kernel: fix crashlog issues on highmem systems

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/target/linux/generic/patches-4.4/930-crashlog.patch b/target/linux/generic/patches-4.4/930-crashlog.patch
index 311a4f1159c4d9e8623b14575d04f34b228c9938..bb97c90196d8b81c2d4fb3acab836a967da5d964 100644 (file)
--- a/target/linux/generic/patches-4.4/930-crashlog.patch
+++ b/target/linux/generic/patches-4.4/930-crashlog.patch
@@ -43,7 +43,7 @@
  
 --- /dev/null
 +++ b/kernel/crashlog.c
-@@ -0,0 +1,196 @@
+@@ -0,0 +1,209 @@
 +/*
 + * Crash information logger
 + * Copyright (C) 2010 Felix Fietkau <nbd@nbd.name>
@@ -103,40 +103,53 @@
 +
 +extern struct list_head *crashlog_modules;
 +
++static bool crashlog_set_addr(phys_addr_t addr, phys_addr_t size)
++{
++      /* Limit to lower 64 MB to avoid highmem */
++      phys_addr_t limit = 64 * 1024 * 1024;
++
++      if (crashlog_addr)
++              return false;
++
++      if (addr > limit)
++              return false;
++
++      if (addr + size > limit)
++              size = limit - addr;
++
++      crashlog_addr = addr + size - CRASHLOG_OFFSET;
++      return true;
++}
++
 +#ifndef CONFIG_NO_BOOTMEM
 +void __init crashlog_init_bootmem(bootmem_data_t *bdata)
 +{
-+      unsigned long addr;
++      phys_addr_t start, end;
 +
-+      if (crashlog_addr)
++      start = PFN_PHYS(bdata->node_low_pfn);
++      end = PFN_PHYS(bdata->node_min_pfn);
++      if (!crashlog_set_addr(start, end - start))
 +              return;
 +
-+      addr = PFN_PHYS(bdata->node_low_pfn) - CRASHLOG_OFFSET;
-+      if (reserve_bootmem(addr, CRASHLOG_SIZE, BOOTMEM_EXCLUSIVE) < 0) {
-+              printk("Crashlog failed to allocate RAM at address 0x%lx\n", addr);
-+              bdata->node_low_pfn -= CRASHLOG_PAGES;
-+              addr = PFN_PHYS(bdata->node_low_pfn);
++      if (reserve_bootmem(crashlog_addr, CRASHLOG_SIZE, BOOTMEM_EXCLUSIVE) < 0) {
++              printk("Crashlog failed to allocate RAM at address 0x%lx\n",
++                     crashlog_addr);
++              crashlog_addr = 0;
 +      }
-+      crashlog_addr = addr;
 +}
 +#endif
 +
 +#ifdef CONFIG_HAVE_MEMBLOCK
 +void __init_memblock crashlog_init_memblock(phys_addr_t addr, phys_addr_t size)
 +{
-+      if (crashlog_addr)
++      if (!crashlog_set_addr(addr, size))
 +              return;
 +
-+      if (size <= CRASHLOG_OFFSET + CRASHLOG_SIZE)
-+              return;
-+
-+      addr += size - CRASHLOG_OFFSET;
-+      if (memblock_reserve(addr, CRASHLOG_SIZE)) {
-+              printk("Crashlog failed to allocate RAM at address 0x%lx\n", (unsigned long) addr);
-+              return;
++      if (memblock_reserve(crashlog_addr, CRASHLOG_SIZE)) {
++              printk("Crashlog failed to allocate RAM at address 0x%lx\n",
++                     crashlog_addr);
++              crashlog_addr = 0;
 +      }
-+
-+      crashlog_addr = addr;
 +}
 +#endif
 +