| Message ID | 1554402838-19008-1-git-send-email-linux@roeck-us.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | [1/4] hwmon: (f71805f) Use request_muxed_region for Super-IO accesses | expand |
On 04/04/2019 19:33, Guenter Roeck wrote: > Super-IO accesses may fail on a system with no or unmapped LPC bus. > > Unable to handle kernel paging request at virtual address ffffffbffee0002e > pgd = ffffffc1d68d4000 > [ffffffbffee0002e] *pgd=0000000000000000, *pud=0000000000000000 > Internal error: Oops: 94000046 [#1] PREEMPT SMP > Modules linked in: f71805f(+) hwmon > CPU: 3 PID: 1659 Comm: insmod Not tainted 4.5.0+ #88 > Hardware name: linux,dummy-virt (DT) > task: ffffffc1f6665400 ti: ffffffc1d6418000 task.ti: ffffffc1d6418000 > PC is at f71805f_find+0x6c/0x358 [f71805f] > > Also, other drivers may attempt to access the LPC bus at the same time, > resulting in undefined behavior. > > Use request_muxed_region() to ensure that IO access on the requested > address space is supported, and to ensure that access by multiple > drivers is synchronized. > > Fixes: e53004e20a58e ("hwmon: New f71805f driver") > Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> > Reported-by: John Garry <john.garry@huawei.com> > Cc: John Garry <john.garry@huawei.com> Acked-by: John Garry <john.garry@huawei.com> > Signed-off-by: Guenter Roeck <linux@roeck-us.net> > --- > drivers/hwmon/f71805f.c | 15 ++++++++++++--- > 1 file changed, 12 insertions(+), 3 deletions(-) > > diff --git a/drivers/hwmon/f71805f.c b/drivers/hwmon/f71805f.c > index 73c681162653..623736d2a7c1 100644 > --- a/drivers/hwmon/f71805f.c > +++ b/drivers/hwmon/f71805f.c > @@ -96,17 +96,23 @@ superio_select(int base, int ld) > outb(ld, base + 1); > } > > -static inline void > +static inline int > superio_enter(int base) > { > + if (!request_muxed_region(base, 2, DRVNAME)) > + return -EBUSY; > + > outb(0x87, base); > outb(0x87, base); > + > + return 0; > } > > static inline void > superio_exit(int base) > { > outb(0xaa, base); > + release_region(base, 2); > } > > /* > @@ -1561,7 +1567,7 @@ static int __init f71805f_device_add(unsigned short address, > static int __init f71805f_find(int sioaddr, unsigned short *address, > struct f71805f_sio_data *sio_data) > { > - int err = -ENODEV; > + int err; > u16 devid; > > static const char * const names[] = { > @@ -1569,8 +1575,11 @@ static int __init f71805f_find(int sioaddr, unsigned short *address, > "F71872F/FG or F71806F/FG", > }; > > - superio_enter(sioaddr); > + err = superio_enter(sioaddr); > + if (err) > + return err; > > + err = -ENODEV; > devid = superio_inw(sioaddr, SIO_REG_MANID); > if (devid != SIO_FINTEK_ID) > goto exit; >
diff --git a/drivers/hwmon/f71805f.c b/drivers/hwmon/f71805f.c index 73c681162653..623736d2a7c1 100644 --- a/drivers/hwmon/f71805f.c +++ b/drivers/hwmon/f71805f.c @@ -96,17 +96,23 @@ superio_select(int base, int ld) outb(ld, base + 1); } -static inline void +static inline int superio_enter(int base) { + if (!request_muxed_region(base, 2, DRVNAME)) + return -EBUSY; + outb(0x87, base); outb(0x87, base); + + return 0; } static inline void superio_exit(int base) { outb(0xaa, base); + release_region(base, 2); } /* @@ -1561,7 +1567,7 @@ static int __init f71805f_device_add(unsigned short address, static int __init f71805f_find(int sioaddr, unsigned short *address, struct f71805f_sio_data *sio_data) { - int err = -ENODEV; + int err; u16 devid; static const char * const names[] = { @@ -1569,8 +1575,11 @@ static int __init f71805f_find(int sioaddr, unsigned short *address, "F71872F/FG or F71806F/FG", }; - superio_enter(sioaddr); + err = superio_enter(sioaddr); + if (err) + return err; + err = -ENODEV; devid = superio_inw(sioaddr, SIO_REG_MANID); if (devid != SIO_FINTEK_ID) goto exit;
Super-IO accesses may fail on a system with no or unmapped LPC bus. Unable to handle kernel paging request at virtual address ffffffbffee0002e pgd = ffffffc1d68d4000 [ffffffbffee0002e] *pgd=0000000000000000, *pud=0000000000000000 Internal error: Oops: 94000046 [#1] PREEMPT SMP Modules linked in: f71805f(+) hwmon CPU: 3 PID: 1659 Comm: insmod Not tainted 4.5.0+ #88 Hardware name: linux,dummy-virt (DT) task: ffffffc1f6665400 ti: ffffffc1d6418000 task.ti: ffffffc1d6418000 PC is at f71805f_find+0x6c/0x358 [f71805f] Also, other drivers may attempt to access the LPC bus at the same time, resulting in undefined behavior. Use request_muxed_region() to ensure that IO access on the requested address space is supported, and to ensure that access by multiple drivers is synchronized. Fixes: e53004e20a58e ("hwmon: New f71805f driver") Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reported-by: John Garry <john.garry@huawei.com> Cc: John Garry <john.garry@huawei.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> --- drivers/hwmon/f71805f.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)