[3/7] nptl: Fix testcases for new pthread cancellation, mechanism

Message ID 5425C337.3010400@linux.vnet.ibm.com
State Superseded
Headers

Commit Message

Adhemerval Zanella Netto Sept. 26, 2014, 7:49 p.m. UTC
  With upcoming fix for BZ#12683, pthread cancellation does not act for:

1. If syscall is blocked but with some side effects already having taken
   place (e.g. a partial read or write)
2. After the syscall has returned.

It is because program need to act on such cases (for instance, to avoid
leak of allocated resources our handling partial read/write).

This patches fixes the NPTL testcase that assumes the old behavior and
also remove the tst-cancel-wrappers.sh test (which checks for symbols
that does not exist anymore).

Tested on x86_64, powerpc64, and powerpc32.

--

	* nptl/Makefile [test-special]: Remove tst-cancel-wrappers rule.
	[generated]: Likewise.
	* nptl/tst-cancel-wrappers.sh: Remove file.
	* nptl/tst-cancel2.c (tf): Add pthread_cancel checks for partial
	read/write due cancel signal.
	* nptl/tst-cancel20.c (sh_body): Likewise.
	(tf_body): Likewise.
	* nptl/tst-cancel21.c (sh_body): Likewise.
	(tf_body): Likewise.
	* nptl/tst-cancel4.c (tf_write): Likewise.
	(tf_send): Likewise.

--
  

Comments

Joseph Myers Sept. 26, 2014, 7:56 p.m. UTC | #1
On Fri, 26 Sep 2014, Adhemerval Zanella wrote:

> This patches fixes the NPTL testcase that assumes the old behavior and
> also remove the tst-cancel-wrappers.sh test (which checks for symbols
> that does not exist anymore).

I don't think there's any clear answer to how it's now tested that all 
these functions are cancellable (e.g. a list of tests in the testsuite, 
for every function that was covered by that test, that test that 
requirement).

For example, where is this tested for pread64?
  
Adhemerval Zanella Netto Sept. 27, 2014, 4:17 p.m. UTC | #2
On 26-09-2014 16:56, Joseph S. Myers wrote:
> On Fri, 26 Sep 2014, Adhemerval Zanella wrote:
>
>> This patches fixes the NPTL testcase that assumes the old behavior and
>> also remove the tst-cancel-wrappers.sh test (which checks for symbols
>> that does not exist anymore).
> I don't think there's any clear answer to how it's now tested that all 
> these functions are cancellable (e.g. a list of tests in the testsuite, 
> for every function that was covered by that test, that test that 
> requirement).
>
> For example, where is this tested for pread64?
>
Indeed, it will require a similar test (although I see tst-cancel-wrapper.sh 
does not really exercise the code itself).  I think add more test like the
ones in tst-cancel4 would be better to check for pread64 and similar functions.
  

Patch

diff --git a/nptl/Makefile b/nptl/Makefile
index 157fe62..cb4bdd7 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -377,8 +377,7 @@  tests-reverse += tst-cancel5 tst-cancel23 tst-vfork1x tst-vfork2x
 ifeq ($(run-built-tests),yes)
 tests-special += $(objpfx)tst-stack3-mem.out $(objpfx)tst-oddstacklimit.out
 ifeq ($(build-shared),yes)
-tests-special += $(objpfx)tst-tls6.out $(objpfx)tst-cleanup0-cmp.out \
-		 $(objpfx)tst-cancel-wrappers.out
+tests-special += $(objpfx)tst-tls6.out $(objpfx)tst-cleanup0-cmp.out
 endif
 endif
 
