Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

Pull pstore updates from Tony Luck:
 "Miscellaneous pstore improvements"

* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  ramoops: make it possible to change mem_type param.
  pstore/ram: verify ramoops header before saving record
  fs/pstore: Optimization function ramoops_init_przs
  fs/pstore: update the backend parameter in pstore module
  pstore: do not use message compression without lock

2 files changed, 39 insertions, 19 deletions

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index c4c9a10c5760..791743deedf1 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -299,7 +299,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
                 bool compressed;
                 size_t total_len;
 
-                if (big_oops_buf) {
+                if (big_oops_buf && is_locked) {
                         dst = big_oops_buf;
                         hsize = sprintf(dst, "%s#%d Part%u\n", why,
                                                         oopscount, part);
@@ -456,6 +456,12 @@ int pstore_register(struct pstore_info *psi)
                 add_timer(&pstore_timer);
         }
 
+        /*
+         * Update the module parameter backend, so it is visible
+         * through /sys/module/pstore/parameters/backend
+         */
+        backend = psi->name;
+
         pr_info("Registered %s as persistent store backend\n", psi->name);
 
         return 0;
diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 44a549beeafa..6c26c4daaec9 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -186,12 +186,34 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
         ssize_t size;
         ssize_t ecc_notice_size;
         struct ramoops_context *cxt = psi->data;
-        struct persistent_ram_zone *prz;
-        int header_length;
+        struct persistent_ram_zone *prz = NULL;
+        int header_length = 0;
+
+        /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
+         * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
+         * valid time stamps, so it is initialized to zero.
+         */
+        time->tv_sec = 0;
+        time->tv_nsec = 0;
+        *compressed = false;
+
+        /* Find the next valid persistent_ram_zone for DMESG */
+        while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
+                prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
+                                           cxt->max_dump_cnt, id, type,
+                                           PSTORE_TYPE_DMESG, 1);
+                if (!prz_ok(prz))
+                        continue;
+                header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
+                                                      time, compressed);
+                /* Clear and skip this DMESG record if it has no valid header */
+                if (!header_length) {
+                        persistent_ram_free_old(prz);
+                        persistent_ram_zap(prz);
+                        prz = NULL;
+                }
+        }
 
-        prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
-                                   cxt->max_dump_cnt, id, type,
-                                   PSTORE_TYPE_DMESG, 1);
         if (!prz_ok(prz))
                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
@@ -204,13 +226,7 @@ static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
         if (!prz_ok(prz))
                 return 0;
 
-        if (!persistent_ram_old(prz))
-                return 0;
-
-        size = persistent_ram_old_size(prz);
-        header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz), time,
-                        compressed);
-        size -= header_length;
+        size = persistent_ram_old_size(prz) - header_length;
 
         /* ECC correction notice */
         ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
@@ -394,18 +410,16 @@ static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
         }
 
         for (i = 0; i < cxt->max_dump_cnt; i++) {
-                size_t sz = cxt->record_size;
-
-                cxt->przs[i] = persistent_ram_new(*paddr, sz, 0,
+                cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
                                                   &cxt->ecc_info,
                                                   cxt->memtype);
                 if (IS_ERR(cxt->przs[i])) {
                         err = PTR_ERR(cxt->przs[i]);
                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
-                                sz, (unsigned long long)*paddr, err);
+                                cxt->record_size, (unsigned long long)*paddr, err);
                         goto fail_prz;
                 }
-                *paddr += sz;
+                *paddr += cxt->record_size;
         }
 
         return 0;
@@ -608,7 +622,7 @@ static void ramoops_register_dummy(void)
 
         dummy_data->mem_size = mem_size;
         dummy_data->mem_address = mem_address;
-        dummy_data->mem_type = 0;
+        dummy_data->mem_type = mem_type;
         dummy_data->record_size = record_size;
         dummy_data->console_size = ramoops_console_size;
         dummy_data->ftrace_size = ramoops_ftrace_size;