fix crash when creating >2GB files on 32bit machine #189
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
hyh19962008
changed the title
|
I was able to create files larger than 4GB now |
|
I made a build on Ubuntu 16.04(Xenial) for testing, it only works well on native 32bit system. Running it on a 64bit system still gets the same problem. |
TheAssassin
reviewed
Nov 25, 2024
Comment on lines
+131
to
+136
| // prevent map_size wrap around on 32bit platform | ||
| // we only need to read section header table, this should be big enough | ||
| if (sizeof(long) == 4 && file_size > UINT_MAX) | ||
| map_size = INT_MAX; | ||
| else | ||
| map_size = (size_t)file_size; |
There was a problem hiding this comment.
We could just always use UINT_MAX, couldn't we?
TheAssassin
requested changes
Nov 26, 2024
| @@ -1,3 +1,4 @@ | |||
| #define _FILE_OFFSET_BITS 64 | |||
There was a problem hiding this comment.
While doing some research on the topic anyway for zsync2/AppImageUpdate (which use libgpgme which in turn uses 64-bit types for file sizes apparently), I found that this is not the right way. You should set it as a compiler definition. Then, you can skip the detection logic and mmap/open work as expected.
In theory, we could also just hardcode UINT_MAX...
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
appimagetool will crash on appimage_get_elf_section_offset_and_length() when creating file larger than 2GB on 32bit machine, because in this line lssek() returns -1 and errno set to EOVERFLOW. map_size with value UINT_MAX(-1) is then passed to mmap().
Adding "#define _FILE_OFFSET_BITS 64" will change off_t to 64bit, then we can get the correct file size from lseek.
related issues:
#21