Messages in this thread | | | Date | Mon, 3 Jul 2023 12:47:33 +0200 | Subject | Re: [PATCH v4 29/33] x86/mm: try VMA lock-based page fault handling first | From | Jiri Slaby <> |
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Cc Jacob Young (from kernel bugzilla)
On 30. 06. 23, 19:40, Suren Baghdasaryan wrote: > On Fri, Jun 30, 2023 at 1:43 AM Jiri Slaby <jirislaby@kernel.org> wrote: >> >> On 30. 06. 23, 10:28, Jiri Slaby wrote: >>> > 2348 >>> clone3({flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID, child_tid=0x7fcaa5882990, parent_tid=0x7fcaa5882990, exit_signal=0, stack=0x7fcaa5082000, stack_size=0x7ffe00, tls=0x7fcaa58826c0} => {parent_tid=[2351]}, 88) = 2351 >>> > 2350 <... clone3 resumed> => {parent_tid=[2372]}, 88) = 2372 >>> > 2351 <... clone3 resumed> => {parent_tid=[2354]}, 88) = 2354 >>> > 2351 <... clone3 resumed> => {parent_tid=[2357]}, 88) = 2357 >>> > 2354 <... clone3 resumed> => {parent_tid=[2355]}, 88) = 2355 >>> > 2355 <... clone3 resumed> => {parent_tid=[2370]}, 88) = 2370 >>> > 2370 mmap(NULL, 262144, PROT_READ|PROT_WRITE, >>> MAP_PRIVATE|MAP_ANONYMOUS, -1, 0 <unfinished ...> >>> > 2370 <... mmap resumed>) = 0x7fca68249000 >>> > 2372 <... clone3 resumed> => {parent_tid=[2384]}, 88) = 2384 >>> > 2384 <... clone3 resumed> => {parent_tid=[2388]}, 88) = 2388 >>> > 2388 <... clone3 resumed> => {parent_tid=[2392]}, 88) = 2392 >>> > 2392 <... clone3 resumed> => {parent_tid=[2395]}, 88) = 2395 >>> > 2395 write(2, "runtime: marked free object in s"..., 36 <unfinished >>> ...> >>> >>> I.e. IIUC, all are threads (CLONE_VM) and thread 2370 mapped ANON >>> 0x7fca68249000 - 0x7fca6827ffff and go in thread 2395 thinks for some >>> reason 0x7fca6824bec8 in that region is "bad". > > Thanks for the analysis Jiri. > Is it possible from these logs to identify whether 2370 finished the > mmap operation before 2395 tried to access 0x7fca6824bec8? That access > has to happen only after mmap finishes mapping the region.
Hi,
it's hard to tell, but I assume so.
For now, forget about this go's overly complicated, hard to reproduce case and concentrate on the very nice reduced testcase in: https://bugzilla.kernel.org/show_bug.cgi?id=217624 ;)
FWIW, I can reproduce using the test case too.
thanks, -- js suse labs
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