| Message ID | 20181207103631.28193-12-richard.henderson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | target/arm: Implement ARMv8.3-PAuth | expand |
On Fri, 7 Dec 2018 at 10:36, Richard Henderson <richard.henderson@linaro.org> wrote: > > This will enable PAuth decode in a subsequent patch. > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > --- > target/arm/translate-a64.c | 34 +++++++++++++++++++++++----------- > 1 file changed, 23 insertions(+), 11 deletions(-) > > diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c > index c84c2dbb66..5fa2647771 100644 > --- a/target/arm/translate-a64.c > +++ b/target/arm/translate-a64.c > @@ -1989,32 +1989,41 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn) > rn = extract32(insn, 5, 5); > op4 = extract32(insn, 0, 5); > > - if (op4 != 0x0 || op3 != 0x0 || op2 != 0x1f) { > - unallocated_encoding(s); > - return; > + if (op2 != 0x1f) { > + goto do_unallocated; > } > > switch (opc) { > case 0: /* BR */ > case 1: /* BLR */ > case 2: /* RET */ > - gen_a64_set_pc(s, cpu_reg(s, rn)); > + if (op3 == 0 && op4 == 0) { > + dst = cpu_reg(s, rn); > + } else { > + goto do_unallocated; > + } > + gen_a64_set_pc(s, dst); > /* BLR also needs to load return address */ > if (opc == 1) { > tcg_gen_movi_i64(cpu_reg(s, 30), s->pc); > } > break; > + > case 4: /* ERET */ > if (s->current_el == 0) { > - unallocated_encoding(s); > - return; > - } > - if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { > - gen_io_start(); > + goto do_unallocated; > } > dst = tcg_temp_new_i64(); > tcg_gen_ld_i64(dst, cpu_env, > offsetof(CPUARMState, elr_el[s->current_el])); > + if (op3 == 0 && op4 == 0) { > + ; > + } else { > + goto do_unallocated; This decode check should go before any code has been emittede (ie before the tcg_gen_ld_i64 above it). > + } > + if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { > + gen_io_start(); > + } > gen_helper_exception_return(cpu_env, dst); > tcg_temp_free_i64(dst); > if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { > @@ -2023,14 +2032,17 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn) > /* Must exit loop to check un-masked IRQs */ > s->base.is_jmp = DISAS_EXIT; > return; > + > case 5: /* DRPS */ > - if (rn != 0x1f) { > - unallocated_encoding(s); > + if (op3 != 0 || op4 != 0 || rn != 0x1f) { > + goto do_unallocated; > } else { > unsupported_encoding(s, insn); > } > return; > + > default: > + do_unallocated: > unallocated_encoding(s); > return; > } thanks -- PMM
On 12/11/18 9:40 AM, Peter Maydell wrote: > On Fri, 7 Dec 2018 at 10:36, Richard Henderson > <richard.henderson@linaro.org> wrote: >> >> This will enable PAuth decode in a subsequent patch. >> >> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> >> --- >> target/arm/translate-a64.c | 34 +++++++++++++++++++++++----------- >> 1 file changed, 23 insertions(+), 11 deletions(-) >> >> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c >> index c84c2dbb66..5fa2647771 100644 >> --- a/target/arm/translate-a64.c >> +++ b/target/arm/translate-a64.c >> @@ -1989,32 +1989,41 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn) >> rn = extract32(insn, 5, 5); >> op4 = extract32(insn, 0, 5); >> >> - if (op4 != 0x0 || op3 != 0x0 || op2 != 0x1f) { >> - unallocated_encoding(s); >> - return; >> + if (op2 != 0x1f) { >> + goto do_unallocated; >> } >> >> switch (opc) { >> case 0: /* BR */ >> case 1: /* BLR */ >> case 2: /* RET */ >> - gen_a64_set_pc(s, cpu_reg(s, rn)); >> + if (op3 == 0 && op4 == 0) { >> + dst = cpu_reg(s, rn); >> + } else { >> + goto do_unallocated; >> + } >> + gen_a64_set_pc(s, dst); >> /* BLR also needs to load return address */ >> if (opc == 1) { >> tcg_gen_movi_i64(cpu_reg(s, 30), s->pc); >> } >> break; >> + >> case 4: /* ERET */ >> if (s->current_el == 0) { >> - unallocated_encoding(s); >> - return; >> - } >> - if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { >> - gen_io_start(); >> + goto