Merge branch 'alignment' of https://github.com/omor1/fio

[fio.git] / os / os-android.h

diff --git a/os/os-android.h b/os/os-android.h
index ba599ddd3f1b84aac116b59511997e1a9ea0285c..c8c6cb85fce1a45ff9bf8bb95e604afdad32f53e 100644 (file)
--- a/os/os-android.h
+++ b/os/os-android.h
@@ -57,22 +57,19 @@
 #define MAP_HUGETLB 0x40000 /* arch specific */
 #endif
 
-
+#ifndef CONFIG_NO_SHM
 /*
- * The Android NDK doesn't currently export <sys/shm.h>, so define the
- * necessary stuff here.
+ * Bionic doesn't support SysV shared memeory, so implement it using ashmem
  */
-
-#include <linux/shm.h>
-#define SHM_HUGETLB    04000
-
 #include <stdio.h>
 #include <linux/ashmem.h>
-#include <sys/mman.h>
+#include <linux/shm.h>
+#define shmid_ds shmid64_ds
+#define SHM_HUGETLB    04000
 
 #define ASHMEM_DEVICE  "/dev/ashmem"
 
-static inline int shmctl (int __shmid, int __cmd, struct shmid_ds *__buf)
+static inline int shmctl(int __shmid, int __cmd, struct shmid_ds *__buf)
 {
        int ret=0;
        if (__cmd == IPC_RMID)
@@ -85,7 +82,7 @@ static inline int shmctl (int __shmid, int __cmd, struct shmid_ds *__buf)
        return ret;
 }
 
-static inline int shmget (key_t __key, size_t __size, int __shmflg)
+static inline int shmget(key_t __key, size_t __size, int __shmflg)
 {
        int fd,ret;
        char keybuf[11];
@@ -99,7 +96,8 @@ static inline int shmget (key_t __key, size_t __size, int __shmflg)
        if (ret < 0)
                goto error;
 
-       ret = ioctl(fd, ASHMEM_SET_SIZE, __size);
+       /* Stores size in first 8 bytes, allocate extra space */
+       ret = ioctl(fd, ASHMEM_SET_SIZE, __size + sizeof(uint64_t));
        if (ret < 0)
                goto error;
 
@@ -110,22 +108,24 @@ error:
        return ret;
 }
 
-static inline void *shmat (int __shmid, const void *__shmaddr, int __shmflg)
+static inline void *shmat(int __shmid, const void *__shmaddr, int __shmflg)
 {
-       size_t *ptr, size = ioctl(__shmid, ASHMEM_GET_SIZE, NULL);
-       ptr = mmap(NULL, size + sizeof(size_t), PROT_READ | PROT_WRITE, MAP_SHARED, __shmid, 0);
-       *ptr = size;    //save size at beginning of buffer, for use with munmap
-       return &ptr[1];
+       size_t size = ioctl(__shmid, ASHMEM_GET_SIZE, NULL);
+       /* Needs to be 8-byte aligned to prevent SIGBUS on 32-bit ARM */
+       uint64_t *ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, __shmid, 0);
+       /* Save size at beginning of buffer, for use with munmap */
+       *ptr = size;
+       return ptr + 1;
 }
 
 static inline int shmdt (const void *__shmaddr)
 {
-       size_t *ptr, size;
-       ptr = (size_t *)__shmaddr;
-       ptr--;
-       size = *ptr;    //find mmap size which we stored at the beginning of the buffer
-       return munmap((void *)ptr, size + sizeof(size_t));
+       /* Find mmap size which we stored at the beginning of the buffer */
+       uint64_t *ptr = (uint64_t *)__shmaddr - 1;
+       size_t size = *ptr;
+       return munmap(ptr, size);
 }
+#endif
 
 #define SPLICE_DEF_SIZE        (64*1024)