diff options
| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-08-19 06:40:25 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-11 18:35:56 +0200 |
| commit | 228b682353045a9fd6da77ff7cf957265fd0e542 (patch) | |
| tree | 45b765102455163eae83406e3534d8e4f4e83f6b /arch | |
| parent | 82090f2b9927f10114e3506652ae3852e3fe329d (diff) | |
powerpc/603: Fix handling of the DIRTY flag
commit 415480dce2ef03bb8335deebd2f402f475443ce0 upstream.
If a page is already mapped RW without the DIRTY flag, the DIRTY
flag is never set and a TLB store miss exception is taken forever.
This is easily reproduced with the following app:
void main(void)
{
volatile char *ptr = mmap(0, 4096, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
*ptr = *ptr;
}
When DIRTY flag is not set, bail out of TLB miss handler and take
a minor page fault which will set the DIRTY flag.
Fixes: f8b58c64eaef ("powerpc/603: let's handle PAGE_DIRTY directly")
Cc: stable@vger.kernel.org # v5.1+
Reported-by: Doug Crawford <doug.crawford@intelight-its.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/80432f71194d7ee75b2f5043ecf1501cf1cca1f3.1566196646.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/head_32.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S index f255e22184b4..534dd2718795 100644 --- a/arch/powerpc/kernel/head_32.S +++ b/arch/powerpc/kernel/head_32.S @@ -557,9 +557,9 @@ DataStoreTLBMiss: cmplw 0,r1,r3 mfspr r2, SPRN_SPRG_PGDIR #ifdef CONFIG_SWAP - li r1, _PAGE_RW | _PAGE_PRESENT | _PAGE_ACCESSED + li r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT | _PAGE_ACCESSED #else - li r1, _PAGE_RW | _PAGE_PRESENT + li r1, _PAGE_RW | _PAGE_DIRTY | _PAGE_PRESENT #endif bge- 112f lis r2, (swapper_pg_dir - PAGE_OFFSET)@ha /* if kernel address, use */ |