Hi Philipp, Thanks for the patch! Only a small issue, quoting from kexec-tools.spec, "Patches 401 through 500 are meant for s390 kexec-tools enablement".

On Wed, Jan 19, 2022 at 11:14:07AM +0100, Philipp Rudo wrote: >Resolves: bz2025860 >Upstream: git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git > >commit 186e7b0752d8fce1618fa37519671c834c46340e >Author: Alexander Egorenkov <egorenar(a)linux.ibm.com&gt; >Date: Wed Dec 15 18:48:53 2021 +0100 > > s390: handle R_390_PLT32DBL reloc entries in machine_apply_elf_rel() > > Starting with gcc 11.3, the C compiler will generate PLT-relative function > calls even if they are local and do not require it. Later on during linking, > the linker will replace all PLT-relative calls to local functions with > PC-relative ones. Unfortunately, the purgatory code of kexec/kdump is > not being linked as a regular executable or shared library would have been, > and therefore, all PLT-relative addresses remain in the generated purgatory > object code unresolved. This in turn lets kexec-tools fail with > "Unknown rela relocation: 0x14 0x73c0901c" for such relocation types. > > Furthermore, the clang C compiler has always behaved like described above > and this commit should fix the purgatory code built with the latter. > > Because the purgatory code is no regular executable or shared library, > contains only calls to local functions and has no PLT, all R_390_PLT32DBL > relocation entries can be resolved just like a R_390_PC32DBL one. > > * https://refspecs.linuxfoundation.org/ELF/zSeries/lzsabi0_zSeries/x1633.ht... > > Relocation entries of purgatory code generated with gcc 11.3 > ------------------------------------------------------------ > > $ readelf -r purgatory/purgatory.o > > Relocation section '.rela.text' at offset 0x6e8 contains 27 entries: > Offset Info Type Sym. Value Sym. Name + Addend > 00000000000c 000300000013 R_390_PC32DBL 0000000000000000 .data + 2 > 00000000001a 001000000014 R_390_PLT32DBL 0000000000000000 sha256_starts + 2 > 000000000030 001100000014 R_390_PLT32DBL 0000000000000000 sha256_update + 2 > 000000000046 001200000014 R_390_PLT32DBL 0000000000000000 sha256_finish + 2 > 000000000050 000300000013 R_390_PC32DBL 0000000000000000 .data + 102 > 00000000005a 001300000014 R_390_PLT32DBL 0000000000000000 memcmp + 2 > ... > 000000000118 001600000014 R_390_PLT32DBL 0000000000000000 setup_arch + 2 > 00000000011e 000300000013 R_390_PC32DBL 0000000000000000 .data + 2 > 00000000012c 000f00000014 R_390_PLT32DBL 0000000000000000 verify_sha256_digest + 2 > 000000000142 001700000014 R_390_PLT32DBL 0000000000000000 > post_verification[...] + 2 > > Relocation entries of purgatory code generated with gcc 11.2 > ------------------------------------------------------------ > > $ readelf -r purgatory/purgatory.o > > Relocation section '.rela.text' at offset 0x6e8 contains 27 entries: > Offset Info Type Sym. Value Sym. Name + Addend > 00000000000e 000300000013 R_390_PC32DBL 0000000000000000 .data + 2 > 00000000001c 001000000013 R_390_PC32DBL 0000000000000000 sha256_starts + 2 > 000000000036 001100000013 R_390_PC32DBL 0000000000000000 sha256_update + 2 > 000000000048 001200000013 R_390_PC32DBL 0000000000000000 sha256_finish + 2 > 000000000052 000300000013 R_390_PC32DBL 0000000000000000 .data + 102 > 00000000005c 001300000013 R_390_PC32DBL 0000000000000000 memcmp + 2 > ... > 00000000011a 001600000013 R_390_PC32DBL 0000000000000000 setup_arch + 2 > 000000000120 000300000013 R_390_PC32DBL 0000000000000000 .data + 122 > 000000000130 000f00000013 R_390_PC32DBL 0000000000000000 verify_sha256_digest + 2 > 000000000146 001700000013 R_390_PC32DBL 0000000000000000 