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| author | Brandon Bergren <bdragon@FreeBSD.org> | 2019-12-12 17:40:32 +0000 |
|---|---|---|
| committer | Brandon Bergren <bdragon@FreeBSD.org> | 2019-12-12 17:40:32 +0000 |
| commit | 44c9aa49ea82d0884ba5b1fe0aa6638b2914de2a (patch) | |
| tree | df9ee6f5b24c03c98b067122f905475a4ca70ed2 /libexec | |
| parent | 4f9ed3156c3aff08629d37c8a89ed5ba525b01c9 (diff) | |
| download | src-44c9aa49ea82d0884ba5b1fe0aa6638b2914de2a.tar.gz src-44c9aa49ea82d0884ba5b1fe0aa6638b2914de2a.zip | |
rtld: do not try to mmap a zero-sized PT_LOAD
When a PT_LOAD segment has a zero p_filesz, skip the data mmap, as mmapping
zero bytes from a file is an error.
A PT_LOAD with zero p_filesz is legal (but somewhat uncommon due to segment
merging in modern linkers, as it is more efficient to merge .data and .bss
by just extending p_memsz in the previous segment, assuming compatible
page protection.)
This was seen on ports/graphics/glew on a powerpc64 ELFv2 experimental
build.
Submitted by: Alfredo Dal'Ava Junior <alfredo.junior@eldorado.org.br>
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D22634
Notes
Notes:
svn path=/head/; revision=355657
Diffstat (limited to 'libexec')
| -rw-r--r-- | libexec/rtld-elf/map_object.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/libexec/rtld-elf/map_object.c b/libexec/rtld-elf/map_object.c index 61a18a46315b..be95a953558a 100644 --- a/libexec/rtld-elf/map_object.c +++ b/libexec/rtld-elf/map_object.c @@ -228,11 +228,12 @@ map_object(int fd, const char *path, const struct stat *sb) data_addr = mapbase + (data_vaddr - base_vaddr); data_prot = convert_prot(segs[i]->p_flags); data_flags = convert_flags(segs[i]->p_flags) | MAP_FIXED; - if (mmap(data_addr, data_vlimit - data_vaddr, data_prot, - data_flags | MAP_PREFAULT_READ, fd, data_offset) == (caddr_t) -1) { - _rtld_error("%s: mmap of data failed: %s", path, - rtld_strerror(errno)); - goto error1; + if (data_vlimit != data_vaddr && + mmap(data_addr, data_vlimit - data_vaddr, data_prot, + data_flags | MAP_PREFAULT_READ, fd, data_offset) == MAP_FAILED) { + _rtld_error("%s: mmap of data failed: %s", path, + rtld_strerror(errno)); + goto error1; } /* Do BSS setup */ |