diff mbox series

[v2,6/7] target/arm: Implement v8.3 FPAC and FPACCOMBINE

Message ID 20230222193544.3392713-7-aaron@os.amperecomputing.com (mailing list archive)
State New, archived
Headers show
Series Implement Most ARMv8.3 Pointer Authentication Features | expand

Commit Message

Aaron Lindsay Feb. 22, 2023, 7:35 p.m. UTC 
Signed-off-by: Aaron Lindsay <aaron@os.amperecomputing.com>
---
 target/arm/pauth_helper.c | 35 ++++++++++++++++++++++++++++++-----
 target/arm/syndrome.h     |  7 +++++++
 2 files changed, 37 insertions(+), 5 deletions(-)

Comments

Richard Henderson Feb. 22, 2023, 9:37 p.m. UTC | #1 
On 2/22/23 09:35, Aaron Lindsay wrote:
> +static G_NORETURN
> +void pauth_fail_exception(CPUARMState *env, bool data, int keynumber, uintptr_t ra)
> +{
> +    int target_el = arm_current_el(env);
> +    if (target_el == 0) {
> +        uint64_t hcr = arm_hcr_el2_eff(env);
> +        if (arm_is_el2_enabled(env) && (hcr & HCR_TGE))
> +            target_el = 2;
> +        else
> +            target_el = 1;
> +    }
> +
> +    raise_exception_ra(env, EXCP_UDEF, syn_pacfail(data, keynumber), target_el, ra);

Use exception_target_el(), no need to check TGE here.

> @@ -406,6 +421,16 @@ static uint64_t pauth_auth(CPUARMState *env, uint64_t ptr, uint64_t modifier,
>           uint64_t xor_mask = MAKE_64BIT_MASK(bot_bit, top_bit - bot_bit + 1) &
>               ~MAKE_64BIT_MASK(55, 1);
>           result = ((ptr ^ pac) & xor_mask) | (ptr & ~xor_mask);
> +        if (cpu_isar_feature(aa64_fpac_combine, env_archcpu(env)) ||
> +                (cpu_isar_feature(aa64_fpac, env_archcpu(env)) &&
> +                 !is_combined)) {

Indentation is off.

> +    int error_code = ((data ? 1 : 0) << 1) | (keynumber);

'? 1 : 0' is not required.


r~
Aaron Lindsay March 22, 2023, 8:33 p.m. UTC | #2 
On Feb 22 11:37, Richard Henderson wrote:
> On 2/22/23 09:35, Aaron Lindsay wrote:
> > @@ -406,6 +421,16 @@ static uint64_t pauth_auth(CPUARMState *env, uint64_t ptr, uint64_t modifier,
> >           uint64_t xor_mask = MAKE_64BIT_MASK(bot_bit, top_bit - bot_bit + 1) &
> >               ~MAKE_64BIT_MASK(55, 1);
> >           result = ((ptr ^ pac) & xor_mask) | (ptr & ~xor_mask);
> > +        if (cpu_isar_feature(aa64_fpac_combine, env_archcpu(env)) ||
> > +                (cpu_isar_feature(aa64_fpac, env_archcpu(env)) &&
> > +                 !is_combined)) {
> 
> Indentation is off.

I pulled `env_archcpu(env)` out of this if-statement in my latest
patchset in addition to the indentation, but am not confident I have
done what you intended. The QEMU Coding Style guide doesn't seem to
address longer statements like this in its section on indentation, so I
attempted to follow other examples in the code, but I'll take further
direction here.

-Aaron
Richard Henderson March 22, 2023, 10:39 p.m. UTC | #3 
On 3/22/23 13:33, Aaron Lindsay wrote:
> On Feb 22 11:37, Richard Henderson wrote:
>> On 2/22/23 09:35, Aaron Lindsay wrote:
>>> @@ -406,6 +421,16 @@ static uint64_t pauth_auth(CPUARMState *env, uint64_t ptr, uint64_t modifier,
>>>            uint64_t xor_mask = MAKE_64BIT_MASK(bot_bit, top_bit - bot_bit + 1) &
>>>                ~MAKE_64BIT_MASK(55, 1);
>>>            result = ((ptr ^ pac) & xor_mask) | (ptr & ~xor_mask);
>>> +        if (cpu_isar_feature(aa64_fpac_combine, env_archcpu(env)) ||
>>> +                (cpu_isar_feature(aa64_fpac, env_archcpu(env)) &&
>>> +                 !is_combined)) {
>>
>> Indentation is off.
> 
> I pulled `env_archcpu(env)` out of this if-statement in my latest
> patchset in addition to the indentation, but am not confident I have
> done what you intended. The QEMU Coding Style guide doesn't seem to
> address longer statements like this in its section on indentation, so I
> attempted to follow other examples in the code, but I'll take further
> direction here.


     if (function(a) ||
         (function(b) &&
          function(c))) {
         ...
1234567890


r~
diff mbox series

Patch

diff --git a/target/arm/pauth_helper.c b/target/arm/pauth_helper.c
index 96770d7860..db6cf9b5bc 100644
--- a/target/arm/pauth_helper.c
+++ b/target/arm/pauth_helper.c
@@ -388,9 +388,24 @@  static uint64_t pauth_original_ptr(uint64_t ptr, ARMVAParameters param)
     return deposit64(ptr, bot_pac_bit, top_pac_bit - bot_pac_bit, extfield);
 }
 
