Re: [tpmdd-devel] [PATCH v4 2/8] tpm: replace dynamically allocated bios_dir with dentry array

2016-10-01 Thread Jarkko Sakkinen 
On Wed, Sep 28, 2016 at 04:34:36AM -0400, Nayna Jain wrote:
> bios_dir is defined as struct dentry **bios_dir, which results in
> dynamic allocation and therefore possibly a memory leak. This patch
> replaces it with struct dentry array(struct dentry *bios_dir[3])
> similar to what is done for sysfs groups.
> 
> Suggested-by: Jason Gunthorpe 
> Signed-off-by: Nayna Jain 
> Reviewed-by: Jason Gunthorpe 
> ---
>  drivers/char/tpm/tpm-chip.c |  8 +++---
>  drivers/char/tpm/tpm.h  |  3 +-
>  drivers/char/tpm/tpm_eventlog.c | 63 
> +++--
>  drivers/char/tpm/tpm_eventlog.h | 10 +++
>  4 files changed, 40 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index e595013..826609d 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -278,14 +278,15 @@ static void tpm_del_char_device(struct tpm_chip *chip)
>  
>  static int tpm1_chip_register(struct tpm_chip *chip)
>  {
> + int rc;
>   if (chip->flags & TPM_CHIP_FLAG_TPM2)
>   return 0;
>  
>   tpm_sysfs_add_device(chip);
>  
> - chip->bios_dir = tpm_bios_log_setup(dev_name(>dev));
> + rc = tpm_bios_log_setup(chip);
>  
> - return 0;
> + return rc;
>  }
>  
>  static void tpm1_chip_unregister(struct tpm_chip *chip)
> @@ -293,8 +294,7 @@ static void tpm1_chip_unregister(struct tpm_chip *chip)
>   if (chip->flags & TPM_CHIP_FLAG_TPM2)
>   return;
>  
> - if (chip->bios_dir)
> - tpm_bios_log_teardown(chip->bios_dir);
> + tpm_bios_log_teardown(chip);
>  }
>  
>  static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 3e952fb..b5866bb 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -171,7 +171,8 @@ struct tpm_chip {
>   unsigned long duration[3]; /* jiffies */
>   bool duration_adjusted;
>  
> - struct dentry **bios_dir;
> + struct dentry *bios_dir[3];
> + unsigned int bios_dir_count;
>  
>   const struct attribute_group *groups[3];
>   unsigned int groups_cnt;
> diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm_eventlog.c
> index 75e6644..f1df782 100644
> --- a/drivers/char/tpm/tpm_eventlog.c
> +++ b/drivers/char/tpm/tpm_eventlog.c
> @@ -332,7 +332,8 @@ static int tpm_bios_measurements_open(struct inode *inode,
>   if (!log)
>   return -ENOMEM;
>  
> - if ((err = read_log(log)))
> + err = read_log(log);
> + if (err)
>   goto out_free;
>  
>   /* now register seq file */
> @@ -368,54 +369,48 @@ static int is_bad(void *p)
>   return 0;
>  }
>  
> -struct dentry **tpm_bios_log_setup(const char *name)
> +int tpm_bios_log_setup(struct tpm_chip *chip)
>  {
> - struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
> + const char *name = dev_name(>dev);
>  
> - tpm_dir = securityfs_create_dir(name, NULL);
> - if (is_bad(tpm_dir))
> - goto out;
> + chip->bios_dir_count = 0;
> + chip->bios_dir[chip->bios_dir_count] =
> + securityfs_create_dir(name, NULL);
> + if (is_bad(chip->bios_dir[chip->bios_dir_count]))
> + goto err;
> + chip->bios_dir_count++;
>  
> - bin_file =
> + chip->bios_dir[chip->bios_dir_count] =
>   securityfs_create_file("binary_bios_measurements",
> -S_IRUSR | S_IRGRP, tpm_dir,
> +S_IRUSR | S_IRGRP, chip->bios_dir[0],
>  (void *)_binary_b_measurments_seqops,
>  _bios_measurements_ops);
> - if (is_bad(bin_file))
> - goto out_tpm;
> + if (is_bad(chip->bios_dir[chip->bios_dir_count]))
> + goto err;
> + chip->bios_dir_count++;
>  
> - ascii_file =
> + chip->bios_dir[chip->bios_dir_count] =
>   securityfs_create_file("ascii_bios_measurements",
> -S_IRUSR | S_IRGRP, tpm_dir,
> +S_IRUSR | S_IRGRP, chip->bios_dir[0],
>  (void *)_ascii_b_measurments_seqops,
>  _bios_measurements_ops);

The following securityfs_create_file calls overwrite the same field,
which leaks memory, as you pass chip->biod_dir[0] to these calls.