post_verification[...] + 2 > > Corresponding s390 kernel discussion: > * https://lore.kernel.org/linux-s390/20211208105801.188140-1-egorenar@linux... > > Signed-off-by: Alexander Egorenkov <egorenar(a)linux.ibm.com&gt; > Reported-by: Tao Liu <ltao(a)redhat.com&gt; > Suggested-by: Philipp Rudo <prudo(a)redhat.com&gt; > Reviewed-by: Philipp Rudo <prudo(a)redhat.com&gt; > [hca(a)linux.ibm.com: changed commit message as requested by Philipp Rudo] > Signed-off-by: Heiko Carstens <hca(a)linux.ibm.com&gt; > Signed-off-by: Simon Horman <horms(a)verge.net.au&gt; > >Signed-off-by: Philipp Rudo <prudo(a)redhat.com&gt; >--- > ...oc_entries_in_machine_apply_elf_rel_.patch | 95 +++++++++++++++++++ > kexec-tools.spec | 3 + > 2 files changed, 98 insertions(+) > create mode 100644 kexec-tools-2.0.23-s390_handle_R_390_PLT32DBL_reloc_entries_in_machine_apply_elf_rel_.patch > >diff --git a/kexec-tools-2.0.23-s390_handle_R_390_PLT32DBL_reloc_entries_in_machine_apply_elf_rel_.patch b/kexec-tools-2.0.23-s390_handle_R_390_PLT32DBL_reloc_entries_in_machine_apply_elf_rel_.patch >new file mode 100644 >index 0000000..10bc5ef >--- /dev/null >+++ b/kexec-tools-2.0.23-s390_handle_R_390_PLT32DBL_reloc_entries_in_machine_apply_elf_rel_.patch >@@ -0,0 +1,95 @@ >+commit 186e7b0752d8fce1618fa37519671c834c46340e >+Author: Alexander Egorenkov <egorenar(a)linux.ibm.com&gt; >+Date: Wed Dec 15 18:48:53 2021 +0100 >+ >+ s390: handle R_390_PLT32DBL reloc entries in machine_apply_elf_rel() >+ >+ Starting with gcc 11.3, the C compiler will generate PLT-relative function >+ calls even if they are local and do not require it. Later on during linking, >+ the linker will replace all PLT-relative calls to local functions with >+ PC-relative ones. Unfortunately, the purgatory code of kexec/kdump is >+ not being linked as a regular executable or shared library would have been, >+ and therefore, all PLT-relative addresses remain in the generated purgatory >+ object code unresolved. This in turn lets kexec-tools fail with >+ "Unknown rela relocation: 0x14 0x73c0901c" for such relocation types. >+ >+ Furthermore, the clang C compiler has always behaved like described above >+ and this commit should fix the purgatory code built with the latter. >+ >+ Because the purgatory code is no regular executable or shared library, >+ contains only calls to local functions and has no PLT, all R_390_PLT32DBL >+ relocation entries can be resolved just like a R_390_PC32DBL one. >+ >+ * https://refspecs.linuxfoundation.org/ELF/zSeries/lzsabi0_zSeries/x1633.ht... >+ >+ Relocation entries of purgatory code generated with gcc 11.3 >+ ------------------------------------------------------------ >+ >+ $ readelf -r purgatory/purgatory.o >+ >+ Relocation section '.rela.text' at offset 0x6e8 contains 27 entries: >+ Offset Info Type Sym. Value Sym. Name + Addend >+ 00000000000c 000300000013 R_390_PC32DBL 0000000000000000 .data + 2 >+ 00000000001a 001000000014 R_390_PLT32DBL 0000000000000000 sha256_starts + 2 >+ 000000000030 001100000014 R_390_PLT32DBL 0000000000000000 sha256_update + 2 >+ 000000000046 001200000014 R_390_PLT32DBL 0000000000000000 sha256_finish + 2 >+ 000000000050 000300000013 R_390_PC32DBL 0000000000000000 .data + 102 >+ 00000000005a 001300000014 R_390_PLT32DBL 0000000000000000 memcmp + 2 >+ ... >+ 000000000118 001600000014 R_390_PLT32DBL 0000000000000000 setup_arch + 2 >+ 00000000011e 000300000013 R_390_PC32DBL 0000000000000000 .data + 2 >+ 00000000012c 000f00000014 R_390_PLT32DBL 0000000000000000 verify_sha256_digest + 2 >+ 000000000142 001700000014 R_390_PLT32DBL 0000000000000000 >+ post_verification[...] + 2 >+ >+ Relocation entries of