[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH v2 3/4] arm: traps: handle unknown exceptions in check_conditional_instr()

On 09/08/2017 20:44, Volodymyr Babchuk wrote:
According to ARM architecture reference manual (ARM DDI 0487A.k page D7-1938,

Please quote a more recent ARM ARM. In general, please use the latest ARM ARM when sending code specific to the architecture.

Assuming this will be fixed in the next revision:

Acked-by: Julien Grall <julien.grall@xxxxxxx>


ARM DDI 0406C.c page B3-1426), exception with unknown reason (HSR.EC == 0)
have no valid bits in HSR (apart from HSR.EC), so we can't check if that was
caused by conditional instruction. We need  assume that it is unconditional.

Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@xxxxxxxx>

- Added reference to the ARM manuals

 xen/arch/arm/traps.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index c07999b..eae2212 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -1717,7 +1717,7 @@ static int check_conditional_instr(struct cpu_user_regs 
     int cond;

     /* Unconditional Exception classes */
-    if ( hsr.ec >= 0x10 )
+    if ( hsr.ec == HSR_EC_UNKNOWN || hsr.ec >= 0x10 )
         return 1;

     /* Check for valid condition in hsr */

Julien Grall

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.