kexec: add BSS to resource tree

Add the BSS to the resource tree just as kernel text and kernel data are in
the resource tree.  The main reason behind this is to avoid crashkernel
reservation in that area.

While it's not strictly necessary to have the BSS in the resource tree (the
actual collision detection is done in the reserve_bootmem() function before),
the usage of the BSS resource should be presented to the user in /proc/iomem
just as Kernel data and Kernel code.

Note: The patch currently is only implemented for x86 and ia64 (because
efi_initialize_iomem_resources() has the same signature on i386 and ia64).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 15 insertions, 3 deletions

diff --git a/arch/x86/kernel/e820_32.c b/arch/x86/kernel/e820_32.c
index 58fd54eb5577..18f500d185a2 100644
--- a/arch/x86/kernel/e820_32.c
+++ b/arch/x86/kernel/e820_32.c
@@ -51,6 +51,13 @@ struct resource code_resource = {
         .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
 };
 
+struct resource bss_resource = {
+        .name   = "Kernel bss",
+        .start  = 0,
+        .end    = 0,
+        .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+
 static struct resource system_rom_resource = {
         .name   = "System ROM",
         .start  = 0xf0000,
@@ -254,7 +261,9 @@ static void __init probe_roms(void)
  * and also for regions reported as reserved by the e820.
  */
 static void __init
-legacy_init_iomem_resources(struct resource *code_resource, struct resource *data_resource)
+legacy_init_iomem_resources(struct resource *code_resource,
+                            struct resource *data_resource,
+                            struct resource *bss_resource)
 {
         int i;
 
@@ -287,6 +296,7 @@ legacy_init_iomem_resources(struct resource *code_resource, struct resource *dat
                          */
                         request_resource(res, code_resource);
                         request_resource(res, data_resource);
+                        request_resource(res, bss_resource);
 #ifdef CONFIG_KEXEC
                         if (crashk_res.start != crashk_res.end)
                                 request_resource(res, &crashk_res);
@@ -307,9 +317,11 @@ static int __init request_standard_resources(void)
 
         printk("Setting up standard PCI resources\n");
         if (efi_enabled)
-                efi_initialize_iomem_resources(&code_resource, &data_resource);
+                efi_initialize_iomem_resources(&code_resource,
+                                &data_resource, &bss_resource);
         else
-                legacy_init_iomem_resources(&code_resource, &data_resource);
+                legacy_init_iomem_resources(&code_resource,
+                                &data_resource, &bss_resource);
 
         /* EFI systems may still have VGA */
         request_resource(&iomem_resource, &video_ram_resource);