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x86: Use __pa_symbol instead of __pa on C visible symbols

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When I made an attempt at separating __pa_symbol and __pa I found that there
were a number of cases where __pa was used on an obvious symbol.

I also caught one non-obvious case as _brk_start and _brk_end are based on the
address of __brk_base which is a C visible symbol.

In mark_rodata_ro I was able to reduce the overhead of kernel symbol to
virtual memory translation by using a combination of __va(__pa_symbol())
instead of page_address(virt_to_page()).

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Link: http://lkml.kernel.org/r/20121116215640.8521.80483.stgit@ahduyck-cp1.jf.intel.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Alexander Duyck
2012-11-16 13:57:13 -08:00
committed by H. Peter Anvin
parent 05a476b6e3
commit fc8d782677
6 changed files with 27 additions and 29 deletions
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18
arch/x86/mm/init_64.c
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@@ -770,12 +770,10 @@ void set_kernel_text_ro(void)
void mark_rodata_ro(void)
{
unsigned long start = PFN_ALIGN(_text);
unsigned long rodata_start =
((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
unsigned long rodata_start = PFN_ALIGN(__start_rodata);
unsigned long end = (unsigned long) &__end_rodata_hpage_align;
unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
unsigned long data_start = (unsigned long) &_sdata;
unsigned long text_end = PFN_ALIGN(&__stop___ex_table);
unsigned long rodata_end = PFN_ALIGN(&__end_rodata);
printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
(end - start) >> 10);
@@ -800,12 +798,12 @@ void mark_rodata_ro(void)
#endif
free_init_pages("unused kernel memory",
(unsigned long) page_address(virt_to_page(text_end)),
(unsigned long)
page_address(virt_to_page(rodata_start)));
(unsigned long) __va(__pa_symbol(text_end)),
(unsigned long) __va(__pa_symbol(rodata_start)));
free_init_pages("unused kernel memory",
(unsigned long) page_address(virt_to_page(rodata_end)),
(unsigned long) page_address(virt_to_page(data_start)));
(unsigned long) __va(__pa_symbol(rodata_end)),
(unsigned long) __va(__pa_symbol(_sdata)));
}
#endif