user/sven/linux.git/kernel, branch v4.19.259

kprobes: Prohibit probes in gate area

2022-09-15T10:17:05Z

commit 1efda38d6f9ba26ac88b359c6277f1172db03f1e upstream. The system call gate area counts as kernel text but trying to install a kprobe in this area fails with an Oops later on. To fix this explicitly disallow the gate area for kprobes. Found by syzkaller with the following reproducer: perf_event_open$cgroup(&(0x7f00000001c0)={0x6, 0x80, 0x0, 0x0, 0x0, 0x0, 0x80ffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @perf_config_ext={0x0, 0xffffffffff600000}}, 0xffffffffffffffff, 0x0, 0xffffffffffffffff, 0x0) Sample report: BUG: unable to handle page fault for address: fffffbfff3ac6000 PGD 6dfcb067 P4D 6dfcb067 PUD 6df8f067 PMD 6de4d067 PTE 0 Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 21978 Comm: syz-executor.2 Not tainted 6.0.0-rc3-00363-g7726d4c3e60b-dirty #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:__insn_get_emulate_prefix arch/x86/lib/insn.c:91 [inline] RIP: 0010:insn_get_emulate_prefix arch/x86/lib/insn.c:106 [inline] RIP: 0010:insn_get_prefixes.part.0+0xa8/0x1110 arch/x86/lib/insn.c:134 Code: 49 be 00 00 00 00 00 fc ff df 48 8b 40 60 48 89 44 24 08 e9 81 00 00 00 e8 e5 4b 39 ff 4c 89 fa 4c 89 f9 48 c1 ea 03 83 e1 07 <42> 0f b6 14 32 38 ca 7f 08 84 d2 0f 85 06 10 00 00 48 89 d8 48 89 RSP: 0018:ffffc900088bf860 EFLAGS: 00010246 RAX: 0000000000040000 RBX: ffffffff9b9bebc0 RCX: 0000000000000000 RDX: 1ffffffff3ac6000 RSI: ffffc90002d82000 RDI: ffffc900088bf9e8 RBP: ffffffff9d630001 R08: 0000000000000000 R09: ffffc900088bf9e8 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffffffff9d630000 R14: dffffc0000000000 R15: ffffffff9d630000 FS: 00007f63eef63640(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff3ac6000 CR3: 0000000029d90005 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: insn_get_prefixes arch/x86/lib/insn.c:131 [inline] insn_get_opcode arch/x86/lib/insn.c:272 [inline] insn_get_modrm+0x64a/0x7b0 arch/x86/lib/insn.c:343 insn_get_sib+0x29a/0x330 arch/x86/lib/insn.c:421 insn_get_displacement+0x350/0x6b0 arch/x86/lib/insn.c:464 insn_get_immediate arch/x86/lib/insn.c:632 [inline] insn_get_length arch/x86/lib/insn.c:707 [inline] insn_decode+0x43a/0x490 arch/x86/lib/insn.c:747 can_probe+0xfc/0x1d0 arch/x86/kernel/kprobes/core.c:282 arch_prepare_kprobe+0x79/0x1c0 arch/x86/kernel/kprobes/core.c:739 prepare_kprobe kernel/kprobes.c:1160 [inline] register_kprobe kernel/kprobes.c:1641 [inline] register_kprobe+0xb6e/0x1690 kernel/kprobes.c:1603 __register_trace_kprobe kernel/trace/trace_kprobe.c:509 [inline] __register_trace_kprobe+0x26a/0x2d0 kernel/trace/trace_kprobe.c:477 create_local_trace_kprobe+0x1f7/0x350 kernel/trace/trace_kprobe.c:1833 perf_kprobe_init+0x18c/0x280 kernel/trace/trace_event_perf.c:271 perf_kprobe_event_init+0xf8/0x1c0 kernel/events/core.c:9888 perf_try_init_event+0x12d/0x570 kernel/events/core.c:11261 perf_init_event kernel/events/core.c:11325 [inline] perf_event_alloc.part.0+0xf7f/0x36a0 kernel/events/core.c:11619 perf_event_alloc kernel/events/core.c:12059 [inline] __do_sys_perf_event_open+0x4a8/0x2a00 kernel/events/core.c:12157 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f63ef7efaed Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f63eef63028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f63ef90ff80 RCX: 00007f63ef7efaed RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00000000200001c0 RBP: 00007f63ef86019c R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000002 R14: 00007f63ef90ff80 R15: 00007f63eef43000 Modules linked in: CR2: fffffbfff3ac6000 ---[ end trace 0000000000000000 ]--- RIP: 0010:__insn_get_emulate_prefix arch/x86/lib/insn.c:91 [inline] RIP: 0010:insn_get_emulate_prefix arch/x86/lib/insn.c:106 [inline] RIP: 0010:insn_get_prefixes.part.0+0xa8/0x1110 arch/x86/lib/insn.c:134 Code: 49 be 00 00 00 00 00 fc ff df 48 8b 40 60 48 89 44 24 08 e9 81 00 00 00 e8 e5 4b 39 ff 4c 89 fa 4c 89 f9 48 c1 ea 03 83 e1 07 <42> 0f b6 14 32 38 ca 7f 08 84 d2 0f 85 06 10 00 00 48 89 d8 48 89 RSP: 0018:ffffc900088bf860 EFLAGS: 00010246 RAX: 0000000000040000 RBX: ffffffff9b9bebc0 RCX: 0000000000000000 RDX: 1ffffffff3ac6000 RSI: ffffc90002d82000 RDI: ffffc900088bf9e8 RBP: ffffffff9d630001 R08: 0000000000000000 R09: ffffc900088bf9e8 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffffffff9d630000 R14: dffffc0000000000 R15: ffffffff9d630000 FS: 00007f63eef63640(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff3ac6000 CR3: 0000000029d90005 CR4: 0000000000770ef0 PKRU: 55555554 ================================================================== Link: https://lkml.kernel.org/r/20220907200917.654103-1-lk@c--e.de cc: "Naveen N. Rao" cc: Anil S Keshavamurthy cc: "David S. Miller" Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Acked-by: Masami Hiramatsu (Google) Signed-off-by: Christian A. Ehrhardt Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

