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uartlite: Fix crash when using as console

PATCH In review Richard Röjfors 2 participants 2 messages Jan 28, 2010 TTY layer and serial drivers

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PATCH 1/1 uartlite: Fix crash when using as console

This patch moves the ulite_console_setup to the .devinit section since it might be called on probe, which is in devinit. Fixes the crash below where the uartlite hw is probed after the .init section is freed from the kernel.

uartlite: ttyUL0 at MMIO 0xc8000100 (irq = 30) is a uartlite

BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<c176720e>] ulite_console_setup+0x6f/0xa8
*pdpt = 0000000036fb0001 *pde = 0000000000000000
Oops: 0000 [#1] PREEMPT SMP
last sysfs file: /sys/devices/pci0000:00/0000:00:1f.1/host0/uevent
Modules linked in: puffin(+) serio_raw

Pid: 151, comm: modprobe Not tainted (2.6.31.5-1.0.b1-b1 #1) POULSBO
EIP: 0060:[<c176720e>] EFLAGS: 00010246 CPU: 0
EIP is at ulite_console_setup+0x6f/0xa8
EAX: c16ec824 EBX: c16ec824 ECX: c176719f EDX: 00000000
ESI: 00000000 EDI: c17b42c4 EBP: f6fd1cf0 ESP: f6fd1cd8
DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
Process modprobe (pid: 151, ti=f6fd0000 task=f6fa1020 task.ti=f6fd0000)

Stack:
 c1031f51 00000000 00000000 00000246 c182237c f7742000 f6fd1d5c c11fd316
<0> c16ec85c f77420d4 0000001e 00000000 00000000 c1633e78 4f494d4d 63783020
<0> 30303038 00303031 f6fd1d3c c10e0786 f6fd1d48 00000000 f6fd1d48 00000000
Call Trace:
 [<c1031f51>] ? register_console+0xf6/0x1fc
 [<c11fd316>] ? uart_add_one_port+0x237/0x2bb
 [<c10e0786>] ? sysfs_add_one+0x13/0xd3
 [<c10e142f>] ? sysfs_do_create_link+0xba/0xfc
 [<c146f200>] ? ulite_probe+0x198/0x1eb
 [<c12064ee>] ? platform_drv_probe+0xc/0xe
 [<c120597b>] ? driver_probe_device+0x79/0x105
 [<c1205a8e>] ? __device_attach+0x28/0x30
 [<c120511f>] ? bus_for_each_drv+0x3d/0x67
 [<c1205af9>] ? device_attach+0x44/0x58
 [<c1205a66>] ? __device_attach+0x0/0x30
 [<c1204fb8>] ? bus_probe_device+0x1f/0x34
 [<c1203e68>] ? device_add+0x385/0x4c0
 [<c148491f>] ? _write_unlock+0x8/0x1f
 [<c1206aac>] ? platform_device_add+0xd9/0x11c
 [<c120c685>] ? mfd_add_devices+0x165/0x1bc
 [<f831b378>] ? puffin_probe+0x2d0/0x390 [puffin]
 [<c11a08ef>] ? pci_match_device+0xa0/0xa7
 [<c11a07bc>] ? local_pci_probe+0xe/0x10
 [<c11a11db>] ? pci_device_probe+0x43/0x66
 [<c120597b>] ? driver_probe_device+0x79/0x105
 [<c1205a4a>] ? __driver_attach+0x43/0x5f
 [<c120535d>] ? bus_for_each_dev+0x3d/0x67
 [<c1205852>] ? driver_attach+0x14/0x16
 [<c1205a07>] ? __driver_attach+0x0/0x5f
 [<c1204dea>] ? bus_add_driver+0xf9/0x220
 [<c1205c8f>] ? driver_register+0x8b/0xeb
 [<c11a1518>] ? __pci_register_driver+0x43/0x9f
 [<c10477ef>] ? __blocking_notifier_call_chain+0x40/0x4c
 [<f831f000>] ? puffin_init+0x0/0x48 [puffin]
 [<f831f017>] ? puffin_init+0x17/0x48 [puffin]
 [<c1001139>] ? do_one_initcall+0x4c/0x131
 [<c105607b>] ? sys_init_module+0xa7/0x1b7
 [<c1002a61>] ? syscall_call+0x7/0xb
 Code: 6e 74 00 00 00 92 33 00 00 18 00 0e 01 73 79 6e 63 65 2d 72 65 67 69 73 74 72 79 0c 00 49 32

00 00 14 00 09 01 61 6c 73 61 2d 69 <6e> 66 6f 00 00 00 42 37 00 00 10 00 07 01 6b 69 6c 6c 61 6c 6c
EIP: [<c176720e>] ulite_console_setup+0x6f/0xa8 SS:ESP 0068:f6fd1cd8
CR2: 0000000000000000

---

drivers/serial/uartlite.c +1 -1
index 377f271..ab2ab3c 100644
@@ -394,7 +394,7 @@ static void ulite_console_write(struct console *co, const char *s,
 		spin_unlock_irqrestore(&port->lock, flags);
 }
 
-static int __init ulite_console_setup(struct console *co, char *options)
+static int __devinit ulite_console_setup(struct console *co, char *options)
 {
 	struct uart_port *port;
 	int baud = 9600;

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Acked-by on v1 1/1
#1 lore raw
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"Richard" == Richard Röjfors <[email protected]> writes:

Richard> This patch moves the ulite_console_setup to the .devinit Richard> section since it might be called on probe, which is in Richard> devinit. Fixes the crash below where the uartlite hw is probed Richard> after the .init section is freed from the kernel.

Having the platform device for the console registerred so late doesn't strike me as very useful, but ok ..

Signature · 5 lines
Bye, Peter Korsgaard
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