Commit 597610eb authored by Peter Maydell's avatar Peter Maydell
Browse files

target/arm: Add v8M stack limit checks on NS function calls 



Check the v8M stack limits when pushing the frame for a
non-secure function call via BLXNS.

In order to be able to generate the exception we need to
promote raise_exception() from being local to op_helper.c
so we can call it from helper.c.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Message-id: 20181002163556.10279-8-peter.maydell@linaro.org
parent c32da7aa

target/arm/helper.c

+4 −0
Original line number Diff line number Diff line
@@ -6738,6 +6738,10 @@ void HELPER(v7m_blxns)(CPUARMState *env, uint32_t dest) 
                      "BLXNS with misaligned SP is UNPREDICTABLE\n");

    }



    if (sp < v7m_sp_limit(env)) {

        raise_exception(env, EXCP_STKOF, 0, 1);

    }



    saved_psr = env->v7m.exception;

    if (env->v7m.control[M_REG_S] & R_V7M_CONTROL_SFPA_MASK) {

        saved_psr |= XPSR_SFPA;

target/arm/internals.h

+9 −0
Original line number Diff line number Diff line
@@ -94,6 +94,15 @@ FIELD(V7M_EXCRET, RES1, 7, 25) /* including the must-be-1 prefix */ 
#define M_FAKE_FSR_NSC_EXEC 0xf /* NS executing in S&NSC memory */

#define M_FAKE_FSR_SFAULT 0xe /* SecureFault INVTRAN, INVEP or AUVIOL */



/**

 * raise_exception: Raise the specified exception.

 * Raise a guest exception with the specified value, syndrome register

 * and target exception level. This should be called from helper functions,

 * and never returns because we will longjump back up to the CPU main loop.

 */

void QEMU_NORETURN raise_exception(CPUARMState *env, uint32_t excp,

                                   uint32_t syndrome, uint32_t target_el);



/*

 * For AArch64, map a given EL to an index in the banked_spsr array.

 * Note that this mapping and the AArch32 mapping defined in bank_number()

target/arm/op_helper.c

+2 −2
Original line number Diff line number Diff line
@@ -28,7 +28,7 @@ 
#define SIGNBIT (uint32_t)0x80000000

#define SIGNBIT64 ((uint64_t)1 << 63)



static void raise_exception(CPUARMState *env, uint32_t excp,

void raise_exception(CPUARMState *env, uint32_t excp,

                     uint32_t syndrome, uint32_t target_el)

{

    CPUState *cs = CPU(arm_env_get_cpu(env));