From 65365aa856e5a258329dc350b02bbb51f84b4c16 Mon Sep 17 00:00:00 2001 From: Nick Alcock Date: Wed, 19 Jun 2019 12:20:47 +0100 Subject: libctf: drop mmap()-based CTF data allocator This allocator has the ostensible benefit that it lets us mprotect() the memory used for CTF storage: but in exchange for this it adds considerable complexity, since we have to track allocation sizes ourselves for use at freeing time, note whether the data we are storing was ctf_data_alloc()ed or not so we know if we can safely mprotect() it... and while the mprotect()ing has found few bugs, it *has* been the cause of more than one due to errors in all this tracking leading to us mprotect()ing bits of the heap and stuff like that. We are about to start composing CTF buffers from pieces so that we can do usage-based optimizations on the strtab. This means we need realloc(), which needs nonportable mremap() and *more* tracking of the *original* allocation size, and the complexity and bureaucracy of all of this is just too high for its negligible benefits. Drop the whole thing and just use malloc() like everyone else. It knows better than we do when it is safe to use mmap() under the covers, anyway. While we're at it, don't leak the entire buffer if ctf_compress_write() fails to compress it. libctf/ * ctf-subr.c (_PAGESIZE): Remove. (ctf_data_alloc): Likewise. (ctf_data_free): Likewise. (ctf_data_protect): Likewise. * ctf-impl.h: Remove declarations. * ctf-create.c (ctf_update): No longer call ctf_data_protect: use ctf_free, not ctf_data_free. (ctf_compress_write): Use ctf_data_alloc, not ctf_alloc. Free the buffer again on compression error. * ctf-open.c (ctf_set_base): No longer track the size: call ctf_free, not ctf_data_free. (upgrade_types): Likewise. Call ctf_alloc, not ctf_data_alloc. (ctf_bufopen): Likewise. No longer call ctf_data_protect. --- libctf/ctf-impl.h | 5 ----- 1 file changed, 5 deletions(-) (limited to 'libctf/ctf-impl.h') diff --git a/libctf/ctf-impl.h b/libctf/ctf-impl.h index 52aef24..44f0493 100644 --- a/libctf/ctf-impl.h +++ b/libctf/ctf-impl.h @@ -343,11 +343,6 @@ extern void *ctf_set_open_errno (int *, int); extern unsigned long ctf_set_errno (ctf_file_t *, int); _libctf_malloc_ -extern void *ctf_data_alloc (size_t); -extern void ctf_data_free (void *, size_t); -extern void ctf_data_protect (void *, size_t); - -_libctf_malloc_ extern void *ctf_mmap (size_t length, size_t offset, int fd); extern void ctf_munmap (void *, size_t); extern ssize_t ctf_pread (int fd, void *buf, ssize_t count, off_t offset); -- cgit v1.1