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| author | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2014-11-07 12:34:52 -0500 |
|---|---|---|
| committer | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2014-11-10 16:15:34 -0500 |
| commit | a988eb00e19e0365bdcb8b3be9ee8d4f6c2c6fbb (patch) | |
| tree | d6fb870e589b0db79200978068e87a9a9e3469fe /sysdeps/powerpc/powerpc32/sysdep.h | |
| parent | 9b4e372e9b5f7f4d028237a52ddbb1fbea425917 (diff) | |
| download | glibc-a988eb00e19e0365bdcb8b3be9ee8d4f6c2c6fbb.tar.gz | |
PowerPC: abort transaction in syscallsazanella/lockelision-ppc
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 enable issues a transaction abort instruction just before all
syscalls if hardware supports hardware transactions.
Diffstat (limited to 'sysdeps/powerpc/powerpc32/sysdep.h')
| -rw-r--r-- | sysdeps/powerpc/powerpc32/sysdep.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/sysdeps/powerpc/powerpc32/sysdep.h b/sysdeps/powerpc/powerpc32/sysdep.h index c8a56aadbf..c4b3ca8696 100644 --- a/sysdeps/powerpc/powerpc32/sysdep.h +++ b/sysdeps/powerpc/powerpc32/sysdep.h @@ -88,7 +88,23 @@ GOT_LABEL: ; \ cfi_endproc; \ ASM_SIZE_DIRECTIVE(name) +#if !defined IS_IN_rtld && defined (ENABLE_LOCK_ELISION) +# define ABORT_TRANSACTION \ + cmpwi 2,0; \ + beq 1f; \ + lwz 0,TM_CAPABLE(2); \ + cmpwi 0,0; \ + beq 1f; \ + li 0,_ABORT_SYSCALL; \ + tabort. 0; \ + .align 4; \ +1: +#else +# define ABORT_TRANSACTION +#endif + #define DO_CALL(syscall) \ + ABORT_TRANSACTION \ li 0,syscall; \ sc |