From 84b2789d61156db0224724806b20110c0d34b07c Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 13 Jan 2021 22:09:42 +0100 Subject: um: separate child and parent errors in clone stub If the two are mixed up, then it looks as though the parent returned an error if the child failed (before) the mmap(), and then the resulting process never gets killed. Fix this by splitting the child and parent errors, reporting and using them appropriately. Signed-off-by: Johannes Berg Signed-off-by: Richard Weinberger --- arch/um/kernel/skas/clone.c | 25 +++++++++++-------------- 1 file changed, 11 insertions(+), 14 deletions(-) (limited to 'arch/um/kernel/skas/clone.c') diff --git a/arch/um/kernel/skas/clone.c b/arch/um/kernel/skas/clone.c index bfb70c456b30..7c592c788cbf 100644 --- a/arch/um/kernel/skas/clone.c +++ b/arch/um/kernel/skas/clone.c @@ -24,29 +24,26 @@ void __attribute__ ((__section__ (".__syscall_stub"))) stub_clone_handler(void) { - struct stub_data *data = (struct stub_data *) STUB_DATA; + int stack; + struct stub_data *data = (void *) ((unsigned long)&stack & ~(UM_KERN_PAGE_SIZE - 1)); long err; err = stub_syscall2(__NR_clone, CLONE_PARENT | CLONE_FILES | SIGCHLD, - STUB_DATA + UM_KERN_PAGE_SIZE / 2 - sizeof(void *)); - if (err != 0) - goto out; + (unsigned long)data + UM_KERN_PAGE_SIZE / 2 - sizeof(void *)); + if (err) { + data->parent_err = err; + goto done; + } err = stub_syscall4(__NR_ptrace, PTRACE_TRACEME, 0, 0, 0); - if (err) - goto out; + if (err) { + data->child_err = err; + goto done; + } remap_stack(data->fd, data->offset); goto done; - out: - /* - * save current result. - * Parent: pid; - * child: retcode of mmap already saved and it jumps around this - * assignment - */ - data->err = err; done: trap_myself(); } -- cgit v1.2.3