From 9167304255940e29423517f63d11bdd968d7685e Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Fri, 19 May 2023 15:11:51 -0700 Subject: elf: Add elf_backend_add_glibc_version_dependency When -z mark-plt is used to add DT_X86_64_PLT, DT_X86_64_PLTSZ and DT_X86_64_PLTENT, the r_addend field of the R_X86_64_JUMP_SLOT relocation stores the offset of the indirect branch instruction. However, glibc versions which don't have this commit in glibc 2.36: commit f8587a61892cbafd98ce599131bf4f103466f084 Author: H.J. Lu Date: Fri May 20 19:21:48 2022 -0700 x86-64: Ignore r_addend for R_X86_64_GLOB_DAT/R_X86_64_JUMP_SLOT According to x86-64 psABI, r_addend should be ignored for R_X86_64_GLOB_DAT and R_X86_64_JUMP_SLOT. Since linkers always set their r_addends to 0, we can ignore their r_addends. Reviewed-by: Fangrui Song won't ignore the r_addend value in the R_X86_64_JUMP_SLOT relocation. Although this commit has been backported to glibc 2.33/2.34/2.35 release branches, it is safer to require glibc 2.36 for such binaries. Extend the glibc version dependency of GLIBC_ABI_DT_RELR for DT_RELR to also add GLIBC_2.36 version dependency for -z mark-plt on the shared C library if it provides a GLIBC_2.XX symbol version. * elflink.c (elf_find_verdep_info): Moved to ... * elf-bfd.h (elf_find_verdep_info): Here. (elf_backend_data): Add elf_backend_add_glibc_version_dependency. (_bfd_elf_link_add_glibc_version_dependency): New function. (_bfd_elf_link_add_dt_relr_dependency): Likewise. * elf64-x86-64.c (elf_x86_64_add_glibc_version_dependency): Likewise. (elf_backend_add_glibc_version_dependency): New. * elflink.c (elf_link_add_dt_relr_dependency): Renamed to ... (elf_link_add_glibc_verneed): This. Modified to support other glibc dependencies. (_bfd_elf_link_add_glibc_version_dependency): Likewise. (_bfd_elf_link_add_dt_relr_dependency): Likewise. (bfd_elf_size_dynamic_sections): Call elf_backend_add_glibc_version_dependency instead of elf_link_add_dt_relr_dependency. * elfxx-target.h (elf_backend_add_glibc_version_dependency): New. (elfNN_bed): Add elf_backend_add_glibc_version_dependency. ld/ * testsuite/ld-x86-64/mark-plt-1a.rd: New file. * testsuite/ld-x86-64/mark-plt-1b.rd: Likewise. * testsuite/ld-x86-64/x86-64.exp: Run -z mark-plt test for GLIBC_2.36 dependency. --- ld/testsuite/ld-x86-64/mark-plt-1a.rd | 7 +++++++ ld/testsuite/ld-x86-64/mark-plt-1b.rd | 7 +++++++ ld/testsuite/ld-x86-64/x86-64.exp | 14 ++++++++++++++ 3 files changed, 28 insertions(+) create mode 100644 ld/testsuite/ld-x86-64/mark-plt-1a.rd create mode 100644 ld/testsuite/ld-x86-64/mark-plt-1b.rd (limited to 'ld') diff --git a/ld/testsuite/ld-x86-64/mark-plt-1a.rd b/ld/testsuite/ld-x86-64/mark-plt-1a.rd new file mode 100644 index 0000000..1234fbe --- /dev/null +++ b/ld/testsuite/ld-x86-64/mark-plt-1a.rd @@ -0,0 +1,7 @@ +#... +Version needs section '.gnu.version_r' contains 1 entry: + Addr: 0x[0-9a-f]+ +Offset: 0x[0-9a-f]+ +Link: +[0-9]+ +\(.dynstr\) + +0+: Version: 1 +File: libc\.so\.6(|\.1) +Cnt: +[0-9]+ +#... + 0x[a-f0-9]+: Name: GLIBC_2.36 Flags: none Version: [0-9]+ +#pass diff --git a/ld/testsuite/ld-x86-64/mark-plt-1b.rd b/ld/testsuite/ld-x86-64/mark-plt-1b.rd new file mode 100644 index 0000000..6556a6d --- /dev/null +++ b/ld/testsuite/ld-x86-64/mark-plt-1b.rd @@ -0,0 +1,7 @@ +#... +Version needs section '.gnu.version_r' contains 1 entry: + Addr: 0x[0-9a-f]+ +Offset: 0x[0-9a-f]+ +Link: +[0-9]+ +\(.dynstr\) + +0+: Version: 1 +File: libc\.so\.6(|\.1) +Cnt: +[0-9]+ +#... + 0x[a-f0-9]+: Name: GLIBC_ABI_DT_RELR Flags: none Version: [0-9]+ +#pass diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp index 03266cb..a1a0422 100644 --- a/ld/testsuite/ld-x86-64/x86-64.exp +++ b/ld/testsuite/ld-x86-64/x86-64.exp @@ -2259,4 +2259,18 @@ run_dump_test "mark-plt-1b-x32" run_dump_test "mark-plt-1c-x32" run_dump_test "mark-plt-1d-x32" +if { [check_compiler_available] } { + run_cc_link_tests [list \ + [list \ + "Build mark-plt-1.so" \ + "-shared -Wl,-z,mark-plt,-z,pack-relative-relocs" \ + "-fPIC" \ + { mark-plt-1.s } \ + {{readelf {-W --version-info} mark-plt-1a.rd} \ + {readelf {-W --version-info} mark-plt-1b.rd}} \ + "mark-plt-1.so" \ + ] \ + ] +} + set ASFLAGS "$saved_ASFLAGS" -- cgit v1.1