[PATCH v2] selftest/powerpc/benchmark: remove requirement libc-dev

[PATCH v2] selftest/powerpc/benchmark: remove requirement libc-dev

[Madhavan Srinivasan]

Currently exec-target.c file is linked as static and this
post a requirement to install libc dev package to build.
Without it, build-break when compiling selftest/powerpc/benchmark.

  CC       exec_target
/usr/bin/ld: cannot find -lc: No such file or directory
collect2: error: ld returned 1 exit status

exec_target.c is using "syscall" library function which
could be replaced with a inline assembly and the same is
proposed as a fix here.

Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
---
Chnagelog v1:
- Add comment for clobber register and proper list of
  clobber registers as suggested by Michael Ellerman and
  Christophe Leroy

 .../selftests/powerpc/benchmarks/Makefile        |  2 +-
 .../selftests/powerpc/benchmarks/exec_target.c   | 16 ++++++++++++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/powerpc/benchmarks/Makefile b/tools/testing/selftests/powerpc/benchmarks/Makefile
index 1321922038d0..ca4483c238b9 100644
--- a/tools/testing/selftests/powerpc/benchmarks/Makefile
+++ b/tools/testing/selftests/powerpc/benchmarks/Makefile
@@ -18,4 +18,4 @@ $(OUTPUT)/context_switch: LDLIBS += -lpthread
 
 $(OUTPUT)/fork: LDLIBS += -lpthread
 
-$(OUTPUT)/exec_target: CFLAGS += -static -nostartfiles
+$(OUTPUT)/exec_target: CFLAGS += -nostartfiles
diff --git a/tools/testing/selftests/powerpc/benchmarks/exec_target.c b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
index c14b0fc1edde..a6408d3f26cd 100644
--- a/tools/testing/selftests/powerpc/benchmarks/exec_target.c
+++ b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
@@ -7,10 +7,22 @@
  */
 
 #define _GNU_SOURCE
-#include <unistd.h>
 #include <sys/syscall.h>
 
 void _start(void)
 {
-	syscall(SYS_exit, 0);
+	asm volatile (
+		"li %%r0, %[sys_exit];"
+		"li %%r3, 0;"
+		"sc;"
+		:
+		: [sys_exit] "i" (SYS_exit)
+		/*
+		 * "sc" will clobber r0, r3-r13, cr0, ctr, xer and memory.
+		 * Even though sys_exit never returns, handle clobber
+		 * registers.
+		 */
+		: "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
+		  "r11", "r12", "r13", "cr0", "ctr", "xer", "memory"
+	);
 }
-- 
2.45.2

Re: [PATCH v2] selftest/powerpc/benchmark: remove requirement libc-dev

[Michael Ellerman]

Madhavan Srinivasan <maddy@linux.ibm.com> writes:
> Currently exec-target.c file is linked as static and this
> post a requirement to install libc dev package to build.

I think specifically the problem is that the test requires a static
libc, which is packaged separately in some distros from the regular libc
headers, am I right?

On Fedora the package is glibc-static, as opposed to glibc-devel, which
the tests still require.

So this patch removes the requirement to have glibc-static installed.
Any idea what the package is called on Debian/Ubuntu?

cheers

> Without it, build-break when compiling selftest/powerpc/benchmark.
>
>   CC       exec_target
> /usr/bin/ld: cannot find -lc: No such file or directory
> collect2: error: ld returned 1 exit status
>
> exec_target.c is using "syscall" library function which
> could be replaced with a inline assembly and the same is
> proposed as a fix here.
>
> Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
> ---
> Chnagelog v1:
> - Add comment for clobber register and proper list of
>   clobber registers as suggested by Michael Ellerman and
>   Christophe Leroy
>
>  .../selftests/powerpc/benchmarks/Makefile        |  2 +-
>  .../selftests/powerpc/benchmarks/exec_target.c   | 16 ++++++++++++++--
>  2 files changed, 15 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/powerpc/benchmarks/Makefile b/tools/testing/selftests/powerpc/benchmarks/Makefile
> index 1321922038d0..ca4483c238b9 100644
> --- a/tools/testing/selftests/powerpc/benchmarks/Makefile
> +++ b/tools/testing/selftests/powerpc/benchmarks/Makefile
> @@ -18,4 +18,4 @@ $(OUTPUT)/context_switch: LDLIBS += -lpthread
>  
>  $(OUTPUT)/fork: LDLIBS += -lpthread
>  
> -$(OUTPUT)/exec_target: CFLAGS += -static -nostartfiles
> +$(OUTPUT)/exec_target: CFLAGS += -nostartfiles
> diff --git a/tools/testing/selftests/powerpc/benchmarks/exec_target.c b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
> index c14b0fc1edde..a6408d3f26cd 100644
> --- a/tools/testing/selftests/powerpc/benchmarks/exec_target.c
> +++ b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
> @@ -7,10 +7,22 @@
>   */
>  
>  #define _GNU_SOURCE
> -#include <unistd.h>
>  #include <sys/syscall.h>
>  
>  void _start(void)
>  {
> -	syscall(SYS_exit, 0);
> +	asm volatile (
> +		"li %%r0, %[sys_exit];"
> +		"li %%r3, 0;"
> +		"sc;"
> +		:
> +		: [sys_exit] "i" (SYS_exit)
> +		/*
> +		 * "sc" will clobber r0, r3-r13, cr0, ctr, xer and memory.
> +		 * Even though sys_exit never returns, handle clobber
> +		 * registers.
> +		 */
> +		: "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
> +		  "r11", "r12", "r13", "cr0", "ctr", "xer", "memory"
> +	);
>  }
> -- 
> 2.45.2

