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* Re: [PATCH v3 1/5] selftests/x86: Simplify the code to get vdso base address in sgx
@ 2021-01-25 18:12 Jarkko Sakkinen
  2021-02-01 11:28 ` Tianjia Zhang
  0 siblings, 1 reply; 3+ messages in thread
From: Jarkko Sakkinen @ 2021-01-25 18:12 UTC (permalink / raw)
  To: Tianjia Zhang
  Cc: Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin,
	Sean Christopherson, Shuah Khan, x86, linux-sgx, linux-kselftest,
	linux-kernel, Jia Zhang

What the short summary is saying now, is that this commit would make the
existing code to use vDSO base address. It's already doing that.

You could instead just "Use getauxval() to simplify the code".

Also, I'd prefer to properly use upper and lower case letter, e.g.  vDSO
instead of vdso.

Reply-To: 
In-Reply-To: <20210124062907.88229-2-tianjia.zhang@linux.alibaba.com>

On Sun, Jan 24, 2021 at 02:29:03PM +0800, Tianjia Zhang wrote:
> This patch uses the library function `getauxval(AT_SYSINFO_EHDR)`
> instead of the custom function `vdso_get_base_addr` to obtain the

Use either double or single quotation mark instead of hyphen.

> base address of vDSO, which will simplify the code implementation.
> 
> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>

This needs to be imperative form, e.g. "Simplify the code implemntation
by using getauxval() instead of a custom function."

> ---
>  tools/testing/selftests/sgx/main.c | 24 ++++--------------------
>  1 file changed, 4 insertions(+), 20 deletions(-)
> 
> diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
> index 724cec700926..365d01dea67b 100644
> --- a/tools/testing/selftests/sgx/main.c
> +++ b/tools/testing/selftests/sgx/main.c
> @@ -15,6 +15,7 @@
>  #include <sys/stat.h>
>  #include <sys/time.h>
>  #include <sys/types.h>
> +#include <sys/auxv.h>
>  #include "defines.h"
>  #include "main.h"
>  #include "../kselftest.h"
> @@ -28,24 +29,6 @@ struct vdso_symtab {
>  	Elf64_Word *elf_hashtab;
>  };
>  
> -static void *vdso_get_base_addr(char *envp[])
> -{
> -	Elf64_auxv_t *auxv;
> -	int i;
> -
> -	for (i = 0; envp[i]; i++)
> -		;
> -
> -	auxv = (Elf64_auxv_t *)&envp[i + 1];
> -
> -	for (i = 0; auxv[i].a_type != AT_NULL; i++) {
> -		if (auxv[i].a_type == AT_SYSINFO_EHDR)
> -			return (void *)auxv[i].a_un.a_val;
> -	}
> -
> -	return NULL;
> -}
> -
>  static Elf64_Dyn *vdso_get_dyntab(void *addr)
>  {
>  	Elf64_Ehdr *ehdr = addr;
> @@ -162,7 +145,7 @@ static int user_handler(long rdi, long rsi, long rdx, long ursp, long r8, long r
>  	return 0;
>  }
>  
> -int main(int argc, char *argv[], char *envp[])
> +int main(int argc, char *argv[])
>  {
>  	struct sgx_enclave_run run;
>  	struct vdso_symtab symtab;
> @@ -203,7 +186,8 @@ int main(int argc, char *argv[], char *envp[])
>  	memset(&run, 0, sizeof(run));
>  	run.tcs = encl.encl_base;
>  
> -	addr = vdso_get_base_addr(envp);
> +	/* Get vDSO base address */
> +	addr = (void *)(uintptr_t)getauxval(AT_SYSINFO_EHDR);

You could just case the result the result directly to void *.

>  	if (!addr)
>  		goto err;
>  
> -- 
> 2.19.1.3.ge56e4f7
> 
> 

/Jarkko

^ permalink raw reply	[flat|nested] 3+ messages in thread
* [PATCH v3 0/5] Some optimizations related to sgx
@ 2021-01-24  6:29 Tianjia Zhang
  2021-01-24  6:29 ` [PATCH v3 1/5] selftests/x86: Simplify the code to get vdso base address in sgx Tianjia Zhang
  0 siblings, 1 reply; 3+ messages in thread
From: Tianjia Zhang @ 2021-01-24  6:29 UTC (permalink / raw)
  To: Jarkko Sakkinen, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
	H. Peter Anvin, Sean Christopherson, Shuah Khan, x86, linux-sgx,
	linux-kselftest, linux-kernel, Jia Zhang
  Cc: Tianjia Zhang

This is an optimization of a set of sgx-related codes, each of which
is independent of the patch. Because the second and third patches have
conflicting dependencies, these patches are put together.

---
v3 changes:
  * split free_cnt count and spin lock optimization into two patches

v2 changes:
  * review suggested changes

Tianjia Zhang (5):
  selftests/x86: Simplify the code to get vdso base address in sgx
  x86/sgx: Optimize the locking range in sgx_sanitize_section()
  x86/sgx: Optimize the free_cnt count in sgx_epc_section
  x86/sgx: Allows ioctl PROVISION to execute before CREATE
  x86/sgx: Remove redundant if conditions in sgx_encl_create

 arch/x86/kernel/cpu/sgx/driver.c   |  1 +
 arch/x86/kernel/cpu/sgx/ioctl.c    |  9 +++++----
 arch/x86/kernel/cpu/sgx/main.c     | 13 +++++--------
 tools/testing/selftests/sgx/main.c | 24 ++++--------------------
 4 files changed, 15 insertions(+), 32 deletions(-)

-- 
2.19.1.3.ge56e4f7


^ permalink raw reply	[flat|nested] 3+ messages in thread
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2021-01-24  6:29 [PATCH v3 0/5] Some optimizations related to sgx Tianjia Zhang
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