pstore: pass allocated memory region back to caller

[linux-2.6.git] / drivers / acpi / apei / erst.c

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index 127408069ca7fa745953fd5a8e164cd74779c680..631b9477b99c02f827103aa00a8d3a83c380d359 100644 (file)
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -932,7 +932,8 @@ static int erst_check_table(struct acpi_table_erst *erst_tab)
 static int erst_open_pstore(struct pstore_info *psi);
 static int erst_close_pstore(struct pstore_info *psi);
 static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
-                          struct timespec *time, struct pstore_info *psi);
+                          struct timespec *time, char **buf,
+                          struct pstore_info *psi);
 static int erst_writer(enum pstore_type_id type, u64 *id, unsigned int part,
                       size_t size, struct pstore_info *psi);
 static int erst_clearer(enum pstore_type_id type, u64 id,
@@ -986,17 +987,23 @@ static int erst_close_pstore(struct pstore_info *psi)
 }
 
 static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
-                          struct timespec *time, struct pstore_info *psi)
+                          struct timespec *time, char **buf,
+                          struct pstore_info *psi)
 {
        int rc;
        ssize_t len = 0;
        u64 record_id;
-       struct cper_pstore_record *rcd = (struct cper_pstore_record *)
-                                       (erst_info.buf - sizeof(*rcd));
+       struct cper_pstore_record *rcd;
+       size_t rcd_len = sizeof(*rcd) + erst_info.bufsize;
 
        if (erst_disable)
                return -ENODEV;
 
+       rcd = kmalloc(rcd_len, GFP_KERNEL);
+       if (!rcd) {
+               rc = -ENOMEM;
+               goto out;
+       }
 skip:
        rc = erst_get_record_id_next(&reader_pos, &record_id);
        if (rc)
@@ -1004,22 +1011,27 @@ skip:
 
        /* no more record */
        if (record_id == APEI_ERST_INVALID_RECORD_ID) {
-               rc = -1;
+               rc = -EINVAL;
                goto out;
        }
 
-       len = erst_read(record_id, &rcd->hdr, sizeof(*rcd) +
-                       erst_info.bufsize);
+       len = erst_read(record_id, &rcd->hdr, rcd_len);
        /* The record may be cleared by others, try read next record */
        if (len == -ENOENT)
                goto skip;
-       else if (len < 0) {
-               rc = -1;
+       else if (len < sizeof(*rcd)) {
+               rc = -EIO;
                goto out;
        }
        if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
                goto skip;
 
+       *buf = kmalloc(len, GFP_KERNEL);
+       if (*buf == NULL) {
+               rc = -ENOMEM;
+               goto out;
+       }
+       memcpy(*buf, rcd->data, len - sizeof(*rcd));
        *id = record_id;
        if (uuid_le_cmp(rcd->sec_hdr.section_type,
                        CPER_SECTION_TYPE_DMESG) == 0)
@@ -1037,6 +1049,7 @@ skip:
        time->tv_nsec = 0;
 
 out:
+       kfree(rcd);
        return (rc < 0) ? rc : (len - sizeof(*rcd));
 }