SMCCC: Hoist SMC_32 sanitization
The SMCCC, part 3 indicates that only the bottom
32-bits of a 32-bit SMC call are valid. The upper
bits must be zero. Lets enforce that so standard
service code can assume its been called that way.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Change-Id: I1bac50fbdc3b6ddca5fe2d1d1f96166a65ac4eb4
diff --git a/services/std_svc/std_svc_setup.c b/services/std_svc/std_svc_setup.c
index 23f13ab..540bb86 100644
--- a/services/std_svc/std_svc_setup.c
+++ b/services/std_svc/std_svc_setup.c
@@ -82,6 +82,15 @@
void *handle,
u_register_t flags)
{
+ if (((smc_fid >> FUNCID_CC_SHIFT) & FUNCID_CC_MASK) == SMC_32) {
+ /* 32-bit SMC function, clear top parameter bits */
+
+ x1 &= UINT32_MAX;
+ x2 &= UINT32_MAX;
+ x3 &= UINT32_MAX;
+ x4 &= UINT32_MAX;
+ }
+
/*
* Dispatch PSCI calls to PSCI SMC handler and return its return
* value