Hi Peter, According to the commit message, this patch adds a new warning for some violations, and it is indeed triggered in our test. We understand that it is kind of expected, and may reveal some existing issues in kernel code, but we don't have enough knowledge about what could be done in the next step, so we send this report FYI. We also spotted similar issues in other testcases after applying this patch. If this report is useful, we can provide more info for further analysis. If you think it's unnecessary for us to send this kind of report, please let us know, and we will consider refining our report rules. Thanks. Below is the full report: Greeting, FYI, we noticed the following commit (built with gcc-11): commit: 652c5bf380ad018e15006a7f8349800245ddbbad ("x86/mm: Refuse W^X violations") https://git.kernel.org/cgit/linux/kernel/git/tip/tip.git x86/mm in testcase: rcuscale version: with following parameters: runtime: 300s scale_type: srcu on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): [ 21.523123][ T3] ------------[ cut here ]------------ [ 21.523996][ T3] CPA refuse W^X violation: 0000000000000060 -> 0000000000000063 range: 0x00000000bea9f000 - 0x00000000bea9ffff PFN 7ea9f [ 21.525620][ T3] WARNING: CPU: 0 PID: 3 at arch/x86/mm/pat/set_memory.c:600 __change_page_attr+0x245/0x260 [ 21.526894][ T3] Modules linked in: torture [ 21.527495][ T3] CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 5.19.0-00430-g652c5bf380ad #1 [ 21.528698][ T3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 [ 21.530114][ T3] Workqueue: events do_free_init [ 21.530828][ T3] EIP: __change_page_attr+0x245/0x260 [ 21.531547][ T3] Code: ff ff ff 8d 87 ff 0f 00 00 ff 75 e4 31 d2 50 8b 45 e0 57 52 31 d2 51 52 50 68 78 53 8d 42 c6 05 bc 3e 03 43 01 e8 81 e4 e7 00 <0f> 0b 83 c4 20 e9 40 ff ff ff e8 1c 91 f2 00 8d b4 26 00 00 00 00 [ 21.534206][ T3] EAX: 00000077 EBX: 7ea9f060 ECX: 42b03540 EDX: 42b0353c [ 21.535211][ T3] ESI: 43f1fea4 EDI: bea9f000 EBP: 43f1fe4c ESP: 43f1fe0c [ 21.536191][ T3] DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 EFLAGS: 00010212 [ 21.537221][ T3] CR0: 80050033 CR2: 01fbaaa8 CR3: 7ea5e000 CR4: 00040690 [ 21.538183][ T3] Call Trace: [ 21.538764][ T3] ? __change_page_attr_set_clr+0x49/0x170 [ 21.539577][ T3] ? _vm_unmap_aliases+0x101/0x120 [ 21.540274][ T3] ? set_direct_map_default_noflush+0x49/0x60 [ 21.541131][ T3] ? __vunmap+0x192/0x270 [ 21.541752][ T3] ? __vfree+0x20/0x50 [ 21.542320][ T3] ? vfree+0x29/0x60 [ 21.542920][ T3] ? module_memfree+0x1b/0x30 [ 21.543599][ T3] ? do_free_init+0x2c/0x50 [ 21.544257][ T3] ? process_one_work+0x20c/0x480 [ 21.544926][ T3] ? worker_thread+0x166/0x3c0 [ 21.545587][ T3] ? kthread+0xbf/0xe0 [ 21.546160][ T3] ? rescuer_thread+0x310/0x310 [ 21.546852][ T3] ? kthread_complete_and_exit+0x20/0x20 [ 21.547632][ T3] ? ret_from_fork+0x19/0x30 [ 21.548284][ T3] irq event stamp: 2399 [ 21.548844][ T3] hardirqs last enabled at (2407): [<410b8aee>] __up_console_sem+0x6e/0x80 [ 21.550018][ T3] hardirqs last disabled at (2414): [<410b8ad5>] __up_console_sem+0x55/0x80 [ 21.551265][ T3] softirqs last enabled at (2432): [<41f8f11c>] __do_softirq+0x2ac/0x3b0 [ 21.552465][ T3] softirqs last disabled at (2423): [<41023525>] do_softirq_own_stack+0x25/0x30 [ 21.553731][ T3] ---[ end trace 0000000000000000 ]--- [ 21.566412][ T617] srcu-scale:--- Start of test: nreaders=1 nwriters=1 verbose=1 shutdown=0 [ 21.574533][ T617] srcu-torture: Creating rcu_scale_reader task [ 21.578917][ T619] srcu-scale: rcu_scale_reader task started [ 21.579927][ T617] srcu-torture: Creating rcu_scale_writer task [ 21.586634][ T620] srcu-scale: rcu_scale_writer task started [ 21.599081][ T204] BUG: unable to handle page fault for address: b9866400 [ 21.600138][ T204] #PF: supervisor write access in kernel mode [ 21.600984][ T204] #PF: error_code(0x0002) - not-present page [ 21.601823][ T204] *pde = 79868063 *pte = 79866060 [ 21.602527][ T204] Oops: 0002 [#1] [ 21.603046][ T204] CPU: 0 PID: 204 Comm: systemd-udevd Tainted: G W 5.19.0-00430-g652c5bf380ad #1 [ 21.604459][ T204] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 [ 21.605875][ T204] EIP: pgd_alloc+0x85/0x130 [ 21.606460][ T204] Code: ff ff 85 c0 0f 85 ab 00 00 00 b8 a0 00 af 42 8d be 04 04 00 00 e8 5b 9d f3 00 a1 00 04 17 43 83 e7 fc 8d 8e 00 04 00 00 29 f9 <89> 86 00 04 00 00 a1 fc 0f 17 43 89 86 fc 0f 00 00 89 f0 be 00 04 [ 21.609008][ T204] EAX: 03957063 EBX: 43f549c0 ECX: fffffffc EDX: ffffffff [ 21.609966][ T204] ESI: b9866000 EDI: b9866404 EBP: bf039dcc ESP: bf039db0 [ 21.610914][ T204] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 EFLAGS: 00010297 [ 21.611938][ T204] CR0: 80050033 CR2: b9866400 CR3: 7e910000 CR4: 00040690 [ 21.612924][ T204] Call Trace: [ 21.613380][ T204] ? mm_init+0x134/0x260 [ 21.614115][ T204] mm_init+0x1b1/0x260 [ 21.614804][ T204] dup_mm+0x41/0xd0 [ 21.615308][ T204] copy_process+0x13c8/0x1660 [ 21.615854][ T204] kernel_clone+0x95/0x480 [ 21.616419][ T204] __ia32_sys_clone+0x6a/0x90 [ 21.617040][ T204] __do_fast_syscall_32+0x71/0xd0 [ 21.617703][ T204] ? lockdep_hardirqs_on_prepare+0x9c/0x150 [ 21.618559][ T204] ? syscall_exit_to_user_mode+0x35/0x50 [ 21.619290][ T204] ? __do_fast_syscall_32+0x7b/0xd0 [ 21.619954][ T204] ? irqentry_exit_to_user_mode+0x23/0x30 [ 21.620690][ T204] ? irqentry_exit+0x5f/0x80 [ 21.621305][ T204] do_fast_syscall_32+0x28/0x60 [ 21.621942][ T204] do_SYSENTER_32+0x15/0x20 [ 21.622553][ T204] entry_SYSENTER_32+0xb0/0x116 [ 21.623240][ T204] EIP: 0x37f6c549 [ 21.623743][ T204] Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 [ 21.626274][ T204] EAX: ffffffda EBX: 01200011 ECX: 00000000 EDX: 00000000 [ 21.627248][ T204] ESI: 00000000 EDI: 37c35868 EBP: 3fe5a3a8 ESP: 3fe5a350 [ 21.628227][ T204] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b EFLAGS: 00000246 [ 21.629259][ T204] Modules linked in: rcuscale torture [ 21.629998][ T204] CR2: 00000000b9866400 [ 21.630559][ T204] ---[ end trace 0000000000000000 ]--- [ 21.631297][ T204] EIP: pgd_alloc+0x85/0x130 [ 21.631932][ T204] Code: ff ff 85 c0 0f 85 ab 00 00 00 b8 a0 00 af 42 8d be 04 04 00 00 e8 5b 9d f3 00 a1 00 04 17 43 83 e7 fc 8d 8e 00 04 00 00 29 f9 <89> 86 00 04 00 00 a1 fc 0f 17 43 89 86 fc 0f 00 00 89 f0 be 00 04 [ 21.634364][ T204] EAX: 03957063 EBX: 43f549c0 ECX: fffffffc EDX: ffffffff [ 21.635119][ T204] ESI: b9866000 EDI: b9866404 EBP: bf039dcc ESP: bf039db0 [ 21.635902][ T204] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 EFLAGS: 00010297 [ 21.636915][ T204] CR0: 80050033 CR2: b9866400 CR3: 7e910000 CR4: 00040690 [ 21.637885][ T204] Kernel panic - not syncing: Fatal exception [ 21.638720][ T204] Kernel Offset: disabled To reproduce: # build kernel cd linux cp config-5.19.0-00430-g652c5bf380ad .config make HOSTCC=gcc-11 CC=gcc-11 ARCH=i386 olddefconfig prepare modules_prepare bzImage modules make HOSTCC=gcc-11 CC=gcc-11 ARCH=i386 INSTALL_MOD_PATH= modules_install cd find lib/ | cpio -o -H newc --quiet | gzip > modules.cgz git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k -m modules.cgz job-script # job-script is attached in this email # if come across any failure that blocks the test, # please remove ~/.lkp and /lkp dir to run from a clean state. -- 0-DAY CI Kernel Test Service https://01.org/lkp