From: Christophe Leroy <[email protected]>
commit b61c38baa98056d4802ff5be5cfb979efc2d0f7a upstream.
WRITE_RO lkdtm test works.
But when selecting CONFIG_DEBUG_RODATA_TEST, the kernel reports
rodata_test: test data was not read only
This is because when rodata test runs, there are still old entries
in TLB.
Flush TLB after setting kernel pages RO or NX.
Fixes: d5f17ee96447 ("powerpc/8xx: don't disable large TLBs with
CONFIG_STRICT_KERNEL_RWX")
Cc: [email protected] # v5.1+
Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link:
https://lore.kernel.org/r/485caac75f195f18c11eb077b0031fdd2bb7fb9e.1587361039.git.christophe.le...@c-s.fr
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/powerpc/mm/nohash/8xx.c | 3 +++
1 file changed, 3 insertions(+)
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -185,6 +185,7 @@ void mmu_mark_initmem_nx(void)
mmu_mapin_ram_chunk(etext8, einittext8, PAGE_KERNEL);
}
}
+ _tlbil_all();
}
#ifdef CONFIG_STRICT_KERNEL_RWX
@@ -199,6 +200,8 @@ void mmu_mark_rodata_ro(void)
~(LARGE_PAGE_SIZE_8M - 1)));
mmu_patch_addis(&patch__dtlbmiss_romem_top, -__pa(_sinittext));
+ _tlbil_all();
+
/* Update page tables for PTDUMP and BDI */
mmu_mapin_ram_chunk(0, sinittext, __pgprot(0));
mmu_mapin_ram_chunk(0, etext, PAGE_KERNEL_ROX);
