Patchwork [v3] Fix clone (CLONE_VM) pid/tid reset (BZ#19957)

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Submitter Andreas Schwab
Date April 22, 2016, 7:40 p.m.
Message ID <87eg9x77q2.fsf@linux-m68k.org>
Download mbox | patch
Permalink /patch/11861/
State New
Headers show

Comments

Andreas Schwab - April 22, 2016, 7:40 p.m.
Adhemerval Zanella <adhemerval.zanella@linaro.org> writes:

> diff --git a/sysdeps/unix/sysv/linux/m68k/clone.S b/sysdeps/unix/sysv/linux/m68k/clone.S
> index 33474cc..84eb2b9 100644
> --- a/sysdeps/unix/sysv/linux/m68k/clone.S
> +++ b/sysdeps/unix/sysv/linux/m68k/clone.S
> @@ -25,7 +25,6 @@
>  #include <tls.h>
>  
>  #define CLONE_VM      0x00000100
> -#define CLONE_THREAD  0x00010000
>  
>  /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
>  	     void *parent_tidptr, void *tls, void *child_tidptr) */
> @@ -101,12 +100,9 @@ thread_start:
>  	subl	%fp, %fp	/* terminate the stack frame */
>  	/* Check and see if we need to reset the PID.  */
>  	movel	%d1, %a1
> -	andl	#CLONE_THREAD, %d1
> +	andl	#CLONE_VM, %d1
>  	jne	donepid
>  	movel	%a1, %d1
> -	movel	#-1, %d0
> -	andl	#CLONE_VM, %d1
> -	jne	gotpid
>  	movel	#SYS_ify (getpid), %d0
>  	trap	#0
>  gotpid:

This can be simplified further:



Andreas.
Adhemerval Zanella Netto - April 22, 2016, 7:57 p.m.
On 22-04-2016 16:40, Andreas Schwab wrote:
> Adhemerval Zanella <adhemerval.zanella@linaro.org> writes:
> 
>> diff --git a/sysdeps/unix/sysv/linux/m68k/clone.S b/sysdeps/unix/sysv/linux/m68k/clone.S
>> index 33474cc..84eb2b9 100644
>> --- a/sysdeps/unix/sysv/linux/m68k/clone.S
>> +++ b/sysdeps/unix/sysv/linux/m68k/clone.S
>> @@ -25,7 +25,6 @@
>>  #include <tls.h>
>>  
>>  #define CLONE_VM      0x00000100
>> -#define CLONE_THREAD  0x00010000
>>  
>>  /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
>>  	     void *parent_tidptr, void *tls, void *child_tidptr) */
>> @@ -101,12 +100,9 @@ thread_start:
>>  	subl	%fp, %fp	/* terminate the stack frame */
>>  	/* Check and see if we need to reset the PID.  */
>>  	movel	%d1, %a1
>> -	andl	#CLONE_THREAD, %d1
>> +	andl	#CLONE_VM, %d1
>>  	jne	donepid
>>  	movel	%a1, %d1
>> -	movel	#-1, %d0
>> -	andl	#CLONE_VM, %d1
>> -	jne	gotpid
>>  	movel	#SYS_ify (getpid), %d0
>>  	trap	#0
>>  gotpid:
> 
> This can be simplified further:
> 
> diff --git a/sysdeps/unix/sysv/linux/m68k/clone.S b/sysdeps/unix/sysv/linux/m68k/clone.S
> index 33474cc..aec12cb 100644
> --- a/sysdeps/unix/sysv/linux/m68k/clone.S
> +++ b/sysdeps/unix/sysv/linux/m68k/clone.S
> @@ -25,7 +25,6 @@
>  #include <tls.h>
>  
>  #define CLONE_VM      0x00000100
> -#define CLONE_THREAD  0x00010000
>  
>  /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
>  	     void *parent_tidptr, void *tls, void *child_tidptr) */
> @@ -100,16 +99,10 @@ thread_start:
>  	cfi_undefined (pc)	/* Mark end of stack */
>  	subl	%fp, %fp	/* terminate the stack frame */
>  	/* Check and see if we need to reset the PID.  */
> -	movel	%d1, %a1
> -	andl	#CLONE_THREAD, %d1
> -	jne	donepid
> -	movel	%a1, %d1
> -	movel	#-1, %d0
>  	andl	#CLONE_VM, %d1
> -	jne	gotpid
> +	jne	donepid
>  	movel	#SYS_ify (getpid), %d0
>  	trap	#0
> -gotpid:
>  	movel	%a0, -(%sp)
>  	movel	%d0, -(%sp)
>  	bsrl	__m68k_read_tp@PLTPC
> 
> 
> Andreas.
> 

Thanks, I use this simplification.

Patch

diff --git a/sysdeps/unix/sysv/linux/m68k/clone.S b/sysdeps/unix/sysv/linux/m68k/clone.S
index 33474cc..aec12cb 100644
--- a/sysdeps/unix/sysv/linux/m68k/clone.S
+++ b/sysdeps/unix/sysv/linux/m68k/clone.S
@@ -25,7 +25,6 @@ 
 #include <tls.h>
 
 #define CLONE_VM      0x00000100
-#define CLONE_THREAD  0x00010000
 
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
 	     void *parent_tidptr, void *tls, void *child_tidptr) */
@@ -100,16 +99,10 @@  thread_start:
 	cfi_undefined (pc)	/* Mark end of stack */
 	subl	%fp, %fp	/* terminate the stack frame */
 	/* Check and see if we need to reset the PID.  */
-	movel	%d1, %a1
-	andl	#CLONE_THREAD, %d1
-	jne	donepid
-	movel	%a1, %d1
-	movel	#-1, %d0
 	andl	#CLONE_VM, %d1
-	jne	gotpid
+	jne	donepid
 	movel	#SYS_ify (getpid), %d0
 	trap	#0
-gotpid:
 	movel	%a0, -(%sp)
 	movel	%d0, -(%sp)
 	bsrl	__m68k_read_tp@PLTPC