ARM: mm: Export __sync_icache_dcache() for xen-privcmd

Forwarded: https://marc.info/?l=linux-arm-kernel&m=153134944429241

The xen-privcmd driver, which can be modular, calls set_pte_at()
which in turn may call __sync_icache_dcache().

The call to __sync_icache_dcache() may be optimised out because it is
conditional on !pte_special(), and xen-privcmd calls pte_mkspecial().
However, in a non-LPAE configuration there is no "special" bit and the
call is really unconditional.

Fixes: 3ad0876554ca ("xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Gbp-Pq: Topic bugfix/arm
Gbp-Pq: Name arm-mm-export-__sync_icache_dcache-for-xen-privcmd.patch

diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 7ff9feea13a6a795c10ece78c46fe70e66efa0c3..6bd4478e2496584845b762dad85d7faef046a4a8 100644 (file)
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -291,6 +291,7 @@ void __sync_icache_dcache(pte_t pteval)
        if (pte_exec(pteval))
                __flush_icache_all();
 }
+EXPORT_SYMBOL_GPL(__sync_icache_dcache);
 #endif
 
 /*