Revert "ld.so: Replace DL_RO_DYN_SECTION with dl_relocate_ld [BZ #28340]" This reverts commit b413280cfb16834450f66f554bc0d618bb513851. It does not work on ppc64le: “ Sorry, this does not appear to work: For !DONT_USE_BOOTSTRAP_MAP, bootstrap_map.l_ld_readonly is not initialized during the initial self-relocation. This is visible as a valgrind failure on powerpc64le-linux-gnu: + /builddir/build/BUILDROOT/glibc-2.34.9000-9.fc36.ppc64le/lib64/ld64.so.2 --library-path /builddir/build/BUILDROOT/glibc-2.34.9000-9.fc36.ppc64le/lib64 /usr/bin/valgrind --error-exitcode=1 /builddir/build/BUILDROOT/glibc-2.34.9000-9.fc36.ppc64le/lib64/ld64.so.2 --library-path /builddir/build/BUILDROOT/glibc-2.34.9000-9.fc36.ppc64le/lib64 /usr/bin/true ==1924587== Memcheck, a memory error detector ==1924587== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al. ==1924587== Using Valgrind-3.17.0 and LibVEX; rerun with -h for copyright info ==1924587== Command: /builddir/build/BUILDROOT/glibc-2.34.9000-9.fc36.ppc64le/lib64/ld64.so.2 --library-path /builddir/build/BUILDROOT/glibc-2.34.9000-9.fc36.ppc64le/lib64 /usr/bin/true ==1924587== ==1924587== Conditional jump or move depends on uninitialised value(s) ==1924587== at 0x191620: elf_get_dynamic_info (get-dynamic-info.h:73) ==1924587== by 0x191620: _dl_start (rtld.c:550) ==1924587== by 0x190677: (below main) (in /builddir/build/BUILDROOT/glibc-2.34.9000-9.fc36.ppc64le/lib64/ld64.so.2) ==1924587== For DONT_USE_BOOTSTRAP_MAP, bootstrap_map.l_ld_readonly is always zero, which is incorrect for RISC-V (which is PI_STATIC_AND_HIDDEN and thus DONT_USE_BOOTSTRAP_MAP). ” diff --git a/elf/Makefile b/elf/Makefile index 0cdccaacb3ca71c5..835b85bd7ce394c1 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -224,7 +224,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-tls-ie tst-tls-ie-dlmopen argv0test \ tst-glibc-hwcaps tst-glibc-hwcaps-prepend tst-glibc-hwcaps-mask \ tst-tls20 tst-tls21 tst-dlmopen-dlerror tst-dlmopen-gethostbyname \ - tst-dl-is_dso tst-ro-dynamic + tst-dl-is_dso # reldep9 tests-internal += loadtest unload unload2 circleload1 \ neededtest neededtest2 neededtest3 neededtest4 \ @@ -360,7 +360,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ libmarkermod4-1 libmarkermod4-2 libmarkermod4-3 libmarkermod4-4 \ tst-tls20mod-bad tst-tls21mod tst-dlmopen-dlerror-mod \ tst-auxvalmod \ - tst-dlmopen-gethostbyname-mod tst-ro-dynamic-mod \ + tst-dlmopen-gethostbyname-mod \ # Most modules build with _ISOMAC defined, but those filtered out # depend on internal headers. @@ -1911,10 +1911,3 @@ $(objpfx)tst-getauxval-static.out: $(objpfx)tst-auxvalmod.so tst-getauxval-static-ENV = LD_LIBRARY_PATH=$(objpfx):$(common-objpfx) $(objpfx)tst-dlmopen-gethostbyname.out: $(objpfx)tst-dlmopen-gethostbyname-mod.so - -$(objpfx)tst-ro-dynamic: $(objpfx)tst-ro-dynamic-mod.so -$(objpfx)tst-ro-dynamic-mod.so: $(objpfx)tst-ro-dynamic-mod.os \ - tst-ro-dynamic-mod.map - $(LINK.o) -nostdlib -nostartfiles -shared -o $@ \ - -Wl,--script=tst-ro-dynamic-mod.map \ - $(objpfx)tst-ro-dynamic-mod.os diff --git a/elf/dl-load.c b/elf/dl-load.c index 6ea71077afc2852c..39e0d074b4a0ab7b 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1149,7 +1149,6 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, such a segment to avoid a crash later. */ l->l_ld = (void *) ph->p_vaddr; l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn)); - l->l_ld_readonly = (ph->p_flags & PF_W) == 0; } break; @@ -1293,7 +1292,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, else