Messages in this thread | | | From | "Winkler, Tomas" <> | Subject | RE: [PATCH] tpm: use get_unaligned_be32 unaligned buffer access. | Date | Wed, 23 Nov 2016 20:56:25 +0000 |
| |
> On Wed, Nov 23, 2016 at 01:04:54PM +0200, Tomas Winkler wrote: > > Use get_unaligned_be32 as b32_to_cpu doesn't work correctly on all > > platforms for unaligned access. > > > > The fix doesn't cover all the cases as also some cast structures have > > members on unaligned addresses. > > I think this is a good idea.. > > > @@ -353,8 +353,8 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 > *buf, size_t bufsiz, > > if (bufsiz > TPM_BUFSIZE) > > bufsiz = TPM_BUFSIZE; > > > > - count = be32_to_cpu(*((__be32 *) (buf + 2))); > > - ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); > > + count = get_unaligned_be32(buf + 2); > > + ordinal = get_unaligned_be32(buf + 6); > > But lets fix this better and get rid of the constants too...
> const tpm_input_header *hdr = buf; > count = be32_to_cpu(hdr->length); > ordinal = be32_to_cpu(hdr->ordinal); > > Compiler will take care of unaligned for __packed.
Yes, compiler takes care at performance penalty but probably we don't care about that much, and readability is maybe more important here. What I've done is pretty much mechanical fix, I agree this is better approach in this particular case.
> > @@ -178,7 +178,7 @@ static int crb_recv(struct tpm_chip *chip, u8 *buf, > size_t count) > > return -EIO; > > > > memcpy_fromio(buf, priv->rsp, 6); > > - expected = be32_to_cpup((__be32 *) &buf[2]); > > + expected = get_unaligned_be32(buf + 2); > > Here too, except tpm_output_header (and is tpm1 and 2 the same here?) > > > @@ -451,7 +452,7 @@ static int tpm_tis_i2c_recv(struct tpm_chip *chip, u8 > *buf, size_t count) > > goto out; > > } > > > > - expected = be32_to_cpu(*(__be32 *)(buf + 2)); > > + expected = get_unaligned_be32(buf + 2); > > Ditto > > > @@ -314,7 +315,7 @@ static int i2c_nuvoton_recv(struct tpm_chip *chip, u8 > *buf, size_t count) > > * convert number of expected bytes field from big endian 32 > bit > > * to machine native > > */ > > - expected = be32_to_cpu(*(__be32 *) (buf + 2)); > > + expected = get_unaligned_be32(buf + 2); > > Ditto > > > if (expected > count) { > > dev_err(dev, "%s() expected > count\n", __func__); > > size = -EIO; > > @@ -442,7 +443,7 @@ static int i2c_nuvoton_send(struct tpm_chip *chip, u8 > *buf, size_t len) > > i2c_nuvoton_ready(chip); > > return rc; > > } > > - ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); > > + ordinal = get_unaligned_be32(buf + 6); > > Ditto > > > @@ -174,8 +173,7 @@ static int tpm_nsc_recv(struct tpm_chip *chip, u8 * > buf, size_t count) > > return -EIO; > > } > > > > - native_size = (__force __be32 *) (buf + 2); > > - size = be32_to_cpu(*native_size); > > + size = get_unaligned_be32(buf + 2); > > Ditto > > > diff --git a/drivers/char/tpm/tpm_tis_core.c > > b/drivers/char/tpm/tpm_tis_core.c index 7993678954a2..5323c54dc917 > > 100644 > > +++ b/drivers/char/tpm/tpm_tis_core.c > > @@ -222,7 +222,7 @@ static int tpm_tis_recv(struct tpm_chip *chip, u8 > *buf, size_t count) > > goto out; > > } > > > > - expected = be32_to_cpu(*(__be32 *) (buf + 2)); > > + expected = get_unaligned_be32(buf + 2); > > Ditto > > > @@ -371,7 +371,7 @@ static int tpm_tis_send_main(struct tpm_chip *chip, > u8 *buf, size_t len) > > goto out_err; > > > > if (chip->flags & TPM_CHIP_FLAG_IRQ) { > > - ordinal = be32_to_cpu(*((__be32 *) (buf + 6))); > > + ordinal = get_unaligned_be32(buf + 6); > > Ditto > > Jason
| |