diff options
Diffstat (limited to 'include/qemu')
| -rw-r--r-- | include/qemu/atomic.h | 8 | ||||
| -rw-r--r-- | include/qemu/osdep.h | 10 | ||||
| -rw-r--r-- | include/qemu/seqlock.h | 4 |
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) |