In message: [linux-yocto][PATCH] powerpc/603: Fix handling of the DIRTY flag on 24/09/2019 zhe...@windriver.com wrote:
> From: Christophe Leroy <christophe.le...@c-s.fr> > > 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: sta...@vger.kernel.org # v5.1+ > Reported-by: Doug Crawford <doug.crawf...@intelight-its.com> > Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> > Signed-off-by: Michael Ellerman <m...@ellerman.id.au> > Link: > https://lore.kernel.org/r/80432f71194d7ee75b2f5043ecf1501cf1cca1f3.1566196646.git.christophe.le...@c-s.fr > Signed-off-by: He Zhe <zhe...@windriver.com> > --- > This is for v5.2/standard/fsl-mpc8315e-rdb. It fixes potential system hang > without any direct warning or error which has not been observed on qemuppc. > > It has not been ported to stable tree. but at least is has been cc'd to stable. I'll watch for it to show up in my future 5.2 -stabe updates. Cheers, Bruce > > arch/powerpc/kernel/head_32.S | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S > index f255e22..534dd27 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 */ > -- > 2.7.4 > -- _______________________________________________ linux-yocto mailing list linux-yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/linux-yocto