Attachment 1209526 Details for Bug 1383986 – Patch disables lock elision by default and enables it with environment variable.

[patch] Patch disables lock elision by default and enables it with environment variable.

glibc-s390-tle-enablement.patch (text/plain), 1.20 KB, created by IBM Bug Proxy on 2016-10-12 10:02:04 UTC

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Creator: IBM Bug Proxy

Created: 2016-10-12 10:02:04 UTC

Size: 1.20 KB

patch

obsolete

>diff --git a/sysdeps/unix/sysv/linux/s390/elision-conf.c b/sysdeps/unix/sysv/linux/s390/elision-conf.c
>index 4441fd9..f3e59c7 100644
>--- a/sysdeps/unix/sysv/linux/s390/elision-conf.c
>+++ b/sysdeps/unix/sysv/linux/s390/elision-conf.c
>@@ -21,6 +21,8 @@
> #include <elision-conf.h>
> #include <unistd.h>
> #include <dl-procinfo.h>
>+#include <string.h>
>+#include <assert.h>
> 
> /* Reasonable initial tuning values, may be revised in the future.
>    This is a conservative initial value.  */
>@@ -64,7 +66,19 @@ elision_init (int argc __attribute__ ((unused)),
>      When false elision is never attempted.  */
>   int elision_available = (GLRO (dl_hwcap) & HWCAP_S390_TE) ? 1 : 0;
> 
>-  __pthread_force_elision = __libc_enable_secure ? 0 : elision_available;
>+  /* Scan the environment to conditionally enable transactional execution,
>+     guaranteeing that the system isn't running secure code.  */
>+  if (elision_available != 0 && __libc_enable_secure == 0)
>+    {
>+      for ( ; *environ != NULL; environ++)
>+	if (**environ == 'L'
>+	    && strcmp (*environ, "LOCK_ELISION_ENABLE=yes") == 0)
>+	  {
>+	    assert (__libc_enable_secure == 0);
>+	    __pthread_force_elision = elision_available;
>+	    break;
>+	  }
>+    }
> }
> 
> #ifdef SHARED

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Attachments on bug 1383986: 1209526 | 1250771 | 1267814