I guess securityfs_remove() returns with NULL input (haven't checked).

/Jarkko

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Re: [tpmdd-devel] [PATCH v4 2/8] tpm: replace dynamically allocated bios_dir with dentry array

2016-10-01 Thread Jarkko Sakkinen 
On Fri, Sep 30, 2016 at 02:31:47PM -0600, Jason Gunthorpe wrote:
> On Fri, Sep 30, 2016 at 10:48:25PM +0300, Jarkko Sakkinen wrote:
> > On Fri, Sep 30, 2016 at 12:30:26PM -0600, Jason Gunthorpe wrote:
> > > On Fri, Sep 30, 2016 at 09:27:03PM +0300, Jarkko Sakkinen wrote:
> > > > On Wed, Sep 28, 2016 at 04:34:36AM -0400, Nayna Jain wrote:
> > > 
> > > > > - struct dentry **bios_dir;
> > > > > + struct dentry *bios_dir[3];
> > > > > + unsigned int bios_dir_count;
> > > > 
> > > > You should rather have a four entry array and use a NULL terminator.
> > > 
> > > Why? Then everything has to compute the length before doing
> > > anything. The basic ops are 'append to back' and 'pop off back' which
> > > require length.
> > 
> > One variable less to struct tpm_chip. The loop that removes the files
> > simply can continue until NULL is encountered.
> 
> We've been over this, the loop has to remove them in reverse over.
> 
> Why are you so concerned about size of tpm_chip??

It's not the size. It's the added complexity.

I'll look into revising this commit a bit in order in order to move
things forward...

/Jarkko

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Re: [tpmdd-devel] [PATCH v4 2/8] tpm: replace dynamically allocated bios_dir with dentry array

2016-09-30 Thread Jason Gunthorpe 
On Fri, Sep 30, 2016 at 10:48:25PM +0300, Jarkko Sakkinen wrote:
> On Fri, Sep 30, 2016 at 12:30:26PM -0600, Jason Gunthorpe wrote:
> > On Fri, Sep 30, 2016 at 09:27:03PM +0300, Jarkko Sakkinen wrote:
> > > On Wed, Sep 28, 2016 at 04:34:36AM -0400, Nayna Jain wrote:
> > 
> > > > -   struct dentry **bios_dir;
> > > > +   struct dentry *bios_dir[3];
> > > > +   unsigned int bios_dir_count;
> > > 
> > > You should rather have a four entry array and use a NULL terminator.
> > 
> > Why? Then everything has to compute the length before doing
> > anything. The basic ops are 'append to back' and 'pop off back' which
> > require length.
> 
> One variable less to struct tpm_chip. The loop that removes the files
> simply can continue until NULL is encountered.

We've been over this, the loop has to remove them in reverse over.

Why are you so concerned about size of tpm_chip??

> Where do you need the length?

Every place that touches the array

Jason

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Re: [tpmdd-devel] [PATCH v4 2/8] tpm: replace dynamically allocated bios_dir with dentry array

2016-09-30 Thread Jarkko Sakkinen 
On Fri, Sep 30, 2016 at 12:30:26PM -0600, Jason Gunthorpe wrote:
> On Fri, Sep 30, 2016 at 09:27:03PM +0300, Jarkko Sakkinen wrote:
> > On Wed, Sep 28, 2016 at 04:34:36AM -0400, Nayna Jain wrote:
> 
> > > - struct dentry **bios_dir;
> > > + struct dentry *bios_dir[3];
> > > + unsigned int bios_dir_count;
> > 
> > You should rather have a four entry array and use a NULL terminator.
> 
> Why? Then everything has to compute the length before doing
> anything. The basic ops are 'append to back' and 'pop off back' which
> require length.

One variable less to struct tpm_chip. The loop that removes the files
simply can continue until NULL is encountered.

Where do you need the length?

> Jason

/Jarkko

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Re: [tpmdd-devel] [PATCH v4 2/8] tpm: replace dynamically allocated bios_dir with dentry array

