[PATCH for-8.2] target/riscv/kvm: fix shadowing in kvm_riscv_(get|put)_regs_csr

[PATCH for-8.2] target/riscv/kvm: fix shadowing in kvm_riscv_(get|put)_regs_csr

[Daniel Henrique Barboza]

KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() use an 'int ret' variable
that is used to do an early 'return' if ret > 0. Both are being called
in functions that are also declaring a 'ret' integer, initialized with
'0', and this integer is used as return of the function.

The result is that the compiler is less than pleased and is pointing
shadowing errors:

../target/riscv/kvm/kvm-cpu.c: In function 'kvm_riscv_get_regs_csr':
../target/riscv/kvm/kvm-cpu.c:90:13: error: declaration of 'ret' shadows a previous local [-Werror=shadow=compatible-local]
   90 |         int ret = kvm_get_one_reg(cs, RISCV_CSR_REG(env, csr), &reg); \
      |             ^~~
../target/riscv/kvm/kvm-cpu.c:539:5: note: in expansion of macro 'KVM_RISCV_GET_CSR'
  539 |     KVM_RISCV_GET_CSR(cs, env, sstatus, env->mstatus);
      |     ^~~~~~~~~~~~~~~~~
../target/riscv/kvm/kvm-cpu.c:536:9: note: shadowed declaration is here
  536 |     int ret = 0;
      |         ^~~

../target/riscv/kvm/kvm-cpu.c: In function 'kvm_riscv_put_regs_csr':
../target/riscv/kvm/kvm-cpu.c:98:13: error: declaration of 'ret' shadows a previous local [-Werror=shadow=compatible-local]
   98 |         int ret = kvm_set_one_reg(cs, RISCV_CSR_REG(env, csr), &reg); \
      |             ^~~
../target/riscv/kvm/kvm-cpu.c:556:5: note: in expansion of macro 'KVM_RISCV_SET_CSR'
  556 |     KVM_RISCV_SET_CSR(cs, env, sstatus, env->mstatus);
      |     ^~~~~~~~~~~~~~~~~
../target/riscv/kvm/kvm-cpu.c:553:9: note: shadowed declaration is here
  553 |     int ret = 0;
      |         ^~~

The macros are doing early returns for non-zero returns and the local
'ret' variable for both functions is used just to do 'return 0', so
remove them from kvm_riscv_get_regs_csr() and kvm_riscv_put_regs_csr()
and do a straight 'return 0' in the end.

For good measure let's also rename the 'ret' variables in
KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() to '_ret' to make them more
resilient to these kind of errors.

Fixes: 937f0b4512 ("target/riscv: Implement kvm_arch_get_registers")
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
 target/riscv/kvm/kvm-cpu.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c
index 78fa1fa162..45b6cf1cfa 100644
--- a/target/riscv/kvm/kvm-cpu.c
+++ b/target/riscv/kvm/kvm-cpu.c
@@ -87,17 +87,17 @@ static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type,
 
 #define KVM_RISCV_GET_CSR(cs, env, csr, reg) \
     do { \
-        int ret = kvm_get_one_reg(cs, RISCV_CSR_REG(env, csr), &reg); \
-        if (ret) { \
-            return ret; \
+        int _ret = kvm_get_one_reg(cs, RISCV_CSR_REG(env, csr), &reg); \
+        if (_ret) { \
+            return _ret; \
         } \
     } while (0)
 
 #define KVM_RISCV_SET_CSR(cs, env, csr, reg) \
     do { \
-        int ret = kvm_set_one_reg(cs, RISCV_CSR_REG(env, csr), &reg); \
-        if (ret) { \
-            return ret; \
+        int _ret = kvm_set_one_reg(cs, RISCV_CSR_REG(env, csr), &reg); \
+        if (_ret) { \
+            return _ret; \
         } \
     } while (0)
 
@@ -533,7 +533,6 @@ static int kvm_riscv_put_regs_core(CPUState *cs)
 
 static int kvm_riscv_get_regs_csr(CPUState *cs)
 {
-    int ret = 0;
     CPURISCVState *env = &RISCV_CPU(cs)->env;
 
