riscv: Mark __se_sys_* functions __used

[PATCH] riscv: Mark __se_sys_* functions __used

Posted by Sami Tolvanen 1 year, 10 months ago

Clang doesn't think ___se_sys_* functions used even though they are
aliased to __se_sys_*, resulting in -Wunused-function warnings when
building rv32. For example:

   mm/oom_kill.c:1195:1: warning: unused function '___se_sys_process_mrelease' [-Wunused-function]
    1195 | SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
         | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/syscalls.h:221:36: note: expanded from macro 'SYSCALL_DEFINE2'
     221 | #define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
         |                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/syscalls.h:231:2: note: expanded from macro 'SYSCALL_DEFINEx'
     231 |         __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/syscall_wrapper.h:81:2: note: expanded from macro '__SYSCALL_DEFINEx'
      81 |         __SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__)                         \
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/riscv/include/asm/syscall_wrapper.h:40:14: note: expanded from macro '__SYSCALL_SE_DEFINEx'
      40 |         static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
         |                     ^~~~~~~~~~~~~~~~~~~~
   <scratch space>:30:1: note: expanded from here
      30 | ___se_sys_process_mrelease
         | ^~~~~~~~~~~~~~~~~~~~~~~~~~
   1 warning generated.

Mark the functions __used explicitly to fix the Clang warnings.

Fixes: a9ad73295cc1 ("riscv: Fix syscall wrapper for >word-size arguments")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
---
 arch/riscv/include/asm/syscall_wrapper.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/syscall_wrapper.h b/arch/riscv/include/asm/syscall_wrapper.h
index 980094c2e976..ac80216549ff 100644
--- a/arch/riscv/include/asm/syscall_wrapper.h
+++ b/arch/riscv/include/asm/syscall_wrapper.h
@@ -36,7 +36,8 @@ asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *);
 					ulong)						\
 			__attribute__((alias(__stringify(___se_##prefix##name))));	\
 	__diag_pop();									\
-	static long noinline ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
+	static long noinline ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
+			__used;								\
 	static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
 
 #define SC_RISCV_REGS_TO_ARGS(x, ...) \

base-commit: 4cece764965020c22cff7665b18a012006359095
-- 
2.44.0.396.g6e790dbe36-goog

Re: [PATCH] riscv: Mark __se_sys_* functions __used

Posted by Conor Dooley 1 year, 10 months ago

On Tue, Mar 26, 2024 at 03:37:13PM +0000, Sami Tolvanen wrote:
> Clang doesn't think ___se_sys_* functions used even though they are
> aliased to __se_sys_*, resulting in -Wunused-function warnings when
> building rv32. For example:
> 
>    mm/oom_kill.c:1195:1: warning: unused function '___se_sys_process_mrelease' [-Wunused-function]
>     1195 | SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
>          | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    include/linux/syscalls.h:221:36: note: expanded from macro 'SYSCALL_DEFINE2'
>      221 | #define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
>          |                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    include/linux/syscalls.h:231:2: note: expanded from macro 'SYSCALL_DEFINEx'
>      231 |         __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
>          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    arch/riscv/include/asm/syscall_wrapper.h:81:2: note: expanded from macro '__SYSCALL_DEFINEx'
>       81 |         __SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__)                         \
>          |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    arch/riscv/include/asm/syscall_wrapper.h:40:14: note: expanded from macro '__SYSCALL_SE_DEFINEx'
>       40 |         static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
>          |                     ^~~~~~~~~~~~~~~~~~~~
>    <scratch space>:30:1: note: expanded from here
>       30 | ___se_sys_process_mrelease
>          | ^~~~~~~~~~~~~~~~~~~~~~~~~~
>    1 warning generated.
> 
> Mark the functions __used explicitly to fix the Clang warnings.
> 
> Fixes: a9ad73295cc1 ("riscv: Fix syscall wrapper for >word-size arguments")
> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

Oh neat, thanks. This was generating a shed load of noise in CI :)
Tested-by: Conor Dooley <conor.dooley@microchip.com>

Thanks,
Conor.

> ---
>  arch/riscv/include/asm/syscall_wrapper.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/riscv/include/asm/syscall_wrapper.h b/arch/riscv/include/asm/syscall_wrapper.h
> index 980094c2e976..ac80216549ff 100644
> --- a/arch/riscv/include/asm/syscall_wrapper.h
> +++ b/arch/riscv/include/asm/syscall_wrapper.h
> @@ -36,7 +36,8 @@ asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *);
>  					ulong)						\
>  			__attribute__((alias(__stringify(___se_##prefix##name))));	\
>  	__diag_pop();									\
> -	static long noinline ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
> +	static long noinline ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
> +			__used;								\
>  	static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
>  
>  #define SC_RISCV_REGS_TO_ARGS(x, ...) \
> 
> base-commit: 4cece764965020c22cff7665b18a012006359095
> -- 
> 2.44.0.396.g6e790dbe36-goog
> 
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH] riscv: Mark __se_sys_* functions __used

