On Sun, Nov 22, 2020 at 11:25 AM Kyle Evans <kev...@freebsd.org> wrote: > > On Sun, Nov 22, 2020 at 10:36 AM Kyle Evans <kev...@freebsd.org> wrote: > > > > On Sun, Nov 22, 2020 at 9:54 AM Guy Yur <guy...@gmail.com> wrote: > > > > > > On 22/11/20 7:00 am, Robert Wing wrote: > > > > Author: rew > > > > Date: Sun Nov 22 05:00:28 2020 > > > > New Revision: 367927 > > > > URL: https://svnweb.freebsd.org/changeset/base/367927 > > > > > > > > Log: > > > > fd: free old file descriptor tables when not shared > > > > > > > > During the life of a process, new file descriptor tables may be > > > > allocated. When > > > > a new table is allocated, the old table is placed in a free list and > > > > held onto > > > > until all processes referencing them exit. > > > > > > > > When a new file descriptor table is allocated, the old file > > > > descriptor table > > > > can be freed when the current process has a single-thread and the > > > > file > > > > descriptor table is not being shared with any other processes. > > > > > > > > Reviewed by: kevans > > > > Approved by: kevans (mentor) > > > > Differential Revision: https://reviews.freebsd.org/D18617 > > > > > > > > Added: > > > > head/tests/sys/kern/fdgrowtable_test.c (contents, props changed) > > > > Modified: > > > > head/sys/kern/kern_descrip.c > > > > head/tests/sys/kern/Makefile > > > > > > Hi, > > > > > > I am getting a kernel panic with this commit when building > > > devel/gmake port and it runs dup2 test in configure script. > > > > > > panic: fc_ioctls != NULL, but fc_nioctls=-16162 > > > ... > > > #10 0xffffffff80655c72 in vpanic (fmt=<optimized out>, ap=<optimized out>) > > > at /usr/src/sys/kern/kern_shutdown.c:907 > > > #11 0xffffffff80655a03 in panic ( > > > fmt=0xffffffff80eb2b78 <cnputs_mtx> "헝\200\377\377\377\377") > > > at /usr/src/sys/kern/kern_shutdown.c:843 > > > #12 0xffffffff805fff9a in filecaps_copy_prep (src=<optimized out>) > > > at /usr/src/sys/kern/kern_descrip.c:1629 > > > #13 kern_dup (td=<optimized out>, mode=<optimized out>, flags=0, > > > old=<optimized out>, new=256) at /usr/src/sys/kern/kern_descrip.c:970 > > > #14 0xffffffff8094a5de in syscallenter (td=<optimized out>) > > > at /usr/src/sys/amd64/amd64/../../kern/subr_syscall.c:189 > > > #15 amd64_syscall (td=0xfffffe00513f8500, traced=0) > > > at /usr/src/sys/amd64/amd64/trap.c:1156 > > > > > > > > > Simplified test program that causes panic: > > > #include <unistd.h> > > > #include <limits.h> > > > > > > int main () > > > { > > > int bad_fd = INT_MAX; > > > dup2 (1, 1); > > > close (0); > > > dup2 (0, 0); > > > dup2 (2, bad_fd); > > > dup2 (2, -1); > > > dup2 (2, 255); > > > dup2 (2, 256); > > > return 0; > > > } > > > > > > > Whoops. =\ > > > > It looks like kern_dup grows the file table but assumes that it can > > continue using oldfe that it fetched from the now-freed table. I > > suspect we just need to refetch oldfde after the grow operation, and > > it might be a good idea (under INVARIANTS) to grab the fp from oldfde > > before we grow the table and assert that the new entry we fetch is the > > same underlying file. > > > > I can confirm that the below fixes it and no other growth spots keep > pointers into the old table around, I'll give it a little bit for any > objections to be raised then commit. >
Bah, sorry, this still isn't right. The other paths may grow the table via fdalloc(). I'll throw up a review for this shortly. _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
