Re: [RFC 09/32] fs/pstore: convert to struct inode_time

From: Kees Cook <keescook@chromium.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
	linux-arch@vger.kernel.org,
	"Joseph S. Myers" <joseph@codesourcery.com>,
	John Stultz <john.stultz@linaro.org>,
	Christoph Hellwig <hch@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	lftan@altera.com, "H. Peter Anvin" <hpa@zytor.com>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	Anton Vorontsov <anton@enomsg.org>,
	Colin Cross <ccross@android.com>, Tony Luck <tony.luck@intel.com>
Subject: Re: [RFC 09/32] fs/pstore: convert to struct inode_time
Date: Fri, 30 May 2014 14:14:39 -0700	[thread overview]
Message-ID: <CAGXu5jLwmhLEqBDToE886=9c70AH7J6_aVqKTcH-KUX2ywzRbQ@mail.gmail.com> (raw)
In-Reply-To: <1401480116-1973111-10-git-send-email-arnd@arndb.de>

On Fri, May 30, 2014 at 1:01 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> pstore uses timestamps encoded in a string as seconds, but on 32-bit systems
> cannot go beyond year 2038 because of the limits of struct timespec.
>
> This converts the pstore code to use the new struct inode_time for timestamps.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Cc: Anton Vorontsov <anton@enomsg.org>
> Cc: Colin Cross <ccross@android.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Tony Luck <tony.luck@intel.com>

I don't see why you don't want to support making Linux work as a time
machine to visit the 70s! ;)