+static G_NORETURN
+void pauth_fail_exception(CPUARMState *env, bool data, int keynumber, uintptr_t ra)
+{
+    int target_el = arm_current_el(env);
+    if (target_el == 0) {
+        uint64_t hcr = arm_hcr_el2_eff(env);
+        if (arm_is_el2_enabled(env) && (hcr & HCR_TGE))
+            target_el = 2;
+        else
+            target_el = 1;
+    }
+
+    raise_exception_ra(env, EXCP_UDEF, syn_pacfail(data, keynumber), target_el, ra);
+}
+
 static uint64_t pauth_auth(CPUARMState *env, uint64_t ptr, uint64_t modifier,
                            ARMPACKey *key, bool data, int keynumber,
-                           bool is_combined)
+                           uintptr_t ra, bool is_combined)
 {
     ARMMMUIdx mmu_idx = arm_stage1_mmu_idx(env);
     ARMVAParameters param = aa64_va_parameters(env, ptr, mmu_idx, data);
@@ -406,6 +421,16 @@  static uint64_t pauth_auth(CPUARMState *env, uint64_t ptr, uint64_t modifier,
         uint64_t xor_mask = MAKE_64BIT_MASK(bot_bit, top_bit - bot_bit + 1) &
             ~MAKE_64BIT_MASK(55, 1);
         result = ((ptr ^ pac) & xor_mask) | (ptr & ~xor_mask);
+        if (cpu_isar_feature(aa64_fpac_combine, env_archcpu(env)) ||
+                (cpu_isar_feature(aa64_fpac, env_archcpu(env)) &&
+                 !is_combined)) {
+            int fpac_top = param.tbi ? 55 : 64;
+            uint64_t fpac_mask = MAKE_64BIT_MASK(bot_bit, fpac_top - bot_bit);
+            test = (result ^ sextract64(result, 55, 1)) & fpac_mask;
+            if (unlikely(test)) {
+                pauth_fail_exception(env, data, keynumber, ra);
+            }
+        }
     } else {
         test = (pac ^ ptr) & ~MAKE_64BIT_MASK(55, 1);
         if (unlikely(extract64(test, bot_bit, top_bit - bot_bit))) {
@@ -519,7 +544,7 @@  static uint64_t pauth_autia(CPUARMState *env, uint64_t x, uint64_t y,
         return x;
     }
     pauth_check_trap(env, el, ra);
-    return pauth_auth(env, x, y, &env->keys.apia, false, 0, is_combined);
+    return pauth_auth(env, x, y, &env->keys.apia, false, 0, ra, is_combined);
 }
 
 uint64_t HELPER(autia)(CPUARMState *env, uint64_t x, uint64_t y)
@@ -540,7 +565,7 @@  static uint64_t pauth_autib(CPUARMState *env, uint64_t x, uint64_t y,
         return x;
     }
     pauth_check_trap(env, el, ra);
-    return pauth_auth(env, x, y, &env->keys.apib, false, 1, is_combined);
+    return pauth_auth(env, x, y, &env->keys.apib, false, 1, ra, is_combined);
 }
 
 uint64_t HELPER(autib)(CPUARMState *env, uint64_t x, uint64_t y)
@@ -561,7 +586,7 @@  static uint64_t pauth_autda(CPUARMState *env, uint64_t x, uint64_t y,
         return x;
     }
     pauth_check_trap(env, el, ra);
-    return pauth_auth(env, x, y, &env->keys.apda, true, 0, is_combined);
+    return pauth_auth(env, x, y, &env->keys.apda, true, 0, ra, is_combined);
 }
 
 uint64_t HELPER(autda)(CPUARMState *env, uint64_t x, uint64_t y)
@@ -582,7 +607,7 @@  static uint64_t pauth_autdb(CPUARMState *env, uint64_t x, uint64_t y,
         return x;
     }
     pauth_check_trap(env, el, ra);
-    return pauth_auth(env, x, y, &env->keys.apdb, true, 1, is_combined);
+    return pauth_auth(env, x, y, &env->keys.apdb, true, 1, ra, is_combined);
 }
 
 uint64_t HELPER(autdb)(CPUARMState *env, uint64_t x, uint64_t y)
diff --git a/target/arm/syndrome.h b/target/arm/syndrome.h
index 73df5e3793..99ed4c7d3d 100644
--- a/target/arm/syndrome.h
+++ b/target/arm/syndrome.h
@@ -48,6 +48,7 @@  enum arm_exception_class {
     EC_AA64_SMC               = 0x17,
     EC_SYSTEMREGISTERTRAP     = 0x18,
     EC_SVEACCESSTRAP          = 0x19,
+    EC_PACFAIL                = 0x1c,
     EC_SMETRAP                = 0x1d,
     EC_INSNABORT              = 0x20,
     EC_INSNABORT_SAME_EL      = 0x21,
@@ -221,6 +222,12 @@  static inline uint32_t syn_smetrap(SMEExceptionType etype, bool is_16bit)
         | (is_16bit ? 0 : ARM_EL_IL) | etype;
 }
 
+static inline uint32_t syn_pacfail(bool data, int keynumber)
+{
+    int error_code = ((data ? 1 : 0) << 1) | (keynumber);
+    return (EC_PACFAIL << ARM_EL_EC_SHIFT) | ARM_EL_IL | error_code;
+}
+
 static inline uint32_t syn_pactrap(void)
 {
     return EC_PACTRAP << ARM_EL_EC_SHIFT;