diff options
| -rw-r--r-- | target-arm/cpu.h | 29 | ||||
| -rw-r--r-- | target-arm/helper.h | 1 | ||||
| -rw-r--r-- | target-arm/op_helper.c | 18 | ||||
| -rw-r--r-- | target-arm/translate-a64.c | 11 | ||||
| -rw-r--r-- | target-arm/translate.c | 11 |
5 files changed, 66 insertions, 4 deletions
diff --git a/target-arm/cpu.h b/target-arm/cpu.h index ab57f55..cc3d0ac 100644 --- a/target-arm/cpu.h +++ b/target-arm/cpu.h @@ -811,14 +811,29 @@ static inline int arm_current_pl(CPUARMState *env) typedef struct ARMCPRegInfo ARMCPRegInfo; -/* Access functions for coprocessor registers. These should return - * 0 on success, or one of the EXCP_* constants if access should cause - * an exception (in which case *value is not written). - */ +typedef enum CPAccessResult { + /* Access is permitted */ + CP_ACCESS_OK = 0, + /* Access fails due to a configurable trap or enable which would + * result in a categorized exception syndrome giving information about + * the failing instruction (ie syndrome category 0x3, 0x4, 0x5, 0x6, + * 0xc or 0x18). + */ + CP_ACCESS_TRAP = 1, + /* Access fails and results in an exception syndrome 0x0 ("uncategorized"). + * Note that this is not a catch-all case -- the set of cases which may + * result in this failure is specifically defined by the architecture. + */ + CP_ACCESS_TRAP_UNCATEGORIZED = 2, +} CPAccessResult; + +/* Access functions for coprocessor registers. These should always succeed. */ typedef int CPReadFn(CPUARMState *env, const ARMCPRegInfo *opaque, uint64_t *value); typedef int CPWriteFn(CPUARMState *env, const ARMCPRegInfo *opaque, uint64_t value); +/* Access permission check functions for coprocessor registers. */ +typedef CPAccessResult CPAccessFn(CPUARMState *env, const ARMCPRegInfo *opaque); /* Hook function for register reset */ typedef void CPResetFn(CPUARMState *env, const ARMCPRegInfo *opaque); @@ -872,6 +887,12 @@ struct ARMCPRegInfo { * 2. both readfn and writefn are specified */ ptrdiff_t fieldoffset; /* offsetof(CPUARMState, field) */ + /* Function for making any access checks for this register in addition to + * those specified by the 'access' permissions bits. If NULL, no extra + * checks required. The access check is performed at runtime, not at + * translate time. + */ + CPAccessFn *accessfn; /* Function for handling reads of this register. If NULL, then reads * will be done by loading from the offset into CPUARMState specified * by fieldoffset. diff --git a/target-arm/helper.h b/target-arm/helper.h index 7c60121..19bd620 100644 --- a/target-arm/helper.h +++ b/target-arm/helper.h @@ -57,6 +57,7 @@ DEF_HELPER_1(cpsr_read, i32, env) DEF_HELPER_3(v7m_msr, void, env, i32, i32) DEF_HELPER_2(v7m_mrs, i32, env, i32) +DEF_HELPER_2(access_check_cp_reg, void, env, ptr) DEF_HELPER_3(set_cp_reg, void, env, ptr, i32) DEF_HELPER_2(get_cp_reg, i32, env, ptr) DEF_HELPER_3(set_cp_reg64, void, env, ptr, i64) diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c index a918e5b..34c5e7f 100644 --- a/target-arm/op_helper.c +++ b/target-arm/op_helper.c @@ -273,6 +273,24 @@ void HELPER(set_user_reg)(CPUARMState *env, uint32_t regno, uint32_t val) } } +void HELPER(access_check_cp_reg)(CPUARMState *env, void *rip) +{ + const ARMCPRegInfo *ri = rip; + switch (ri->accessfn(env, ri)) { + case CP_ACCESS_OK: + return; + case CP_ACCESS_TRAP: + case CP_ACCESS_TRAP_UNCATEGORIZED: + /* These cases will eventually need to generate different + * syndrome information. + */ + break; + default: + g_assert_not_reached(); + } + raise_exception(env, EXCP_UDEF); +} + void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value) { const ARMCPRegInfo *ri = rip; diff --git a/target-arm/translate-a64.c b/target-arm/translate-a64.c index f6500e5..e70d14f 100644 --- a/target-arm/translate-a64.c +++ b/target-arm/translate-a64.c @@ -1193,6 +1193,17 @@ static void handle_sys(DisasContext *s, uint32_t insn, bool isread, return; } + if (ri->accessfn) { + /* Emit code to perform further access permissions checks at + * runtime; this may result in an exception. + */ + TCGv_ptr tmpptr; + gen_a64_set_pc_im(s->pc - 4); + tmpptr = tcg_const_ptr(ri); + gen_helper_access_check_cp_reg(cpu_env, tmpptr); + tcg_temp_free_ptr(tmpptr); + } + /* Handle special cases first */ switch (ri->type & ~(ARM_CP_FLAG_MASK & ~ARM_CP_SPECIAL)) { case ARM_CP_NOP: diff --git a/target-arm/translate.c b/target-arm/translate.c index 6d822c6..0805053 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -6837,6 +6837,17 @@ static int disas_coproc_insn(CPUARMState * env, DisasContext *s, uint32_t insn) return 1; } + if (ri->accessfn) { + /* Emit code to perform further access permissions checks at + * runtime; this may result in an exception. + */ + TCGv_ptr tmpptr; + gen_set_pc_im(s, s->pc); + tmpptr = tcg_const_ptr(ri); + gen_helper_access_check_cp_reg(cpu_env, tmpptr); + tcg_temp_free_ptr(tmpptr); + } + /* Handle special cases first */ switch (ri->type & ~(ARM_CP_FLAG_MASK & ~ARM_CP_SPECIAL)) { case ARM_CP_NOP: |