kprobes: don't call disarm_kprobe() for disabled kprobes

2022-09-05T08:26:35Z

commit 9c80e79906b4ca440d09e7f116609262bb747909 upstream. The assumption in __disable_kprobe() is wrong, and it could try to disarm an already disarmed kprobe and fire the WARN_ONCE() below. [0] We can easily reproduce this issue. 1. Write 0 to /sys/kernel/debug/kprobes/enabled. # echo 0 > /sys/kernel/debug/kprobes/enabled 2. Run execsnoop. At this time, one kprobe is disabled. # /usr/share/bcc/tools/execsnoop & [1] 2460 PCOMM PID PPID RET ARGS # cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE] 3. Write 1 to /sys/kernel/debug/kprobes/enabled, which changes kprobes_all_disarmed to false but does not arm the disabled kprobe. # echo 1 > /sys/kernel/debug/kprobes/enabled # cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE] 4. Kill execsnoop, when __disable_kprobe() calls disarm_kprobe() for the disabled kprobe and hits the WARN_ONCE() in __disarm_kprobe_ftrace(). # fg /usr/share/bcc/tools/execsnoop ^C Actually, WARN_ONCE() is fired twice, and __unregister_kprobe_top() misses some cleanups and leaves the aggregated kprobe in the hash table. Then, __unregister_trace_kprobe() initialises tk->rp.kp.list and creates an infinite loop like this. aggregated kprobe.list -> kprobe.list -. ^ | '.__.' In this situation, these commands fall into the infinite loop and result in RCU stall or soft lockup. cat /sys/kernel/debug/kprobes/list : show_kprobe_addr() enters into the infinite loop with RCU. /usr/share/bcc/tools/execsnoop : warn_kprobe_rereg() holds kprobe_mutex, and __get_valid_kprobe() is stuck in the loop. To avoid the issue, make sure we don't call disarm_kprobe() for disabled kprobes. [0] Failed to disarm kprobe-ftrace at __x64_sys_execve+0x0/0x40 (error -2) WARNING: CPU: 6 PID: 2460 at kernel/kprobes.c:1130 __disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129) Modules linked in: ena CPU: 6 PID: 2460 Comm: execsnoop Not tainted 5.19.0+ #28 Hardware name: Amazon EC2 c5.2xlarge/, BIOS 1.0 10/16/2017 RIP: 0010:__disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129) Code: 24 8b 02 eb c1 80 3d c4 83 f2 01 00 75 d4 48 8b 75 00 89 c2 48 c7 c7 90 fa 0f 92 89 04 24 c6 05 ab 83 01 e8 e4 94 f0 ff <0f> 0b 8b 04 24 eb b1 89 c6 48 c7 c7 60 fa 0f 92 89 04 24 e8 cc 94 RSP: 0018:ffff9e6ec154bd98 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffffffff930f7b00 RCX: 0000000000000001 RDX: 0000000080000001 RSI: ffffffff921461c5 RDI: 00000000ffffffff RBP: ffff89c504286da8 R08: 0000000000000000 R09: c0000000fffeffff R10: 0000000000000000 R11: ffff9e6ec154bc28 R12: ffff89c502394e40 R13: ffff89c502394c00 R14: ffff9e6ec154bc00 R15: 0000000000000000 FS: 00007fe800398740(0000) GS:ffff89c812d80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00057f010 CR3: 0000000103b54006 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: __disable_kprobe (kernel/kprobes.c:1716) disable_kprobe (kernel/kprobes.c:2392) __disable_trace_kprobe (kernel/trace/trace_kprobe.c:340) disable_trace_kprobe (kernel/trace/trace_kprobe.c:429) perf_trace_event_unreg.isra.2 (./include/linux/tracepoint.h:93 kernel/trace/trace_event_perf.c:168) perf_kprobe_destroy (kernel/trace/trace_event_perf.c:295) _free_event (kernel/events/core.c:4971) perf_event_release_kernel (kernel/events/core.c:5176) perf_release (kernel/events/core.c:5186) __fput (fs/file_table.c:321) task_work_run (./include/linux/sched.h:2056 (discriminator 1) kernel/task_work.c:179 (discriminator 1)) exit_to_user_mode_prepare (./include/linux/resume_user_mode.h:49 kernel/entry/common.c:169 kernel/entry/common.c:201) syscall_exit_to_user_mode (./arch/x86/include/asm/jump_label.h:55 ./arch/x86/include/asm/nospec-branch.h:384 ./arch/x86/include/asm/entry-common.h:94 kernel/entry/common.c:133 kernel/entry/common.c:296) do_syscall_64 (arch/x86/entry/common.c:87) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) RIP: 0033:0x7fe7ff210654 Code: 15 79 89 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb be 0f 1f 00 8b 05 9a cd 20 00 48 63 ff 85 c0 75 11 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3a f3 c3 48 83 ec 18 48 89 7c 24 08 e8 34 fc RSP: 002b:00007ffdbd1d3538 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007fe7ff210654 RDX: 0000000000000000 RSI: 0000000000002401 RDI: 0000000000000008 RBP: 0000000000000000 R08: 94ae31d6fda838a4 R0900007fe8001c9d30 R10: 00007ffdbd1d34b0 R11: 0000000000000246 R12: 00007ffdbd1d3600 R13: 0000000000000000 R14: fffffffffffffffc R15: 00007ffdbd1d3560 Link: https://lkml.kernel.org/r/20220813020509.90805-1-kuniyu@amazon.com Fixes: 69d54b916d83 ("kprobes: makes kprobes/enabled works correctly for optimized kprobes.") Signed-off-by: Kuniyuki Iwashima Reported-by: Ayushman Dutta Cc: "Naveen N. Rao" Cc: Anil S Keshavamurthy Cc: "David S. Miller" Cc: Masami Hiramatsu Cc: Wang Nan Cc: Kuniyuki Iwashima Cc: Kuniyuki Iwashima Cc: Ayushman Dutta Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead

2022-09-05T08:26:34Z

commit c3b0f72e805f0801f05fa2aa52011c4bfc694c44 upstream. ftrace_startup does not remove ops from ftrace_ops_list when ftrace_startup_enable fails: register_ftrace_function ftrace_startup __register_ftrace_function ... add_ftrace_ops(&ftrace_ops_list, ops) ... ... ftrace_startup_enable // if ftrace failed to modify, ftrace_disabled is set to 1 ... return 0 // ops is in the ftrace_ops_list. When ftrace_disabled = 1, unregister_ftrace_function simply returns without doing anything: unregister_ftrace_function ftrace_shutdown if (unlikely(ftrace_disabled)) return -ENODEV; // return here, __unregister_ftrace_function is not executed, // as a result, ops is still in the ftrace_ops_list __unregister_ftrace_function ... If ops is dynamically allocated, it will be free later, in this case, is_ftrace_trampoline accesses NULL pointer: is_ftrace_trampoline ftrace_ops_trampoline do_for_each_ftrace_op(op, ftrace_ops_list) // OOPS! op may be NULL! Syzkaller reports as follows: [ 1203.506103] BUG: kernel NULL pointer dereference, address: 000000000000010b [ 1203.508039] #PF: supervisor read access in kernel mode [ 1203.508798] #PF: error_code(0x0000) - not-present page [ 1203.509558] PGD 800000011660b067 P4D 800000011660b067 PUD 130fb8067 PMD 0 [ 1203.510560] Oops: 0000 [#1] SMP KASAN PTI [ 1203.511189] CPU: 6 PID: 29532 Comm: syz-executor.2 Tainted: G B W 5.10.0 #8 [ 1203.512324] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 1203.513895] RIP: 0010:is_ftrace_trampoline+0x26/0xb0 [ 1203.514644] Code: ff eb d3 90 41 55 41 54 49 89 fc 55 53 e8 f2 00 fd ff 48 8b 1d 3b 35 5d 03 e8 e6 00 fd ff 48 8d bb 90 00 00 00 e8 2a 81 26 00 <48> 8b ab 90 00 00 00 48 85 ed 74 1d e8 c9 00 fd ff 48 8d bb 98 00 [ 1203.518838] RSP: 0018:ffffc900012cf960 EFLAGS: 00010246 [ 1203.520092] RAX: 0000000000000000 RBX: 000000000000007b RCX: ffffffff8a331866 [ 1203.521469] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000010b [ 1203.522583] RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8df18b07 [ 1203.523550] R10: fffffbfff1be3160 R11: 0000000000000001 R12: 0000000000478399 [ 1203.524596] R13: 0000000000000000 R14: ffff888145088000 R15: 0000000000000008 [ 1203.525634] FS: 00007f429f5f4700(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000 [ 1203.526801] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1203.527626] CR2: 000000000000010b CR3: 0000000170e1e001 CR4: 00000000003706e0 [ 1203.528611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1203.529605] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Therefore, when ftrace_startup_enable fails, we need to rollback registration process and remove ops from ftrace_ops_list. Link: https://lkml.kernel.org/r/20220818032659.56209-1-yangjihong1@huawei.com Suggested-by: Steven Rostedt Signed-off-by: Yang Jihong Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

sched/deadline: Fix priority inheritance with multiple scheduling classes

2022-09-05T08:26:28Z

commit 2279f540ea7d05f22d2f0c4224319330228586bc upstream. Glenn reported that "an application [he developed produces] a BUG in deadline.c when a SCHED_DEADLINE task contends with CFS tasks on nested PTHREAD_PRIO_INHERIT mutexes. I believe the bug is triggered when a CFS task that was boosted by a SCHED_DEADLINE task boosts another CFS task (nested priority inheritance). ------------[ cut here ]------------ kernel BUG at kernel/sched/deadline.c:1462! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 12 PID: 19171 Comm: dl_boost_bug Tainted: ... Hardware name: ... RIP: 0010:enqueue_task_dl+0x335/0x910 Code: ... RSP: 0018:ffffc9000c2bbc68 EFLAGS: 00010002 RAX: 0000000000000009 RBX: ffff888c0af94c00 RCX: ffffffff81e12500 RDX: 000000000000002e RSI: ffff888c0af94c00 RDI: ffff888c10b22600 RBP: ffffc9000c2bbd08 R08: 0000000000000009 R09: 0000000000000078 R10: ffffffff81e12440 R11: ffffffff81e1236c R12: ffff888bc8932600 R13: ffff888c0af94eb8 R14: ffff888c10b22600 R15: ffff888bc8932600 FS: 00007fa58ac55700(0000) GS:ffff888c10b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa58b523230 CR3: 0000000bf44ab003 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? intel_pstate_update_util_hwp+0x13/0x170 rt_mutex_setprio+0x1cc/0x4b0 task_blocks_on_rt_mutex+0x225/0x260 rt_spin_lock_slowlock_locked+0xab/0x2d0 rt_spin_lock_slowlock+0x50/0x80 hrtimer_grab_expiry_lock+0x20/0x30 hrtimer_cancel+0x13/0x30 do_nanosleep+0xa0/0x150 hrtimer_nanosleep+0xe1/0x230 ? __hrtimer_init_sleeper+0x60/0x60 __x64_sys_nanosleep+0x8d/0xa0 do_syscall_64+0x4a/0x100 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fa58b52330d ... ---[ end trace 0000000000000002 ]— He also provided a simple reproducer creating the situation below: So the execution order of locking steps are the following (N1 and N2 are non-deadline tasks. D1 is a deadline task. M1 and M2 are mutexes that are enabled * with priority inheritance.) Time moves forward as this timeline goes down: N1 N2 D1 | | | | | | Lock(M1) | | | | | | Lock(M2) | | | | | | Lock(M2) | | | | Lock(M1) | | (!!bug triggered!) | Daniel reported a similar situation as well, by just letting ksoftirqd run with DEADLINE (and eventually block on a mutex). Problem is that boosted entities (Priority Inheritance) use static DEADLINE parameters of the top priority waiter. However, there might be cases where top waiter could be a non-DEADLINE entity that is currently boosted by a DEADLINE entity from a different lock chain (i.e., nested priority chains involving entities of non-DEADLINE classes). In this case, top waiter static DEADLINE parameters could be null (initialized to 0 at fork()) and replenish_dl_entity() would hit a BUG(). Fix this by keeping track of the original donor and using its parameters when a task is boosted. Reported-by: Glenn Elliott Reported-by: Daniel Bristot de Oliveira Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Tested-by: Daniel Bristot de Oliveira Link: https://lkml.kernel.org/r/20201117061432.517340-1-juri.lelli@redhat.com [Ankit: Regenerated the patch for v4.19.y] Signed-off-by: Ankit Jain Signed-off-by: Greg Kroah-Hartman

sched/deadline: Fix stale throttling on de-/boosted tasks

2022-09-05T08:26:28Z

commit 46fcc4b00c3cca8adb9b7c9afdd499f64e427135 upstream. When a boosted task gets throttled, what normally happens is that it's immediately enqueued again with ENQUEUE_REPLENISH, which replenishes the runtime and clears the dl_throttled flag. There is a special case however: if the throttling happened on sched-out and the task has been deboosted in the meantime, the replenish is skipped as the task will return to its normal scheduling class. This leaves the task with the dl_throttled flag set. Now if the task gets boosted up to the deadline scheduling class again while it is sleeping, it's still in the throttled state. The normal wakeup however will enqueue the task with ENQUEUE_REPLENISH not set, so we don't actually place it on the rq. Thus we end up with a task that is runnable, but not actually on the rq and neither a immediate replenishment happens, nor is the replenishment timer set up, so the task is stuck in forever-throttled limbo. Clear the dl_throttled flag before dropping back to the normal scheduling class to fix this issue. Signed-off-by: Lucas Stach Signed-off-by: Peter Zijlstra (Intel) Acked-by: Juri Lelli Link: https://lkml.kernel.org/r/20200831110719.2126930-1-l.stach@pengutronix.de [Ankit: Regenerated the patch for v4.19.y] Signed-off-by: Ankit Jain Signed-off-by: Greg Kroah-Hartman

sched/deadline: Unthrottle PI boosted threads while enqueuing

2022-09-05T08:26:28Z

commit feff2e65efd8d84cf831668e182b2ce73c604bbb upstream. stress-ng has a test (stress-ng --cyclic) that creates a set of threads under SCHED_DEADLINE with the following parameters: dl_runtime = 10000 (10 us) dl_deadline = 100000 (100 us) dl_period = 100000 (100 us) These parameters are very aggressive. When using a system without HRTICK set, these threads can easily execute longer than the dl_runtime because the throttling happens with 1/HZ resolution. During the main part of the test, the system works just fine because the workload does not try to run over the 10 us. The problem happens at the end of the test, on the exit() path. During exit(), the threads need to do some cleanups that require real-time mutex locks, mainly those related to memory management, resulting in this scenario: Note: locks are rt_mutexes... ------------------------------------------------------------------------ TASK A: TASK B: TASK C: activation activation activation lock(a): OK! lock(b): OK! lock(a) -> block (task A owns it) -> self notice/set throttled +--< -> arm replenished timer | switch-out | lock(b) | -> B prio> | -> boost TASK B | unlock(a) switch-out | -> handle lock a to B | -> wakeup(B) | -> B is throttled: | -> do not enqueue | switch-out | | +---------------------> replenishment timer -> TASK B is boosted: -> do not enqueue ------------------------------------------------------------------------ BOOM: TASK B is runnable but !enqueued, holding TASK C: the system crashes with hung task C. This problem is avoided by removing the throttle state from the boosted thread while boosting it (by TASK A in the example above), allowing it to be queued and run boosted. The next replenishment will take care of the runtime overrun, pushing the deadline further away. See the "while (dl_se->runtime <= 0)" on replenish_dl_entity() for more information. Reported-by: Mark Simmons Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Juri Lelli Tested-by: Mark Simmons Link: https://lkml.kernel.org/r/5076e003450835ec74e6fa5917d02c4fa41687e6.1600170294.git.bristot@redhat.com [Ankit: Regenerated the patch for v4.19.y] Signed-off-by: Ankit Jain Signed-off-by: Greg Kroah-Hartman

