[PATCH 3.16 024/192] xen: avoid type warning in xchg_xen_ulong

Ben Hutchings
2017-10-09T13:19:47Z

From: Arnd Bergmann <arnd@arndb.de>

commit 9cc91f212111cdcbefa02dcdb7dd443f224bf52c upstream.

The improved type-checking version of container_of() triggers a warning for
xchg_xen_ulong, pointing out that 'xen_ulong_t' is unsigned, but atomic64_t
contains a signed value:

drivers/xen/events/events_2l.c: In function 'evtchn_2l_handle_events':
drivers/xen/events/events_2l.c:187:1020: error: call to '__compiletime_assert_187' declared with attribute error: pointer type mismatch in container_of()

This adds a cast to work around the warning.

Cc: Ian Abbott <abbotti@mev.co.uk>
Fixes: 85323a991d40 ("xen: arm: mandate EABI and use generic atomic operations.")
Fixes: daa2ac80834d ("kernel.h: handle pointers to arrays better in container_of()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/arm/include/asm/xen/events.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/include/asm/xen/events.h
+++ b/arch/arm/include/asm/xen/events.h
@@ -16,7 +16,7 @@ static inline int xen_irqs_disabled(stru
return raw_irqs_disabled_flags(regs->ARM_cpsr);
}

-#define xchg_xen_ulong(ptr, val) atomic64_xchg(container_of((ptr), \
+#define xchg_xen_ulong(ptr, val) atomic64_xchg(container_of((long long*)(ptr),\
atomic64_t, \
counter), (val))