--- binutils-2.20/bfd/elf-bfd.h +++ binutils-2.20/bfd/elf-bfd.h @@ -1527,6 +1527,9 @@ struct elf_obj_tdata /* Segment flags for the PT_GNU_STACK segment. */ unsigned int stack_flags; + /* Segment flags for the PT_PAX_FLAGS segment. */ + unsigned int pax_flags; + /* Symbol version definitions in external objects. */ Elf_Internal_Verdef *verdef; --- binutils-2.20/bfd/elf.c +++ binutils-2.20/bfd/elf.c @@ -1081,6 +1081,7 @@ get_segment_type (unsigned int p_type) case PT_GNU_EH_FRAME: pt = "EH_FRAME"; break; case PT_GNU_STACK: pt = "STACK"; break; case PT_GNU_RELRO: pt = "RELRO"; break; + case PT_PAX_FLAGS: pt = "PAX_FLAGS"; break; default: pt = NULL; break; } return pt; @@ -2379,6 +2380,9 @@ bfd_section_from_phdr (bfd *abfd, Elf_Internal_Phdr *hdr, int index) case PT_GNU_RELRO: return _bfd_elf_make_section_from_phdr (abfd, hdr, index, "relro"); + case PT_PAX_FLAGS: + return _bfd_elf_make_section_from_phdr (abfd, hdr, index, "pax_flags"); + default: /* Check for any processor-specific program segment types. */ bed = get_elf_backend_data (abfd); @@ -3393,6 +3397,11 @@ get_program_header_size (bfd *abfd, struct bfd_link_info *info) ++segs; } + { + /* We need a PT_PAX_FLAGS segment. */ + ++segs; + } + for (s = abfd->sections; s != NULL; s = s->next) { if ((s->flags & SEC_LOAD) != 0 @@ -3972,6 +3981,20 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info) } } + { + amt = sizeof (struct elf_segment_map); + m = bfd_zalloc (abfd, amt); + if (m == NULL) + goto error_return; + m->next = NULL; + m->p_type = PT_PAX_FLAGS; + m->p_flags = elf_tdata (abfd)->pax_flags; + m->p_flags_valid = 1; + + *pm = m; + pm = &m->next; + } + free (sections); elf_tdata (abfd)->segment_map = mfirst; } @@ -5176,7 +5199,8 @@ rewrite_elf_program_header (bfd *ibfd, bfd *obfd) 6. PT_TLS segment includes only SHF_TLS sections. 7. SHF_TLS sections are only in PT_TLS or PT_LOAD segments. 8. PT_DYNAMIC should not contain empty sections at the beginning - (with the possible exception of .dynamic). */ + (with the possible exception of .dynamic). + 9. PT_PAX_FLAGS segments do not include any sections. */ #define IS_SECTION_IN_INPUT_SEGMENT(section, segment, bed) \ ((((segment->p_paddr \ ? IS_CONTAINED_BY_LMA (section, segment, segment->p_paddr) \ @@ -5184,6 +5208,7 @@ rewrite_elf_program_header (bfd *ibfd, bfd *obfd) && (section->flags & SEC_ALLOC) != 0) \ || IS_NOTE (segment, section)) \ && segment->p_type != PT_GNU_STACK \ + && segment->p_type != PT_PAX_FLAGS \ && (segment->p_type != PT_TLS \ || (section->flags & SEC_THREAD_LOCAL)) \ && (segment->p_type == PT_LOAD \ --- binutils-2.20/bfd/elflink.c +++ binutils-2.20/bfd/elflink.c @@ -5465,16 +5465,30 @@ bfd_elf_size_dynamic_sections (bfd *output_bfd, return TRUE; bed = get_elf_backend_data (output_bfd); + + elf_tdata (output_bfd)->pax_flags = PF_NORANDEXEC; + if (info->execheap) + elf_tdata (output_bfd)->pax_flags |= PF_NOMPROTECT; + else if (info->noexecheap) + elf_tdata (output_bfd)->pax_flags |= PF_MPROTECT; + if (info->execstack) - elf_tdata (output_bfd)->stack_flags = PF_R | PF_W | PF_X; + { + elf_tdata (output_bfd)->stack_flags = PF_R | PF_W | PF_X; + elf_tdata (output_bfd)->pax_flags |= PF_EMUTRAMP; + } else if (info->noexecstack) - elf_tdata (output_bfd)->stack_flags = PF_R | PF_W; + { + elf_tdata (output_bfd)->stack_flags = PF_R | PF_W; + elf_tdata (output_bfd)->pax_flags |= PF_NOEMUTRAMP; + } else { bfd *inputobj; asection *notesec = NULL; int exec = 0; + elf_tdata (output_bfd)->pax_flags |= PF_NOEMUTRAMP; for (inputobj = info->input_bfds; inputobj; inputobj = inputobj->link_next) @@ -5487,7 +5501,11 @@ bfd_elf_size_dynamic_sections (bfd *output_bfd, if (s) { if (s->flags & SEC_CODE) - exec = PF_X; + { + elf_tdata (output_bfd)->pax_flags &= ~PF_NOEMUTRAMP; + elf_tdata (output_bfd)->pax_flags |= PF_EMUTRAMP; + exec = PF_X; + } notesec = s; } else if (bed->default_execstack) --- binutils-2.20/binutils/readelf.c +++ binutils-2.20/binutils/readelf.c @@ -2556,6 +2556,7 @@ get_segment_type (unsigned long p_type) return "GNU_EH_FRAME"; case PT_GNU_STACK: return "GNU_STACK"; case PT_GNU_RELRO: return "GNU_RELRO"; + case PT_PAX_FLAGS: return "PAX_FLAGS"; default: if ((p_type >= PT_LOPROC) && (p_type <= PT_HIPROC)) --- binutils-2.20/include/bfdlink.h +++ binutils-2.20/include/bfdlink.h @@ -319,6 +319,14 @@ struct bfd_link_info /* TRUE if PT_GNU_RELRO segment should be created. */ unsigned int relro: 1; + /* TRUE if PT_PAX_FLAGS segment should be created with PF_NOMPROTECT + flags. */ + unsigned int execheap: 1; + + /* TRUE if PT_PAX_FLAGS segment should be created with PF_MPROTECT + flags. */ + unsigned int noexecheap: 1; + /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ unsigned int warn_shared_textrel: 1; --- binutils-2.20/include/elf/common.h +++ binutils-2.20/include/elf/common.h @@ -422,6 +422,7 @@ #define PT_SUNW_EH_FRAME PT_GNU_EH_FRAME /* Solaris uses the same value */ #define PT_GNU_STACK (PT_LOOS + 0x474e551) /* Stack flags */ #define PT_GNU_RELRO (PT_LOOS + 0x474e552) /* Read-only after relocation */ +#define PT_PAX_FLAGS (PT_LOOS + 0x5041580) /* PaX flags */ /* Program segment permissions, in program header p_flags field. */ @@ -432,6 +433,21 @@ #define PF_MASKOS 0x0FF00000 /* New value, Oct 4, 1999 Draft */ #define PF_MASKPROC 0xF0000000 /* Processor-specific reserved bits */ +/* Flags to control PaX behavior. */ + +#define PF_PAGEEXEC (1 << 4) /* Enable PAGEEXEC */ +#define PF_NOPAGEEXEC (1 << 5) /* Disable PAGEEXEC */ +#define PF_SEGMEXEC (1 << 6) /* Enable SEGMEXEC */ +#define PF_NOSEGMEXEC (1 << 7) /* Disable SEGMEXEC */ +#define PF_MPROTECT (1 << 8) /* Enable MPROTECT */ +#define PF_NOMPROTECT (1 << 9) /* Disable MPROTECT */ +#define PF_RANDEXEC (1 << 10) /* Enable RANDEXEC */ +#define PF_NORANDEXEC (1 << 11) /* Disable RANDEXEC */ +#define PF_EMUTRAMP (1 << 12) /* Enable EMUTRAMP */ +#define PF_NOEMUTRAMP (1 << 13) /* Disable EMUTRAMP */ +#define PF_RANDMMAP (1 << 14) /* Enable RANDMMAP */ +#define PF_NORANDMMAP (1 << 15) /* Disable RANDMMAP */ + /* Values for section header, sh_type field. */ #define SHT_NULL 0 /* Section header table entry unused */ --- binutils-2.20/ld/emultempl/elf32.em +++ binutils-2.20/ld/emultempl/elf32.em @@ -2159,6 +2159,16 @@ fragment <