powerpc/kasan: Remove unnecessary page table locking (7c31c05e) · Commits · 戴 / test

Commit ("powerpc/kasan: Fix parallel loading of modules.") added spinlocks to manage parallele module loading. Since then commit ("powerpc/32: Force KASAN_VMALLOC for modules") converted the module loading to KASAN_VMALLOC. The spinlocking has then become unneeded and can be removed to simplify kasan_init_shadow_page_tables() Also remove inclusion of linux/moduleloader.h and linux/vmalloc.h which are not needed anymore since the removal of modules management. Signed-off-by:

Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by:

Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/81a4d3aee8b82bc1355595935c8f4ad9d3b22a83.1589866984.git.christophe.leroy@csgroup.eu

arch/powerpc/mm/kasan/kasan_init_32.c

+4 −15

Original line number	Diff line number	Diff line
		@@ -5,9 +5,7 @@
		#include <linux/kasan.h>
		#include <linux/printk.h>
		#include <linux/memblock.h>
		#include <linux/moduleloader.h>
		#include <linux/sched/task.h>
		#include <linux/vmalloc.h>
		#include <asm/pgalloc.h>
		#include <asm/code-patching.h>
		#include <mm/mmu_decl.h>
		@@ -34,31 +32,22 @@ static int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned
		{
		pmd_t *pmd;
		unsigned long k_cur, k_next;
		pte_t *new = NULL;

		pmd = pmd_ptr_k(k_start);

		for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
		pte_t *new;

		k_next = pgd_addr_end(k_cur, k_end);
		if ((void )pmd_page_vaddr(pmd) != kasan_early_shadow_pte)
		continue;

		if (!new)
		new = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);

		if (!new)
		return -ENOMEM;
		kasan_populate_pte(new, PAGE_KERNEL);

		smp_wmb(); /* See comment in __pte_alloc */

		spin_lock(&init_mm.page_table_lock);
		/* Has another populated it ? */
		if (likely((void )pmd_page_vaddr(pmd) == kasan_early_shadow_pte)) {
		pmd_populate_kernel(&init_mm, pmd, new);
		new = NULL;
		}
		spin_unlock(&init_mm.page_table_lock);
		}
		return 0;
		}

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