| Message ID | 1620991027-25856-1-git-send-email-zheyuma97@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | serial: rp2: disable interrupt in rp2_probe(): | expand |
On Fri, May 14, 2021 at 11:17:07AM +0000, Zheyu Ma wrote: > In 'rp2_probe', the driver registers 'rp2_uart_interrupt' then calls > 'rp2_fw_cb' through 'request_firmware_nowait'. In 'rp2_fw_cb', if the > firmware don't exists, function just return without initializing ports > of 'rp2_card'. But now the interrupt handler function has been registered, > and when an interrupt comes('rp2' may shares an interrupt line with other > devices), 'rp2_uart_interrupt' may access those ports then causing NULL > pointer dereference or other bugs. > > Fix this by disabling interrupt after registering 'rp2_uart_interrupt', > and enable it in 'rp2_uart_startup'. What prevents an interrupt from coming in right after callin rp2_uart_interrupt()? The driver has to be able to handle that. Why is the interrupt being registered before the firmware is loaded? That should be the proper fix as once you register an interrupt, the driver HAS to be able to properly handle it. thanks, greg k-h
On Thu, May 20, 2021 at 10:30 PM Greg KH <gregkh@linuxfoundation.org> wrote: > > On Fri, May 14, 2021 at 11:17:07AM +0000, Zheyu Ma wrote: > > In 'rp2_probe', the driver registers 'rp2_uart_interrupt' then calls > > 'rp2_fw_cb' through 'request_firmware_nowait'. In 'rp2_fw_cb', if the > > firmware don't exists, function just return without initializing ports > > of 'rp2_card'. But now the interrupt handler function has been registered, > > and when an interrupt comes('rp2' may shares an interrupt line with other > > devices), 'rp2_uart_interrupt' may access those ports then causing NULL > > pointer dereference or other bugs. > > > > Fix this by disabling interrupt after registering 'rp2_uart_interrupt', > > and enable it in 'rp2_uart_startup'. > > What prevents an interrupt from coming in right after callin > rp2_uart_interrupt()? The driver has to be able to handle that. Why is > the interrupt being registered before the firmware is loaded? That > should be the proper fix as once you register an interrupt, the driver > HAS to be able to properly handle it. > > thanks, > > greg k-h Thanks for your comments, I will reconsider this patch and send the second version of the patch. Zheyu Ma
diff --git a/drivers/tty/serial/rp2.c b/drivers/tty/serial/rp2.c index d60abffab70e..88b95d19266a 100644 --- a/drivers/tty/serial/rp2.c +++ b/drivers/tty/serial/rp2.c @@ -526,6 +526,7 @@ static int rp2_uart_startup(struct uart_port *port) RP2_TXRX_CTL_RX_TRIG_1); rp2_rmw(up, RP2_CHAN_STAT, 0, 0); rp2_mask_ch_irq(up, up->idx, 1); + enable_irq(port->irq); return 0; } @@ -782,6 +783,7 @@ static int rp2_probe(struct pci_dev *pdev, IRQF_SHARED, DRV_NAME, card); if (rc) return rc; + disable_irq(pdev->irq); /* * Only catastrophic errors (e.g. ENOMEM) are reported here.
In 'rp2_probe', the driver registers 'rp2_uart_interrupt' then calls 'rp2_fw_cb' through 'request_firmware_nowait'. In 'rp2_fw_cb', if the firmware don't exists, function just return without initializing ports of 'rp2_card'. But now the interrupt handler function has been registered, and when an interrupt comes('rp2' may shares an interrupt line with other devices), 'rp2_uart_interrupt' may access those ports then causing NULL pointer dereference or other bugs. Fix this by disabling interrupt after registering 'rp2_uart_interrupt', and enable it in 'rp2_uart_startup'. The KASAN's report reveals it: NFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.19.177-gdba4159c14ef-dirty #45 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59- gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xec/0x156 lib/dump_stack.c:118 assign_lock_key kernel/locking/lockdep.c:727 [inline] register_lock_class+0x14e5/0x1ba0 kernel/locking/lockdep.c:753 __lock_acquire+0x187/0x3750 kernel/locking/lockdep.c:3303 lock_acquire+0x124/0x340 kernel/locking/lockdep.c:3907 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x32/0x50 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] rp2_ch_interrupt drivers/tty/serial/rp2.c:466 [inline] rp2_asic_interrupt.isra.9+0x15d/0x990 drivers/tty/serial/rp2.c:493 rp2_uart_interrupt+0x49/0xe0 drivers/tty/serial/rp2.c:504 __handle_irq_event_percpu+0xfb/0x770 kernel/irq/handle.c:149 handle_irq_event_percpu+0x79/0x150 kernel/irq/handle.c:189 handle_irq_event+0xac/0x140 kernel/irq/handle.c:206 handle_fasteoi_irq+0x232/0x5c0 kernel/irq/chip.c:725 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x230/0x3a0 arch/x86/kernel/irq_64.c:87 do_IRQ+0xa7/0x1e0 arch/x86/kernel/irq.c:247 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:670 </IRQ> RIP: 0010:native_safe_halt+0x28/0x30 arch/x86/include/asm/irqflags.h:61 Code: 00 00 55 be 04 00 