Rather than applying masks to the provided values, make assertions about them being valid - otherwise we'd just try to paper over bugs.
Signed-off-by: Oswald Buddenhagen oswald.buddenhagen@gmx.de --- sound/pci/emu10k1/io.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-)
diff --git a/sound/pci/emu10k1/io.c b/sound/pci/emu10k1/io.c index aee84c3f9f37..ced69165d69a 100644 --- a/sound/pci/emu10k1/io.c +++ b/sound/pci/emu10k1/io.c @@ -18,14 +18,27 @@ #include <linux/export.h> #include "p17v.h"
+static inline bool check_ptr_reg(struct snd_emu10k1 *emu, unsigned int reg) +{ + if (snd_BUG_ON(!emu)) + return false; + if (snd_BUG_ON(reg & (emu->audigy ? (0xffff0000 & ~A_PTR_ADDRESS_MASK) + : (0xffff0000 & ~PTR_ADDRESS_MASK)))) + return false; + if (snd_BUG_ON(reg & 0x0000ffff & ~PTR_CHANNELNUM_MASK)) + return false; + return true; +} + unsigned int snd_emu10k1_ptr_read(struct snd_emu10k1 * emu, unsigned int reg, unsigned int chn) { unsigned long flags; unsigned int regptr, val; unsigned int mask;
- mask = emu->audigy ? A_PTR_ADDRESS_MASK : PTR_ADDRESS_MASK; - regptr = ((reg << 16) & mask) | (chn & PTR_CHANNELNUM_MASK); + regptr = (reg << 16) | chn; + if (!check_ptr_reg(emu, regptr)) + return 0;
if (reg & 0xff000000) { unsigned char size, offset; @@ -57,18 +70,20 @@ void snd_emu10k1_ptr_write(struct snd_emu10k1 *emu, unsigned int reg, unsigned i unsigned long flags; unsigned int mask;
- if (snd_BUG_ON(!emu)) + regptr = (reg << 16) | chn; + if (!check_ptr_reg(emu, regptr)) return; - mask = emu->audigy ? A_PTR_ADDRESS_MASK : PTR_ADDRESS_MASK; - regptr = ((reg << 16) & mask) | (chn & PTR_CHANNELNUM_MASK);
if (reg & 0xff000000) { unsigned char size, offset;
size = (reg >> 24) & 0x3f; offset = (reg >> 16) & 0x1f; - mask = ((1 << size) - 1) << offset; - data = (data << offset) & mask; + mask = (1 << size) - 1; + if (snd_BUG_ON(data & ~mask)) + return; + mask <<= offset; + data <<= offset;
spin_lock_irqsave(&emu->emu_lock, flags); outl(regptr, emu->port + PTR);