The current code that switches into HYP mode doesn't bother to set up a stack for HYP mode. This doesn't work for EFI applications as they expect a usable stack. Fix this by saving the stack pointer before switching and use it to set SP_hyp from monitor. This restores the stack pointer when we drop into HYP mode.
Signed-off-by: Mark Kettenis kettenis@openbsd.org --- arch/arm/cpu/armv7/nonsec_virt.S | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm/cpu/armv7/nonsec_virt.S b/arch/arm/cpu/armv7/nonsec_virt.S index 56bdba1d38..246d817340 100644 --- a/arch/arm/cpu/armv7/nonsec_virt.S +++ b/arch/arm/cpu/armv7/nonsec_virt.S @@ -52,9 +52,9 @@ _secure_monitor: bl psci_stack_setup
@ Configure the PSCI backend - push {r0, r1, r2, ip} + push {r0, r1, r2, r3, ip} bl psci_arch_init - pop {r0, r1, r2, ip} + pop {r0, r1, r2, r3, ip} #endif
#ifdef CONFIG_ARM_ERRATA_773022 @@ -80,6 +80,7 @@ _secure_monitor: #ifdef CONFIG_ARMV7_VIRT orreq r5, r5, #0x100 @ allow HVC instruction moveq r6, #HYP_MODE @ Enter the kernel as HYP + msreq sp_hyp, r3 @ restore saved stack #endif
mcr p15, 0, r5, c1, c1, 0 @ write SCR (with NS bit set) @@ -106,6 +107,7 @@ ENTRY(_do_nonsec_entry) mov r0, r1 mov r1, r2 mov r2, r3 + mov r3, sp smc #0 ENDPROC(_do_nonsec_entry)