@@ -572,7 +571,7 @@  $(objpfx)$(multidir)/crtn.o: $(objpfx)crtn.o $(objpfx)$(multidir)/
 endif
 
 generated += libpthread_nonshared.a \
-	     multidir.mk tst-atfork2.mtrace tst-cancel-wrappers.out \
+	     multidir.mk tst-atfork2.mtrace \
 	     tst-tls6.out
 
 generated += $(objpfx)tst-atfork2.mtrace \
@@ -587,18 +586,6 @@  generated += banner.h
 LDFLAGS-pthread.so += -e __nptl_main
 endif
 
-ifeq ($(run-built-tests),yes)
-ifeq (yes,$(build-shared))
-$(objpfx)tst-cancel-wrappers.out: tst-cancel-wrappers.sh
-	$(SHELL) $< '$(NM)' \
-		    $(common-objpfx)libc_pic.a \
-		    $(common-objpfx)libc.a \
-		    $(objpfx)libpthread_pic.a \
-		    $(objpfx)libpthread.a > $@; \
-	$(evaluate-test)
-endif
-endif
-
 tst-exec4-ARGS = $(host-test-program-cmd)
 
 $(objpfx)tst-execstack: $(libdl)
diff --git a/nptl/tst-cancel-wrappers.sh b/nptl/tst-cancel-wrappers.sh
deleted file mode 100644
index e41ed51..0000000
--- a/nptl/tst-cancel-wrappers.sh
+++ /dev/null
@@ -1,92 +0,0 @@ 
-#! /bin/sh
-# Test whether all cancelable functions are cancelable.
-# Copyright (C) 2002-2014 Free Software Foundation, Inc.
-# This file is part of the GNU C Library.
-# Contributed by Jakub Jelinek <jakub@redhat.com>, 2002.
-
-# The GNU C Library is free software; you can redistribute it and/or
-# modify it under the terms of the GNU Lesser General Public
-# License as published by the Free Software Foundation; either
-# version 2.1 of the License, or (at your option) any later version.
-
-# The GNU C Library is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-# Lesser General Public License for more details.
-
-# You should have received a copy of the GNU Lesser General Public
-# License along with the GNU C Library; if not, see
-# <http://www.gnu.org/licenses/>.
-
-NM="$1"; shift
-while [ $# -gt 0 ]; do
-  ( $NM -P $1; echo 'end[end]:' ) | gawk ' BEGIN {
-C["accept"]=1
-C["close"]=1
-C["connect"]=1
-C["creat"]=1
-C["fcntl"]=1
-C["fdatasync"]=1
-C["fsync"]=1
-C["msgrcv"]=1
-C["msgsnd"]=1
-C["msync"]=1
-C["nanosleep"]=1
-C["open"]=1
-C["open64"]=1
-C["pause"]=1
-C["poll"]=1
-C["pread"]=1
-C["pread64"]=1
-C["pselect"]=1
-C["pwrite"]=1
-C["pwrite64"]=1
-C["read"]=1
-C["readv"]=1
-C["recv"]=1
-C["recvfrom"]=1
-C["recvmsg"]=1
-C["select"]=1
-C["send"]=1
-C["sendmsg"]=1
-C["sendto"]=1
-C["sigpause"]=1
-C["sigsuspend"]=1
-C["sigwait"]=1
-C["sigwaitinfo"]=1
-C["tcdrain"]=1
-C["wait"]=1
-C["waitid"]=1
-C["waitpid"]=1
-C["write"]=1
-C["writev"]=1
-C["__xpg_sigpause"]=1
-}
-/:$/ {
-  if (seen)
-    {
-      if (!seen_enable || !seen_disable)
-	{
-	  printf "in '$1'(%s) %s'\''s cancellation missing\n", object, seen
-	  ret = 1
-	}
-    }
-  seen=""
-  seen_enable=""
-  seen_disable=""
-  object=gensub(/^.*\[(.*)\]:$/,"\\1","",$0)
-  next
-}
-{
-  if (C[$1] && $2 ~ /^[TW]$/)
-    seen=$1
-  else if ($1 ~ /^([.]|)__(libc|pthread)_enable_asynccancel$/ && $2 == "U")
-    seen_enable=1
-  else if ($1 ~ /^([.]|)__(libc|pthread)_disable_asynccancel$/ && $2 == "U")
-    seen_disable=1
-}
-END {
-  exit ret
-}' || exit
-  shift
-done
diff --git a/nptl/tst-cancel2.c b/nptl/tst-cancel2.c
index 2d834de..cb807c4 100644
--- a/nptl/tst-cancel2.c
+++ b/nptl/tst-cancel2.c
@@ -33,6 +33,9 @@  tf (void *arg)
   char buf[100000];
 
