um: Do not use printk in userspace trampoline

The trampoline is running in a cloned process. It is not safe to use
printk for error printing there.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index ed20cefb29634910b90ec4df2416e36de061b092..1f5c3f2523d1e29782eb2edc04de3728ef6de8db 100644 (file)
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -221,8 +221,8 @@ static int userspace_tramp(void *stack)
        addr = mmap64((void *) STUB_CODE, UM_KERN_PAGE_SIZE,
                      PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
        if (addr == MAP_FAILED) {
-               printk(UM_KERN_ERR "mapping mmap stub at 0x%lx failed, errno = %d\n",
-                      STUB_CODE, errno);
+               os_info("mapping mmap stub at 0x%lx failed, errno = %d\n",
+                       STUB_CODE, errno);
                exit(1);
        }
 
@@ -231,8 +231,8 @@ static int userspace_tramp(void *stack)
                    STUB_DATA_PAGES * UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
                    MAP_FIXED | MAP_SHARED, fd, offset);
        if (addr == MAP_FAILED) {
-               printk(UM_KERN_ERR "mapping segfault stack at 0x%lx failed, errno = %d\n",
-                      STUB_DATA, errno);
+               os_info("mapping segfault stack at 0x%lx failed, errno = %d\n",
+                       STUB_DATA, errno);
                exit(1);
        }
 
@@ -242,8 +242,8 @@ static int userspace_tramp(void *stack)
        sa.sa_sigaction = (void *) segv_handler;
        sa.sa_restorer = NULL;
        if (sigaction(SIGSEGV, &sa, NULL) < 0) {
-               printk(UM_KERN_ERR "%s - setting SIGSEGV handler failed - errno = %d\n",
-                      __func__, errno);
+               os_info("%s - setting SIGSEGV handler failed - errno = %d\n",
+                       __func__, errno);
                exit(1);
        }