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authorAdhemerval Zanella <azanella@linux.vnet.ibm.com>2014-11-07 12:34:52 -0500
committerAdhemerval Zanella <azanella@linux.vnet.ibm.com>2015-01-12 06:32:08 -0500
commit56cf2763819d2f721c98f2b8bcc04a3c673837d3 (patch)
tree5d2fde37897779f64b83951c1ef99406fd384055 /sysdeps/powerpc/nptl/tls.h
parent4b45943a6f62cfc239e79ad8902f5c7f71fd13ec (diff)
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powerpc: abort transaction in syscalls
Linux kernel powerpc documentation states issuing a syscall inside a transaction is not recommended and may lead to undefined behavior. It also states syscalls does not abort transactoin neither they run in transactional state. To avoid side-effects being visible outside transactions, GLIBC with lock elision enabled will issue a transaction abort instruction just before all syscalls if hardware supports hardware transactions.
Diffstat (limited to 'sysdeps/powerpc/nptl/tls.h')
-rw-r--r--sysdeps/powerpc/nptl/tls.h19
1 files changed, 17 insertions, 2 deletions
diff --git a/sysdeps/powerpc/nptl/tls.h b/sysdeps/powerpc/nptl/tls.h
index 753381f95d..1f3d97a995 100644
--- a/sysdeps/powerpc/nptl/tls.h
+++ b/sysdeps/powerpc/nptl/tls.h
@@ -63,6 +63,8 @@ typedef union dtv
are private. */
typedef struct
{
+ /* Indicate if HTM capable (ISA 2.07). */
+ int tm_capable;
/* Reservation for Dynamic System Optimizer ABI. */
uintptr_t dso_slot2;
uintptr_t dso_slot1;
@@ -130,11 +132,17 @@ register void *__thread_register __asm__ ("r13");
special attention since 'errno' is not yet available and if the
operation can cause a failure 'errno' must not be touched. */
# define TLS_INIT_TP(tcbp) \
- (__thread_register = (void *) (tcbp) + TLS_TCB_OFFSET, NULL)
+ ({ \
+ __thread_register = (void *) (tcbp) + TLS_TCB_OFFSET; \
+ THREAD_SET_TM_CAPABLE (GLRO (dl_hwcap2) & PPC_FEATURE2_HAS_HTM ? 1 : 0); \
+ NULL; \
+ })
/* Value passed to 'clone' for initialization of the thread register. */
# define TLS_DEFINE_INIT_TP(tp, pd) \
- void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
+ void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE; \
+ (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].tm_capable) = \
+ THREAD_GET_TM_CAPABLE ();
/* Return the address of the dtv for the current thread. */
# define THREAD_DTV() \
@@ -188,6 +196,13 @@ register void *__thread_register __asm__ ("r13");
+ TLS_PRE_TCB_SIZE))[-1].pointer_guard \
= THREAD_GET_POINTER_GUARD())
+/* tm_capable field in TCB head. */
+# define THREAD_GET_TM_CAPABLE() \
+ (((tcbhead_t *) ((char *) __thread_register \
+ - TLS_TCB_OFFSET))[-1].tm_capable)
+# define THREAD_SET_TM_CAPABLE(value) \
+ (THREAD_GET_TM_CAPABLE () = (value))
+
/* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
different value to mean unset l_tls_offset. */
# define NO_TLS_OFFSET -1