diff options
Diffstat (limited to 'libelf')
| -rw-r--r-- | libelf/ChangeLog | 5 | ||||
| -rw-r--r-- | libelf/elf_update.c | 7 |
2 files changed, 10 insertions, 2 deletions
diff --git a/libelf/ChangeLog b/libelf/ChangeLog index 30017cd7..2d240074 100644 --- a/libelf/ChangeLog +++ b/libelf/ChangeLog @@ -1,3 +1,8 @@ +2015-06-16 Mark Wielaard <[email protected]> + + * elf_update.c (write_file): Always also use ftruncate before + posix_fallocate to make sure file has the right size. + 2015-06-04 Mark Wielaard <[email protected]> * elf_getdata.c (__libelf_type_aligns): Add entries for ELF_T_EHDR, diff --git a/libelf/elf_update.c b/libelf/elf_update.c index 9e34c466..9eb007bd 100644 --- a/libelf/elf_update.c +++ b/libelf/elf_update.c @@ -60,15 +60,18 @@ write_file (Elf *elf, off_t size, int change_bo, size_t shnum) new file. We truncate the file later in this case. Note we use posix_fallocate to make sure the file content is really - there. Using ftruncate might mean the file is extended, but space + there. Only using ftruncate might mean the file is extended, but space isn't allocated yet. This might cause a SIGBUS once we write into the mmapped space and the disk is full. Using fallocate might fail on some file systems. posix_fallocate is required to extend the file and allocate enough space even if the underlying filesystem would - normally return EOPNOTSUPP. */ + normally return EOPNOTSUPP. Note that we do also need to ftruncate + in case the maximum_size isn't known and the file needs to be shorter + because posix_fallocate can only extend. */ if (elf->parent == NULL && (elf->maximum_size == ~((size_t) 0) || (size_t) size > elf->maximum_size) + && unlikely (ftruncate (elf->fildes, size) != 0) && unlikely (posix_fallocate (elf->fildes, 0, size) != 0)) { __libelf_seterrno (ELF_E_WRITE_ERROR); |