pstore: Split pstore fragile flags

This patch adds new PSTORE_FLAGS for each pstore type so that they can
be enabled separately.  This is a preparation for ongoing virtio-pstore
work to support those types flexibly.

The PSTORE_FLAGS_FRAGILE is changed to PSTORE_FLAGS_DMESG to preserve the
original behavior.

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>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: linux-acpi@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
[kees: retained "FRAGILE" for now to make merges easier]
Signed-off-by: Kees Cook <keescook@chromium.org>

5 files changed, 21 insertions, 10 deletions

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index f096ab3cb54d..ec4f507b524f 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -938,7 +938,7 @@ static int erst_clearer(enum pstore_type_id type, u64 id, int count,
 static struct pstore_info erst_info = {
         .owner          = THIS_MODULE,
         .name           = "erst",
-        .flags          = PSTORE_FLAGS_FRAGILE,
+        .flags          = PSTORE_FLAGS_DMESG,
         .open           = erst_open_pstore,
         .close          = erst_close_pstore,
         .read           = erst_reader,
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 30a24d09ea6c..4daa5acd9117 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -362,7 +362,7 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
 static struct pstore_info efi_pstore_info = {
         .owner          = THIS_MODULE,
         .name           = "efi",
-        .flags          = PSTORE_FLAGS_FRAGILE,
+        .flags          = PSTORE_FLAGS_DMESG,
         .open           = efi_pstore_open,
         .close          = efi_pstore_close,
         .read           = efi_pstore_read,
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 16ecca5b72d8..76dd604a0f2c 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -659,13 +659,14 @@ int pstore_register(struct pstore_info *psi)
         if (pstore_is_mounted())
                 pstore_get_records(0);
 
-        pstore_register_kmsg();
-
-        if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
+        if (psi->flags & PSTORE_FLAGS_DMESG)
+                pstore_register_kmsg();
+        if (psi->flags & PSTORE_FLAGS_CONSOLE)
                 pstore_register_console();
+        if (psi->flags & PSTORE_FLAGS_FTRACE)
                 pstore_register_ftrace();
+        if (psi->flags & PSTORE_FLAGS_PMSG)
                 pstore_register_pmsg();
-        }
 
         if (pstore_update_ms >= 0) {
                 pstore_timer.expires = jiffies +
@@ -689,12 +690,14 @@ EXPORT_SYMBOL_GPL(pstore_register);
 
 void pstore_unregister(struct pstore_info *psi)
 {
-        if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) {
+        if (psi->flags & PSTORE_FLAGS_PMSG)
                 pstore_unregister_pmsg();
+        if (psi->flags & PSTORE_FLAGS_FTRACE)
                 pstore_unregister_ftrace();
+        if (psi->flags & PSTORE_FLAGS_CONSOLE)
                 pstore_unregister_console();
-        }
-        pstore_unregister_kmsg();
+        if (psi->flags & PSTORE_FLAGS_DMESG)
+                pstore_unregister_kmsg();
 
         free_buf_for_compression();
 
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 2340262a7e97..c2ebf5084977 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -623,6 +623,8 @@ static int ramoops_probe(struct platform_device *pdev)
                 goto fail_clear;
         }
 
+        cxt->pstore.flags = PSTORE_FLAGS_ALL;
+
         err = pstore_register(&cxt->pstore);
         if (err) {
                 pr_err("registering with pstore failed\n");
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 899e95e84400..f5806b2a6f7a 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -74,7 +74,13 @@ struct pstore_info {
         void            *data;
 };
 
-#define PSTORE_FLAGS_FRAGILE    1
+#define PSTORE_FLAGS_DMESG      (1 << 0)
+#define PSTORE_FLAGS_FRAGILE    PSTORE_FLAGS_DMESG
+#define PSTORE_FLAGS_CONSOLE    (1 << 1)
+#define PSTORE_FLAGS_FTRACE     (1 << 2)
+#define PSTORE_FLAGS_PMSG       (1 << 3)
+
+#define PSTORE_FLAGS_ALL        ((1 << 4) - 1)
 
 extern int pstore_register(struct pstore_info *);
 extern void pstore_unregister(struct pstore_info *);