Bug 253602
| Summary: | devel/glib20: Local patch to glib20 uses a broken and unstable fdwalk implementation | ||||||||||
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| Product: | Ports & Packages | Reporter: | John Baldwin <jhb> | ||||||||
| Component: | Individual Port(s) | Assignee: | freebsd-desktop (Team) <desktop> | ||||||||
| Status: | Closed FIXED | ||||||||||
| Severity: | Affects Only Me | CC: | fullermd, jhb, ps, tcberner | ||||||||
| Priority: | --- | Flags: | tcberner:
maintainer-feedback+
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| Version: | Latest | ||||||||||
| Hardware: | Any | ||||||||||
| OS: | Any | ||||||||||
| Attachments: |
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Created attachment 222576 [details]
build with libutil
Created attachment 222645 [details]
build with libutil
Full patch now up for review at https://reviews.freebsd.org/D28904. A commit references this bug: Author: jhb Date: Fri Feb 26 19:31:05 UTC 2021 New revision: 566632 URL: https://svnweb.freebsd.org/changeset/ports/566632 Log: Use kinfo_getfile() to implement fdwalk(). Previously, the kern.file sysctl (which queries the global file table) was queried and the results saved in an on-stack buffer. With a sufficiently active system the sysctl's output could overflow the stack's available space. Instead, switch to kinfo_getfile() from libutil. This uses a sysctl which queries only the open files for the current process, and it uses heap space instead of the stack to store the sysctl output. PR: 253602 Submitted by: ps (build glue patches) Reported by: ps Reviewed by: bapt MFH: 2021Q1 Differential Revision: https://reviews.freebsd.org/D28904 Changes: head/devel/glib20/Makefile head/devel/glib20/files/patch-glib_gspawn.c head/devel/glib20/files/patch-glib_meson.build head/devel/glib20/files/patch-meson.build For a data point, I also had glib failing in poudriere on one machine, and with the committed changes it now works. Thanks for fixing this. mfg Tobias I never got the ok to MFH, but a new quarterly branch has been created so the MFH no longer matters. (In reply to John Baldwin from comment #7) FWIW, MFHs don't require approvals since ports r556626 but the template had "Approved by" until ports r568802. |
Created attachment 222539 [details] Patch to the port Paul Saab found that devel/glib20 was failing to build in a poudriere jail on one of his machines. We tracked this down to the alloca() in our local patch to add fdwalk2() failing and overflowing the stack. The reason is that the fdwalk2() implementation uses the kern.file sysctl which fetches a _global_ table of all open files across all processes, meaning that the amount of required memory scales with the number of processes in the system. fdwalk2() should instead be using kinfo_getfile() from libutil which fetches only the open files for the current process (which also uses malloc() to avoid stack limit issues). While here, I also noticed that fdwalk2() failed to propagate the callback's return value to the caller and instead always returns 0 since *ret was never assigned a value. The attached patch is untested, but should fix both of these issues. I wasn't quite sure how to convince glib20's port to add libutil as an explicit dependency (e.g. in LDFLAGS), so I'm hopeful a port maintainer can add that missing bit and finish this the rest of the way.