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| author |   Michael Ellerman <mpe@ellerman.id.au> | 2018-08-14 21:05:20 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-10-20 13:26:47 +1100 |
| commit | 81d1b54dec95209ab5e5be2cf37182885f998753 (patch) | |
| tree | b000c4e17f7f1ea73f36d1def2309ff860dc69ff /arch/powerpc/mm/pgtable-radix.c | |
| parent | powerpc/mm/radix: Fix overuse of small pages in splitting logic (diff) | |
| download | linux-dev-81d1b54dec95209ab5e5be2cf37182885f998753.tar.xz linux-dev-81d1b54dec95209ab5e5be2cf37182885f998753.zip | |
powerpc/mm/radix: Fix small page at boundary when splitting
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel
text read only.
Currently we always use a small page at the text/data boundary, even
when that's not necessary:
Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
This is because the check that the mapping crosses the __init_begin
boundary is too strict, it also returns true when we map exactly up to
the boundary.
So fix it to check that the mapping would actually map past
__init_begin, and with that we see:
Mapped 0x0000000000000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/mm/pgtable-radix.c')
| -rw-r--r-- | arch/powerpc/mm/pgtable-radix.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c index bb85c58b96c8..7a44ec276290 100644 --- a/arch/powerpc/mm/pgtable-radix.c +++ b/arch/powerpc/mm/pgtable-radix.c @@ -295,14 +295,14 @@ retry: if (split_text_mapping && (mapping_size == PUD_SIZE) && (addr < __pa_symbol(__init_begin)) && - (addr + mapping_size) >= __pa_symbol(__init_begin)) { + (addr + mapping_size) > __pa_symbol(__init_begin)) { max_mapping_size = PMD_SIZE; goto retry; } if (split_text_mapping && (mapping_size == PMD_SIZE) && (addr < __pa_symbol(__init_begin)) && - (addr + mapping_size) >= __pa_symbol(__init_begin)) { + (addr + mapping_size) > __pa_symbol(__init_begin)) { mapping_size = PAGE_SIZE; psize = mmu_virtual_psize; } |