Allow PT_NOTES segments to be located anywhere in the executable
image. The dynamic linker still requires that program headers of the executable or dso are mapped by a PT_LOAD segment. Reviewed by: emaste, jhb Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Differential revision: https://reviews.freebsd.org/D3871
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6c775eb64e
commit
bd56d410c4
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=289324
@ -88,6 +88,8 @@ map_object(int fd, const char *path, const struct stat *sb)
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size_t relro_size;
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Elf_Addr note_start;
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Elf_Addr note_end;
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char *note_map;
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size_t note_map_len;
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hdr = get_elf_header(fd, path);
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if (hdr == NULL)
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@ -108,6 +110,7 @@ map_object(int fd, const char *path, const struct stat *sb)
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relro_size = 0;
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note_start = 0;
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note_end = 0;
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note_map = NULL;
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segs = alloca(sizeof(segs[0]) * hdr->e_phnum);
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stack_flags = RTLD_DEFAULT_STACK_PF_EXEC | PF_R | PF_W;
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while (phdr < phlimit) {
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@ -150,9 +153,20 @@ map_object(int fd, const char *path, const struct stat *sb)
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case PT_NOTE:
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if (phdr->p_offset > PAGE_SIZE ||
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phdr->p_offset + phdr->p_filesz > PAGE_SIZE)
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break;
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phdr->p_offset + phdr->p_filesz > PAGE_SIZE) {
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note_map_len = round_page(phdr->p_offset +
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phdr->p_filesz) - trunc_page(phdr->p_offset);
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note_map = mmap(NULL, note_map_len, PROT_READ,
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MAP_PRIVATE, fd, trunc_page(phdr->p_offset));
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if (note_map == MAP_FAILED) {
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_rtld_error("%s: error mapping PT_NOTE (%d)", path, errno);
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goto error;
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}
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note_start = (Elf_Addr)(note_map + phdr->p_offset -
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trunc_page(phdr->p_offset));
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} else {
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note_start = (Elf_Addr)(char *)hdr + phdr->p_offset;
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}
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note_end = note_start + phdr->p_filesz;
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break;
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}
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@ -295,12 +309,16 @@ map_object(int fd, const char *path, const struct stat *sb)
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obj->relro_size = round_page(relro_size);
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if (note_start < note_end)
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digest_notes(obj, note_start, note_end);
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if (note_map != NULL)
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munmap(note_map, note_map_len);
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munmap(hdr, PAGE_SIZE);
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return (obj);
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error1:
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munmap(mapbase, mapsize);
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error:
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if (note_map != NULL && note_map != MAP_FAILED)
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munmap(note_map, note_map_len);
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munmap(hdr, PAGE_SIZE);
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return (NULL);
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}
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