x86*: Return syscall error for lll_futex_wake.

It is very very possible that the futex syscall returns an error and that the caller of lll_futex_wake may want to look at that error and propagate the failure. This patch allows a caller to see the syscall error. There are no users of the syscall error at present, but future cleanups are now be able to check for the error. -- nplt/ 2013-06-10 Carlos O'Donell <carlos@redhat.com> * sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_futex_wake): Return syscall error. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_futex_wake): Return syscall error.
git-mirror · Jun 10, 2013 · be11d71 · be11d71
1 parent 0efa6f8
commit be11d71
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diff --git a/nptl/ChangeLog b/nptl/ChangeLog
@@ -1,3 +1,10 @@
+2013-06-10  Carlos O'Donell  <carlos@redhat.com>
+
+	* sysdeps/unix/sysv/linux/i386/lowlevellock.h
+	(lll_futex_wake): Return syscall error.
+	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
+	(lll_futex_wake): Return syscall error.
+
 2013-08-06   Ondřej Bílka  <neleai@seznam.cz>
 
 	* sysdeps/pthread/allocalim.h: (__libc_use_alloca): Fix warning.

diff --git a/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/i386/lowlevellock.h
@@ -224,20 +224,21 @@ LLL_STUB_UNWIND_INFO_END
 
 
 #define lll_futex_wake(futex, nr, private) \
-  do {									      \
-    int __ignore;							      \
+  ({									      \
+    int __status;							      \
     register __typeof (nr) _nr asm ("edx") = (nr);			      \
     LIBC_PROBE (lll_futex_wake, 3, futex, nr, private);                       \
     __asm __volatile (LLL_EBX_LOAD					      \
 		      LLL_ENTER_KERNEL					      \
 		      LLL_EBX_LOAD					      \
-		      : "=a" (__ignore)					      \
+		      : "=a" (__status)					      \
 		      : "0" (SYS_futex), LLL_EBX_REG (futex),		      \
 			"c" (__lll_private_flag (FUTEX_WAKE, private)),	      \
 			"d" (_nr),					      \
 			"i" (0) /* phony, to align next arg's number */,      \
 			"i" (offsetof (tcbhead_t, sysinfo)));		      \
-  } while (0)
+    __status;								      \
+  })
 
 
 /* NB: in the lll_trylock macro we simply return the value in %eax

diff --git a/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
@@ -225,17 +225,18 @@ LLL_STUB_UNWIND_INFO_END
 
 
 #define lll_futex_wake(futex, nr, private) \
-  do {									      \
-    int __ignore;							      \
+  ({									      \
+    int __status;							      \
     register __typeof (nr) _nr __asm ("edx") = (nr);			      \
     LIBC_PROBE (lll_futex_wake, 3, futex, nr, private);                       \
     __asm __volatile ("syscall"						      \
-		      : "=a" (__ignore)					      \
+		      : "=a" (__status)					      \
 		      : "0" (SYS_futex), "D" (futex),			      \
 			"S" (__lll_private_flag (FUTEX_WAKE, private)),	      \
 			"d" (_nr)					      \
 		      : "memory", "cc", "r10", "r11", "cx");		      \
-  } while (0)
+    __status;								      \
+  })
 
 
 /* NB: in the lll_trylock macro we simply return the value in %eax