     KVM_RISCV_GET_CSR(cs, env, sstatus, env->mstatus);
@@ -545,12 +544,12 @@ static int kvm_riscv_get_regs_csr(CPUState *cs)
     KVM_RISCV_GET_CSR(cs, env, stval, env->stval);
     KVM_RISCV_GET_CSR(cs, env, sip, env->mip);
     KVM_RISCV_GET_CSR(cs, env, satp, env->satp);
-    return ret;
+
+    return 0;
 }
 
 static int kvm_riscv_put_regs_csr(CPUState *cs)
 {
-    int ret = 0;
     CPURISCVState *env = &RISCV_CPU(cs)->env;
 
     KVM_RISCV_SET_CSR(cs, env, sstatus, env->mstatus);
@@ -563,7 +562,7 @@ static int kvm_riscv_put_regs_csr(CPUState *cs)
     KVM_RISCV_SET_CSR(cs, env, sip, env->mip);
     KVM_RISCV_SET_CSR(cs, env, satp, env->satp);
 
-    return ret;
+    return 0;
 }
 
 static int kvm_riscv_get_regs_fp(CPUState *cs)
-- 
2.41.0

Re: [PATCH for-8.2] target/riscv/kvm: fix shadowing in kvm_riscv_(get|put)_regs_csr

[Philippe Mathieu-Daudé]

On 23/11/23 11:13, Daniel Henrique Barboza wrote:
> KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() use an 'int ret' variable
> that is used to do an early 'return' if ret > 0. Both are being called
> in functions that are also declaring a 'ret' integer, initialized with
> '0', and this integer is used as return of the function.
> 
> The result is that the compiler is less than pleased and is pointing
> shadowing errors:
> 
> ../target/riscv/kvm/kvm-cpu.c: In function 'kvm_riscv_get_regs_csr':
> ../target/riscv/kvm/kvm-cpu.c:90:13: error: declaration of 'ret' shadows a previous local [-Werror=shadow=compatible-local]
>     90 |         int ret = kvm_get_one_reg(cs, RISCV_CSR_REG(env, csr), &reg); \
>        |             ^~~
> ../target/riscv/kvm/kvm-cpu.c:539:5: note: in expansion of macro 'KVM_RISCV_GET_CSR'
>    539 |     KVM_RISCV_GET_CSR(cs, env, sstatus, env->mstatus);
>        |     ^~~~~~~~~~~~~~~~~
> ../target/riscv/kvm/kvm-cpu.c:536:9: note: shadowed declaration is here
>    536 |     int ret = 0;


> The macros are doing early returns for non-zero returns and the local
> 'ret' variable for both functions is used just to do 'return 0', so
> remove them from kvm_riscv_get_regs_csr() and kvm_riscv_put_regs_csr()
> and do a straight 'return 0' in the end.
> 
> For good measure let's also rename the 'ret' variables in
> KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() to '_ret' to make them more
> resilient to these kind of errors.
> 
> Fixes: 937f0b4512 ("target/riscv: Implement kvm_arch_get_registers")
> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
>   target/riscv/kvm/kvm-cpu.c | 19 +++++++++----------
>   1 file changed, 9 insertions(+), 10 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH for-8.2] target/riscv/kvm: fix shadowing in kvm_riscv_(get|put)_regs_csr

[Philippe Mathieu-Daudé]

