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x86/mm: Add sync_global_pgds() for configuration with 5-level paging 

This basically restores slightly modified version of original
sync_global_pgds() which we had before folded p4d was introduced.

The only modification is protection against 'addr' overflow.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170606113133.22974-11-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Kirill A. Shutemov 2017-06-06 14:31:29 +03:00 committed by Ingo Molnar
parent 032370b9c8
commit 141efad7d7
1 changed files with 39 additions and 0 deletions
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39
arch/x86/mm/init_64.c
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@ -92,6 +92,44 @@ __setup("noexec32=", nonx32_setup);
* When memory was added make sure all the processes MM have
* suitable PGD entries in the local PGD level page.
*/
#ifdef CONFIG_X86_5LEVEL
void sync_global_pgds(unsigned long start, unsigned long end)
{
unsigned long addr;
for (addr = start; addr <= end; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
const pgd_t *pgd_ref = pgd_offset_k(addr);
struct page *page;
/* Check for overflow */
if (addr < start)
break;
if (pgd_none(*pgd_ref))
continue;
spin_lock(&pgd_lock);
list_for_each_entry(page, &pgd_list, lru) {
pgd_t *pgd;
spinlock_t *pgt_lock;
pgd = (pgd_t *)page_address(page) + pgd_index(addr);
/* the pgt_lock only for Xen */
pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
spin_lock(pgt_lock);
if (!pgd_none(*pgd_ref) && !pgd_none(*pgd))
BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref));
if (pgd_none(*pgd))
set_pgd(pgd, *pgd_ref);
spin_unlock(pgt_lock);
}
spin_unlock(&pgd_lock);
}
}
#else
void sync_global_pgds(unsigned long start, unsigned long end)
{
unsigned long addr;
@ -135,6 +173,7 @@ void sync_global_pgds(unsigned long start, unsigned long end)
spin_unlock(&pgd_lock);
}
}
#endif
/*
* NOTE: This function is marked __ref because it calls __init function