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author | kib <kib@FreeBSD.org> | 2017-07-05 06:32:53 +0000 |
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committer | kib <kib@FreeBSD.org> | 2017-07-05 06:32:53 +0000 |
commit | 3f0d261f813c3b4177b881eb99b41b17f1caa4c9 (patch) | |
tree | 2ab9d6cc8b48ab9e47df9b69e9290b800e427ab5 | |
parent | c3699e91289a5a02b0c16eec22ee4d6ad7d9602e (diff) | |
download | FreeBSD-src-3f0d261f813c3b4177b881eb99b41b17f1caa4c9.zip FreeBSD-src-3f0d261f813c3b4177b881eb99b41b17f1caa4c9.tar.gz |
MFC r320318:
Use address space guard to implement inter-segment gap.
-rw-r--r-- | libexec/rtld-elf/map_object.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/libexec/rtld-elf/map_object.c b/libexec/rtld-elf/map_object.c index 6f77d98..1009e09 100644 --- a/libexec/rtld-elf/map_object.c +++ b/libexec/rtld-elf/map_object.c @@ -41,6 +41,8 @@ static Elf_Ehdr *get_elf_header(int, const char *, const struct stat *); static int convert_flags(int); /* Elf flags -> mmap flags */ +int __getosreldate(void); + /* * Map a shared object into memory. The "fd" argument is a file descriptor, * which must be open on the object and positioned at its beginning. @@ -190,7 +192,9 @@ map_object(int fd, const char *path, const struct stat *sb) base_vlimit = round_page(segs[nsegs]->p_vaddr + segs[nsegs]->p_memsz); mapsize = base_vlimit - base_vaddr; base_addr = (caddr_t) base_vaddr; - base_flags = MAP_PRIVATE | MAP_ANON | MAP_NOCORE; + base_flags = __getosreldate() >= P_OSREL_MAP_GUARD || + (P_OSREL_MAJOR(__getosreldate()) == 11 && __getosreldate() >= + P_OSREL_MAP_GUARD_11) ? MAP_GUARD : MAP_PRIVATE | MAP_ANON | MAP_NOCORE; if (npagesizes > 1 && round_page(segs[0]->p_filesz) >= pagesizes[1]) base_flags |= MAP_ALIGNED_SUPER; if (base_vaddr != 0) |