@@ -69,17 +69,18 @@ handle_signal (int signum)
FAIL ();
return;
}
- /* Do not check name for signal trampoline. */
- i = 2;
- if (!match (symbols[i++], "read"))
+
+ /* Do not check name for signal trampoline or cancellable syscall
+ wrappers (__syscall_cancel*). */
+ for (; i < n - 1; i++)
+ if (match (symbols[i], "read"))
+ break;
+ if (i == n - 1)
{
- /* Perhaps symbols[2] is __kernel_vsyscall? */
- if (!match (symbols[i++], "read"))
- {
- FAIL ();
- return;
- }
+ FAIL ();
+ return;
}
+
for (; i < n - 1; i++)
if (!match (symbols[i], "fn"))
{
@@ -166,6 +166,10 @@ 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 to the SIGCANCEL, but the thread may still be pending
+ cancellation. */
+ pthread_testcancel ();
pthread_cleanup_pop (0);
@@ -743,6 +747,10 @@ tf_send (void *arg)
char mem[WRITE_BUFFER_SIZE];
send (tempfd2, mem, arg == NULL ? sizeof (mem) : 1, 0);
+ /* The send can return a value higher than 0 (meaning partial send)
+ due to the SIGCANCEL, but the thread may still be pending
+ cancellation. */
+ pthread_testcancel ();
pthread_cleanup_pop (0);
From: Adhemerval Zanella <adhemerval.zanella@linaro.com> 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. The main change is due the fact programs need to act in syscalls with side-effects (for instance, to avoid leak of allocated resources or handle partial read/write). This patch changes the NPTL testcase that assumes the old behavior and also changes the tst-backtrace{5,6} to ignore the cancellable wrappers. Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32, aarch64-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu, powerpc-linux-gnu, sparcv9-linux-gnu, and sparc64-linux-gnu. * debug/tst-backtrace5.c (handle_signal): Avoid cancellable wrappers in backtrace analysis. * nptl/tst-cancel4.c (tf_write): Handle cancelled syscall with side-effects. (tf_send): Likewise. --- ChangeLog | 6 ++++++ debug/tst-backtrace5.c | 19 ++++++++++--------- nptl/tst-cancel4.c | 8 ++++++++ 3 files changed, 24 insertions(+), 9 deletions(-) -- 2.17.1