uClibc-ng-1.0.17 pthread race condition crash

leaf-uClibc-changes.diff

diff --git a/repo/toolchain/buildtool.cfg b/repo/toolchain/buildtool.cfg
index a07053b..c4cd0c4 100644
--- a/repo/toolchain/buildtool.cfg
+++ b/repo/toolchain/buildtool.cfg
@@ -69,6 +69,13 @@
        Envname = UC_PATCH6
 </File>
 
+<File sigaction-nop-pthread_cancel.patch>
+       Server = localrepo
+       Directory = toolchain
+       Revision = HEAD
+       Envname = UC_PATCH11
+</File>
+
 # from buildtool.org
 <File 850-libstdcxx-uclibc-c99.patch>
        Server = localrepo
diff --git a/repo/toolchain/buildtool.mk b/repo/toolchain/buildtool.mk
index 0bf488e..86bc497 100644
--- a/repo/toolchain/buildtool.mk
+++ b/repo/toolchain/buildtool.mk
@@ -46,6 +46,7 @@ $(UCLIBC_DIR)/.source:
        #cat $(UC_PATCH8) | patch -p1 -d $(UCLIBC_DIR)
        #cat $(UC_PATCH9) | patch -p1 -d $(UCLIBC_DIR)
        #cat $(UC_PATCH10) | patch -p1 -d $(UCLIBC_DIR)
+       cat $(UC_PATCH11) | patch -p0 -d $(UCLIBC_DIR)
        touch $(UCLIBC_DIR)/.source
 
 $(BINUTILS_DIR)/.source:

ntpd-thread-test.c

#include <pthread.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>

/* This code is originally from https://github.com/ntp-project/ntp/blob/stable/ntpd/ntpd.c#L252
 * running under uClibc-ng-1.0.17:
 * # for i in `seq 1 10`; do ./ntpd-thread-test; done
 * looks good
 * looks good
 * looks good
 * looks good
 * looks good
 * looks good
 * looks good
 * Segmentation fault
 * looks good
 * looks good
 */

// note: this is only true for x86 platforms, can vary on other hardware
#define PTHREAD_STACK_MIN       16384

static void*
my_pthread_warmup_worker(
        void *thread_args)
{
        (void)thread_args;
        for (;;)
                sleep(10);
        return NULL;
}

/* pre-heat threading: create a thread and cancel it, just to exercise
 * thread cancellation.
 */
static void
my_pthread_warmup(void)
{
        pthread_t       thread;
        pthread_attr_t  thr_attr;
        int             rc;

        pthread_attr_init(&thr_attr);
        rc = pthread_attr_setstacksize(&thr_attr, PTHREAD_STACK_MIN);
        if (0 != rc)
                printf("my_pthread_warmup: pthread_attr_setstacksize() -> %s\n",
                        strerror(rc));
        rc = pthread_create(&thread, &thr_attr, my_pthread_warmup_worker, NULL);
        pthread_attr_destroy(&thr_attr);
        if (0 != rc) {
                printf("my_pthread_warmup: pthread_create() -> %s\n",
                        strerror(rc));
        } else {
                pthread_cancel(thread);
                pthread_join(thread, NULL);
        }
}

int main() {
  my_pthread_warmup();
  printf("looks good\n");
}

repo_toolchain_sigaction-nop-pthread_cancel.patch

--- libc/sysdeps/linux/i386/sigaction.c.orig    2017-05-02 22:57:58.552332704 -0400
+++ libc/sysdeps/linux/i386/sigaction.c 2017-05-02 22:58:19.920574694 -0400
@@ -115,6 +115,7 @@
 /* The return code for realtime-signals.  */
 # define RESTORE2(name, syscall) \
 __asm__        (                                               \
+        "       nop\n"                                  \
        ".text\n"                                       \
        "__" #name ":\n"                                \
        "       movl    $" #syscall ", %eax\n"          \
@@ -128,6 +129,7 @@
 # undef RESTORE2
 # define RESTORE2(name, syscall) \
 __asm__ (                                              \
+        "       nop\n"                                  \
        ".text\n"                                       \
        "__" #name ":\n"                                \
        "       popl    %eax\n"                         \