purgatory code generated with gcc 11.2 >+ ------------------------------------------------------------ >+ >+ $ readelf -r purgatory/purgatory.o >+ >+ Relocation section '.rela.text' at offset 0x6e8 contains 27 entries: >+ Offset Info Type Sym. Value Sym. Name + Addend >+ 00000000000e 000300000013 R_390_PC32DBL 0000000000000000 .data + 2 >+ 00000000001c 001000000013 R_390_PC32DBL 0000000000000000 sha256_starts + 2 >+ 000000000036 001100000013 R_390_PC32DBL 0000000000000000 sha256_update + 2 >+ 000000000048 001200000013 R_390_PC32DBL 0000000000000000 sha256_finish + 2 >+ 000000000052 000300000013 R_390_PC32DBL 0000000000000000 .data + 102 >+ 00000000005c 001300000013 R_390_PC32DBL 0000000000000000 memcmp + 2 >+ ... >+ 00000000011a 001600000013 R_390_PC32DBL 0000000000000000 setup_arch + 2 >+ 000000000120 000300000013 R_390_PC32DBL 0000000000000000 .data + 122 >+ 000000000130 000f00000013 R_390_PC32DBL 0000000000000000 verify_sha256_digest + 2 >+ 000000000146 001700000013 R_390_PC32DBL 0000000000000000 post_verification[...] + 2 >+ >+ Corresponding s390 kernel discussion: >+ * https://lore.kernel.org/linux-s390/20211208105801.188140-1-egorenar@linux... >+ >+ Signed-off-by: Alexander Egorenkov <egorenar(a)linux.ibm.com&gt; >+ Reported-by: Tao Liu <ltao(a)redhat.com&gt; >+ Suggested-by: Philipp Rudo <prudo(a)redhat.com&gt; >+ Reviewed-by: Philipp Rudo <prudo(a)redhat.com&gt; >+ [hca(a)linux.ibm.com: changed commit message as requested by Philipp Rudo] >+ Signed-off-by: Heiko Carstens <hca(a)linux.ibm.com&gt; >+ Signed-off-by: Simon Horman <horms(a)verge.net.au&gt; >+ >+diff --git a/kexec/arch/s390/kexec-elf-rel-s390.c b/kexec/arch/s390/kexec-elf-rel-s390.c >+index a5e1b73455785ae3bc3aa72b3beee13ae202e82f..91ba86a9991dad4271b834fc3b24861c40309e52 100644 >+--- a/kexec/arch/s390/kexec-elf-rel-s390.c >++++ b/kexec/arch/s390/kexec-elf-rel-s390.c >+@@ -56,6 +56,7 @@ void machine_apply_elf_rel(struct mem_ehdr *UNUSED(ehdr), >+ case R_390_PC16: /* PC relative 16 bit. */ >+ case R_390_PC16DBL: /* PC relative 16 bit shifted by 1. */ >+ case R_390_PC32DBL: /* PC relative 32 bit shifted by 1. */ >++ case R_390_PLT32DBL: /* 32 bit PC rel. PLT shifted by 1. */ >+ case R_390_PC32: /* PC relative 32 bit. */ >+ case R_390_PC64: /* PC relative 64 bit. */ >+ val -= address; >+@@ -63,7 +64,7 @@ void machine_apply_elf_rel(struct mem_ehdr *UNUSED(ehdr), >+ *(unsigned short *) loc = val; >+ else if (r_type == R_390_PC16DBL) >+ *(unsigned short *) loc = val >> 1; >+- else if (r_type == R_390_PC32DBL) >++ else if (r_type == R_390_PC32DBL || r_type == R_390_PLT32DBL) >+ *(unsigned int *) loc = val >> 1; >+ else if (r_type == R_390_PC32) >+ *(unsigned int *) loc = val; >diff --git a/kexec-tools.spec b/kexec-tools.spec >index 7419723..f687449 100644 >--- a/kexec-tools.spec >+++ b/kexec-tools.spec >@@ -110,6 +110,7 @@ Requires: systemd-udev%{?_isa} > # > # Patches 601 onward are generic patches > # >+Patch601: ./kexec-tools-2.0.23-s390_handle_R_390_PLT32DBL_reloc_entries_in_machine_apply_elf_rel_.patch > > %description > kexec-tools provides /sbin/kexec binary that facilitates a new >@@ -125,6 +126,8 @@ mkdir -p -m755 kcp > tar -z -x -v -f %{SOURCE9} > tar -z -x -v -f %{SOURCE19} > >+%patch601 -p1 >+ > %ifarch ppc > %define archdef ARCH=ppc > %endif >-- >2.34.1 >_______________________________________________ >kexec mailing list -- kexec(a)lists.fedoraproject.org >To unsubscribe send an email to kexec-leave(a)lists.fedoraproject.org >Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines >List Archives: https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org >Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure