Jan Kiszka <[email protected]> writes:
> On 09.03.21 05:45, hongzha1 via Xenomai wrote: >> Ask for switching back to oob mode once ptrace core tell that >> current is resuming from a stopped state, leaving space for >> other runnable RT threads of the process to take over. >> >> Signed-off-by: hongzha1 <[email protected]> >> >> diff --git a/kernel/cobalt/dovetail/kevents.c >> b/kernel/cobalt/dovetail/kevents.c >> index 966a63ce0..a640c4d9e 100644 >> --- a/kernel/cobalt/dovetail/kevents.c >> +++ b/kernel/cobalt/dovetail/kevents.c >> @@ -492,6 +492,8 @@ static void handle_ptrace_cont(void) >> unregister_debugged_thread(curr); >> >> xnthread_set_localinfo(curr, XNHICCUP); >> + >> + dovetail_request_ucall(current); >> } >> >> xnlock_put_irqrestore(&nklock, s); >> diff --git a/kernel/cobalt/dovetail/sched.c b/kernel/cobalt/dovetail/sched.c >> index de7c43b70..2bdddfeef 100644 >> --- a/kernel/cobalt/dovetail/sched.c >> +++ b/kernel/cobalt/dovetail/sched.c >> @@ -56,9 +56,21 @@ int pipeline_leave_inband(void) >> >> int pipeline_leave_oob_prepare(void) >> { >> - dovetail_leave_oob(); >> + int suspmask = XNRELAX; >> + struct xnthread *curr = xnthread_current(); >> >> - return XNRELAX; >> + dovetail_leave_oob(); >> + /* >> + * If current is being debugged, record that it should migrate >> + * back in case it resumes in userspace. If it resumes in >> + * kernel space, i.e. over a restarting syscall, the >> + * associated hardening will clear XNCONTHI. >> + */ >> + if (xnthread_test_state(curr, XNSSTEP)) { >> + xnthread_set_info(curr, XNCONTHI); >> + suspmask |= XNDBGSTOP; >> + } >> + return suspmask; >> } >> >> void pipeline_leave_oob_finish(void) >> > > I've applied this to wip/dovetail, but that alone does not fix > ptrace/gdb use cases yet: > > (gdb latency -> run) > [ 52.097078] ------------[ cut here ]------------ > [ 52.097079] WARNING: CPU: 2 PID: 1318 at ../kernel/irq/pipeline.c:316 > inband_irq_enable+0x10/0x20 > [ 52.097079] Modules linked in: 9p > [ 52.097080] CPU: 2 PID: 1318 Comm: latency Not tainted 5.10.19+ #41 > [ 52.097080] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS > rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 > [ 52.097080] IRQ stage: Linux > [ 52.097081] RIP: 0010:inband_irq_enable+0x10/0x20 > [ 52.097081] Code: 00 00 00 01 75 ee e8 cf fa ff ff 53 9d 5b c3 66 66 2e 0f > 1f 84 00 00 00 00 00 80 3d 9a 38 b3 02 00 75 09 9c 58 f6 c4 02 75 02 <0f> 0b > eb 8c 66 66 2e 0f 1f 84 00 00 00 00 00 90 0f 1f 44 00 00 48 > [ 52.097081] RSP: 0000:ffffc90000783f20 EFLAGS: 00010046 > [ 52.097082] RAX: 0000000000000046 RBX: ffffc90000783f58 RCX: > 0000000000000000 > [ 52.097082] RDX: ffffc90000783ef0 RSI: ffffffff8109e600 RDI: > ffffffff81d4eee2 > [ 52.097082] RBP: ffff888006e70000 R08: 0000000000000000 R09: > 0000000000000000 > [ 52.097083] R10: 0000000000000000 R11: 0000000000000000 R12: > 0000000000004000 > [ 52.097083] R13: 0000000000000000 R14: 0000000000000000 R15: > 0000000000000000 > [ 52.097083] FS: 00007ffff7fe6640(0000) GS:ffff88803ed00000(0000) > knlGS:0000000000000000 > [ 52.097084] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 52.097084] CR2: 00007ffff7243610 CR3: 00000000070c6001 CR4: > 0000000000370ee0 > [ 52.097084] Call Trace: > [ 52.097084] noist_exc_debug+0xf7/0x180 > [ 52.097085] ? asm_exc_debug+0x23/0x30 > [ 52.097085] asm_exc_debug+0x2b/0x30 > [ 52.097085] RIP: 0033:0x401df3 > [ 52.097086] Code: 00 00 e9 b0 fb ff ff ff 25 62 44 20 00 68 44 00 00 00 e9 > a0 fb ff ff ff 25 5a 44 20 00 68 45 00 00 00 e9 90 fb ff ff 31 ed 90 <e8> f9 > 30 01 00 48 8d 65 d8 5b 41 5c 41 5d 41 70 44 40 00 48 c7 c1 > [ 52.097086] RSP: 002b:00007fffffffe1c0 EFLAGS: 00000346 > [ 52.097086] RAX: 00007ffff7ffe0e0 RBX: 00007ffff7ffe0e0 RCX: > 00007ffff7df23c7 > [ 52.097087] RDX: 0000103e00000000 RSI: 0000000000000000 RDI: > 0000000000000000 > [ 52.097087] RBP: 00007fffffffe3a0 R08: 00007ffff6e8f008 R09: > 0000000000000009 > [ 52.097087] R10: 00007ffff7ffd990 R11: 0000000000000206 R12: > 0000000000000000 > [ 52.097087] R13: 00007ffff7ffe110 R14: 00007ffff7ffe110 R15: > 00007ffff7fe6640 > [ 52.097088] irq event stamp: 0 > [ 52.097088] hardirqs last enabled at (0): [<0000000000000000>] 0x0 > [ 52.097088] hardirqs last disabled at (0): [<ffffffff8106c648>] > copy_process+0x718/0x1cd0 > [ 52.097089] softirqs last enabled at (0): [<ffffffff8106c648>] > copy_process+0x718/0x1cd0 > [ 52.097089] softirqs last disabled at (0): [<0000000000000000>] 0x0 > [ 52.097089] ---[ end trace b07496576d3779dc ]--- > > Do I miss some other patch? > > Jan This may help: diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 719ef25e43d0cd1..f15a07967070264 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1025,7 +1025,7 @@ static __always_inline void exc_debug_user(struct pt_regs *regs, goto out; /* It's safe to allow irq's after DR6 has been saved */ - local_irq_enable(); + local_irq_enable_full(); if (v8086_mode(regs)) { handle_vm86_trap((struct kernel_vm86_regs *)regs, 0, X86_TRAP_DB); @@ -1038,7 +1038,7 @@ static __always_inline void exc_debug_user(struct pt_regs *regs, send_sigtrap(regs, 0, get_si_code(dr6)); out_irq: - local_irq_disable(); + local_irq_disable_full(); out: instrumentation_end(); irqentry_exit_to_user_mode(regs); -- Philippe.