Re: [PATCH v2] selftest/powerpc/benchmark: remove requirement libc-dev

[Madhavan Srinivasan]

[-- Attachment #1: Type: text/plain, Size: 3294 bytes --]


On 8/13/24 1:11 PM, Michael Ellerman wrote:
> Madhavan Srinivasan<maddy@linux.ibm.com>  writes:
>> Currently exec-target.c file is linked as static and this
>> post a requirement to install libc dev package to build.
> I think specifically the problem is that the test requires a static
> libc, which is packaged separately in some distros from the regular libc
> headers, am I right?
Thats right
> On Fedora the package is glibc-static, as opposed to glibc-devel, which
> the tests still require.
>
> So this patch removes the requirement to have glibc-static installed.
> Any idea what the package is called on Debian/Ubuntu?
This is what i could find in ubuntu VM, package is "libgcc-13-dev"
Description about this package

Binary package "libgcc-13-dev" in ubuntu noble Noble (24.04) 
libgcc-13-dev GCC support library (development files) This package 
contains the headers and static library files necessary for building C 
programs which use libgcc, libgomp, libquadmath, libssp or libitm.

Maddy
>
> cheers
>
>> Without it, build-break when compiling selftest/powerpc/benchmark.
>>
>>    CC       exec_target
>> /usr/bin/ld: cannot find -lc: No such file or directory
>> collect2: error: ld returned 1 exit status
>>
>> exec_target.c is using "syscall" library function which
>> could be replaced with a inline assembly and the same is
>> proposed as a fix here.
>>
>> Suggested-by: Michael Ellerman<mpe@ellerman.id.au>
>> Signed-off-by: Madhavan Srinivasan<maddy@linux.ibm.com>
>> ---
>> Chnagelog v1:
>> - Add comment for clobber register and proper list of
>>    clobber registers as suggested by Michael Ellerman and
>>    Christophe Leroy
>>
>>   .../selftests/powerpc/benchmarks/Makefile        |  2 +-
>>   .../selftests/powerpc/benchmarks/exec_target.c   | 16 ++++++++++++++--
>>   2 files changed, 15 insertions(+), 3 deletions(-)
>>
>> diff --git a/tools/testing/selftests/powerpc/benchmarks/Makefile b/tools/testing/selftests/powerpc/benchmarks/Makefile
>> index 1321922038d0..ca4483c238b9 100644
>> --- a/tools/testing/selftests/powerpc/benchmarks/Makefile
>> +++ b/tools/testing/selftests/powerpc/benchmarks/Makefile
>> @@ -18,4 +18,4 @@ $(OUTPUT)/context_switch: LDLIBS += -lpthread
>>   
>>   $(OUTPUT)/fork: LDLIBS += -lpthread
>>   
>> -$(OUTPUT)/exec_target: CFLAGS += -static -nostartfiles
>> +$(OUTPUT)/exec_target: CFLAGS += -nostartfiles
>> diff --git a/tools/testing/selftests/powerpc/benchmarks/exec_target.c b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
>> index c14b0fc1edde..a6408d3f26cd 100644
>> --- a/tools/testing/selftests/powerpc/benchmarks/exec_target.c
>> +++ b/tools/testing/selftests/powerpc/benchmarks/exec_target.c
>> @@ -7,10 +7,22 @@
>>    */
>>   
>>   #define _GNU_SOURCE
>> -#include <unistd.h>
>>   #include <sys/syscall.h>
>>   
>>   void _start(void)
>>   {
>> -	syscall(SYS_exit, 0);
>> +	asm volatile (
>> +		"li %%r0, %[sys_exit];"
>> +		"li %%r3, 0;"
>> +		"sc;"
>> +		:
>> +		: [sys_exit] "i" (SYS_exit)
>> +		/*
>> +		 * "sc" will clobber r0, r3-r13, cr0, ctr, xer and memory.
>> +		 * Even though sys_exit never returns, handle clobber
>> +		 * registers.
>> +		 */
>> +		: "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
>> +		  "r11", "r12", "r13", "cr0", "ctr", "xer", "memory"
>> +	);
>>   }
>> -- 
>> 2.45.2

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Re: [PATCH v2] selftest/powerpc/benchmark: remove requirement libc-dev

[Michael Ellerman]

On Mon, 12 Aug 2024 15:11:52 +0530, Madhavan Srinivasan wrote:
> Currently exec-target.c file is linked as static and this
> post a requirement to install libc dev package to build.
> Without it, build-break when compiling selftest/powerpc/benchmark.
> 
>   CC       exec_target
> /usr/bin/ld: cannot find -lc: No such file or directory
> collect2: error: ld returned 1 exit status
> 
> [...]

Applied to powerpc/next.

[1/1] selftest/powerpc/benchmark: remove requirement libc-dev
      https://git.kernel.org/powerpc/c/8c9c01ce695eea84d19482e7429e3d54ceb7585c

cheers