9saW51eF9SRURJUl9GT1Jfc3RyY21wKToKIAlyZXQKIC5zaXplIFZHXyhhbWQ2NF9saW51eF9S RURJUl9GT1Jfc3RyY21wKSwgLi1WR18oYW1kNjRfbGludXhfUkVESVJfRk9SX3N0cmNtcCkKIAor Lmdsb2JhbCBWR18oYW1kNjRfbGludXhfUkVESVJfRk9SX21lbWNtcCkKKy50eXBlICAgVkdfKGFt ZDY0X2xpbnV4X1JFRElSX0ZPUl9tZW1jbXApLCBAZnVuY3Rpb24KK1ZHXyhhbWQ2NF9saW51eF9S RURJUl9GT1JfbWVtY21wKToKKwl4b3JsCSVlY3gsICVlY3gKKwlqbXAJMmYKKzE6CisJbW92emJs CSglcmRpLCAlcmN4KSwgJWVheAorCW1vdnpibAkoJXJzaSwgJXJjeCksICVyOGQKKwlhZGRxCSQx LCAlcmN4CisJc3VibAklcjhkLCAlZWF4CisJam5lCTNmCisyOgorCWNtcHEJJXJjeCwgJXJkeAor CWpuZQkxYgorCXhvcmwJJWVheCwgJWVheAorMzoKKwlyZXQKKy5zaXplIFZHXyhhbWQ2NF9saW51 eF9SRURJUl9GT1JfbWVtY21wKSwgLi1WR18oYW1kNjRfbGludXhfUkVESVJfRk9SX21lbWNtcCkK KwogLmdsb2JhbCBWR18oYW1kNjRfbGludXhfUkVESVJfRk9SX2luZGV4KQogLnR5cGUgICBWR18o YW1kNjRfbGludXhfUkVESVJfRk9SX2luZGV4KSwgQGZ1bmN0aW9uCiBWR18oYW1kNjRfbGludXhf UkVESVJfRk9SX2luZGV4KToKZGlmZiAtLWdpdCBhL2NvcmVncmluZC9wdWJfY29yZV90cmFtcG9s aW5lLmggYi9jb3JlZ3JpbmQvcHViX2NvcmVfdHJhbXBvbGluZS5oCmluZGV4IGQwYmQ2Yjg1OTc0 MjI2M2UuLjNkMmY3ZTlmMzJiNzI5ZmUgMTAwNjQ0Ci0tLSBhL2NvcmVncmluZC9wdWJfY29yZV90 cmFtcG9saW5lLmgKKysrIGIvY29yZWdyaW5kL3B1Yl9jb3JlX3RyYW1wb2xpbmUuaApAQCAtODIs NiArODIsNyBAQCBleHRlcm4gQWRkciBWR18oYW1kNjRfbGludXhfUkVESVJfRk9SX3Z0aW1lKTsK IGV4dGVybiBBZGRyIFZHXyhhbWQ2NF9saW51eF9SRURJUl9GT1JfdmdldGNwdSk7CiBleHRlcm4g VUludCBWR18oYW1kNjRfbGludXhfUkVESVJfRk9SX3N0cmxlbikoIHZvaWQqICk7CiBleHRlcm4g SW50IFZHXyhhbWQ2NF9saW51eF9SRURJUl9GT1Jfc3RyY21wKSggdm9pZCosIHZvaWQqICk7Citl eHRlcm4gSW50IFZHXyhhbWQ2NF9saW51eF9SRURJUl9GT1JfbWVtY21wKSggdm9pZCosIHZvaWQq LCBTaXplVCApOwogZXh0ZXJuIENoYXIqIFZHXyhhbWQ2NF9saW51eF9SRURJUl9GT1JfaW5kZXgp ICggY29uc3QgQ2hhciosIEludCApOwogI2VuZGlmCiAK