00 00 48 c7 c7 00 c2 2f 8c 48 89 e5 e8 fb 31 e7 f8 8b 05 75 af 8d 03 85 c0 7e 07 0f 00 2d 8a 61 65 00 fb f4 <5d> c3 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 RSP: 0018:ffff88806b71fcc8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffde RAX: 0000000000000000 RBX: ffffffff8bde7e48 RCX: ffffffff88a21285 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8c2fc200 RBP: ffff88806b71fcc8 R08: fffffbfff185f840 R09: fffffbfff185f840 R10: 0000000000000001 R11: fffffbfff185f840 R12: 0000000000000002 R13: ffffffff8bea18a0 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x6f/0x360 arch/x86/kernel/process.c:557 arch_cpu_idle+0xf/0x20 arch/x86/kernel/process.c:548 default_idle_call+0x3b/0x60 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x2ab/0x3c0 kernel/sched/idle.c:263 cpu_startup_entry+0xcb/0xe0 kernel/sched/idle.c:369 start_secondary+0x3b8/0x4e0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 PGD 8000000056d27067 P4D 8000000056d27067 PUD 56d28067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.19.177-gdba4159c14ef-dirty #45 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59- gc9ba5276e321-prebuilt.qemu.org 04/01/2014 RIP: 0010:readl arch/x86/include/asm/io.h:59 [inline] RIP: 0010:rp2_ch_interrupt drivers/tty/serial/rp2.c:472 [inline] RIP: 0010:rp2_asic_interrupt.isra.9+0x181/0x990 drivers/tty/serial/rp2.c: 493 Code: df e8 43 5d c2 05 48 8d 83 e8 01 00 00 48 89 85 60 ff ff ff 48 c1 e8 03 42 80 3c 30 00 0f 85 aa 07 00 00 48 8b 83 e8 01 00 00 <8b> 40 10 89 c1 89 85 68 ff ff ff 48 8b 83 e8 01 00 00 89 48 10 83 RSP: 0018:ffff88806c287cd0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88806ade6820 RCX: ffffffff814300b1 RDX: 1ffff1100d5bcd06 RSI: 0000000000000004 RDI: ffff88806ade6820 RBP: ffff88806c287db8 R08: ffffed100d5bcd05 R09: ffffed100d5bcd05 R10: 0000000000000001 R11: ffffed100d5bcd04 R12: ffffc90001e00000 R13: ffff888069654e10 R14: dffffc0000000000 R15: ffff888069654df0 FS: 0000000000000000(0000) GS:ffff88806c280000(0000) knlGS: 0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 000000006892c000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> rp2_uart_interrupt+0x49/0xe0 drivers/tty/serial/rp2.c:504 __handle_irq_event_percpu+0xfb/0x770 kernel/irq/handle.c:149 handle_irq_event_percpu+0x79/0x150 kernel/irq/handle.c:189 handle_irq_event+0xac/0x140 kernel/irq/handle.c:206 handle_fasteoi_irq+0x232/0x5c0 kernel/irq/chip.c:725 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline] handle_irq+0x230/0x3a0 arch/x86/kernel/irq_64.c:87 do_IRQ+0xa7/0x1e0 arch/x86/kernel/irq.c:247 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:670 </IRQ> RIP: 0010:native_safe_halt+0x28/0x30 arch/x86/include/asm/irqflags.h:61 Code: 00 00 55 be 04 00 00 00 48 c7 c7 00 c2 2f 8c 48 89 e5 e8 fb 31 e7 f8 8b 05 75 af 8d 03 85 c0 7e 07 0f 00 2d 8a 61 65 00 fb f4 <5d> c3 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 RSP: 0018:ffff88806b71fcc8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffde RAX: 0000000000000000 RBX: ffffffff8bde7e48 RCX: ffffffff88a21285 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8c2fc200 RBP: ffff88806b71fcc8 R08: fffffbfff185f840 R09: fffffbfff185f840 R10: 0000000000000001 R11: fffffbfff185f840 R12: 0000000000000002 R13: ffffffff8bea18a0 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x6f/0x360 arch/x86/kernel/process.c:557 arch_cpu_idle+0xf/0x20 arch/x86/kernel/process.c:548 default_idle_call+0x3b/0x60 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x2ab/0x3c0 kernel/sched/idle.c:263 cpu_startup_entry+0xcb/0xe0 kernel/sched/idle.c:369 start_secondary+0x3b8/0x4e0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 Modules linked in: Dumping ftrace buffer: (ftrace buffer empty) CR2: 0000000000000010 ---[ end trace 11804dbb55cb1a64 ]--- RIP: 0010:readl arch/x86/include/asm/io.h:59 [inline] RIP: 0010:rp2_ch_interrupt drivers/tty/serial/rp2.c:472 [inline] RIP: 0010:rp2_asic_interrupt.isra.9+0x181/0x990 drivers/tty/serial/rp2.c: 493 Code: df e8 43 5d c2 05 48 8d 83 e8 01 00 00 48 89 85 60 ff ff ff 48 c1 e8 03 42 80 3c 30 00 0f 85 aa 07 00 00 48 8b 83 e8 01 00 00 <8b> 40 10 89 c1 89 85 68 ff ff ff 48 8b 83 e8 01 00 00 89 48 10 83 RSP: 0018:ffff88806c287cd0 EFLAGS: 00010046 RAX: 0000000000000000 RBX: ffff88806ade6820 RCX: ffffffff814300b1 RDX: 1ffff1100d5bcd06 RSI: 0000000000000004 RDI: ffff88806ade6820 RBP: ffff88806c287db8 R08: ffffed100d5bcd05 R09: ffffed100d5bcd05 R10: 0000000000000001 R11: ffffed100d5bcd04 R12: ffffc90001e00000 R13: ffff888069654e10 R14: dffffc0000000000 R15: ffff888069654df0 FS: 0000000000000000(0000) GS:ffff88806c280000(0000) knlGS: 0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 000000006892c000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> --- drivers/tty/serial/rp2.c | 2 ++ 1 file changed, 2 insertions(+)