diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2021-01-13 22:09:42 +0100 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2021-02-12 21:34:33 +0100 |
| commit | 84b2789d61156db0224724806b20110c0d34b07c (patch) | |
| tree | 2af3dfceb3fb3fc0271c0cc742db74b9c10afffe /arch/um/os-Linux | |
| parent | a7d48886cacf8b426e0079bca9639d2657cf2d38 (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/os-Linux')
| -rw-r--r-- | arch/um/os-Linux/skas/process.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c index d910e25c273e..623b0aeadf4c 100644 --- a/arch/um/os-Linux/skas/process.c +++ b/arch/um/os-Linux/skas/process.c @@ -545,8 +545,14 @@ int copy_context_skas0(unsigned long new_stack, int pid) * and child's mmap2 calls */ *data = ((struct stub_data) { - .offset = MMAP_OFFSET(new_offset), - .fd = new_fd + .offset = MMAP_OFFSET(new_offset), + .fd = new_fd, + .parent_err = -ESRCH, + .child_err = 0, + }); + + *child_data = ((struct stub_data) { + .child_err = -ESRCH, }); err = ptrace_setregs(pid, thread_regs); @@ -564,9 +570,6 @@ int copy_context_skas0(unsigned long new_stack, int pid) return err; } - /* set a well known return code for detection of child write failure */ - child_data->err = 12345678; - /* * Wait, until parent has finished its work: read child's pid from * parent's stack, and check, if bad result. @@ -581,7 +584,7 @@ int copy_context_skas0(unsigned long new_stack, int pid) wait_stub_done(pid); - pid = data->err; + pid = data->parent_err; if (pid < 0) { printk(UM_KERN_ERR "copy_context_skas0 - stub-parent reports " "error %d\n", -pid); @@ -593,10 +596,10 @@ int copy_context_skas0(unsigned long new_stack, int pid) * child's stack and check it. */ wait_stub_done(pid); - if (child_data->err != STUB_DATA) { - printk(UM_KERN_ERR "copy_context_skas0 - stub-child reports " - "error %ld\n", child_data->err); - err = child_data->err; + if (child_data->child_err != STUB_DATA) { + printk(UM_KERN_ERR "copy_context_skas0 - stub-child %d reports " + "error %ld\n", pid, data->child_err); + err = data->child_err; goto out_kill; } |