Message ID | 1446969067-29016-1-git-send-email-jarkko.sakkinen@linux.intel.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
On Sun, Nov 08, 2015 at 09:51:07AM +0200, Jarkko Sakkinen wrote: > + if (rc && rc != -ENOENT) { > + tpm_chip_unregister(chip); > + return rc; > + } > + } This is still goofy looking, the list_add_tail_rcu should be the last thing done and cannot fail. Just code this with the usual goto based unwind and goto to do tpm_dev_del_device for the above failure. > + > return 0; > out_err: > tpm1_chip_unregister(chip); Which avoids calling tpm1_chip_unregister and tpm_chip_unregister in the same function, which looks so wrong to a casual read.. Jason ------------------------------------------------------------------------------ Presto, an open source distributed SQL query engine for big data, initially developed by Facebook, enables you to easily query your data on Hadoop in a more interactive manner. Teradata is also now providing full enterprise support for Presto. Download a free open source copy now. http://pubads.g.doubleclick.net/gampad/clk?id=250295911&iu=/4140
On Mon, Nov 09, 2015 at 03:47:20PM -0700, Jason Gunthorpe wrote: > On Sun, Nov 08, 2015 at 09:51:07AM +0200, Jarkko Sakkinen wrote: > > + if (rc && rc != -ENOENT) { > > + tpm_chip_unregister(chip); > > + return rc; > > + } > > + } > > This is still goofy looking, the list_add_tail_rcu should be the last > thing done and cannot fail. Just code this with the usual goto based > unwind and goto to do tpm_dev_del_device for the above failure. Agreed that this would be cleaner. > > + > > return 0; > > out_err: > > tpm1_chip_unregister(chip); > > Which avoids calling tpm1_chip_unregister and tpm_chip_unregister in > the same function, which looks so wrong to a casual read.. I'm not going to change the current patch at this point of release cycle but this clean up definitely makes sense later on. > Jason /Jarkko ------------------------------------------------------------------------------
Jarkko, On Sun, Nov 08, 2015 at 09:51:07AM +0200, Jarkko Sakkinen wrote: > __compat_only_sysfs_link_entry_to_kobj() was unconditionally called for > TPM1 chips, which caused crash on Acer C720 laptop where DSM for the > ACPI object did not exist. > > There are two reasons for unwanted behavior: > > * The code did not check whether > __compat_only_sysfs_link_entry_to_kobj() returned -ENOENT. This is > OK. It just meanst that ppi is not available. > * The code did not clean up properly. Compat link should added only > after all other init is done. > > This patch sorts out these issues. > > Fixes: 9b774d5cf2db > Reported-by: Jeremiah Mahler <jmmahler@gmail.com> > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > Tested-by: Jeremiah Mahler <jmmahler@gmail.com> > --- > drivers/char/tpm/tpm-chip.c | 18 ++++++++++-------- > 1 file changed, 10 insertions(+), 8 deletions(-) > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > index a5cdce7..45cc39a 100644 > --- a/drivers/char/tpm/tpm-chip.c > +++ b/drivers/char/tpm/tpm-chip.c > @@ -226,14 +226,6 @@ int tpm_chip_register(struct tpm_chip *chip) > if (rc) > goto out_err; > > - if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { > - rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj, > - &chip->dev.kobj, > - "ppi"); > - if (rc) > - goto out_err; > - } > - > /* Make the chip available. */ > spin_lock(&driver_lock); > list_add_tail_rcu(&chip->list, &tpm_chip_list); > @@ -241,6 +233,16 @@ int tpm_chip_register(struct tpm_chip *chip) > > chip->flags |= TPM_CHIP_FLAG_REGISTERED; > > + if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { > + rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj, > + &chip->dev.kobj, > + "ppi"); > + if (rc && rc != -ENOENT) { > + tpm_chip_unregister(chip); > + return rc; > + } > + } > + > return 0; > out_err: > tpm1_chip_unregister(chip); > -- > 2.5.0 > This patch doesn't apply to the latest linux-next (20151109). I think I may be missing a dependent patch. Do you know which one?
On Mon, Nov 09, 2015 at 10:11:41PM -0800, Jeremiah Mahler wrote: > Jarkko, > > On Sun, Nov 08, 2015 at 09:51:07AM +0200, Jarkko Sakkinen wrote: > > __compat_only_sysfs_link_entry_to_kobj() was unconditionally called for > > TPM1 chips, which caused crash on Acer C720 laptop where DSM for the > > ACPI object did not exist. > > > > There are two reasons for unwanted behavior: > > > > * The code did not check whether > > __compat_only_sysfs_link_entry_to_kobj() returned -ENOENT. This is > > OK. It just meanst that ppi is not available. > > * The code did not clean up properly. Compat link should added only > > after all other init is done. > > > > This patch sorts out these issues. > > > > Fixes: 9b774d5cf2db > > Reported-by: Jeremiah Mahler <jmmahler@gmail.com> > > Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > Tested-by: Jeremiah Mahler <jmmahler@gmail.com> > > --- > > drivers/char/tpm/tpm-chip.c | 18 ++++++++++-------- > > 1 file changed, 10 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > > index a5cdce7..45cc39a 100644 > > --- a/drivers/char/tpm/tpm-chip.c > > +++ b/drivers/char/tpm/tpm-chip.c > > @@ -226,14 +226,6 @@ int tpm_chip_register(struct tpm_chip *chip) > > if (rc) > > goto out_err; > > > > - if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { > > - rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj, > > - &chip->dev.kobj, > > - "ppi"); > > - if (rc) > > - goto out_err; > > - } > > - > > /* Make the chip available. */ > > spin_lock(&driver_lock); > > list_add_tail_rcu(&chip->list, &tpm_chip_list); > > @@ -241,6 +233,16 @@ int tpm_chip_register(struct tpm_chip *chip) > > > > chip->flags |= TPM_CHIP_FLAG_REGISTERED; > > > > + if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { > > + rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj, > > + &chip->dev.kobj, > > + "ppi"); > > + if (rc && rc != -ENOENT) { > > + tpm_chip_unregister(chip); > > + return rc; > > + } > > + } > > + > > return 0; > > out_err: > > tpm1_chip_unregister(chip); > > -- > > 2.5.0 > > > > This patch doesn't apply to the latest linux-next (20151109). I think I > may be missing a dependent patch. Do you know which one? It is expected as there are 7 other bug fixes that I'm including to the next pull rquest and this is on top. > - Jeremiah Mahler /Jarkko ------------------------------------------------------------------------------
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index a5cdce7..45cc39a 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -226,14 +226,6 @@ int tpm_chip_register(struct tpm_chip *chip) if (rc) goto out_err; - if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { - rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj, - &chip->dev.kobj, - "ppi"); - if (rc) - goto out_err; - } - /* Make the chip available. */ spin_lock(&driver_lock); list_add_tail_rcu(&chip->list, &tpm_chip_list); @@ -241,6 +233,16 @@ int tpm_chip_register(struct tpm_chip *chip) chip->flags |= TPM_CHIP_FLAG_REGISTERED; + if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) { + rc = __compat_only_sysfs_link_entry_to_kobj(&chip->pdev->kobj, + &chip->dev.kobj, + "ppi"); + if (rc && rc != -ENOENT) { + tpm_chip_unregister(chip); + return rc; + } + } + return 0; out_err: tpm1_chip_unregister(chip);