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Commit c7e220ef authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Greg Kroah-Hartman
Browse files

powerpc/mm/hash: Handle mmap_min_addr correctly in get_unmapped_area topdown search 



commit 3b4d07d2674f6b4a9281031f99d1f7efd325b16d upstream.

When doing top-down search the low_limit is not PAGE_SIZE but rather
max(PAGE_SIZE, mmap_min_addr). This handle cases in which mmap_min_addr >
PAGE_SIZE.

Fixes: fba2369e ("mm: use vm_unmapped_area() on powerpc architecture")
Reviewed-by: default avatarLaurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a78c3898

arch/powerpc/mm/slice.c

+6 −4
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/spinlock.h>

#include <linux/export.h>

#include <linux/hugetlb.h>

#include <linux/security.h>

#include <asm/mman.h>

#include <asm/mmu.h>

#include <asm/copro.h>
@@ -376,6 +377,7 @@ static unsigned long slice_find_area_topdown(struct mm_struct *mm, 
	int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);

	unsigned long addr, found, prev;

	struct vm_unmapped_area_info info;

	unsigned long min_addr = max(PAGE_SIZE, mmap_min_addr);



	info.flags = VM_UNMAPPED_AREA_TOPDOWN;

	info.length = len;
@@ -392,7 +394,7 @@ static unsigned long slice_find_area_topdown(struct mm_struct *mm, 
	if (high_limit > DEFAULT_MAP_WINDOW)

		addr += mm->context.slb_addr_limit - DEFAULT_MAP_WINDOW;



	while (addr > PAGE_SIZE) {

	while (addr > min_addr) {

		info.high_limit = addr;

		if (!slice_scan_available(addr - 1, available, 0, &addr))

			continue;
@@ -404,8 +406,8 @@ static unsigned long slice_find_area_topdown(struct mm_struct *mm, 
		 * Check if we need to reduce the range, or if we can

		 * extend it to cover the previous available slice.

		 */

		if (addr < PAGE_SIZE)

			addr = PAGE_SIZE;

		if (addr < min_addr)

			addr = min_addr;

		else if (slice_scan_available(addr - 1, available, 0, &prev)) {

			addr = prev;

			goto prev_slice;
@@ -527,7 +529,7 @@ unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len, 
		addr = _ALIGN_UP(addr, page_size);

		slice_dbg(" aligned addr=%lx\n", addr);

		/* Ignore hint if it's too large or overlaps a VMA */

		if (addr > high_limit - len ||

		if (addr > high_limit - len || addr < mmap_min_addr ||

		    !slice_area_is_free(mm, addr, len))

			addr = 0;

	}