Update the info for resurrection of fstat/newfstatat #195
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
The decision of reviving newfstatat will render all previous releases incomplete.
|
Draft. The content may subject to changes. And the commits will be rebased & (partially) squashed. |
xry111
commented
Jul 4, 2024
docs/world-compat-details/index.md
Outdated
| 为了能让这部分程序正常运行，需要调整上述函数的行为，当 `statx` 返回 `ENOSYS` 时， | ||
| 改为使用 `fstat` 或 `newfstatat`；同时，需要在新世界的内核中补充 `fstat` 和 `newfstatat` 的实现。 | ||
| 为了能让这部分程序正常运行，如果 Glibc 版本低于 2.41，需要调整上述函数的行为，当 `statx` 返回 `ENOSYS` 时， | ||
| 改为使用 `fstat` 或 `newfstatat`；同时，如果新世界内核版本低于 6.11，则需要为其补充 `fstat` 和 `newfstatat` 的实现。 |
There was a problem hiding this comment.
TODO: list backport versions here (6.6.xx and 6.1.yy). The backport is making more chaos to me.
xry111
commented
Jul 4, 2024
|
|
||
| 在 2.38 的 glibc 中，所有 `*stat*` 函数会在编译期通过宏指令检查内核是否提供了 `fstat` 或 `newfstatat` 的定义， | ||
| 如果没有，那么这些函数会调用 `statx`[^7] 并负责转换数据结构。这意味着，与旧世界相比，这些 `*stat*` 函数对外呈现的行为是不变的， | ||
| 新旧世界的函数是二进制兼容的。本节会着重讨论其向内核发出系统调用的行为区别。 | ||
|
|
||
| 在 2.41 的 glibc 中，如果其在构建时被配置为仅兼容 6.11 或更新版本的内核 |
There was a problem hiding this comment.
NOT to list backport versions here. We cannot support them rationally in Glibc.
xry111
commented
Jul 4, 2024
Even x86_64 statx does not fallback if configured with --enable-kernel >= 5.19. In practice on x86_64 Firefox sandbox work fine with a Glibc configured --enable-kernel=6.8 (because statx is rarely directly invoked, thus if Glibc does not invoke it for stat/fstat/fstatat etc. it shouldn't be invoked). So (hopefully) these stupidcomp sandboxes will work on LoongArch OOtB with a Glibc configured --enable-kernel >= 6.11.
The field names are different.
… use statx directly
xry111
commented
Jul 4, 2024
| @@ -7,5 +7,5 @@ portingEfforts: | |||
| link: '' | |||
| supportStatus: Released | |||
| releasedSinceVersion: '5.19' | |||
| goodSinceVersion: '6.2' | |||
| goodSinceVersion: '6.11' | |||
There was a problem hiding this comment.
Maybe 6.10(.x) or 6.9.x considering they are fanatical enough to backport this.
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.
I'm much annoyed by this change. It will introduces chaos to Glibc (and maybe others using something like
#ifdef __NR_fstat).<rant>To me the decision is based on the unfair and incorrect favor to some Google products and "commercial" distros, and Linus' personal feeling, instead of good technical reasons.</rant>