Posted by Alexandre Ghiti 1 year, 10 months ago

Hi Sami,

On 26/03/2024 16:37, Sami Tolvanen wrote:
> Clang doesn't think ___se_sys_* functions used even though they are
> aliased to __se_sys_*, resulting in -Wunused-function warnings when
> building rv32. For example:
>
>     mm/oom_kill.c:1195:1: warning: unused function '___se_sys_process_mrelease' [-Wunused-function]
>      1195 | SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
>           | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     include/linux/syscalls.h:221:36: note: expanded from macro 'SYSCALL_DEFINE2'
>       221 | #define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
>           |                                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     include/linux/syscalls.h:231:2: note: expanded from macro 'SYSCALL_DEFINEx'
>       231 |         __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
>           |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     arch/riscv/include/asm/syscall_wrapper.h:81:2: note: expanded from macro '__SYSCALL_DEFINEx'
>        81 |         __SYSCALL_SE_DEFINEx(x, sys, name, __VA_ARGS__)                         \
>           |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     arch/riscv/include/asm/syscall_wrapper.h:40:14: note: expanded from macro '__SYSCALL_SE_DEFINEx'
>        40 |         static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
>           |                     ^~~~~~~~~~~~~~~~~~~~
>     <scratch space>:30:1: note: expanded from here
>        30 | ___se_sys_process_mrelease
>           | ^~~~~~~~~~~~~~~~~~~~~~~~~~
>     1 warning generated.
>
> Mark the functions __used explicitly to fix the Clang warnings.
>
> Fixes: a9ad73295cc1 ("riscv: Fix syscall wrapper for >word-size arguments")
> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>


Do you have the link of the report? So we can add a Closes tag.


> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
> Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> ---
>   arch/riscv/include/asm/syscall_wrapper.h | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/syscall_wrapper.h b/arch/riscv/include/asm/syscall_wrapper.h
> index 980094c2e976..ac80216549ff 100644
> --- a/arch/riscv/include/asm/syscall_wrapper.h
> +++ b/arch/riscv/include/asm/syscall_wrapper.h
> @@ -36,7 +36,8 @@ asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *);
>   					ulong)						\
>   			__attribute__((alias(__stringify(___se_##prefix##name))));	\
>   	__diag_pop();									\
> -	static long noinline ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
> +	static long noinline ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))	\
> +			__used;								\
>   	static long ___se_##prefix##name(__MAP(x,__SC_LONG,__VA_ARGS__))
>   
>   #define SC_RISCV_REGS_TO_ARGS(x, ...) \
>
> base-commit: 4cece764965020c22cff7665b18a012006359095


You can add:

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>

As the commit fixed here was merged in 6.9, this should go into fixes.

Thanks,

Alex

Re: [PATCH] riscv: Mark __se_sys_* functions __used

Posted by Sami Tolvanen 1 year, 10 months ago

On Tue, Mar 26, 2024 at 6:43 PM Alexandre Ghiti <alex@ghiti.fr> wrote:
>
> Do you have the link of the report? So we can add a Closes tag.

Sure, this was reported here:

https://lore.kernel.org/lkml/56d3285a-ed22-44bd-8c22-ce51ad159a81@linaro.org/

Sami

Re: [PATCH] riscv: Mark __se_sys_* functions __used

Posted by Alexandre Ghiti 1 year, 10 months ago

On 26/03/2024 19:55, Sami Tolvanen wrote:
> On Tue, Mar 26, 2024 at 6:43 PM Alexandre Ghiti <alex@ghiti.fr> wrote:
>> Do you have the link of the report? So we can add a Closes tag.
> Sure, this was reported here:
>
> https://lore.kernel.org/lkml/56d3285a-ed22-44bd-8c22-ce51ad159a81@linaro.org/


For b4:

Closes: 
https://lore.kernel.org/lkml/56d3285a-ed22-44bd-8c22-ce51ad159a81@linaro.org/

I was expecting the "direct" lkft link though, @Daniel do you have any?

Thanks,

Alex


>
> Sami
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH] riscv: Mark __se_sys_* functions __used

Posted by Daniel Díaz 1 year, 10 months ago

Hello!

On Tue, 26 Mar 2024 at 13:56, Alexandre Ghiti <alex@ghiti.fr> wrote:
> On 26/03/2024 19:55, Sami Tolvanen wrote:
> > On Tue, Mar 26, 2024 at 6:43 PM Alexandre Ghiti <alex@ghiti.fr> wrote:
> >> Do you have the link of the report? So we can add a Closes tag.
> > Sure, this was reported here:
> >
> > https://lore.kernel.org/lkml/56d3285a-ed22-44bd-8c22-ce51ad159a81@linaro.org/
>
> For b4:
>
> Closes:
> https://lore.kernel.org/lkml/56d3285a-ed22-44bd-8c22-ce51ad159a81@linaro.org/
>
> I was expecting the "direct" lkft link though, @Daniel do you have any?

No, that's the extent of that report.

Greetings!

Daniel Díaz
daniel.diaz@linaro.org