target/sh4: Return error if CPUClass::get_phys_page_debug() fails

[PATCH] target/sh4: Return error if CPUClass::get_phys_page_debug() fails

Posted by Philippe Mathieu-Daudé 4 years, 9 months ago

If the get_physical_address() call fails, the SH4 get_phys_page_debug()
handler returns an uninitialized address. Instead return -1, which
correspond to "no page found" (see cpu_get_phys_page_debug() doc
string).

This fixes a warning emitted when building with CFLAGS=-O3
(using GCC 10.2.1 20201125):

  target/sh4/helper.c: In function ‘superh_cpu_get_phys_page_debug’:
  target/sh4/helper.c:446:12: warning: ‘physical’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    446 |     return physical;
        |            ^~~~~~~~

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 target/sh4/helper.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/target/sh4/helper.c b/target/sh4/helper.c
index bd8e034f174..2d622081e85 100644
--- a/target/sh4/helper.c
+++ b/target/sh4/helper.c
@@ -441,9 +441,12 @@ hwaddr superh_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
     target_ulong physical;
     int prot;
 
-    get_physical_address(&cpu->env, &physical, &prot, addr, MMU_DATA_LOAD);
+    if (get_physical_address(&cpu->env, &physical, &prot, addr, MMU_DATA_LOAD)
+            == MMU_OK) {
+        return physical;
+    }
 
-    return physical;
+    return -1;
 }
 
 void cpu_load_tlb(CPUSH4State * env)
-- 
2.26.3

Re: [PATCH] target/sh4: Return error if CPUClass::get_phys_page_debug() fails

Posted by Richard Henderson 4 years, 9 months ago

On 5/5/21 9:10 AM, Philippe Mathieu-Daudé wrote:
> If the get_physical_address() call fails, the SH4 get_phys_page_debug()
> handler returns an uninitialized address. Instead return -1, which
> correspond to "no page found" (see cpu_get_phys_page_debug() doc
> string).
> 
> This fixes a warning emitted when building with CFLAGS=-O3
> (using GCC 10.2.1 20201125):
> 
>    target/sh4/helper.c: In function ‘superh_cpu_get_phys_page_debug’:
>    target/sh4/helper.c:446:12: warning: ‘physical’ may be used uninitialized in this function [-Wmaybe-uninitialized]
>      446 |     return physical;
>          |            ^~~~~~~~
> 
> Signed-off-by: Philippe Mathieu-Daudé<f4bug@amsat.org>
> ---
>   target/sh4/helper.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

Re: [PATCH] target/sh4: Return error if CPUClass::get_phys_page_debug() fails

Posted by Yoshinori Sato 4 years, 9 months ago

On Thu, 06 May 2021 01:10:46 +0900,
Philippe Mathieu-Daudé wrote:
> 
> If the get_physical_address() call fails, the SH4 get_phys_page_debug()
> handler returns an uninitialized address. Instead return -1, which
> correspond to "no page found" (see cpu_get_phys_page_debug() doc
> string).
> 
> This fixes a warning emitted when building with CFLAGS=-O3
> (using GCC 10.2.1 20201125):
> 
>   target/sh4/helper.c: In function ‘superh_cpu_get_phys_page_debug’:
>   target/sh4/helper.c:446:12: warning: ‘physical’ may be used uninitialized in this function [-Wmaybe-uninitialized]
>     446 |     return physical;
>         |            ^~~~~~~~
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  target/sh4/helper.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/target/sh4/helper.c b/target/sh4/helper.c
> index bd8e034f174..2d622081e85 100644
> --- a/target/sh4/helper.c
> +++ b/target/sh4/helper.c
> @@ -441,9 +441,12 @@ hwaddr superh_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
>      target_ulong physical;
>      int prot;
>  
> -    get_physical_address(&cpu->env, &physical, &prot, addr, MMU_DATA_LOAD);
> +    if (get_physical_address(&cpu->env, &physical, &prot, addr, MMU_DATA_LOAD)
> +            == MMU_OK) {
> +        return physical;
> +    }
>  
> -    return physical;
> +    return -1;
>  }
>  
>  void cpu_load_tlb(CPUSH4State * env)
> -- 
> 2.26.3
> 
> 

Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp>

-- 
Yosinori Sato

Re: [PATCH] target/sh4: Return error if CPUClass::get_phys_page_debug() fails

Posted by Laurent Vivier 4 years, 9 months ago

Le 05/05/2021 à 18:10, Philippe Mathieu-Daudé a écrit :
> If the get_physical_address() call fails, the SH4 get_phys_page_debug()
> handler returns an uninitialized address. Instead return -1, which
> correspond to "no page found" (see cpu_get_phys_page_debug() doc
> string).
> 
> This fixes a warning emitted when building with CFLAGS=-O3
> (using GCC 10.2.1 20201125):
> 
>   target/sh4/helper.c: In function ‘superh_cpu_get_phys_page_debug’:
>   target/sh4/helper.c:446:12: warning: ‘physical’ may be used uninitialized in this function [-Wmaybe-uninitialized]
>     446 |     return physical;
>         |            ^~~~~~~~
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  target/sh4/helper.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/target/sh4/helper.c b/target/sh4/helper.c
> index bd8e034f174..2d622081e85 100644
> --- a/target/sh4/helper.c
> +++ b/target/sh4/helper.c
> @@ -441,9 +441,12 @@ hwaddr superh_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
>      target_ulong physical;
>      int prot;
>  
> -    get_physical_address(&cpu->env, &physical, &prot, addr, MMU_DATA_LOAD);
> +    if (get_physical_address(&cpu->env, &physical, &prot, addr, MMU_DATA_LOAD)
> +            == MMU_OK) {
> +        return physical;
> +    }
>  
> -    return physical;
> +    return -1;
>  }
>  
>  void cpu_load_tlb(CPUSH4State * env)
> 

Applied to my trivial-patches branch.

Thanks,
Laurent

Re: [PATCH] target/sh4: Return error if CPUClass::get_phys_page_debug() fails

Posted by Philippe Mathieu-Daudé 4 years, 9 months ago

Cc'ing qemu-trivial@

On 5/5/21 6:10 PM, Philippe Mathieu-Daudé wrote:
> If the get_physical_address() call fails, the SH4 get_phys_page_debug()
> handler returns an uninitialized address. Instead return -1, which
> correspond to "no page found" (see cpu_get_phys_page_debug() doc
> string).
> 
> This fixes a warning emitted when building with CFLAGS=-O3
> (using GCC 10.2.1 20201125):
> 
>   target/sh4/helper.c: In function ‘superh_cpu_get_phys_page_debug’:
>   target/sh4/helper.c:446:12: warning: ‘physical’ may be used uninitialized in this function [-Wmaybe-uninitialized]
>     446 |     return physical;
>         |            ^~~~~~~~
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  target/sh4/helper.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/target/sh4/helper.c b/target/sh4/helper.c
> index bd8e034f174..2d622081e85 100644
> --- a/target/sh4/helper.c
> +++ b/target/sh4/helper.c
> @@ -441,9 +441,12 @@ hwaddr superh_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
>      target_ulong physical;
>      int prot;
>  
> -    get_physical_address(&cpu->env, &physical, &prot, addr, MMU_DATA_LOAD);
> +    if (get_physical_address(&cpu->env, &physical, &prot, addr, MMU_DATA_LOAD)
> +            == MMU_OK) {
> +        return physical;
> +    }
>  
> -    return physical;
> +    return -1;
>  }
>  
>  void cpu_load_tlb(CPUSH4State * env)
>