The patch titled
Subject: lib/ioremap: ensure phys_addr actually corresponds to a physical address
has been added to the -mm tree. Its filename is
lib-ioremap-ensure-phys_addr-actually-corresponds-to-a-physical-address.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/lib-ioremap-ensure-phys_addr-actually-corresponds-to-a-physical-address.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/lib-ioremap-ensure-phys_addr-actually-corresponds-to-a-physical-address.patch
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The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Will Deacon <will.deacon@xxxxxxx>
Subject: lib/ioremap: ensure phys_addr actually corresponds to a physical address
The current ioremap() code uses a phys_addr variable at each level of page
table, which is confusingly offset by subtracting the base virtual address
being mapped so that adding the current virtual address back on when
iterating through the page table entries gives back the corresponding
physical address.
This is fairly confusing and results in all users of phys_addr having to
add the current virtual address back on. Instead, this patch just updates
phys_addr when iterating over the page table entries, ensuring that it's
always up-to-date and doesn't require explicit offsetting.
Link: http://lkml.kernel.org/r/1544120495-17438-5-git-send-email-will.deacon@xxxxxxx
Signed-off-by: Will Deacon <will.deacon@xxxxxxx>
Tested-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Cc: Chintan Pandya <cpandya@xxxxxxxxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/ioremap.c | 28 ++++++++++++----------------
1 file changed, 12 insertions(+), 16 deletions(-)
--- a/lib/ioremap.c~lib-ioremap-ensure-phys_addr-actually-corresponds-to-a-physical-address
+++ a/lib/ioremap.c
@@ -101,19 +101,18 @@ static inline int ioremap_pmd_range(pud_
pmd_t *pmd;
unsigned long next;
- phys_addr -= addr;
pmd = pmd_alloc(&init_mm, pud, addr);
if (!pmd)
return -ENOMEM;
do {
next = pmd_addr_end(addr, end);
- if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr + addr, prot))
+ if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot))
continue;
- if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
+ if (ioremap_pte_range(pmd, addr, next, phys_addr, prot))
return -ENOMEM;
- } while (pmd++, addr = next, addr != end);
+ } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
return 0;
}
@@ -142,19 +141,18 @@ static inline int ioremap_pud_range(p4d_
pud_t *pud;
unsigned long next;
- phys_addr -= addr;
pud = pud_alloc(&init_mm, p4d, addr);
if (!pud)
return -ENOMEM;
do {
next = pud_addr_end(addr, end);
- if (ioremap_try_huge_pud(pud, addr, next, phys_addr + addr, prot))
+ if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot))
continue;
- if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
+ if (ioremap_pmd_range(pud, addr, next, phys_addr, prot))
return -ENOMEM;
- } while (pud++, addr = next, addr != end);
+ } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
return 0;
}
@@ -164,7 +162,6 @@ static inline int ioremap_p4d_range(pgd_
p4d_t *p4d;
unsigned long next;
- phys_addr -= addr;
p4d = p4d_alloc(&init_mm, pgd, addr);
if (!p4d)
return -ENOMEM;
@@ -173,14 +170,14 @@ static inline int ioremap_p4d_range(pgd_
if (ioremap_p4d_enabled() &&
((next - addr) == P4D_SIZE) &&
- IS_ALIGNED(phys_addr + addr, P4D_SIZE)) {
- if (p4d_set_huge(p4d, phys_addr + addr, prot))
+ IS_ALIGNED(phys_addr, P4D_SIZE)) {
+ if (p4d_set_huge(p4d, phys_addr, prot))
continue;
}
- if (ioremap_pud_range(p4d, addr, next, phys_addr + addr, prot))
+ if (ioremap_pud_range(p4d, addr, next, phys_addr, prot))
return -ENOMEM;
- } while (p4d++, addr = next, addr != end);
+ } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
return 0;
}
@@ -196,14 +193,13 @@ int ioremap_page_range(unsigned long add
BUG_ON(addr >= end);
start = addr;
- phys_addr -= addr;
pgd = pgd_offset_k(addr);
do {
next = pgd_addr_end(addr, end);
- err = ioremap_p4d_range(pgd, addr, next, phys_addr+addr, prot);
+ err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot);
if (err)
break;
- } while (pgd++, addr = next, addr != end);
+ } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
flush_cache_vmap(start, end);
_
Patches currently in -mm which might be from will.deacon@xxxxxxx are
ioremap-rework-pxd_free_pyd_page-api.patch
arm64-mmu-drop-pxd_present-checks-from-pxd_free_pyd_table.patch
x86-pgtable-drop-pxd_none-checks-from-pxd_free_pyd_table.patch
lib-ioremap-ensure-phys_addr-actually-corresponds-to-a-physical-address.patch
lib-ioremap-ensure-break-before-make-is-used-for-huge-p4d-mappings.patch
