Commit 2a25dc7c authored by Thomas Gleixner's avatar Thomas Gleixner

x86/mm/init32: Mark text and rodata RO in one go

The sequence of marking text and rodata read-only in 32bit init is:

  set_ro(text);
  kernel_set_to_readonly = 1;
  set_ro(rodata);

When kernel_set_to_readonly is 1 it enables the protection mechanism in CPA
for the read only regions. With the upcoming checks for existing mappings
this consequently triggers the warning about an existing mapping being
incorrect vs. static protections because rodata has not been converted yet.

There is no technical reason to split the two, so just combine the RO
protection to convert text and rodata in one go.

Convert the printks to pr_info while at it.
Reported-by: default avatarkernel test robot <rong.a.chen@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarDave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180917143545.731701535@linutronix.de
parent 6bf4ca7f
...@@ -923,34 +923,19 @@ static void mark_nxdata_nx(void) ...@@ -923,34 +923,19 @@ static void mark_nxdata_nx(void)
void mark_rodata_ro(void) void mark_rodata_ro(void)
{ {
unsigned long start = PFN_ALIGN(_text); unsigned long start = PFN_ALIGN(_text);
unsigned long size = PFN_ALIGN(_etext) - start; unsigned long size = (unsigned long)__end_rodata - start;
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
printk(KERN_INFO "Write protecting the kernel text: %luk\n", pr_info("Write protecting kernel text and read-only data: %luk\n",
size >> 10); size >> 10);
kernel_set_to_readonly = 1; kernel_set_to_readonly = 1;
#ifdef CONFIG_CPA_DEBUG #ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: Reverting %lx-%lx\n", pr_info("Testing CPA: Reverting %lx-%lx\n", start, start + size);
start, start+size);
set_pages_rw(virt_to_page(start), size>>PAGE_SHIFT);
printk(KERN_INFO "Testing CPA: write protecting again\n");
set_pages_ro(virt_to_page(start), size>>PAGE_SHIFT);
#endif
start += size;
size = (unsigned long)__end_rodata - start;
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
size >> 10);
#ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, start + size);
set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
printk(KERN_INFO "Testing CPA: write protecting again\n"); pr_info("Testing CPA: write protecting again\n");
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
#endif #endif
mark_nxdata_nx(); mark_nxdata_nx();
......
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