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authorJohannes Berg <johannes.berg@intel.com>2021-01-13 22:09:42 +0100
committerRichard Weinberger <richard@nod.at>2021-02-12 21:34:33 +0100
commit84b2789d61156db0224724806b20110c0d34b07c (patch)
tree2af3dfceb3fb3fc0271c0cc742db74b9c10afffe /arch/um/kernel
parenta7d48886cacf8b426e0079bca9639d2657cf2d38 (diff)
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 <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/kernel')
-rw-r--r--arch/um/kernel/skas/clone.c25
1 files changed, 11 insertions, 14 deletions
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();
}