diff options
| -rw-r--r-- | arch/s390/kernel/crash_dump.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index 8d7332d4444c..1662f1d81abe 100644 --- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -53,6 +53,8 @@ struct save_area { }; static LIST_HEAD(dump_save_areas); +static DEFINE_MUTEX(memcpy_real_mutex); +static char memcpy_real_buf[PAGE_SIZE]; /* * Allocate a save area @@ -178,25 +180,21 @@ int copy_oldmem_kernel(void *dst, unsigned long src, size_t count) */ static int copy_to_user_real(void __user *dest, unsigned long src, unsigned long count) { - int offs = 0, size, rc; - char *buf; + unsigned long offs = 0, size; - buf = (char *)__get_free_page(GFP_KERNEL); - if (!buf) - return -ENOMEM; - rc = -EFAULT; + mutex_lock(&memcpy_real_mutex); while (offs < count) { size = min(PAGE_SIZE, count - offs); - if (memcpy_real(buf, src + offs, size)) - goto out; - if (copy_to_user(dest + offs, buf, size)) - goto out; + if (memcpy_real(memcpy_real_buf, src + offs, size)) + break; + if (copy_to_user(dest + offs, memcpy_real_buf, size)) + break; offs += size; } - rc = 0; -out: - free_page((unsigned long)buf); - return rc; + mutex_unlock(&memcpy_real_mutex); + if (offs < count) + return -EFAULT; + return 0; } /* |