Hi, Running v6.12.4, I can trigger the following WARNING
[ 62.374530] WARNING: CPU: 0 PID: 133 at lib/iov_iter.c:344 copy_page_to_iter+0x44/0x148 [ 62.375388] Modules linked in: [ 62.375747] CPU: 0 UID: 0 PID: 133 Comm: grep Tainted: G D 6.12.4 #51 [ 62.376452] Tainted: [D]=DIE [ 62.376732] Hardware name: linux,dummy-virt (DT) [ 62.377147] pstate: 21400005 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 62.377794] pc : copy_page_to_iter+0x44/0x148 [ 62.378196] lr : pipe_read+0x104/0x3d0 [ 62.378530] sp : ffff800083b7bc00 [ 62.378816] x29: ffff800083b7bc00 x28: 0000000000001000 x27: fff00000c21f73c0 [ 62.379494] x26: ffff800083b7bd60 x25: 0000000000000014 x24: 0000000000001000 [ 62.380171] x23: 0000000000000000 x22: fff00000c21f73e0 x21: 0000000000000015 [ 62.380891] x20: 0000000000001000 x19: 0000000000000000 x18: 0000000000000000 [ 62.381536] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 62.382185] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [ 62.382831] x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 [ 62.383478] x8 : fff00000c1603400 x7 : 0000000000000000 x6 : 00000000000000a0 [ 62.384153] x5 : 0000000000000000 x4 : ffffc1ffc30867c0 x3 : 0000000000001000 [ 62.384798] x2 : 000000000000103f x1 : 000000000000003f x0 : ffffc1ffc30867c0 [ 62.385441] Call trace: [ 62.385684] copy_page_to_iter+0x44/0x148 [ 62.386091] pipe_read+0x104/0x3d0 [ 62.386413] vfs_read+0x294/0x2fc [ 62.386728] ksys_read+0xdc/0xf4 [ 62.387025] __arm64_sys_read+0x1c/0x28 [ 62.387400] invoke_syscall+0x48/0x110 [ 62.387759] el0_svc_common.constprop.0+0x40/0xe0 [ 62.388178] do_el0_svc+0x1c/0x28 [ 62.388525] el0_svc+0x30/0xd0 [ 62.388818] el0t_64_sync_handler+0xc0/0xc4 [ 62.389233] el0t_64_sync+0x190/0x194 [ 62.389663] ---[ end trace 0000000000000000 ]--- With trace_pipe and grep. $ cat trace_pipe | grep foo and $ while true; do echo "foo" > trace_marker; done Is that a known problem? Eventually this ends up in a more serious BUG such as BUG: Bad page map in process cat pte:72616d5f676e6963 pmd:800000102279003 Or. Unable to handle kernel paging request at virtual address fff82e2dee2e2d80
