pstore: Add pmsg - user-space accessible pstore object

A secured user-space accessible pstore object. Writes
to /dev/pmsg0 are appended to the buffer, on reboot
the persistent contents are available in
/sys/fs/pstore/pmsg-ramoops-[ID].

One possible use is syslogd, or other daemon, can
write messages, then on reboot provides a means to
triage user-space activities leading up to a panic
as a companion to the pstore dmesg or console logs.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

2 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index ece0c6bbfcc5..8884f6e507f7 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -39,6 +39,7 @@ enum pstore_type_id {
         PSTORE_TYPE_PPC_RTAS    = 4,
         PSTORE_TYPE_PPC_OF      = 5,
         PSTORE_TYPE_PPC_COMMON  = 6,
+        PSTORE_TYPE_PMSG        = 7,
         PSTORE_TYPE_UNKNOWN     = 255
 };
 
diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h
index 4af3fdc85b01..9c9d6c154c8e 100644
--- a/include/linux/pstore_ram.h
+++ b/include/linux/pstore_ram.h
@@ -81,6 +81,7 @@ struct ramoops_platform_data {
         unsigned long   record_size;
         unsigned long   console_size;
         unsigned long   ftrace_size;
+        unsigned long   pmsg_size;
         int             dump_oops;
         struct persistent_ram_ecc_info ecc_info;
 };