Acked-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/firmware/efi/efi-pstore.c | 28 ++++++++++++++--------------
>  fs/pstore/inode.c                 |  2 +-
>  fs/pstore/internal.h              |  2 +-
>  fs/pstore/platform.c              |  2 +-
>  fs/pstore/ram.c                   | 18 ++++++++++--------
>  include/linux/pstore.h            |  4 ++--
>  6 files changed, 29 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
> index 4b9dc83..a1e4153 100644
> --- a/drivers/firmware/efi/efi-pstore.c
> +++ b/drivers/firmware/efi/efi-pstore.c
> @@ -32,7 +32,7 @@ struct pstore_read_data {
>         u64 *id;
>         enum pstore_type_id *type;
>         int *count;
> -       struct timespec *timespec;
> +       struct inode_time *inode_time;
>         bool *compressed;
>         char **buf;
>  };
> @@ -63,8 +63,8 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
>                    cb_data->type, &part, &cnt, &time, &data_type) == 5) {
>                 *cb_data->id = generic_id(time, part, cnt);
>                 *cb_data->count = cnt;
> -               cb_data->timespec->tv_sec = time;
> -               cb_data->timespec->tv_nsec = 0;
> +               cb_data->inode_time->tv_sec = time;
> +               cb_data->inode_time->tv_nsec = 0;
>                 if (data_type == 'C')
>                         *cb_data->compressed = true;
>                 else
> @@ -73,8 +73,8 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
>                    cb_data->type, &part, &cnt, &time) == 4) {
>                 *cb_data->id = generic_id(time, part, cnt);
>                 *cb_data->count = cnt;
> -               cb_data->timespec->tv_sec = time;
> -               cb_data->timespec->tv_nsec = 0;
> +               cb_data->inode_time->tv_sec = time;
> +               cb_data->inode_time->tv_nsec = 0;
>                 *cb_data->compressed = false;
>         } else if (sscanf(name, "dump-type%u-%u-%lu",
>                           cb_data->type, &part, &time) == 3) {
> @@ -85,8 +85,8 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
>                  */
>                 *cb_data->id = generic_id(time, part, 0);
>                 *cb_data->count = 0;
> -               cb_data->timespec->tv_sec = time;
> -               cb_data->timespec->tv_nsec = 0;
> +               cb_data->inode_time->tv_sec = time;
> +               cb_data->inode_time->tv_nsec = 0;
>                 *cb_data->compressed = false;
>         } else
>                 return 0;
> @@ -208,7 +208,7 @@ static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
>   *           and pstore will stop reading entry.
>   */
>  static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
> -                              int *count, struct timespec *timespec,
> +                              int *count, struct inode_time *inode_time,
>                                char **buf, bool *compressed,
>                                struct pstore_info *psi)
>  {
> @@ -218,7 +218,7 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
>         data.id = id;
>         data.type = type;
>         data.count = count;
> -       data.timespec = timespec;
> +       data.inode_time = inode_time;
>         data.compressed = compressed;
>         data.buf = buf;
>
> @@ -266,7 +266,7 @@ struct pstore_erase_data {
>         u64 id;
>         enum pstore_type_id type;
>         int count;
> -       struct timespec time;
> +       struct inode_time time;
>         efi_char16_t *name;
>  };
>
> @@ -292,8 +292,8 @@ static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
>                  * Check if an old format, which doesn't support
>                  * holding multiple logs, remains.
>                  */
> -               sprintf(name_old, "dump-type%u-%u-%lu", ed->type,
> -                       (unsigned int)ed->id, ed->time.tv_sec);
> +               sprintf(name_old, "dump-type%u-%u-%llu", ed->type,
> +                       (unsigned int)ed->id, (u64)ed->time.tv_sec);
>
>                 for (i = 0; i < DUMP_NAME_LEN; i++)
>                         efi_name_old[i] = name_old[i];
> @@ -319,7 +319,7 @@ static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
>  }
>
>  static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
> -                           struct timespec time, struct pstore_info *psi)
> +                           struct inode_time time, struct pstore_info *psi)
>  {
>         struct pstore_erase_data edata;
>         struct efivar_entry *entry = NULL;
> @@ -330,7 +330,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
>
>         do_div(id, 1000);
>         part = do_div(id, 100);
> -       sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, time.tv_sec);
> +       sprintf(name, "dump-type%u-%u-%d-%llu", type, part, count, (u64)time.tv_sec);
>
>         for (i = 0; i < DUMP_NAME_LEN; i++)
>                 efi_name[i] = name[i];
> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
> index 192297b..6f3925f 100644
> --- a/fs/pstore/inode.c
> +++ b/fs/pstore/inode.c
> @@ -277,7 +277,7 @@ int pstore_is_mounted(void)
>   */
>  int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
>                   char *data, bool compressed, size_t size,
> -                 struct timespec time, struct pstore_info *psi)
> +                 struct inode_time time, struct pstore_info *psi)
>  {
>         struct dentry           *root = pstore_sb->s_root;
>         struct dentry           *dentry;
> diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
> index 3b3d305..eb9c4eb 100644
> --- a/fs/pstore/internal.h
> +++ b/fs/pstore/internal.h
> @@ -51,7 +51,7 @@ extern void   pstore_set_kmsg_bytes(int);
>  extern void    pstore_get_records(int);
>  extern int     pstore_mkfile(enum pstore_type_id, char *psname, u64 id,
>                               int count, char *data, bool compressed,
> -                             size_t size, struct timespec time,
> +                             size_t size, struct inode_time time,
>                               struct pstore_info *psi);
>  extern int     pstore_is_mounted(void);
>
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index 0a9b72c..06f2628 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -475,7 +475,7 @@ void pstore_get_records(int quiet)
>         u64                     id;
>         int                     count;
>         enum pstore_type_id     type;
> -       struct timespec         time;
> +       struct inode_time       time;
>         int                     failed = 0, rc;
>         bool                    compressed;
>         int                     unzipped_len = -1;
> diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
> index 3b57443..50d7298 100644
> --- a/fs/pstore/ram.c
> +++ b/fs/pstore/ram.c
> @@ -135,29 +135,31 @@ ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
>         return prz;
>  }
>
> -static void ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
> +static void ramoops_read_kmsg_hdr(char *buffer, struct inode_time *time,
>                                   bool *compressed)
>  {
>         char data_type;
> +       u64 seconds;
>
> -       if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
> -                       &time->tv_sec, &time->tv_nsec, &data_type) == 3) {
> +       if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%llu.%lu-%c\n",
> +                       &seconds, &time->tv_nsec, &data_type) == 3) {
>                 if (data_type == 'C')
>                         *compressed = true;
>                 else
>                         *compressed = false;
> -       } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n",
> -                       &time->tv_sec, &time->tv_nsec) == 2) {
> +       } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%llu.%lu\n",
> +                       &seconds, &time->tv_nsec) == 2) {
>                         *compressed = false;
>         } else {
> -               time->tv_sec = 0;
> +               seconds = 0;
>                 time->tv_nsec = 0;
>                 *compressed = false;
>         }
> +       time->tv_sec = seconds;
>  }
>
>  static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
> -                                  int *count, struct timespec *time,
> +                                  int *count, struct inode_time *time,
>                                    char **buf, bool *compressed,
>                                    struct pstore_info *psi)
>  {
> @@ -278,7 +280,7 @@ static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
>  }
>
>  static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
> -                               struct timespec time, struct pstore_info *psi)
> +                               struct inode_time time, struct pstore_info *psi)
>  {
>         struct ramoops_context *cxt = psi->data;
>         struct persistent_ram_zone *prz;
> diff --git a/include/linux/pstore.h b/include/linux/pstore.h
> index ece0c6b..f293905 100644
> --- a/include/linux/pstore.h
> +++ b/include/linux/pstore.h
> @@ -55,7 +55,7 @@ struct pstore_info {
>         int             (*open)(struct pstore_info *psi);
>         int             (*close)(struct pstore_info *psi);
>         ssize_t         (*read)(u64 *id, enum pstore_type_id *type,
> -                       int *count, struct timespec *time, char **buf,
> +                       int *count, struct inode_time *time, char **buf,
>                         bool *compressed, struct pstore_info *psi);
>         int             (*write)(enum pstore_type_id type,
>                         enum kmsg_dump_reason reason, u64 *id,
> @@ -66,7 +66,7 @@ struct pstore_info {
>                         unsigned int part, const char *buf, bool compressed,
>                         size_t size, struct pstore_info *psi);
>         int             (*erase)(enum pstore_type_id type, u64 id,
> -                       int count, struct timespec time,
> +                       int count, struct inode_time time,
>                         struct pstore_info *psi);
>         void            *data;
>  };
> --
> 1.8.3.2
>

-- 
Kees Cook
Chrome OS Security