From 6b7aaad9ba4f2a059a70014be12a921eceebfc47 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Mon, 25 Sep 2006 23:33:02 -0700 Subject: [PATCH] [PATCH] uml: Fix handling of failed execs of helpers There were some bugs in handling failures to exec helper programs. errno was passed back from the child with the wrong sign. It was also ignored. In the case where it mattered, the errno from the (successful) read in the parent was used instead. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/os-Linux/helper.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c index 6987d1d247a2..cd15b9df5b5c 100644 --- a/arch/um/os-Linux/helper.c +++ b/arch/um/os-Linux/helper.c @@ -42,7 +42,7 @@ static int helper_child(void *arg) if(data->pre_exec != NULL) (*data->pre_exec)(data->pre_data); execvp(argv[0], argv); - errval = errno; + errval = -errno; printk("helper_child - execve of '%s' failed - errno = %d\n", argv[0], errno); os_write_file(data->fd, &errval, sizeof(errval)); kill(os_getpid(), SIGKILL); @@ -62,7 +62,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv, stack = *stack_out; else stack = alloc_stack(0, __cant_sleep()); if(stack == 0) - return(-ENOMEM); + return -ENOMEM; ret = os_pipe(fds, 1, 0); if(ret < 0){ @@ -95,16 +95,16 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv, /* Read the errno value from the child, if the exec failed, or get 0 if * the exec succeeded because the pipe fd was set as close-on-exec. */ n = os_read_file(fds[0], &ret, sizeof(ret)); - if (n < 0) { - printk("run_helper : read on pipe failed, ret = %d\n", -n); - ret = n; - kill(pid, SIGKILL); - CATCH_EINTR(waitpid(pid, NULL, 0)); - } else if(n != 0){ - CATCH_EINTR(n = waitpid(pid, NULL, 0)); - ret = -errno; - } else { + if(n == 0) ret = pid; + else { + if(n < 0){ + printk("run_helper : read on pipe failed, ret = %d\n", + -n); + ret = n; + kill(pid, SIGKILL); + } + CATCH_EINTR(waitpid(pid, NULL, 0)); } out_close: