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Re: [PATCH v3] Fix clone (CLONE_VM) pid/tid reset (BZ#19957)
- From: Andreas Schwab <schwab at linux-m68k dot org>
- To: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- Cc: libc-alpha at sourceware dot org
- Date: Fri, 22 Apr 2016 21:40:21 +0200
- Subject: Re: [PATCH v3] Fix clone (CLONE_VM) pid/tid reset (BZ#19957)
- Authentication-results: sourceware.org; auth=none
- References: <1461351245-22814-1-git-send-email-adhemerval dot zanella at linaro dot org>
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.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."