pstore: Replace arguments for write_buf_user() API

Removes argument list in favor of pstore record, though the user buffer
remains passed separately since it must carry the __user annotation.

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

4 files changed, 30 insertions, 51 deletions

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 5eecf9012459..1e6642a2063e 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -639,47 +639,36 @@ static int pstore_write_compat(struct pstore_record *record)
         return record->psi->write_buf(record);
 }
 
-static int pstore_write_buf_user_compat(enum pstore_type_id type,
-                               enum kmsg_dump_reason reason,
-                               u64 *id, unsigned int part,
-                               const char __user *buf,
-                               bool compressed, size_t size,
-                               struct pstore_info *psi)
+static int pstore_write_buf_user_compat(struct pstore_record *record,
+                                        const char __user *buf)
 {
         unsigned long flags = 0;
-        size_t i, bufsize = size;
+        size_t i, bufsize, total_size = record->size;
         long ret = 0;
 
-        if (unlikely(!access_ok(VERIFY_READ, buf, size)))
+        if (unlikely(!access_ok(VERIFY_READ, buf, total_size)))
                 return -EFAULT;
+        bufsize = total_size;
         if (bufsize > psinfo->bufsize)
                 bufsize = psinfo->bufsize;
+        record->buf = psinfo->buf;
         spin_lock_irqsave(&psinfo->buf_lock, flags);
-        for (i = 0; i < size; ) {
-                struct pstore_record record = {
-                        .type = type,
-                        .reason = reason,
-                        .id = id,
-                        .part = part,
-                        .buf = psinfo->buf,
-                        .compressed = compressed,
-                        .psi = psi,
-                };
-                size_t c = min(size - i, bufsize);
+        for (i = 0; i < total_size; ) {
+                size_t c = min(total_size - i, bufsize);
 
-                ret = __copy_from_user(psinfo->buf, buf + i, c);
+                ret = __copy_from_user(record->buf, buf + i, c);
                 if (unlikely(ret != 0)) {
                         ret = -EFAULT;
                         break;
                 }
-                record.size = c;
-                ret = psi->write_buf(&record);
+                record->size = c;
+                ret = record->psi->write_buf(record);
                 if (unlikely(ret < 0))
                         break;
                 i += c;
         }
         spin_unlock_irqrestore(&psinfo->buf_lock, flags);
-        return unlikely(ret < 0) ? ret : size;
+        return unlikely(ret < 0) ? ret : total_size;
 }
 
 /*
diff --git a/fs/pstore/pmsg.c b/fs/pstore/pmsg.c
index 78f6176c020f..ce35907602de 100644
--- a/fs/pstore/pmsg.c
+++ b/fs/pstore/pmsg.c
@@ -23,7 +23,11 @@ static DEFINE_MUTEX(pmsg_lock);
 static ssize_t write_pmsg(struct file *file, const char __user *buf,
                           size_t count, loff_t *ppos)
 {
-        u64 id;
+        struct pstore_record record = {
+                .type = PSTORE_TYPE_PMSG,
+                .size = count,
+                .psi = psinfo,
+        };
         int ret;
 
         if (!count)
@@ -34,8 +38,7 @@ static ssize_t write_pmsg(struct file *file, const char __user *buf,
                 return -EFAULT;
 
         mutex_lock(&pmsg_lock);
-        ret = psinfo->write_buf_user(PSTORE_TYPE_PMSG, 0, &id, 0, buf, 0, count,
-                                     psinfo);
+        ret = psinfo->write_buf_user(&record, buf);
         mutex_unlock(&pmsg_lock);
         return ret ? ret : count;
 }
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index a7cdde60b1f9..d85e1adae1b6 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -451,19 +451,15 @@ static int notrace ramoops_pstore_write_buf(struct pstore_record *record)
         return 0;
 }
 
-static int notrace ramoops_pstore_write_buf_user(enum pstore_type_id type,
-                                                 enum kmsg_dump_reason reason,
-                                                 u64 *id, unsigned int part,
-                                                 const char __user *buf,
-                                                 bool compressed, size_t size,
-                                                 struct pstore_info *psi)
+static int notrace ramoops_pstore_write_buf_user(struct pstore_record *record,
+                                                 const char __user *buf)
 {
-        if (type == PSTORE_TYPE_PMSG) {
-                struct ramoops_context *cxt = psi->data;
+        if (record->type == PSTORE_TYPE_PMSG) {
+                struct ramoops_context *cxt = record->psi->data;
 
                 if (!cxt->mprz)
                         return -ENOMEM;
-                return persistent_ram_write_user(cxt->mprz, buf, size);
+                return persistent_ram_write_user(cxt->mprz, buf, record->size);
         }
 
         return -EINVAL;
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index cbf5e561778d..9b85d3eeca83 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -152,18 +152,11 @@ struct pstore_record {
  *
  * @write_buf_user:
  *      Perform a frontend write to a backend record, using a specified
- *      buffer that is coming directly from userspace.
- *
- *      @type:  in: pstore record type to write
- *      @reason:
- *              in: pstore write reason
- *      @id:    out: unique identifier for the record
- *      @part:  in: position in a multipart write
- *      @buf:   in: pointer to userspace contents to write to backend record
- *      @compressed:
- *              in: if the record is compressed
- *      @size:  in: size of the write
- *      @psi:   in: pointer to the struct pstore_info for the backend
+ *      buffer that is coming directly from userspace, instead of the
+ *      @record @buf.
+ *
+ *      @record:        pointer to record metadata.
+ *      @buf:           pointer to userspace contents to write to backend
  *
  *      Returns 0 on success, and non-zero on error.
  *
@@ -196,10 +189,8 @@ struct pstore_info {
         ssize_t         (*read)(struct pstore_record *record);
         int             (*write)(struct pstore_record *record);
         int             (*write_buf)(struct pstore_record *record);
-        int             (*write_buf_user)(enum pstore_type_id type,
-                        enum kmsg_dump_reason reason, u64 *id,
-                        unsigned int part, const char __user *buf,
-                        bool compressed, size_t size, struct pstore_info *psi);
+        int             (*write_buf_user)(struct pstore_record *record,
+                                          const char __user *buf);
         int             (*erase)(struct pstore_record *record);
 };