pstore: Make ramoops_init_przs generic for other prz arrays

Currently ramoops_init_przs() is hard wired only for panic dump zone
array. In preparation for the ftrace zone array (one zone per-cpu) and pmsg
zone array, make the function more generic to be able to handle this case.

Heavily based on similar work from Joel Fernandes.

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

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 86ac59066fba9d9f89eb0d8dcbde04496f2d7154..34294c32af0b8242341e4e0c7bae45391d8bfa81 100644 (file)
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -405,53 +405,78 @@ static void ramoops_free_przs(struct ramoops_context *cxt)
 }
 
 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
-                            phys_addr_t *paddr, size_t dump_mem_sz)
+                            struct persistent_ram_zone ***przs,
+                            phys_addr_t *paddr, size_t mem_sz,
+                            ssize_t record_size,
+                            unsigned int *cnt, u32 sig, u32 flags)
 {
        int err = -ENOMEM;
        int i;
+       size_t zone_sz;
+       struct persistent_ram_zone **prz_ar;
 
-       if (!cxt->record_size)
+       /* Allocate nothing for 0 mem_sz or 0 record_size. */
+       if (mem_sz == 0 || record_size == 0) {
+               *cnt = 0;
                return 0;
-
-       if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
-               dev_err(dev, "no room for dumps\n");
-               return -ENOMEM;
        }
 
-       cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
-       if (!cxt->max_dump_cnt)
-               return -ENOMEM;
+       /*
+        * If we have a negative record size, calculate it based on
+        * mem_sz / *cnt. If we have a positive record size, calculate
+        * cnt from mem_sz / record_size.
+        */
+       if (record_size < 0) {
+               if (*cnt == 0)
+                       return 0;
+               record_size = mem_sz / *cnt;
+               if (record_size == 0)
+                       goto fail;
+       } else {
+               *cnt = mem_sz / record_size;
+               if (*cnt == 0)
+                       goto fail;
+       }
 
-       cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
-                            GFP_KERNEL);
-       if (!cxt->przs) {
-               dev_err(dev, "failed to initialize a prz array for dumps\n");
-               goto fail_mem;
+       if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
+               dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
+                       mem_sz, (unsigned long long)*paddr,
+                       cxt->size, (unsigned long long)cxt->phys_addr);
+               goto fail;
        }
 
-       for (i = 0; i < cxt->max_dump_cnt; i++) {
-               cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
+       zone_sz = mem_sz / *cnt;
+       if (!zone_sz)
+               goto fail;
+
+       prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
+       if (!prz_ar)
+               goto fail;
+
+       for (i = 0; i < *cnt; i++) {
+               prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
                                                  &cxt->ecc_info,
-                                                 cxt->memtype, 0);
-               if (IS_ERR(cxt->przs[i])) {
-                       err = PTR_ERR(cxt->przs[i]);
+                                                 cxt->memtype, flags);
+               if (IS_ERR(prz_ar[i])) {
+                       err = PTR_ERR(prz_ar[i]);
                        dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
-                               cxt->record_size, (unsigned long long)*paddr, err);
+                               record_size, (unsigned long long)*paddr, err);
 
                        while (i > 0) {
                                i--;
-                               persistent_ram_free(cxt->przs[i]);
+                               persistent_ram_free(prz_ar[i]);
                        }
-                       goto fail_prz;
+                       kfree(prz_ar);
+                       goto fail;
                }
-               *paddr += cxt->record_size;
+               *paddr += zone_sz;
        }
 
+       *przs = prz_ar;
        return 0;
-fail_prz:
-       kfree(cxt->przs);
-fail_mem:
-       cxt->max_dump_cnt = 0;
+
+fail:
+       *cnt = 0;
        return err;
 }
 
@@ -605,7 +630,8 @@ static int ramoops_probe(struct platform_device *pdev)
 
        dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
                        - cxt->pmsg_size;
-       err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
+       err = ramoops_init_przs(dev, cxt, &cxt->przs, &paddr, dump_mem_sz,
+                               cxt->record_size, &cxt->max_dump_cnt, 0, 0);
        if (err)
                goto fail_out;