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| author | Konstantin Belousov <kib@FreeBSD.org> | 2017-06-24 17:04:27 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2017-06-24 17:04:27 +0000 |
| commit | a36deee3d3e5a5048de8cff2f33166579b98fb5e (patch) | |
| tree | 42af35f498e7dcb21be5591c4eba1c084e922c2b /libexec | |
| parent | 19bd0d9c85ccd7bfe34a26d8b386112c6746d795 (diff) | |
| download | src-a36deee3d3e5a5048de8cff2f33166579b98fb5e.tar.gz src-a36deee3d3e5a5048de8cff2f33166579b98fb5e.zip | |
Use address space guard to implement inter-segment gap.
Rtld checks and use old MAP_ANON/PROT_NONE method of creating gap if
running on old kernel.
Reviewed by: alc, markj
Tested by: pho, Qualys
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Notes
Notes:
svn path=/head/; revision=320318
Diffstat (limited to 'libexec')
| -rw-r--r-- | libexec/rtld-elf/map_object.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/libexec/rtld-elf/map_object.c b/libexec/rtld-elf/map_object.c index 6f77d987e771..bcda2819d611 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 +192,8 @@ 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 ? 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) |