diff options
Diffstat (limited to 'ld.so-Replace-DL_RO_DYN_SECTION-with-dl_relocate_ld-.patch')
| -rw-r--r-- | ld.so-Replace-DL_RO_DYN_SECTION-with-dl_relocate_ld-.patch | 515 |
1 files changed, 515 insertions, 0 deletions
diff --git a/ld.so-Replace-DL_RO_DYN_SECTION-with-dl_relocate_ld-.patch b/ld.so-Replace-DL_RO_DYN_SECTION-with-dl_relocate_ld-.patch new file mode 100644 index 0000000..077b996 --- /dev/null +++ b/ld.so-Replace-DL_RO_DYN_SECTION-with-dl_relocate_ld-.patch @@ -0,0 +1,515 @@ +From b413280cfb16834450f66f554bc0d618bb513851 Mon Sep 17 00:00:00 2001 +From: "H.J. Lu" <hjl.tools@gmail.com> +Date: Thu, 16 Sep 2021 08:15:29 -0700 +Subject: [PATCH] ld.so: Replace DL_RO_DYN_SECTION with dl_relocate_ld [BZ + #28340] + +We can't relocate entries in dynamic section if it is readonly: + +1. Add a l_ld_readonly field to struct link_map to indicate if dynamic +section is readonly and set it based on p_flags of PT_DYNAMIC segment. +2. Replace DL_RO_DYN_SECTION with dl_relocate_ld to decide if dynamic +section should be relocated. +3. Remove DL_RO_DYN_TEMP_CNT. +4. Don't use a static dynamic section to make readonly dynamic section +in vDSO writable. +5. Remove the temp argument from elf_get_dynamic_info. + +This fixes BZ #28340. + +Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org> +--- + elf/Makefile | 11 +++++++++-- + elf/dl-load.c | 3 ++- + elf/dl-reloc-static-pie.c | 12 +++++++++++- + elf/get-dynamic-info.h | 21 +++------------------ + elf/rtld.c | 6 ++++-- + elf/setup-vdso.h | 5 ++--- + elf/tst-ro-dynamic-mod.c | 19 +++++++++++++++++++ + elf/tst-ro-dynamic-mod.map | 16 ++++++++++++++++ + elf/tst-ro-dynamic.c | 31 +++++++++++++++++++++++++++++++ + include/link.h | 3 +++ + sysdeps/generic/dl-relocate-ld.h | 32 ++++++++++++++++++++++++++++++++ + sysdeps/generic/ldsodefs.h | 7 ++----- + sysdeps/mips/dl-relocate-ld.h | 32 ++++++++++++++++++++++++++++++++ + sysdeps/mips/ldsodefs.h | 4 ---- + sysdeps/riscv/dl-relocate-ld.h | 32 ++++++++++++++++++++++++++++++++ + sysdeps/riscv/ldsodefs.h | 5 ----- + 16 files changed, 198 insertions(+), 41 deletions(-) + create mode 100644 elf/tst-ro-dynamic-mod.c + create mode 100644 elf/tst-ro-dynamic-mod.map + create mode 100644 elf/tst-ro-dynamic.c + create mode 100644 sysdeps/generic/dl-relocate-ld.h + create mode 100644 sysdeps/mips/dl-relocate-ld.h + create mode 100644 sysdeps/riscv/dl-relocate-ld.h + +diff --git a/elf/Makefile b/elf/Makefile +index 835b85b..0cdccaa 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-dl-is_dso tst-ro-dynamic + # 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-dlmopen-gethostbyname-mod tst-ro-dynamic-mod \ + + # Most modules build with _ISOMAC defined, but those filtered out + # depend on internal headers. +@@ -1911,3 +1911,10 @@ $(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 39e0d07..6ea7107 100644 +--- a/elf/dl-load.c ++++ b/elf/dl-load.c +@@ -1149,6 +1149,7 @@ _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; + +@@ -1292,7 +1293,7 @@ _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, NULL); ++ elf_get_dynamic_info (l); + + /* 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 289651b..68ded17 100644 +--- a/elf/dl-reloc-static-pie.c ++++ b/elf/dl-reloc-static-pie.c +@@ -40,7 +40,17 @@ _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 ()); +- elf_get_dynamic_info (main_map, NULL); ++ ++ 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); + + # 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 d8ec323..4aa2058 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, ElfW(Dyn) *temp) ++elf_get_dynamic_info (struct link_map *l) + { + #if __ELF_NATIVE_CLASS == 32 + typedef Elf32_Word d_tag_utype; +@@ -69,28 +69,15 @@ elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp) + 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) ++ if (l->l_addr != 0 && dl_relocate_ld (l)) + { + ElfW(Addr) l_addr = l->l_addr; +- int cnt = 0; + + # define ADJUST_DYN_INFO(tag) \ + do \ + if (info[tag] != NULL) \ +- { \ +- 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; \ +- } \ ++ info[tag]->d_un.d_ptr += l_addr; \ + while (0) + + ADJUST_DYN_INFO (DT_HASH); +@@ -107,9 +94,7 @@ elf_get_dynamic_info (struct link_map *l, ElfW(Dyn) *temp) + 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 742c413..8d2bba3 100644 +--- a/elf/rtld.c ++++ b/elf/rtld.c +@@ -463,6 +463,7 @@ _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; +@@ -546,7 +547,7 @@ _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, NULL); ++ elf_get_dynamic_info (&bootstrap_map); + + #if NO_TLS_OFFSET != 0 + bootstrap_map.l_tls_offset = NO_TLS_OFFSET; +@@ -1468,6 +1469,7 @@ 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 +@@ -1613,7 +1615,7 @@ 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, NULL); ++ elf_get_dynamic_info (main_map); + + /* 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 86c491e..f44748b 100644 +--- a/elf/setup-vdso.h ++++ b/elf/setup-vdso.h +@@ -33,8 +33,6 @@ 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; +@@ -45,6 +43,7 @@ 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) + { +@@ -65,7 +64,7 @@ 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, dyn_temp); ++ elf_get_dynamic_info (l); + _dl_setup_hash (l); + l->l_relocated = 1; + +diff --git a/elf/tst-ro-dynamic-mod.c b/elf/tst-ro-dynamic-mod.c +new file mode 100644 +index 0000000..6d99925 +--- /dev/null ++++ b/elf/tst-ro-dynamic-mod.c +@@ -0,0 +1,19 @@ ++/* 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 ++ <https://www.gnu.org/licenses/>. */ ++ ++int foo = -1; +diff --git a/elf/tst-ro-dynamic-mod.map b/elf/tst-ro-dynamic-mod.map +new file mode 100644 +index 0000000..2fe4a29 +--- /dev/null ++++ b/elf/tst-ro-dynamic-mod.map +@@ -0,0 +1,16 @@ ++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 +new file mode 100644 +index 0000000..3a18f87 +--- /dev/null ++++ b/elf/tst-ro-dynamic.c +@@ -0,0 +1,31 @@ ++/* 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 ++ <https://www.gnu.org/licenses/>. */ ++ ++#include <support/check.h> ++#include <support/test-driver.h> ++ ++extern int foo; ++ ++static int ++do_test (void) ++{ ++ TEST_COMPARE (foo, -1); ++ return 0; ++} ++ ++#include <support/test-driver.c> +diff --git a/include/link.h b/include/link.h +index 7b8250d..484ee6c 100644 +--- a/include/link.h ++++ b/include/link.h +@@ -205,6 +205,7 @@ 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, +@@ -342,6 +343,8 @@ struct link_map + unsigned long long int l_serial; + }; + ++#include <dl-relocate-ld.h> ++ + /* 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 +new file mode 100644 +index 0000000..5fae206 +--- /dev/null ++++ b/sysdeps/generic/dl-relocate-ld.h +@@ -0,0 +1,32 @@ ++/* 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 ++ <https://www.gnu.org/licenses/>. */ ++ ++#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 6e50fcd..d49529d 100644 +--- a/sysdeps/generic/ldsodefs.h ++++ b/sysdeps/generic/ldsodefs.h +@@ -75,11 +75,8 @@ __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. */ +-#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 ++#define D_PTR(map, i) \ ++ ((map)->i->d_un.d_ptr + (dl_relocate_ld (map) ? 0 : (map)->l_addr)) + + /* 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 +new file mode 100644 +index 0000000..0c18d9a +--- /dev/null ++++ b/sysdeps/mips/dl-relocate-ld.h +@@ -0,0 +1,32 @@ ++/* 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 ++ <https://www.gnu.org/licenses/>. */ ++ ++#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 4db7c60..36fd09a 100644 +--- a/sysdeps/mips/ldsodefs.h ++++ b/sysdeps/mips/ldsodefs.h +@@ -75,10 +75,6 @@ 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 <ldsodefs.h> + + /* 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 +new file mode 100644 +index 0000000..1032745 +--- /dev/null ++++ b/sysdeps/riscv/dl-relocate-ld.h +@@ -0,0 +1,32 @@ ++/* 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 ++ <https://www.gnu.org/licenses/>. */ ++ ++#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 0c69671..8947ffe 100644 +--- a/sysdeps/riscv/ldsodefs.h ++++ b/sysdeps/riscv/ldsodefs.h +@@ -38,11 +38,6 @@ 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 <ldsodefs.h> + + #endif +-- +1.8.3.1 + |