kernel/sys_ni: add compat entry for fadvise64_64

2022-09-05T08:26:28Z

commit a8faed3a02eeb75857a3b5d660fa80fe79db77a3 upstream. When CONFIG_ADVISE_SYSCALLS is not set/enabled and CONFIG_COMPAT is set/enabled, the riscv compat_syscall_table references 'compat_sys_fadvise64_64', which is not defined: riscv64-linux-ld: arch/riscv/kernel/compat_syscall_table.o:(.rodata+0x6f8): undefined reference to `compat_sys_fadvise64_64' Add 'fadvise64_64' to kernel/sys_ni.c as a conditional COMPAT function so that when CONFIG_ADVISE_SYSCALLS is not set, there is a fallback function available. Link: https://lkml.kernel.org/r/20220807220934.5689-1-rdunlap@infradead.org Fixes: d3ac21cacc24 ("mm: Support compiling out madvise and fadvise") Signed-off-by: Randy Dunlap Suggested-by: Arnd Bergmann Reviewed-by: Arnd Bergmann Cc: Josh Triplett Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

audit: fix potential double free on error path from fsnotify_add_inode_mark

2022-09-05T08:26:28Z

commit ad982c3be4e60c7d39c03f782733503cbd88fd2a upstream. Audit_alloc_mark() assign pathname to audit_mark->path, on error path from fsnotify_add_inode_mark(), fsnotify_put_mark will free memory of audit_mark->path, but the caller of audit_alloc_mark will free the pathname again, so there will be double free problem. Fix this by resetting audit_mark->path to NULL pointer on error path from fsnotify_add_inode_mark(). Cc: stable@vger.kernel.org Fixes: 7b1293234084d ("fsnotify: Add group pointer in fsnotify_init_mark()") Signed-off-by: Gaosheng Cui Reviewed-by: Jan Kara Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

tracing/probes: Have kprobes and uprobes use $COMM too

2022-08-25T09:15:48Z

commit ab8384442ee512fc0fc72deeb036110843d0e7ff upstream. Both $comm and $COMM can be used to get current->comm in eprobes and the filtering and histogram logic. Make kprobes and uprobes consistent in this regard and allow both $comm and $COMM as well. Currently kprobes and uprobes only handle $comm, which is inconsistent with the other utilities, and can be confusing to users. Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.org/ Cc: stable@vger.kernel.org Cc: Ingo Molnar Cc: Andrew Morton Cc: Tzvetomir Stoyanov Cc: Tom Zanussi Fixes: 533059281ee5 ("tracing: probeevent: Introduce new argument fetching code") Suggested-by: Masami Hiramatsu (Google) Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

watchdog: export lockup_detector_reconfigure

2022-08-25T09:15:46Z

[ Upstream commit 7c56a8733d0a2a4be2438a7512566e5ce552fccf ] In some circumstances it may be interesting to reconfigure the watchdog from inside the kernel. On PowerPC, this may helpful before and after a LPAR migration (LPM) is initiated, because it implies some latencies, watchdog, and especially NMI watchdog is expected to be triggered during this operation. Reconfiguring the watchdog with a factor, would prevent it to happen too frequently during LPM. Rename lockup_detector_reconfigure() as __lockup_detector_reconfigure() and create a new function lockup_detector_reconfigure() calling __lockup_detector_reconfigure() under the protection of watchdog_mutex. Signed-off-by: Laurent Dufour [mpe: Squash in build fix from Laurent, reported by Sachin] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220713154729.80789-3-ldufour@linux.ibm.com Signed-off-by: Sasha Levin