leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

um: separate child and parent errors in clone stub

Browse Source 
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>
This commit is contained in:
Johannes Berg
2021-01-13 22:09:42 +01:00
committed by Richard Weinberger
parent a7d48886ca
commit 84b2789d61
5 changed files with 27 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
arch/um/kernel/skas/clone.c
View File

@@ -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();
}