On 23/11/23 11:23, Philippe Mathieu-Daudé wrote:
> On 23/11/23 11:13, Daniel Henrique Barboza wrote:
>> KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() use an 'int ret' variable
>> that is used to do an early 'return' if ret > 0. Both are being called
>> in functions that are also declaring a 'ret' integer, initialized with
>> '0', and this integer is used as return of the function.
>>
>> The result is that the compiler is less than pleased and is pointing
>> shadowing errors:
>>
>> ../target/riscv/kvm/kvm-cpu.c: In function 'kvm_riscv_get_regs_csr':
>> ../target/riscv/kvm/kvm-cpu.c:90:13: error: declaration of 'ret' 
>> shadows a previous local [-Werror=shadow=compatible-local]
>>     90 |         int ret = kvm_get_one_reg(cs, RISCV_CSR_REG(env, 
>> csr), &reg); \
>>        |             ^~~
>> ../target/riscv/kvm/kvm-cpu.c:539:5: note: in expansion of macro 
>> 'KVM_RISCV_GET_CSR'
>>    539 |     KVM_RISCV_GET_CSR(cs, env, sstatus, env->mstatus);
>>        |     ^~~~~~~~~~~~~~~~~
>> ../target/riscv/kvm/kvm-cpu.c:536:9: note: shadowed declaration is here
>>    536 |     int ret = 0;
> 
> 
>> The macros are doing early returns for non-zero returns and the local
>> 'ret' variable for both functions is used just to do 'return 0', so
>> remove them from kvm_riscv_get_regs_csr() and kvm_riscv_put_regs_csr()
>> and do a straight 'return 0' in the end.
>>
>> For good measure let's also rename the 'ret' variables in
>> KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() to '_ret' to make them more
>> resilient to these kind of errors.
>>
>> Fixes: 937f0b4512 ("target/riscv: Implement kvm_arch_get_registers")
>> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
>> ---
>>   target/riscv/kvm/kvm-cpu.c | 19 +++++++++----------
>>   1 file changed, 9 insertions(+), 10 deletions(-)
> 
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Also:

Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Alistair, if you don't have any pending riscv pull request
I can take this patch with the one I plan to post tomorrow
(this is the last fix missing to get our CI green again).

Re: [PATCH for-8.2] target/riscv/kvm: fix shadowing in kvm_riscv_(get|put)_regs_csr

[Alistair Francis]

On Mon, Dec 4, 2023 at 3:00 AM Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>
> On 23/11/23 11:23, Philippe Mathieu-Daudé wrote:
> > On 23/11/23 11:13, Daniel Henrique Barboza wrote:
> >> KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() use an 'int ret' variable
> >> that is used to do an early 'return' if ret > 0. Both are being called
> >> in functions that are also declaring a 'ret' integer, initialized with
> >> '0', and this integer is used as return of the function.
> >>
> >> The result is that the compiler is less than pleased and is pointing
> >> shadowing errors:
> >>
> >> ../target/riscv/kvm/kvm-cpu.c: In function 'kvm_riscv_get_regs_csr':
> >> ../target/riscv/kvm/kvm-cpu.c:90:13: error: declaration of 'ret'
> >> shadows a previous local [-Werror=shadow=compatible-local]
> >>     90 |         int ret = kvm_get_one_reg(cs, RISCV_CSR_REG(env,
> >> csr), &reg); \
> >>        |             ^~~
> >> ../target/riscv/kvm/kvm-cpu.c:539:5: note: in expansion of macro
> >> 'KVM_RISCV_GET_CSR'
> >>    539 |     KVM_RISCV_GET_CSR(cs, env, sstatus, env->mstatus);
> >>        |     ^~~~~~~~~~~~~~~~~
> >> ../target/riscv/kvm/kvm-cpu.c:536:9: note: shadowed declaration is here
> >>    536 |     int ret = 0;
> >
> >
> >> The macros are doing early returns for non-zero returns and the local
> >> 'ret' variable for both functions is used just to do 'return 0', so
> >> remove them from kvm_riscv_get_regs_csr() and kvm_riscv_put_regs_csr()
> >> and do a straight 'return 0' in the end.
> >>
> >> For good measure let's also rename the 'ret' variables in
> >> KVM_RISCV_GET_CSR() and KVM_RISCV_SET_CSR() to '_ret' to make them more
> >> resilient to these kind of errors.
> >>
> >> Fixes: 937f0b4512 ("target/riscv: Implement kvm_arch_get_registers")
> >> Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> >> ---
> >>   target/riscv/kvm/kvm-cpu.c | 19 +++++++++----------
> >>   1 file changed, 9 insertions(+), 10 deletions(-)
> >
> > Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

>
> Also:
>
> Tested-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>
> Alistair, if you don't have any pending riscv pull request
> I can take this patch with the one I plan to post tomorrow
> (this is the last fix missing to get our CI green again).

Go for it! That would be really helpful

Alistair

>