Date: Tue, 28 Jul 2026 15:01:57 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 297121] LinuxKPI: uma_zalloc_debug: zone "malloc-16" with the following non-sleepable locks held (alloc_bounce_zone) Message-ID: <bug-297121-227@https.bugs.freebsd.org/bugzilla/>
index | next in thread | raw e-mail
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=297121 Bug ID: 297121 Summary: LinuxKPI: uma_zalloc_debug: zone "malloc-16" with the following non-sleepable locks held (alloc_bounce_zone) Product: Base System Version: CURRENT Hardware: amd64 OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: bz@FreeBSD.org CC: jhb@FreeBSD.org, markj@FreeBSD.org I got a problem report on testing a wireless driver (unrelated as the problem is in general LinuxKPI code). Filing the PR as I currently cannot debug it to the end and do not want to lose it. I cannot remember this reported in the last years. amd64, 16GB memory, but in general it seems this is LinuxKPI holding the lock and running into the alloc_bounce_zone() case which adds sysctls which will malloc with M_WAITOK (compared to everything else in the path). Cc: jhb, markj as you've done some the bounce buffer paths for this. I wonder how to best avoid that problem. Multiple of these with different malloc-XXx zones: uma_zalloc_debug: zone "malloc-16" with the following non-sleepable locks held: exclusive sleep mutex lkpi-priv-dma (lkpi-priv-dma) r = 0 (0xfffff800115263a0) locked @ /usr/src/sys/compat/linuxkpi/common/src/linux_pci.c:1746 stack backtrace: #0 0xffffffff80c8f27c at witness_debugger+0x6c #1 0xffffffff80c90b7c at witness_warn+0x4bc #2 0xffffffff8100596f at uma_zalloc_debug+0x3f #3 0xffffffff810054b7 at uma_zalloc_arg+0x27 #4 0xffffffff80be07dd at malloc+0x7d #5 0xffffffff80c20ffb at sysctl_add_oid+0x6b #6 0xffffffff81155d3f at alloc_bounce_zone+0x19f #7 0xffffffff81154ca0 at bounce_bus_dmamap_create+0x180 #8 0xffffffff80ef467f at linux_dma_map_phys_common+0x9f #9 0xffffffff80ef4514 at lkpi_dma_map_phys+0x24 ... lock order reversal: (sleepable after non-sleepable) 1st 0xfffff800115263a0 lkpi-priv-dma (lkpi-priv-dma, sleep mutex) @ /usr/src/sys/compat/linuxkpi/common/src/linux_pci.c:1746 2nd 0xffffffff81de6ce8 sysctl lock (sysctl lock, sleepable rm) @ /usr/src/sys/kern/kern_sysctl.c:886 lock order lkpi-priv-dma -> sysctl lock attempted at: #0 0xffffffff80c8ee3b at witness_checkorder+0xd3b #1 0xffffffff80c09a14 at _rm_wlock_debug+0x64 #2 0xffffffff80c21070 at sysctl_add_oid+0xe0 #3 0xffffffff81155d3f at alloc_bounce_zone+0x19f #4 0xffffffff81154ca0 at bounce_bus_dmamap_create+0x180 #5 0xffffffff80ef467f at linux_dma_map_phys_common+0x9f #6 0xffffffff80ef4514 at lkpi_dma_map_phys+0x24 ... -- You are receiving this mail because: You are the assignee for the bug.home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-297121-227>