   while (write (fd[1], buf, sizeof (buf)) > 0);
+  /* The write can return a value higher than 0 (meaning partial write)
+     due the SIGCANCEL, but the thread may still pending cancellation.  */
+  pthread_testcancel ();
 
   return (void *) 42l;
 }
diff --git a/nptl/tst-cancel20.c b/nptl/tst-cancel20.c
index 703e558..0d54b21 100644
--- a/nptl/tst-cancel20.c
+++ b/nptl/tst-cancel20.c
@@ -49,6 +49,9 @@  sh_body (void)
       puts ("read succeeded");
       exit (1);
     }
+  /* The read can return a value higher than 0 (meaning partial reads)
+     due the SIGCANCEL, but the thread may still pending cancellation.  */
+  pthread_testcancel ();
 
   pthread_cleanup_pop (0);
 }
@@ -84,7 +87,8 @@  tf_body (void)
       puts ("read succeeded");
       exit (1);
     }
-
+  /* Check for partial read.  */
+  pthread_testcancel ();
   read (fd[0], &c, 1);
 
   pthread_cleanup_pop (0);
diff --git a/nptl/tst-cancel21.c b/nptl/tst-cancel21.c
index ddcea90..35a56dc 100644
--- a/nptl/tst-cancel21.c
+++ b/nptl/tst-cancel21.c
@@ -50,6 +50,9 @@  sh_body (void)
       puts ("read succeeded");
       exit (1);
     }
+  /* The write can return a value higher than 0 (meaning partial write)
+     due the SIGCANCEL, but the thread may still pending cancellation.  */
+  pthread_testcancel ();
 
   pthread_cleanup_pop (0);
 }
@@ -85,6 +88,8 @@  tf_body (void)
       puts ("read succeeded");
       exit (1);
     }
+  /* Check partial read.  */
+  pthread_testcancel ();
 
   read (fd[0], &c, 1);
 
diff --git a/nptl/tst-cancel4.c b/nptl/tst-cancel4.c
index 93080b2..fd4ea42 100644
--- a/nptl/tst-cancel4.c
+++ b/nptl/tst-cancel4.c
@@ -38,8 +38,10 @@ 
 #include <sys/un.h>
 #include <sys/wait.h>
 
-#include "pthreadP.h"
-
+/* The signal used for asynchronous cancelation.  */
+#ifndef SIGCANCEL
+# define SIGCANCEL       __SIGRTMIN
+#endif
 
 /* Since STREAMS are not supported in the standard Linux kernel and
    there we don't advertise STREAMS as supported is no need to test
@@ -247,6 +249,9 @@  tf_write  (void *arg)
   char buf[WRITE_BUFFER_SIZE];
   memset (buf, '\0', sizeof (buf));
   s = write (fd, buf, sizeof (buf));
+  /* The write can return a value higher than 0 (meaning partial write)
+     due the SIGCANCEL, but the thread may still pending cancellation.  */
+  pthread_testcancel ();
 
   pthread_cleanup_pop (0);
 
@@ -1139,6 +1144,8 @@  tf_send (void *arg)
   char mem[700000];
 
   send (tempfd2, mem, arg == NULL ? sizeof (mem) : 1, 0);
+  /* Check for partial send.  */
+  pthread_testcancel ();
 
   pthread_cleanup_pop (0);