Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Thread Sanitizer fixes (Alex)
* Coverity fixes (David)
* test-qht fixes (Emilio)
* QOM interface for info irq/info pic (Hervé)
* -rtc clock=rt fix (Junlian)
* mux chardev fixes (Marc-André)
* nicer report on death by signal (Michal)
* qemu-tech TLC (Paolo)
* MSI support for edu device (Peter)
* qemu-nbd --offset fix (Tomáš)

# gpg: Signature made Fri 07 Oct 2016 17:25:10 BST
# gpg:                using RSA key 0xBFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (39 commits)
  qemu-doc: merge qemu-tech and qemu-doc
  qemu-tech: rewrite some parts
  qemu-tech: reorganize content
  qemu-tech: move TCG test documentation to tests/tcg/README
  qemu-tech: move user mode emulation features from qemu-tech
  qemu-tech: document lazy condition code evaluation in cpu.h
  qemu-tech: move text from qemu-tech to tcg/README
  qemu-doc: drop installation and compilation notes
  qemu-doc: replace introduction with the one from the internals manual
  qemu-tech: drop index
  test-qht: perform lookups under rcu_read_lock
  qht: fix unlock-after-free segfault upon resizing
  qht: simplify qht_reset_size
  qemu-nbd: Shrink image size by specified offset
  qemu_kill_report: Report PID name too
  util: Introduce qemu_get_pid_name
  char: update read handler in all cases
  char: use a fixed idx for child muxed chr
  i8259: give ISA device when registering ISA ioports
  .travis.yml: add gcc sanitizer build
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 19 insertions, 3 deletions

diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index 0cce246ea9..c4f6950fcb 100644
--- a/include/qemu/atomic.h
+++ b/include/qemu/atomic.h
@@ -82,7 +82,7 @@
  */
 #if defined(__SANITIZE_THREAD__)
 #define smp_read_barrier_depends() ({ barrier(); __atomic_thread_fence(__ATOMIC_CONSUME); })
-#elsif defined(__alpha__)
+#elif defined(__alpha__)
 #define smp_read_barrier_depends()   asm volatile("mb":::"memory")
 #else
 #define smp_read_barrier_depends()   barrier()
@@ -92,6 +92,12 @@
 /* Weak atomic operations prevent the compiler moving other
  * loads/stores past the atomic operation load/store. However there is
  * no explicit memory barrier for the processor.
+ *
+ * The C11 memory model says that variables that are accessed from
+ * different threads should at least be done with __ATOMIC_RELAXED
+ * primitives or the result is undefined. Generally this has little to
+ * no effect on the generated code but not using the atomic primitives
+ * will get flagged by sanitizers as a violation.
  */
 #define atomic_read(ptr)                              \
     ({                                                \
diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 9e9fa61546..384bfe245f 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -388,6 +388,16 @@ void os_mem_prealloc(int fd, char *area, size_t sz, Error **errp);
 int qemu_read_password(char *buf, int buf_size);
 
 /**
+ * qemu_get_pid_name:
+ * @pid: pid of a process
+ *
+ * For given @pid fetch its name. Caller is responsible for
+ * freeing the string when no longer needed.
+ * Returns allocated string on success, NULL on failure.
+ */
+char *qemu_get_pid_name(pid_t pid);
+
+/**
  * qemu_fork:
  *
  * A version of fork that avoids signal handler race
diff --git a/include/qemu/seqlock.h b/include/qemu/seqlock.h
index 2e2be4c4f0..8dee11d101 100644
--- a/include/qemu/seqlock.h
+++ b/include/qemu/seqlock.h
@@ -31,7 +31,7 @@ static inline void seqlock_init(QemuSeqLock *sl)
 /* Lock out other writers and update the count.  */
 static inline void seqlock_write_begin(QemuSeqLock *sl)
 {
-    ++sl->sequence;
+    atomic_set(&sl->sequence, sl->sequence + 1);
 
     /* Write sequence before updating other fields.  */
     smp_wmb();
@@ -42,7 +42,7 @@ static inline void seqlock_write_end(QemuSeqLock *sl)
     /* Write other fields before finalizing sequence.  */
     smp_wmb();
 
-    ++sl->sequence;
+    atomic_set(&sl->sequence, sl->sequence + 1);
 }
 
 static inline unsigned seqlock_read_begin(QemuSeqLock *sl)