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| author | Guenter Roeck <linux@roeck-us.net> | 2019-04-04 19:52:43 +0200 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2019-04-16 02:19:53 +0200 |
| commit | 73e6ff71a7ea924fb7121d576a2d41e3be3fc6b5 (patch) | |
| tree | 2ec2ad53703c91a3409f8df0892f91a2e5149411 /drivers/hwmon | |
| parent | hwmon: (ina2xx) Fix build warning (diff) | |
| download | linux-73e6ff71a7ea924fb7121d576a2d41e3be3fc6b5.tar.xz linux-73e6ff71a7ea924fb7121d576a2d41e3be3fc6b5.zip | |
hwmon: (f71805f) Use request_muxed_region for Super-IO accesses
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>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/f71805f.c | 15 |
1 files 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 @@ exit: 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; |