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From:   Ard Biesheuvel <ardb@kernel.org>
To:     linux-efi@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, Ard Biesheuvel <ardb@kernel.org>,
        Matthew Garrett <mjg59@srcf.ucam.org>,
        Peter Jones <pjones@redhat.com>, Jeremy Kerr <jk@ozlabs.org>,
        Tony Luck <tony.luck@intel.com>,
        Kees Cook <keescook@chromium.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>
Subject: [PATCH v3 1/9] pstore: Add priv field to pstore_record for backend specific use
Date:   Fri, 24 Jun 2022 10:49:17 +0200
Message-Id: <20220624084925.724516-2-ardb@kernel.org>
In-Reply-To: <20220624084925.724516-1-ardb@kernel.org>
References: <20220624084925.724516-1-ardb@kernel.org>
MIME-Version: 1.0
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The EFI pstore backend will need to store per-record variable name data
when we switch away from the efivars layer. Add a priv field to struct
pstore_record, and document it as holding a backend specific pointer
that is assumed to be a kmalloc()d buffer, and will be kfree()d when the
entire record is freed.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 fs/pstore/inode.c      | 1 +
 fs/pstore/platform.c   | 1 +
 include/linux/pstore.h | 4 ++++
 3 files changed, 6 insertions(+)

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 14658b009f1b..ffbadb8b3032 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -55,6 +55,7 @@ static void free_pstore_private(struct pstore_private *private)
 		return;
 	if (private->record) {
 		kfree(private->record->buf);
+		kfree(private->record->priv);
 		kfree(private->record);
 	}
 	kfree(private);
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index e26162f102ff..0c034ea39954 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -769,6 +769,7 @@ void pstore_get_backend_records(struct pstore_info *psi,
 		if (rc) {
 			/* pstore_mkfile() did not take record, so free it. */
 			kfree(record->buf);
+			kfree(record->priv);
 			kfree(record);
 			if (rc != -EEXIST || !quiet)
 				failed++;
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index e97a8188f0fd..638507a3c8ff 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -57,6 +57,9 @@ struct pstore_info;
  * @size:	size of @buf
  * @ecc_notice_size:
  *		ECC information for @buf
+ * @priv:	pointer for backend specific use, will be
+ *		kfree()d by the pstore core if non-NULL
+ *		when the record is freed.
  *
  * Valid for PSTORE_TYPE_DMESG @type:
  *
@@ -74,6 +77,7 @@ struct pstore_record {
 	char			*buf;
 	ssize_t			size;
 	ssize_t			ecc_notice_size;
+	void			*priv;
 
 	int			count;
 	enum kmsg_dump_reason	reason;
-- 
2.35.1