2016-09-30 Thread Jarkko Sakkinen 
On Wed, Sep 28, 2016 at 04:34:36AM -0400, Nayna Jain wrote:
> bios_dir is defined as struct dentry **bios_dir, which results in
> dynamic allocation and therefore possibly a memory leak. This patch
> replaces it with struct dentry array(struct dentry *bios_dir[3])
> similar to what is done for sysfs groups.
> 
> Suggested-by: Jason Gunthorpe 
> Signed-off-by: Nayna Jain 
> Reviewed-by: Jason Gunthorpe 
> ---
>  drivers/char/tpm/tpm-chip.c |  8 +++---
>  drivers/char/tpm/tpm.h  |  3 +-
>  drivers/char/tpm/tpm_eventlog.c | 63 
> +++--
>  drivers/char/tpm/tpm_eventlog.h | 10 +++
>  4 files changed, 40 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> index e595013..826609d 100644
> --- a/drivers/char/tpm/tpm-chip.c
> +++ b/drivers/char/tpm/tpm-chip.c
> @@ -278,14 +278,15 @@ static void tpm_del_char_device(struct tpm_chip *chip)
>  
>  static int tpm1_chip_register(struct tpm_chip *chip)
>  {
> + int rc;
>   if (chip->flags & TPM_CHIP_FLAG_TPM2)
>   return 0;
>  
>   tpm_sysfs_add_device(chip);
>  
> - chip->bios_dir = tpm_bios_log_setup(dev_name(>dev));
> + rc = tpm_bios_log_setup(chip);
>  
> - return 0;
> + return rc;
>  }
>  
>  static void tpm1_chip_unregister(struct tpm_chip *chip)
> @@ -293,8 +294,7 @@ static void tpm1_chip_unregister(struct tpm_chip *chip)
>   if (chip->flags & TPM_CHIP_FLAG_TPM2)
>   return;
>  
> - if (chip->bios_dir)
> - tpm_bios_log_teardown(chip->bios_dir);
> + tpm_bios_log_teardown(chip);
>  }
>  
>  static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 3e952fb..b5866bb 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -171,7 +171,8 @@ struct tpm_chip {
>   unsigned long duration[3]; /* jiffies */
>   bool duration_adjusted;
>  
> - struct dentry **bios_dir;
> + struct dentry *bios_dir[3];
> + unsigned int bios_dir_count;

You should rather have a four entry array and use a NULL terminator.

>   const struct attribute_group *groups[3];
>   unsigned int groups_cnt;
> diff --git a/drivers/char/tpm/tpm_eventlog.c b/drivers/char/tpm/tpm_eventlog.c
> index 75e6644..f1df782 100644
> --- a/drivers/char/tpm/tpm_eventlog.c
> +++ b/drivers/char/tpm/tpm_eventlog.c
> @@ -332,7 +332,8 @@ static int tpm_bios_measurements_open(struct inode *inode,
>   if (!log)
>   return -ENOMEM;
>  
> - if ((err = read_log(log)))
> + err = read_log(log);
> + if (err)
>   goto out_free;
>  
>   /* now register seq file */
> @@ -368,54 +369,48 @@ static int is_bad(void *p)
>   return 0;
>  }
>  
> -struct dentry **tpm_bios_log_setup(const char *name)
> +int tpm_bios_log_setup(struct tpm_chip *chip)
>  {
> - struct dentry **ret = NULL, *tpm_dir, *bin_file, *ascii_file;
> + const char *name = dev_name(>dev);
>  
> - tpm_dir = securityfs_create_dir(name, NULL);
> - if (is_bad(tpm_dir))
> - goto out;
> + chip->bios_dir_count = 0;
> + chip->bios_dir[chip->bios_dir_count] =
> + securityfs_create_dir(name, NULL);
> + if (is_bad(chip->bios_dir[chip->bios_dir_count]))
> + goto err;
> + chip->bios_dir_count++;
>  
> - bin_file =
> + chip->bios_dir[chip->bios_dir_count] =
>   securityfs_create_file("binary_bios_measurements",
> -S_IRUSR | S_IRGRP, tpm_dir,
> +S_IRUSR | S_IRGRP, chip->bios_dir[0],
>  (void *)_binary_b_measurments_seqops,
>  _bios_measurements_ops);
> - if (is_bad(bin_file))
> - goto out_tpm;
> + if (is_bad(chip->bios_dir[chip->bios_dir_count]))
> + goto err;
> + chip->bios_dir_count++;
>  
> - ascii_file =
> + chip->bios_dir[chip->bios_dir_count] =
>   securityfs_create_file("ascii_bios_measurements",
> -S_IRUSR | S_IRGRP, tpm_dir,
> +S_IRUSR | S_IRGRP, chip->bios_dir[0],
>  (void *)_ascii_b_measurments_seqops,
>  _bios_measurements_ops);
> - if (is_bad(ascii_file))
> - goto out_bin;
> + if (is_bad(chip->bios_dir[chip->bios_dir_count]))
> + goto err;
> + chip->bios_dir_count++;
>  
> - ret = kmalloc(3 * sizeof(struct dentry *), GFP_KERNEL);
> - if (!ret)
> - goto out_ascii;
> -
> - ret[0] = ascii_file;
> - ret[1] = bin_file;
> - ret[2] = tpm_dir;
> -
> - return ret;
> + return 0;
>  
> -out_ascii:
> - securityfs_remove(ascii_file);
> -out_bin:
> - securityfs_remove(bin_file);
> -out_tpm:
> -