Commit e0dd31b9 authored Nov 04, 2019 by Alastair D'Silva Committed by Greg Kroah-Hartman Dec 17, 2019

powerpc: Allow 64bit VDSO __kernel_sync_dicache to work across ranges >4GB



commit f9ec11165301982585e5e5f606739b5bae5331f3 upstream.

When calling __kernel_sync_dicache with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.

This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-3-alastair@au1.ibm.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 919fc442

arch/powerpc/kernel/vdso64/cacheflush.S

+2 −2

Original line number	Diff line number	Diff line
		@@ -39,7 +39,7 @@ V_FUNCTION_BEGIN(__kernel_sync_dicache)
		subf r8,r6,r4 /* compute length */
		add r8,r8,r5 /* ensure we get enough */
		lwz r9,CFG_DCACHE_LOGBLOCKSZ(r10)
		srw. r8,r8,r9 /* compute line count */
		srd. r8,r8,r9 /* compute line count */
		crclr cr0*4+so
		beqlr /* nothing to do? */
		mtctr r8
		@@ -56,7 +56,7 @@ V_FUNCTION_BEGIN(__kernel_sync_dicache)
		subf r8,r6,r4 /* compute length */
		add r8,r8,r5
		lwz r9,CFG_ICACHE_LOGBLOCKSZ(r10)
		srw. r8,r8,r9 /* compute line count */
		srd. r8,r8,r9 /* compute line count */
		crclr cr0*4+so
		beqlr /* nothing to do? */
		mtctr r8