diff mbox series

[28/29] x86/mm: Report actual image regions in /proc/iomem

Message ID 20190926175602.33098-29-keescook@chromium.org (mailing list archive)
State Not Applicable
Headers show
Series vmlinux.lds.h: Refactor EXCEPTION_TABLE and NOTES | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch next (6edfc6487b474fe01857dc3f1a9cd701bb9b21c8)
snowpatch_ozlabs/checkpatch warning total: 0 errors, 0 warnings, 1 checks, 30 lines checked

Commit Message

Kees Cook Sept. 26, 2019, 5:56 p.m. UTC 
The resource reservations in made for the kernel image did not reflect
the gaps between text, rodata, and data. This adds the rodata resource
and updates the start/end calculations to match the respective calls to
free_kernel_image_pages().

Before (booted with "nokaslr" for easier comparison):

00100000-bffd9fff : System RAM
  01000000-01e011d0 : Kernel code
  01e011d1-025619bf : Kernel data
  02a95000-035fffff : Kernel bss

After:

00100000-bffd9fff : System RAM
  01000000-01e011d0 : Kernel code
  02000000-023d4fff : Kernel rodata
  02400000-025619ff : Kernel data
  02a95000-035fffff : Kernel bss

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/x86/kernel/setup.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Comments

Borislav Petkov Oct. 10, 2019, 6 p.m. UTC | #1 
On Thu, Sep 26, 2019 at 10:56:01AM -0700, Kees Cook wrote:
> The resource reservations in made for the kernel image did not reflect
			      ^
			      /proc/iomem

> the gaps between text, rodata, and data. This adds the rodata resource

s/This adds/Add/

> and updates the start/end calculations to match the respective calls to

s/updates/update/

> free_kernel_image_pages().
> 
> Before (booted with "nokaslr" for easier comparison):

...
diff mbox series

Patch

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index bbe35bf879f5..0bc71ee3a9c3 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -143,6 +143,13 @@  struct boot_params boot_params;
 /*
  * Machine setup..
  */
+static struct resource rodata_resource = {
+	.name	= "Kernel rodata",
+	.start	= 0,
+	.end	= 0,
+	.flags	= IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM
+};
+
 static struct resource data_resource = {
 	.name	= "Kernel data",
 	.start	= 0,
@@ -951,7 +958,9 @@  void __init setup_arch(char **cmdline_p)
 
 	code_resource.start = __pa_symbol(_text);
 	code_resource.end = __pa_symbol(_etext)-1;
-	data_resource.start = __pa_symbol(_etext);
+	rodata_resource.start = __pa_symbol(__start_rodata);
+	rodata_resource.end = __pa_symbol(__end_rodata)-1;
+	data_resource.start = __pa_symbol(_sdata);
 	data_resource.end = __pa_symbol(_edata)-1;
 	bss_resource.start = __pa_symbol(__bss_start);
 	bss_resource.end = __pa_symbol(__bss_stop)-1;
@@ -1040,6 +1049,7 @@  void __init setup_arch(char **cmdline_p)
 
 	/* after parse_early_param, so could debug it */
 	insert_resource(&iomem_resource, &code_resource);
+	insert_resource(&iomem_resource, &rodata_resource);
 	insert_resource(&iomem_resource, &data_resource);
 	insert_resource(&iomem_resource, &bss_resource);