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>

2 files changed, 14 insertions, 4 deletions

diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c
index 8e4894b205e2..3f7ea13358e9 100644
--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -1090,7 +1090,8 @@ efi_memmap_init(unsigned long *s, unsigned long *e)
 
 void
 efi_initialize_iomem_resources(struct resource *code_resource,
-                               struct resource *data_resource)
+                               struct resource *data_resource,
+                               struct resource *bss_resource)
 {
         struct resource *res;
         void *efi_map_start, *efi_map_end, *p;
@@ -1171,6 +1172,7 @@ efi_initialize_iomem_resources(struct resource *code_resource,
                          */
                         insert_resource(res, code_resource);
                         insert_resource(res, data_resource);
+                        insert_resource(res, bss_resource);
 #ifdef CONFIG_KEXEC
                         insert_resource(res, &efi_memmap_res);
                         insert_resource(res, &boot_param_res);
diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index cbf67f1aa291..ae6c3c02e117 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -90,7 +90,12 @@ static struct resource code_resource = {
         .name   = "Kernel code",
         .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
 };
-extern char _text[], _end[], _etext[];
+
+static struct resource bss_resource = {
+        .name   = "Kernel bss",
+        .flags  = IORESOURCE_BUSY | IORESOURCE_MEM
+};
+extern char _text[], _end[], _etext[], _edata[], _bss[];
 
 unsigned long ia64_max_cacheline_size;
 
@@ -200,8 +205,11 @@ static int __init register_memory(void)
         code_resource.start = ia64_tpa(_text);
         code_resource.end   = ia64_tpa(_etext) - 1;
         data_resource.start = ia64_tpa(_etext);
-        data_resource.end   = ia64_tpa(_end) - 1;
-        efi_initialize_iomem_resources(&code_resource, &data_resource);
+        data_resource.end   = ia64_tpa(_edata) - 1;
+        bss_resource.start  = ia64_tpa(_bss);
+        bss_resource.end    = ia64_tpa(_end) - 1;
+        efi_initialize_iomem_resources(&code_resource, &data_resource,
+                        &bss_resource);
 
         return 0;
 }