do_unallocated; >> } >> dst = tcg_temp_new_i64(); >> tcg_gen_ld_i64(dst, cpu_env, >> offsetof(CPUARMState, elr_el[s->current_el])); >> + if (op3 == 0 && op4 == 0) { >> + ; >> + } else { >> + goto do_unallocated; > > > This decode check should go before any code has been > emittede (ie before the tcg_gen_ld_i64 above it). Well, it could, but only if we duplicate the ld_i64 in the various branches that require it. E.g. if (op3 == 0 && op4 == 0) { tcg_gen_ld_i64(...); } else if (dc_ir_feature(aa64_pauth, s) && ...) { tcg_gen_ld_i64(...); if (s->pauth_active) { gen_helper_auti*(...); } } else { goto do_unallocated; } which I suppose isn't so bad. What I have isn't an error because the ld_i64 will simply be deleted as dead code by the tcg optimizer. But I'll rearrange anyway. r~
On Wed, 12 Dec 2018 at 19:20, Richard Henderson <richard.henderson@linaro.org> wrote: > > On 12/11/18 9:40 AM, Peter Maydell wrote: > > On Fri, 7 Dec 2018 at 10:36, Richard Henderson > > <richard.henderson@linaro.org> wrote: > >> > >> This will enable PAuth decode in a subsequent patch. > >> > >> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> > > This decode check should go before any code has been > > emittede (ie before the tcg_gen_ld_i64 above it). > > Well, it could, but only if we duplicate the ld_i64 in the various branches > that require it. E.g. > > if (op3 == 0 && op4 == 0) { > tcg_gen_ld_i64(...); > } else if (dc_ir_feature(aa64_pauth, s) && ...) { > tcg_gen_ld_i64(...); > if (s->pauth_active) { > gen_helper_auti*(...); > } > } else { > goto do_unallocated; > } > > which I suppose isn't so bad. > > What I have isn't an error because the ld_i64 will simply be deleted as dead > code by the tcg optimizer. But I'll rearrange anyway. You'd also need to manually free the 'dst' TCG temp before the goto. The A32/T32 decoder is full of (harmless) "leaked" TCG temps in error-exit paths, which is one reason I think it's nicer to fully decode before proceeding to codegen. thanks -- PMM
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index c84c2dbb66..5fa2647771 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -1989,32 +1989,41 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn) rn = extract32(insn, 5, 5); op4 = extract32(insn, 0, 5); - if (op4 != 0x0 || op3 != 0x0 || op2 != 0x1f) { - unallocated_encoding(s); - return; + if (op2 != 0x1f) { + goto do_unallocated; } switch (opc) { case 0: /* BR */ case 1: /* BLR */ case 2: /* RET */ - gen_a64_set_pc(s, cpu_reg(s, rn)); + if (op3 == 0 && op4 == 0) { + dst = cpu_reg(s, rn); + } else { + goto do_unallocated; + } + gen_a64_set_pc(s, dst); /* BLR also needs to load return address */ if (opc == 1) { tcg_gen_movi_i64(cpu_reg(s, 30), s->pc); } break; + case 4: /* ERET */ if (s->current_el == 0) { - unallocated_encoding(s); - return; - } - if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { - gen_io_start(); + goto do_unallocated; } dst = tcg_temp_new_i64(); tcg_gen_ld_i64(dst, cpu_env, offsetof(CPUARMState, elr_el[s->current_el])); + if (op3 == 0 && op4 == 0) { + ; + } else { + goto do_unallocated; + } + if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { + gen_io_start(); + } gen_helper_exception_return(cpu_env, dst); tcg_temp_free_i64(dst); if (tb_cflags(s->base.tb) & CF_USE_ICOUNT) { @@ -2023,14 +2032,17 @@ static void disas_uncond_b_reg(DisasContext *s, uint32_t insn) /* Must exit loop to check un-masked IRQs */ s->base.is_jmp = DISAS_EXIT; return; + case 5: /* DRPS */ - if (rn != 0x1f) { - unallocated_encoding(s); + if (op3 != 0 || op4 != 0 || rn != 0x1f) { + goto do_unallocated; } else { unsupported_encoding(s, insn); } return; + default: + do_unallocated: unallocated_encoding(s); return; }
This will enable PAuth decode in a subsequent patch. Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- target/arm/translate-a64.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) -- 2.17.2