l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr); - elf_get_dynamic_info (l); + elf_get_dynamic_info (l, NULL); /* Make sure we are not dlopen'ing an object that has the DF_1_NOOPEN flag set, or a PIE object. */ diff --git a/elf/dl-reloc-static-pie.c b/elf/dl-reloc-static-pie.c index 68ded176cd2db1a9..289651b3414284d2 100644 --- a/elf/dl-reloc-static-pie.c +++ b/elf/dl-reloc-static-pie.c @@ -40,17 +40,7 @@ _dl_relocate_static_pie (void) /* Read our own dynamic section and fill in the info array. */ main_map->l_ld = ((void *) main_map->l_addr + elf_machine_dynamic ()); - - const ElfW(Phdr) *ph, *phdr = GL(dl_phdr); - size_t phnum = GL(dl_phnum); - for (ph = phdr; ph < &phdr[phnum]; ++ph) - if (ph->p_type == PT_DYNAMIC) - { - main_map->l_ld_readonly = (ph->p_flags & PF_W) == 0; - break; - } - - elf_get_dynamic_info (main_map); + elf_get_dynamic_info (main_map, NULL); # ifdef ELF_MACHINE_BEFORE_RTLD_RELOC ELF_MACHINE_BEFORE_RTLD_RELOC (main_map->l_info); diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h index 4aa2058abf6443c9..d8ec32377d37635c 100644 --- a/elf/get-dynamic-info.h +++ b/elf/get-dynamic-info.h @@ -28,7 +28,7 @@ static auto #endif inline void __attribute__ ((unused, always_inline)) -elf_get_dynamic_info (struct link_map *l) +elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp) { #if __ELF_NATIVE_CLASS == 32 typedef Elf32_Word d_tag_utype; @@ -69,15 +69,28 @@ elf_get_dynamic_info (struct link_map *l) info[i] = dyn; } +#define DL_RO_DYN_TEMP_CNT 8 + +#ifndef DL_RO_DYN_SECTION /* Don't adjust .dynamic unnecessarily. */ - if (l->l_addr != 0 && dl_relocate_ld (l)) + if (l->l_addr != 0) { ElfW(Addr) l_addr = l->l_addr; + int cnt = 0; # define ADJUST_DYN_INFO(tag) \ do \ if (info[tag] != NULL) \ - info[tag]->d_un.d_ptr += l_addr; \ + { \ + if (temp) \ + { \ + temp[cnt].d_tag = info[tag]->d_tag; \ + temp[cnt].d_un.d_ptr = info[tag]->d_un.d_ptr + l_addr; \ + info[tag] = temp + cnt++; \ + } \ + else \ + info[tag]->d_un.d_ptr += l_addr; \ + } \ while (0) ADJUST_DYN_INFO (DT_HASH); @@ -94,7 +107,9 @@ elf_get_dynamic_info (struct link_map *l) ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM)); ADJUST_DYN_INFO (ADDRIDX (DT_GNU_HASH)); # undef ADJUST_DYN_INFO + assert (cnt <= DL_RO_DYN_TEMP_CNT); } +#endif if (info[DT_PLTREL] != NULL) { #if ELF_MACHINE_NO_RELA diff --git a/elf/rtld.c b/elf/rtld.c index 8d2bba3d43f0a828..742c413c48d4930b 100644 --- a/elf/rtld.c +++ b/elf/rtld.c @@ -463,7 +463,6 @@ _dl_start_final (void *arg, struct dl_start_final_info *info) #ifndef DONT_USE_BOOTSTRAP_MAP GL(dl_rtld_map).l_addr = info->l.l_addr; GL(dl_rtld_map).l_ld = info->l.l_ld; - GL(dl_rtld_map).l_ld_readonly = info->l.l_ld_readonly; memcpy (GL(dl_rtld_map).l_info, info->l.l_info, sizeof GL(dl_rtld_map).l_info); GL(dl_rtld_map).l_mach = info->l.l_mach; @@ -547,7 +546,7 @@ _dl_start (void *arg) /* Read our own dynamic section and fill in the info array. */ bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic (); - elf_get_dynamic_info (&bootstrap_map); + elf_get_dynamic_info (&bootstrap_map, NULL); #if NO_TLS_OFFSET != 0 bootstrap_map.l_tls_offset = NO_TLS_OFFSET; @@ -1469,7 +1468,6 @@ dl_main (const ElfW(Phdr) *phdr, /* This tells us where to find the dynamic section, which tells us everything we need to do. */ main_map->l_ld = (void *) main_map->l_addr + ph->p_vaddr; - main_map->l_ld_readonly = (ph->p_flags & PF_W) == 0; break; case PT_INTERP: /* This "interpreter segment" was used by the program loader to @@ -1615,7 +1613,7 @@ dl_main (const ElfW(Phdr) *phdr, if (! rtld_is_main) { /* Extract the contents of the dynamic section for easy access. */ - elf_get_dynamic_info (main_map); + elf_get_dynamic_info (main_map, NULL); /* If the main map is libc.so, update the base namespace to refer to this map. If libc.so is loaded later, this happens diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h index f44748bc9858e5fd..86c491e49c98345d 100644 --- a/elf/setup-vdso.h +++ b/elf/setup-vdso.h @@ -33,6 +33,8 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)), 0, LM_ID_BASE); if (__glibc_likely (l != NULL)) { + static ElfW(Dyn) dyn_temp[DL_RO_DYN_TEMP_CNT] attribute_relro; + l->l_phdr = ((const void *) GLRO(dl_sysinfo_dso) + GLRO(dl_sysinfo_dso)->e_phoff); l->l_phnum = GLRO(dl_sysinfo_dso)->e_phnum; @@ -43,7 +45,6 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)), { l->l_ld = (void *) ph->p_vaddr; l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn)); - l->l_ld_readonly = (ph->p_flags & PF_W) == 0; } else if (ph->p_type == PT_LOAD) { @@ -64,7 +65,7 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)), l->l_map_end += l->l_addr; l->l_text_end += l->l_addr; l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr); - elf_get_dynamic_info (l); + elf_get_dynamic_info (l, dyn_temp); _dl_setup_hash (l); l->l_relocated = 1; diff --git a/elf/tst-ro-dynamic-mod.c b/elf/tst-ro-dynamic-mod.c deleted file mode 100644 index 6d99925964c50caf..0000000000000000 --- a/elf/tst-ro-dynamic-mod.c +++ /dev/null @@ -1,19 +0,0 @@ -/* Test case for DSO with readonly dynamic section. - Copyright (C) 2021 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -int foo = -1; diff --git a/elf/tst-ro-dynamic-mod.map b/elf/tst-ro-dynamic-mod.map deleted file mode 100644 index 2fe4a2998cddd587..0000000000000000 --- a/elf/tst-ro-dynamic-mod.map +++ /dev/null @@ -1,16 +0,0 @@ -SECTIONS -{ - . = SIZEOF_HEADERS; - .dynamic : { *(.dynamic) } :text :dynamic - .rodata : { *(.data*) *(.bss*) } :text - /DISCARD/ : { - *(.note.gnu.property) - } - .note : { *(.note.*) } :text :note -} -PHDRS -{ - text PT_LOAD FLAGS(5) FILEHDR PHDRS; - dynamic PT_DYNAMIC FLAGS(4); - note PT_NOTE FLAGS(4); -} diff --git a/elf/tst-ro-dynamic.c b/elf/tst-ro-dynamic.c deleted file mode 100644 index 3a18f8789ad386bb..0000000000000000 --- a/elf/tst-ro-dynamic.c +++ /dev/null @@ -1,31 +0,0 @@ -/* Test case for DSO with readonly dynamic section. - Copyright (C) 2021 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#include -#include - -extern int foo; - -static int -do_test (void) -{ - TEST_COMPARE (foo, -1); - return 0; -} - -#include diff --git a/include/link.h b/include/link.h index 484ee6cb1bc6e298..7b8250db36ebfcee 100644 --- a/include/link.h +++ b/include/link.h @@ -205,7 +205,6 @@ struct link_map unsigned int l_free_initfini:1; /* Nonzero if l_initfini can be freed, ie. not allocated with the dummy malloc in ld.so. */ - unsigned int l_ld_readonly:1; /* Nonzero if dynamic section is readonly. */ /* NODELETE status of the map. Only valid for maps of type lt_loaded. Lazy binding sets l_nodelete_active directly, @@ -343,8 +342,6 @@ struct link_map unsigned long long int l_serial; }; -#include - /* Information used by audit modules. For most link maps, this data immediate follows the link map in memory. For the dynamic linker, it is allocated separately. See link_map_audit_state in diff --git a/sysdeps/generic/dl-relocate-ld.h b/sysdeps/generic/dl-relocate-ld.h deleted file mode 100644 index 5fae206db9941e97..0000000000000000 --- a/sysdeps/generic/dl-relocate-ld.h +++ /dev/null @@ -1,32 +0,0 @@ -/* Check if dynamic section should be relocated. Generic version. - Copyright (C) 2021 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#ifndef _DL_RELOCATE_LD_H -#define _DL_RELOCATE_LD_H - -/* Return true if dynamic section in the shared library L should be - relocated. */ - -static inline bool -dl_relocate_ld (const struct link_map *l) -{ - /* Don't relocate dynamic section if it is readonly */ - return !l->l_ld_readonly; -} - -#endif /* _DL_RELOCATE_LD_H */ diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h index d49529da0db59f8b..6e50fcd7cd9a18d6 100644 --- a/sysdeps/generic/ldsodefs.h +++ b/sysdeps/generic/ldsodefs.h @@ -75,8 +75,11 @@ __BEGIN_DECLS have to be accessed via the D_PTR macro. The macro is needed since for most architectures the entry is already relocated - but for some not and we need to relocate at access time. */ -#define D_PTR(map, i) \ - ((map)->i->d_un.d_ptr + (dl_relocate_ld (map) ? 0 : (map)->l_addr)) +#ifdef DL_RO_DYN_SECTION +# define D_PTR(map, i) ((map)->i->d_un.d_ptr + (map)->l_addr) +#else +# define D_PTR(map, i) (map)->i->d_un.d_ptr +#endif /* Result of the lookup functions and how to retrieve the base address. */ typedef struct link_map *lookup_t; diff --git a/sysdeps/mips/dl-relocate-ld.h b/sysdeps/mips/dl-relocate-ld.h deleted file mode 100644 index 0c18d9a567cad54f..0000000000000000 --- a/sysdeps/mips/dl-relocate-ld.h +++ /dev/null @@ -1,32 +0,0 @@ -/* Check if dynamic section should be relocated. MIPS version. - Copyright (C) 2021 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#ifndef _DL_RELOCATE_LD_H -#define _DL_RELOCATE_LD_H - -/* Return true if dynamic section in the shared library L should be - relocated. */ - -static inline bool -dl_relocate_ld (const struct link_map *l) -{ - /* Never relocate dynamic section. */ - return false; -} - -#endif /* _DL_RELOCATE_LD_H */ diff --git a/sysdeps/mips/ldsodefs.h b/sysdeps/mips/ldsodefs.h index 36fd09a8bdb4cacf..4db7c60e38e42ef2 100644 --- a/sysdeps/mips/ldsodefs.h +++ b/sysdeps/mips/ldsodefs.h @@ -75,6 +75,10 @@ struct La_mips_64_retval; struct La_mips_64_retval *, \ const char *); +/* The MIPS ABI specifies that the dynamic section has to be read-only. */ + +#define DL_RO_DYN_SECTION 1 + #include_next /* The 64-bit MIPS ELF ABI uses an unusual reloc format. Each diff --git a/sysdeps/riscv/dl-relocate-ld.h b/sysdeps/riscv/dl-relocate-ld.h deleted file mode 100644 index 10327454b17a7097..0000000000000000 --- a/sysdeps/riscv/dl-relocate-ld.h +++ /dev/null @@ -1,32 +0,0 @@ -/* Check if dynamic section should be relocated. RISC-V version. - Copyright (C) 2021 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - . */ - -#ifndef _DL_RELOCATE_LD_H -#define _DL_RELOCATE_LD_H - -/* Return true if dynamic section in the shared library L should be - relocated. */ - -static inline bool -dl_relocate_ld (const struct link_map *l) -{ - /* Never relocate dynamic section for ABI compatibility. */ - return false; -} - -#endif /* _DL_RELOCATE_LD_H */ diff --git a/sysdeps/riscv/ldsodefs.h b/sysdeps/riscv/ldsodefs.h index 8947ffe4b5026a2e..0c696714a7a93cff 100644 --- a/sysdeps/riscv/ldsodefs.h +++ b/sysdeps/riscv/ldsodefs.h @@ -38,6 +38,11 @@ struct La_riscv_retval; struct La_riscv_retval *, \ const char *); +/* Although the RISC-V ABI does not specify that the dynamic section has + to be read-only, it needs to be kept for ABI compatibility. */ + +#define DL_RO_DYN_SECTION 1 + #include_next #endif