Guenter Roeck <linux@xxxxxxxxxxxx> 于2019年7月24日周三 下午10:40写道: > > When instantiating tcpm on an NXP OM 13588 board with NXP PTN5110, > the following crash is seen when writing into the 'preferred_role' > sysfs attribute. > > Unable to handle kernel NULL pointer dereference at virtual address 00000028 > pgd = f69149ad > [00000028] *pgd=00000000 > Internal error: Oops: 5 [#1] THUMB2 > Modules linked in: tcpci tcpm > CPU: 0 PID: 1882 Comm: bash Not tainted 5.1.18-sama5-armv7-r2 #4 > Hardware name: Atmel SAMA5 > PC is at tcpm_try_role+0x3a/0x4c [tcpm] > LR is at tcpm_try_role+0x15/0x4c [tcpm] > pc : [<bf8000e2>] lr : [<bf8000bd>] psr: 60030033 > sp : dc1a1e88 ip : c03fb47d fp : 00000000 > r10: dc216190 r9 : dc1a1f78 r8 : 00000001 > r7 : df4ae044 r6 : dd032e90 r5 : dd1ce340 r4 : df4ae054 > r3 : 00000000 r2 : 00000000 r1 : 00000000 r0 : df4ae044 > Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA Thumb Segment none > Control: 50c53c7d Table: 3efec059 DAC: 00000051 > Process bash (pid: 1882, stack limit = 0x6a6d4aa5) > Stack: (0xdc1a1e88 to 0xdc1a2000) > 1e80: dd05d808 dd1ce340 00000001 00000007 dd1ce340 c03fb4a7 > 1ea0: 00000007 00000007 dc216180 00000000 00000000 c01e1e03 00000000 00000000 > 1ec0: c0907008 dee98b40 c01e1d5d c06106c4 00000000 00000000 00000007 c0194e8b > 1ee0: 0000000a 00000400 00000000 c01a97db dc22bf00 ffffe000 df4b6a00 df745900 > 1f00: 00000001 00000001 000000dd c01a9c2f 7aeab3be c0907008 00000000 dc22bf00 > 1f20: c0907008 00000000 00000000 00000000 00000000 7aeab3be 00000007 dee98b40 > 1f40: 005dc318 dc1a1f78 00000000 00000000 00000007 c01969f7 0000000a c01a20cb > 1f60: dee98b40 c0907008 dee98b40 005dc318 00000000 c0196b9b 00000000 00000000 > 1f80: dee98b40 7aeab3be 00000074 005dc318 b6f3bdb0 00000004 c0101224 dc1a0000 > 1fa0: 00000004 c0101001 00000074 005dc318 00000001 005dc318 00000007 00000000 > 1fc0: 00000074 005dc318 b6f3bdb0 00000004 00000007 00000007 00000000 00000000 > 1fe0: 00000004 be800880 b6ed35b3 b6e5c746 60030030 00000001 00000000 00000000 > [<bf8000e2>] (tcpm_try_role [tcpm]) from [<c03fb4a7>] (preferred_role_store+0x2b/0x5c) > [<c03fb4a7>] (preferred_role_store) from [<c01e1e03>] (kernfs_fop_write+0xa7/0x150) > [<c01e1e03>] (kernfs_fop_write) from [<c0194e8b>] (__vfs_write+0x1f/0x104) > [<c0194e8b>] (__vfs_write) from [<c01969f7>] (vfs_write+0x6b/0x104) > [<c01969f7>] (vfs_write) from [<c0196b9b>] (ksys_write+0x43/0x94) > [<c0196b9b>] (ksys_write) from [<c0101001>] (ret_fast_syscall+0x1/0x62) > > Since commit 96232cbc6c994 ("usb: typec: tcpm: support get typec and pd > config from device properties"), the 'config' pointer in struct tcpc_dev > is optional when registering a Type-C port. Since it is optional, we have > to check if it is NULL before dereferencing it. > > Reported-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> > Cc: Douglas Gilbert <dgilbert@xxxxxxxxxxxx> > Fixes: 96232cbc6c994 ("usb: typec: tcpm: support get typec and pd config from device properties") > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Reviewed-by: Jun Li <jun.li@xxxxxxx> > --- > v2: Added missing Cc:. Sorry for the noise. > > Doug: > I didn't add your Tested-by: since I added more code. > It would be great if you can re-test. > > drivers/usb/typec/tcpm/tcpm.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > index fba32d84e578..77f71f602f73 100644 > --- a/drivers/usb/typec/tcpm/tcpm.c > +++ b/drivers/usb/typec/tcpm/tcpm.c > @@ -379,7 +379,8 @@ static enum tcpm_state tcpm_default_state(struct tcpm_port *port) > return SNK_UNATTACHED; > else if (port->try_role == TYPEC_SOURCE) > return SRC_UNATTACHED; > - else if (port->tcpc->config->default_role == TYPEC_SINK) > + else if (port->tcpc->config && > + port->tcpc->config->default_role == TYPEC_SINK) > return SNK_UNATTACHED; > /* Fall through to return SRC_UNATTACHED */ > } else if (port->port_type == TYPEC_PORT_SNK) { > @@ -4114,7 +4115,7 @@ static int tcpm_try_role(const struct typec_capability *cap, int role) > mutex_lock(&port->lock); > if (tcpc->try_role) > ret = tcpc->try_role(tcpc, role); > - if (!ret && !tcpc->config->try_role_hw) > + if (!ret && (!tcpc->config || !tcpc->config->try_role_hw)) > port->try_role = role; > port->try_src_count = 0; > port->try_snk_count = 0; > @@ -4701,7 +4702,7 @@ static int tcpm_copy_caps(struct tcpm_port *port, > port->typec_caps.prefer_role = tcfg->default_role; > port->typec_caps.type = tcfg->type; > port->typec_caps.data = tcfg->data; > - port->self_powered = port->tcpc->config->self_powered; > + port->self_powered = tcfg->self_powered; > > return 0; > } > -- > 2.7.4 >