Messages in this thread | | | Date | Tue, 11 Jul 2023 09:11:53 +0200 | From | Willy Tarreau <> | Subject | Re: [PATCH] tools/nolibc: completely remove optional environ support |
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On Mon, Jul 10, 2023 at 07:51:53PM +0200, Thomas Weißschuh wrote: > On 2023-07-10 19:43:27+0200, Willy Tarreau wrote: > > Hi Thomas, > > > > On Mon, Jul 10, 2023 at 07:22:53PM +0200, Thomas Weißschuh wrote: > > > In commit 52e423f5b93e ("tools/nolibc: export environ as a weak symbol on i386") > > > and friends the asm startup logic was extended to directly populate the > > > "environ" array. > > > > > > This makes it impossible for "environ" to be dropped by the linker. > > > Therefore also drop the other logic to handle non-present "environ". > > > > Hmmm OK but at least I'd like that we continue to reference it from > > nolibc-test to make sure it's still visible. Maybe we could just check > > that it's always equal to envp ? If we drop its reference from there, > > sooner or later someone will find it interesting to rename it and some > > programs referencing it will break. > > Easy enough to test for. I'll send a v2.
Thanks!
> > > Note: > > > > > > Given that nowadays both _auxv and environ are mandatory symbols imposed > > > by nolibc of pointer size does it make sense to keep the code to make > > > int-sized errno optional? > > > > While it indeed used to be related to having a data segment or not > > initially, it still has an impact on our ability to completely drop > > the errno setting code from all syscalls. Given the SET_ERRNO() macro > > now I guess it's very cheap to keep it, don't you think ? > > SET_ERRNO irks me a tiny bit :-)
To be honest, it's the same for me. but it's cheap. And when you rebuild a binary without it you can observe significant savings that can be important for those who are space-constrained.
> But it's easy enough to keep, let's do so. > Just wanted to have brought it up.
Yes, you're totally right to raise this, thank you!
Willy
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